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william
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A320, autopilot soon after takeoff

Fri Nov 17, 2017 10:33 pm

https://www.youtube.com/watch?v=S7a7nEmTzL8

One notices in alot of videos of A320s right after take off going to autopilot. In the above video I think they are flying the Carnarsie departure and the autopilot is activated not soon after takoff. Is that SOP for Airbus, or does Boeing state the same?

And why in some videos does the PF not have his or her hands on the throttles but the non flying pilot does?
 
Woodreau
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 12:03 am

minimum altitude for autopilot engagement is 100ft AGL after takeoff in SRS mode (after 5 seconds) or go-around.

Autopilot engagement is personal preference.

Non-flying pilot normally does not have his or her hands on the thrust levers. If the pilot had his hands on the thrust levers, then he's the flying pilot.
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AA737-823
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 2:09 am

william wrote:
https://www.youtube.com/watch?v=S7a7nEmTzL8

One notices in alot of videos of A320s right after take off going to autopilot. In the above video I think they are flying the Carnarsie departure and the autopilot is activated not soon after takoff. Is that SOP for Airbus, or does Boeing state the same?

And why in some videos does the PF not have his or her hands on the throttles but the non flying pilot does?


I believe the 737NG autopilot is capable of taking over from as low as 600 ft AGL.

Regarding whose hands are on which knobs, I'm not going to use PF/PM/PNF here, but rather captain and first officer.
At some carriers, if the first officer is performing the takeoff, the CAPT will have his hands on the throttles, because an abort is his decision to make.
So in that scenario, the PNF would have his hands on the power levers.
But I think different airlines have different SOP's in that regard- others will have to chime in.
 
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 3:34 am

The L1011 could take off with the
autopilot already engaged (in control wheel steering mode)
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BravoOne
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 2:35 pm

Don't recall ever using CWS on any L1011. I was told once that the KC10 had this feature but never saw anything like that on any DC10 either.
 
Flow2706
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 3:41 pm

As mentioned earlier, the Autopilot can be engaged really early. It's really depending on company philosophy and personal preference - in my first company the training department encouraged everybody to use as much automation as possible because "that's how the Airbus is designed to be flown" (they have a point there, but of course it is important to stay sharp with manual flying skills as well). In this company most people engaged the AP at around 400ft and some Captains would actually "remind" you to engage the autopilot if it was not on at around 1000ft. In the other two companies I have worked so far it is more dependent on who is flying. I personally fly manually until flap retraction most of the time, but depending on the situation I could engage the AP earlier or later (if I have thunderstorms in the vicinity of the airport or if some technical event happens right after takeoff I will probably put the autopilot in earlier to give me more mental capacity to deal with the problem - if I am well rested and its a nice day I sometimes fly manually up to FL100...if the aircraft is really heavy, I will really wait until flaps retraction. The margin between flap retraction speed and Vfe is not that big if the aircraft is heavy and if the PM is busy, flap autoretraction from 1+F to 1 does not work for any technical reason or in gusty conditions it could be possible to have a flap overspeed and its easier to raise the nose to stop the speed from increasing toward the flap limit speed instead of of selecting a Speed on the FCU etc....this is however personal technique, not SOP). I think most of my colleagues are similar in this respect.
 
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 3:46 pm

Thank you for the posts. A320 has auto flap retraction? How does that work? And why would you engage the autopilot earlier with storms in the area, I thought it would be the opposite?

Thank you again to all for taking the time to answer my question.
 
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Re: A320, autopilot soon after takeoff

Sat Nov 18, 2017 4:30 pm

william wrote:
Thank you for the posts. A320 has auto flap retraction? How does that work? And why would you engage the autopilot earlier with storms in the area, I thought it would be the opposite?

Thank you again to all for taking the time to answer my question.

If you move the flap lever to position 1 on the ground (on A320) the aircraft will go to configuration 1+F (Slats and some degrees of flaps). The maximum speed for this configuration is 215kts. If you move the flap lever to the same position in flight you will get configuration 1 (same amount of slats, but no flap extension). The limit speed for this configuration is 230kts. If the aircraft is very heavy the minimum speed to go from configuration 1+F to zero can approach or exceed 215kts. As there is no way to go from Config 1+F to Config 1 by action on the flap lever (except by going to zero briefly and then back to one in flight but this is not how its supposed to be done) the flaps will automatically retract at 210kts, putting the aircraft into configuration 1 and thereby increasing the maximum speed to 230kts.
If you have thunderstorms (or other problems) you obviously want to avoid entering the thunderstorm. The crew will be busy with interpreting the weather radar picture, discussing and agreeing on a suitable route through the storm area and negotiating this with ATC while still having to do the normal procedures during the takeoff/climb phase (flap retraction, altimeter setting, checklist etc.). Flying the aircraft manually will of course increase the workload on the PF (and also on the PM who has to monitor the manual flying from the PF), thereby taking mental capacity away from other tasks (weather avoidance, normal procedures). The same principle applies to technical problems - if you have an engine failure after V1 usually the PF would stabilize and trim (rudder trim) the aircraft and make sure its climbing away safely and then engage the autopilot, freeing up resources to deal with ECAM, ATC and other procedures (the autopilot can fly the aircraft reasonably well on single engine, although I sometimes find the use of rudder from the autopilot rather miserable on a single engine approach, but it is possible&approved to do a single engine auto land - this is what I have seen on the simulator during my LPC/OPC checks, luckily I never had an engine failure on the real aircraft yet).
 
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 3:04 am

AA737-823 wrote:
william wrote:
https://www.youtube.com/watch?v=S7a7nEmTzL8

One notices in alot of videos of A320s right after take off going to autopilot. In the above video I think they are flying the Carnarsie departure and the autopilot is activated not soon after takoff. Is that SOP for Airbus, or does Boeing state the same?

And why in some videos does the PF not have his or her hands on the throttles but the non flying pilot does?


I believe the 737NG autopilot is capable of taking over from as low as 600 ft AGL.

Regarding whose hands are on which knobs, I'm not going to use PF/PM/PNF here, but rather captain and first officer.
At some carriers, if the first officer is performing the takeoff, the CAPT will have his hands on the throttles, because an abort is his decision to make.
So in that scenario, the PNF would have his hands on the power levers.
But I think different airlines have different SOP's in that regard- others will have to chime in.


IIRC, the minimum is 500 feet for the 737 and 200 feet for other Boeing models. I can look in the AFMs later if anyone wants a confirmed response, but I think what I stated is correct.
 
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 3:25 am

Airbus 330/350 is similar to 320. One of the pilots has his hand on the thrust levers until V1, at which point the hand comes off. At some operators this pilot is the PF, at others it is always the Captain. At my operator it is always the Captain. If the takeoff must be rejected, it is the Captain's decision. He/she will command "stop" and retard the thrust levers. Upon saying "stop" the Captain becomes PF is he/she wasn't already. This is the only time when control is passed without the phrase "I have control".

Autopilot use depends on preference and workload. If you're flying out of a familiar airport, it's not too busy, etc, by all means hand fly. If you're flying out of an unfamiliar airport with traffic and/or weather, get the autopilot in so you can focus on the big picture. For example, in windshear conditions, we are encouraged to engage the autopilot so we can focus on what the plane is doing big picture. An autopilot is a tool which shall be used appropriately to the situation.

The 330/350 have similar auto-retraction logic to that described by Flow2706. 200 knots for the 330 and 210 for the 350. Decreases workload and decreases the chance of a flap overspeed.
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 4:36 am

I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 4:41 am

Starlionblue wrote:
I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.


Well, there are still throttles. It's just that the thrust levers do not directly control the throttles.
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 4:45 am

DocLightning wrote:
Starlionblue wrote:
I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.


Well, there are still throttles. It's just that the thrust levers do not directly control the throttles.


I'll have to disagree on that. Throttling on a reciprocating engine specifically refers to the function of the butterfly valve, which restricts ("throttles") the air intake to control power. As well put on Wikipedia**: A throttle is the mechanism by which fluid flow is managed by constriction or obstruction.

In contrast, on a turbine engine, thrust is controlled by varying fuel flow, not by throttling the air intake.

A nitpick, but this is the forum for such. :)



**https://en.wikipedia.org/wiki/Throttle
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 4:53 am

Starlionblue wrote:
In contrast, on a turbine engine, thrust is controlled by varying fuel flow, not by throttling the air intake.

A nitpick, but this is the forum for such. :)



**https://en.wikipedia.org/wiki/Throttle


I defer to your expertise, but there may be regional variations. My reading is that fuel flow can be varied by pump rate or constricting the fuel line. I'm finding a lot of engineering texts and articles using that term for gas turbine engines. Perhaps it is a common, but technically incorrect vernacular. Certainly, the situation is quite different than that of a reciprocating engine.
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 6:19 am

DocLightning wrote:
Starlionblue wrote:
In contrast, on a turbine engine, thrust is controlled by varying fuel flow, not by throttling the air intake.

A nitpick, but this is the forum for such. :)



**https://en.wikipedia.org/wiki/Throttle


I defer to your expertise, but there may be regional variations. My reading is that fuel flow can be varied by pump rate or constricting the fuel line. I'm finding a lot of engineering texts and articles using that term for gas turbine engines. Perhaps it is a common, but technically incorrect vernacular. Certainly, the situation is quite different than that of a reciprocating engine.


Good points.

Vernacular vs reality? Discuss... ;)
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 3:59 pm

Starlionblue wrote:
Airbus 330/350 is similar to 320. One of the pilots has his hand on the thrust levers until V1, at which point the hand comes off. At some operators this pilot is the PF, at others it is always the Captain. At my operator it is always the Captain. If the takeoff must be rejected, it is the Captain's decision. He/she will command "stop" and retard the thrust levers. Upon saying "stop" the Captain becomes PF is he/she wasn't already. This is the only time when control is passed without the phrase "I have control".

Autopilot use depends on preference and workload. If you're flying out of a familiar airport, it's not too busy, etc, by all means hand fly. If you're flying out of an unfamiliar airport with traffic and/or weather, get the autopilot in so you can focus on the big picture. For example, in windshear conditions, we are encouraged to engage the autopilot so we can focus on what the plane is doing big picture. An autopilot is a tool which shall be used appropriately to the situation.

The 330/350 have similar auto-retraction logic to that described by Flow2706. 200 knots for the 330 and 210 for the 350. Decreases workload and decreases the chance of a flap overspeed.


Thank you for your answers. As someone old enough to remember the Eastern crash at JFK, Pan Am at NOL crash on take off due to Windshear, and vividly remember the Delta crash though on landing at DFW. I find your statement to have autopilot fly the aircraft when windshear is in the area. Will Law protections in an Airbus do a better job of flying out of a windshear than pilot?
 
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 4:09 pm

Starlionblue wrote:
I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.

I noticed when advancing the "levers" one hears a click as if pushing through indentions. So I take it "Flex" is the takeoff indention one moves the Levers too for takeoff? In Boeing aircraft one can hear the pilot pull back on the thrust levers (so weird to say that) to keep under the 250 knot limit under 10K feet. How is this accomplished in Airbus aircraft? Or is there a lever indention for that?

Thank you again for taking the time to answer my question.
 
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Re: A320, autopilot soon after takeoff

Mon Nov 20, 2017 6:32 pm

william wrote:
Starlionblue wrote:
I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.

I noticed when advancing the "levers" one hears a click as if pushing through indentions. So I take it "Flex" is the takeoff indention one moves the Levers too for takeoff? In Boeing aircraft one can hear the pilot pull back on the thrust levers (so weird to say that) to keep under the 250 knot limit under 10K feet. How is this accomplished in Airbus aircraft? Or is there a lever indention for that?

Thank you again for taking the time to answer my question.



If a commercial aircraft is trying to avoid going over the 250 knot restriction under 10000: it will only be in level flight, and you will hear the thrust come back significantly (well below cruise thrust) really the speed in climb is controlled by the pitch and climb rate because we are often unrestricted on climb to 10000 feet. It is more likely you are hearing the selection of “climb thrust.” Takeoff thrust is generally the highest thrust setting, and can only be used for a short period of time (sometimes with a significant de-rated thrust takeoff, engine power may be increased to climb thrust). Most aircraft have a takeoff setting and a climb setting and takeoff setting, Different aircraft have different methods of “selecting climb thrust”. On the Airbus, it’s moving the thrust levers back a detent, on Boeings it is a function of a button press (the 757/767 have a climb thrust button over the gear lever, on other Boeings it seams to be engaging VNAV on the Autopilot control panel).
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Re: A320, autopilot soon after takeoff

Tue Nov 21, 2017 1:22 am

william wrote:
Starlionblue wrote:
Airbus 330/350 is similar to 320. One of the pilots has his hand on the thrust levers until V1, at which point the hand comes off. At some operators this pilot is the PF, at others it is always the Captain. At my operator it is always the Captain. If the takeoff must be rejected, it is the Captain's decision. He/she will command "stop" and retard the thrust levers. Upon saying "stop" the Captain becomes PF is he/she wasn't already. This is the only time when control is passed without the phrase "I have control".

Autopilot use depends on preference and workload. If you're flying out of a familiar airport, it's not too busy, etc, by all means hand fly. If you're flying out of an unfamiliar airport with traffic and/or weather, get the autopilot in so you can focus on the big picture. For example, in windshear conditions, we are encouraged to engage the autopilot so we can focus on what the plane is doing big picture. An autopilot is a tool which shall be used appropriately to the situation.

The 330/350 have similar auto-retraction logic to that described by Flow2706. 200 knots for the 330 and 210 for the 350. Decreases workload and decreases the chance of a flap overspeed.


Thank you for your answers. As someone old enough to remember the Eastern crash at JFK, Pan Am at NOL crash on take off due to Windshear, and vividly remember the Delta crash though on landing at DFW. I find your statement to have autopilot fly the aircraft when windshear is in the area. Will Law protections in an Airbus do a better job of flying out of a windshear than pilot?


The autopilot tends to be more accurate at following the flight path than the pilot. ;) I believe the thinking is that having the autopilot and importantly autothrust engaged will allow the pilots better situational awareness. In sim training, the method is to respond to the windshear manually and engage the AP in as soon as practical. I'll note that on the 330 the autopilot disengages if alpha goes above alpha prot, so that's an additional wrinkle. An accurate flight path as followed by the AP decreases the chance of getting into alpha prot.

There are a few automation features that aid in windshear encounters:
- Alpha floor ((autothrust function) gives automatic engagement of TOGA if alpha goes above a certain value between alpha prot and alpha max..
- High alpha protection (flight envelope function). If Alpha goes above Alpha prot, pitch commands give an alpha, not a load factor. Pulling back to the stop means you get max possible lift, which is at an alpha very close to stall. So you can just hold the stick full back. Easy. Once at Alpha Max, the flight envelope function gives automatic pitch down to protect from stall and automatically retracts the speedbrakes.
- SRS pitch orders on the flight director (flight guidance function) during initial climb or go around. Follow SRS orders for best climb performance.
- Ground speed mini on approach (autothrust function) protects against speed decay.


william wrote:
Starlionblue wrote:
I'll add my traditional nitpick. On both Airbus and Boeing the levers are thrust levers, not throttles. There's nothing to actually "throttle" like on a piston engine. If you say "throttles" in an Airbus course you'll be corrected rather forcefully. :D

The thrust automation on Airbus is "autothrust" while on Boeing it is "autothrottle". I've never understood why Boeing calls it "autothrottle" but there you go.

I noticed when advancing the "levers" one hears a click as if pushing through indentions. So I take it "Flex" is the takeoff indention one moves the Levers too for takeoff? In Boeing aircraft one can hear the pilot pull back on the thrust levers (so weird to say that) to keep under the 250 knot limit under 10K feet. How is this accomplished in Airbus aircraft? Or is there a lever indention for that?

Thank you again for taking the time to answer my question.


There are three detents for the Airbus thrust levers (four if you count IDLE). CLB, the normal position in flight, FLEX/MCT for FLEX take-off or max continuous thrust, and TOGA for TOGA. Takeoffs are in FLEX or TOGA. To get to FLEX you go from IDLE, through CLB ("click") to FLEX. To get to TOGA you go through FLEX as well ("click" again") and push to the stops.

With the autothrust armed, at the acceleration height the FD pitch mode mode changes from SRS to CLB (or OPEN CLB). At this point the pilot flying will pull the thrust levers from TOGA or FLEX/MCT back to CLB. This engaged the Autothrust. Staying under the 250 knot limit, or any other speed constraint can be done in a few different ways.
- In managed speed the plane will automatically follow speed constraints as long as they are programmed into the FM. Typically speed constraints are part of the SID coding so they'll be there.
- Using a pre-selected speed for climb. This speed will be entered in the FM for the climb phase. Once out of SRS, the target speed will automatically go to that value and the speed will become selected. For example if a noise abatement procedure calls for green dot to 3000 feet, you'd enter green dot (max L/D) as the pre-selected speed. Once above 3000 feet, you would push for managed speed and the aircraft will accelerate above green dot. Now in managed speed, any speed constraints coded in the SID would be respected as per the above.
- Setting a speed manually on the FCU/ACP and pulling for selected speed.

I don't know for Boeing but presumably if the autothrottle is engaged you can pretty much do the same things. AFAIK the autothrust/autothrottle functions are not that different between the manufacturers, but Airbus encourages the use of autothrust as much as possible, while the Boeing guys seem to use manual thrust more.

Saying "autothrust" becomes natural with practice. Also it means you don't get glared at by instructors as much. :lol:
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william
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Re: A320, autopilot soon after takeoff

Tue Nov 21, 2017 2:51 pm

[quote.

There are a few automation features that aid in windshear encounters:
- Alpha floor ((autothrust function) gives automatic engagement of TOGA if alpha goes above a certain value between alpha prot and alpha max..
- High alpha protection (flight envelope function). If Alpha goes above Alpha prot, pitch commands give an alpha, not a load factor. Pulling back to the stop means you get max possible lift, which is at an alpha very close to stall. So you can just hold the stick full back. Easy. Once at Alpha Max, the flight envelope function gives automatic pitch down to protect from stall and automatically retracts the speedbrakes.
- SRS pitch orders on the flight director (flight guidance function) during initial climb or go around. Follow SRS orders for best climb performance.
- Ground speed mini on approach (autothrust function) protects against speed decay.

:[/quote]





Wow ! I have researched the "Laws" built in protection in Airbus's but this thread makes it easier to understand in actual application.

We cannot go back in time, but I do wander if Delta 188 that crashed at DFW had been a A330 would the result been much different.

Thank you again for taking the time to answer my questions.
Last edited by william on Tue Nov 21, 2017 2:56 pm, edited 1 time in total.
 
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Re: A320, autopilot soon after takeoff

Tue Nov 21, 2017 2:55 pm

[quote=
There are three detents for the Airbus thrust levers (four if you count IDLE). CLB, the normal position in flight, FLEX/MCT for FLEX take-off or max continuous thrust, and TOGA for TOGA. Takeoffs are in FLEX or TOGA. To get to FLEX you go from IDLE, through CLB ("click") to FLEX. To get to TOGA you go through FLEX as well ("click" again") and push to the stops.

With the autothrust armed, at the acceleration height the FD pitch mode mode changes from SRS to CLB (or OPEN CLB). At this point the pilot flying will pull the thrust levers from TOGA or FLEX/MCT back to CLB. This engaged the Autothrust. Staying under the 250 knot limit, or any other speed constraint can be done in a few different ways.
- In managed speed the plane will automatically follow speed constraints as long as they are programmed into the FM. Typically speed constraints are part of the SID coding so they'll be there.
- Using a pre-selected speed for climb. This speed will be entered in the FM for the climb phase. Once out of SRS, the target speed will automatically go to that value and the speed will become selected. For example if a noise abatement procedure calls for green dot to 3000 feet, you'd enter green dot (max L/D) as the pre-selected speed. Once above 3000 feet, you would push for managed speed and the aircraft will accelerate above green dot. Now in managed speed, any speed constraints coded in the SID would be respected as per the above.
- Setting a speed manually on the FCU/ACP and pulling for selected speed.

I don't know for Boeing but presumably if the autothrottle is engaged you can pretty much do the same things. AFAIK the autothrust/autothrottle functions are not that different between the manufacturers, but Airbus encourages the use of autothrust as much as possible, while the Boeing guys seem to use manual thrust more.

Saying "autothrust" becomes natural with practice. Also it means you don't get glared at by instructors as much. :lol:[/quote]






So what detent is the "autothrust" in when on approach? So you move the levers to idle during descent? How does FM manage the speed during the landing phase of flight?
 
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Re: A320, autopilot soon after takeoff

Tue Nov 21, 2017 3:42 pm

william wrote:
So what detent is the "autothrust" in when on approach? So you move the levers to idle during descent? How does FM manage the speed during the landing phase of flight?

The auto thrust is usually left in the climb detent from thrust reduction after takeoff (from FLX or TOGA to CLB) until around 20 feet (depending on conditions, 10ft on auto land) on landing. If you decide to fly using manual thrust the thrust lever is moved between Idle and the Climb detent to control the thrust (however auto thrust use is recommended by Airbus, so most pilots would leave the auto thrust on during most approaches at least on A320).
Speed can be either managed or selected. Managed means the target speed is controlled by the FMGS. In the descend phase above FL100 (with no speed constraints) the speed will be an econ speed calculated by the FMGS (depending on weight, wind, cost index etc.). Below FL100 the target speed will be 250kts - but it is possible to remove this constraint or move it to an other altitude. Once the approach phase is activated (this can be either done manually on the PERF page or automatically when the aircraft overflies the DECEL Pseudo Waypoint) the target speed will be Vapp (possibly modified by a function called Groundspeed Mini). However with autothrust on the aircraft won't decelerate below the maneuvering speed/minimum Flap/Slat retraction Speed (Greendot, S/F Speeds) in managed speed (it is however possible to select a speed below Green Dot/S/F on the FCU as long as it is above Vls). If is always possible to select a speed target on the FCU if the managed speeds are not appropriate - for example it is very common to get a speed constraint of 160kts to 4 miles final. As it is not possible to fulfill this request by using managed speed a speed target of 160kts would be manually selected on the FCU in this case.
Groundspeed Mini (GS Mini) is a function that changes the managed speed target to protect the aircraft from wind shifts. The basic theory is that the aircraft "knows" the wind on the ground (it is entered into the FMGC during approach preparation) and therefore know how much the wind will change before landing - f.e. if the landing runway is 25 and the ground Wind is 250 with 5kts and the aircraft (flying at 2000ft) calculates the current wind to be 250 with 20kts the managed speed will shift up by 15kts to anticipate the speed loss due to the wind change (I read that on some Airbus types there is a factor that reduced the amount of change due to GS Mini due to the aerodynamic characteristics of the aircraft - on the A320CEO however it uses 100% of the difference in windspeed).
 
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Re: A320, autopilot soon after takeoff

Tue Nov 21, 2017 3:56 pm

My instructor had told me at the airlines they want you to engage the autopilot at 700 ft. He had trained with Delta in the early 2000s. Obviously, it will vary with airlines but I thought it was too soon after take-off.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 12:42 am

william wrote:

There are a few automation features that aid in windshear encounters:
- Alpha floor ((autothrust function) gives automatic engagement of TOGA if alpha goes above a certain value between alpha prot and alpha max..
- High alpha protection (flight envelope function). If Alpha goes above Alpha prot, pitch commands give an alpha, not a load factor. Pulling back to the stop means you get max possible lift, which is at an alpha very close to stall. So you can just hold the stick full back. Easy. Once at Alpha Max, the flight envelope function gives automatic pitch down to protect from stall and automatically retracts the speedbrakes.
- SRS pitch orders on the flight director (flight guidance function) during initial climb or go around. Follow SRS orders for best climb performance.
- Ground speed mini on approach (autothrust function) protects against speed decay.







Wow ! I have researched the "Laws" built in protection in Airbus's but this thread makes it easier to understand in actual application.

We cannot go back in time, but I do wander if Delta 188 that crashed at DFW had been a A330 would the result been much different.

Thank you again for taking the time to answer my questions.


You mean Delta flight 191 in 1985? The outcome today would probably have been different, but not necessarily thanks to Airbus control laws.

Regardless of aircraft, the decision to continue the approach through a thunderstorm contributed to the crash. However, at the time windshear awareness was not what it is today. Windshear is the "big bad" nowadays. Airports and aircraft have windshear detection systems, SOPs are different and recurrent windshear training is mandatory. In fact, one of the regulation changes after Delta 191 was mandating onboard windshear detection systems.

In a modern aircraft regardless of manufacturer, the crew would have been aware of the windshear earlier, probably even before entering it. The response would be an immediate go around with TOGA thrust. At this point the features listed above would assist the pilots, but the important action (going around) is already done.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 12:57 am

william wrote:
There are three detents for the Airbus thrust levers (four if you count IDLE). CLB, the normal position in flight, FLEX/MCT for FLEX take-off or max continuous thrust, and TOGA for TOGA. Takeoffs are in FLEX or TOGA. To get to FLEX you go from IDLE, through CLB ("click") to FLEX. To get to TOGA you go through FLEX as well ("click" again") and push to the stops.

With the autothrust armed, at the acceleration height the FD pitch mode mode changes from SRS to CLB (or OPEN CLB). At this point the pilot flying will pull the thrust levers from TOGA or FLEX/MCT back to CLB. This engaged the Autothrust. Staying under the 250 knot limit, or any other speed constraint can be done in a few different ways.
- In managed speed the plane will automatically follow speed constraints as long as they are programmed into the FM. Typically speed constraints are part of the SID coding so they'll be there.
- Using a pre-selected speed for climb. This speed will be entered in the FM for the climb phase. Once out of SRS, the target speed will automatically go to that value and the speed will become selected. For example if a noise abatement procedure calls for green dot to 3000 feet, you'd enter green dot (max L/D) as the pre-selected speed. Once above 3000 feet, you would push for managed speed and the aircraft will accelerate above green dot. Now in managed speed, any speed constraints coded in the SID would be respected as per the above.
- Setting a speed manually on the FCU/ACP and pulling for selected speed.

I don't know for Boeing but presumably if the autothrottle is engaged you can pretty much do the same things. AFAIK the autothrust/autothrottle functions are not that different between the manufacturers, but Airbus encourages the use of autothrust as much as possible, while the Boeing guys seem to use manual thrust more.

Saying "autothrust" becomes natural with practice. Also it means you don't get glared at by instructors as much. :lol:


So what detent is the "autothrust" in when on approach? So you move the levers to idle during descent? How does FM manage the speed during the landing phase of flight?


As mentioned by Flow2706, with the autothrust on, the thrust levers stay in the CLB detent from acceleration altitude to the flare. On the 330, you'd pull back to IDLE around 30 feet. If doing an autoland you wait for the "RETARD" command from the system, so the thrust stays in a bit longer.

The autothrust will vary thrust as required to maintain the managed target speed or selected speed given the current flight path. The current thrust limit is displayed on the EWD (Engine Warning Display) next to the primary engine indication, EPR or N1 for 330 and thrust for 350.

If the engines go to idle, "IDLE" will appear in the primary engine indication and the thrust mode in the FMA will change to THR IDLE.

If speed is managed, the speed progression from cruise to landing is:
- Managed speed target for the descent phase. In a managed descent, the speed is allowed to vary within a range.
(- Any speed constraint such as 250 below 10000.)
(- If holding, whatever the local regulation for speed in a hold is.)
- When the approach phase is activated, green dot.
- When flaps 1 is selected, S speed.
- When flaps 2 and 3 are selected, F speed for flaps 2 and 3 respectively.
- When flaps FULL is selected, Vapp.
- When IDLE is selected in the flare, autothrust is deactivated.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 4:02 am

In the 320, once you pull the thrust levers from the TOGA or FLEX detent to the CLB detent at acceleration altitude in the takeoff climb, you don’t normally touch or move the thrust levers until 20/30 feet in the flare just before landing. Auto thrust controls the thrust the whole time.

Even though the pilot does not use the thrust levers to control engine thrust, the pilot does control engine thrust indirectly through the flight control panel, either by commanding climb thrust or idle thrust through the use of open climb or open descent, or some intermediate thrust though managed speed or selected speed.

At my airline, below 10,000 feet we normally don’t leave the aircraft in managed speed or managed descent. Instead we use selected speed and a combination of open descent or vertical speed depending on what we’re trying to achieve. Speeds are normally 250, then when it’s time to slow for configuring, 200 and 180 are selected for flaps 1 and 2. Then after gear down we push for managed speed again to gain the gs mini protection and configure final flaps for the last 1500ft/5 mile final.

About half the time I’ll turn off autothrust in the descent below FL180 to remain proficient in the use of manual thrust for the descent and approach phase, so after the autothrust is turned off I just treat the airbus as a very big regional jet.
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 2:45 pm

Starlionblue wrote:
william wrote:

There are a few automation features that aid in windshear encounters:
- Alpha floor ((autothrust function) gives automatic engagement of TOGA if alpha goes above a certain value between alpha prot and alpha max..
- High alpha protection (flight envelope function). If Alpha goes above Alpha prot, pitch commands give an alpha, not a load factor. Pulling back to the stop means you get max possible lift, which is at an alpha very close to stall. So you can just hold the stick full back. Easy. Once at Alpha Max, the flight envelope function gives automatic pitch down to protect from stall and automatically retracts the speedbrakes.
- SRS pitch orders on the flight director (flight guidance function) during initial climb or go around. Follow SRS orders for best climb performance.
- Ground speed mini on approach (autothrust function) protects against speed decay.







Wow ! I have researched the "Laws" built in protection in Airbus's but this thread makes it easier to understand in actual application.

We cannot go back in time, but I do wander if Delta 188 that crashed at DFW had been a A330 would the result been much different.

Thank you again for taking the time to answer my questions.


You mean Delta flight 191 in 1985? The outcome today would probably have been different, but not necessarily thanks to Airbus control laws.

Regardless of aircraft, the decision to continue the approach through a thunderstorm contributed to the crash. However, at the time windshear awareness was not what it is today. Windshear is the "big bad" nowadays. Airports and aircraft have windshear detection systems, SOPs are different and recurrent windshear training is mandatory. In fact, one of the regulation changes after Delta 191 was mandating onboard windshear detection systems.

In a modern aircraft regardless of manufacturer, the crew would have been aware of the windshear earlier, probably even before entering it. The response would be an immediate go around with TOGA thrust. At this point the features listed above would assist the pilots, but the important action (going around) is already done.


Yes, Delta 191, thank you for the correction. This crash always bothers me because of my familiarity with DFW Airport (as a FF, always connecting through DFW) . Reassuring to know technology today alerts the pilot to TOGA the "autothrust" and get out of there instead sticking to the approach.
 
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Starlionblue
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 3:27 pm

Technology certainly helps but I think windshear awareness is the biggest part. There's just more awareness of the dangers nowadays compared to 30-40 years ago.

If you go to TOGA you're just asking for everything the engines have to give. Autothrust is not involved.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
BoeingGuy
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 4:40 pm

william wrote:
Starlionblue wrote:
william wrote:

There are a few automation features that aid in windshear encounters:
- Alpha floor ((autothrust function) gives automatic engagement of TOGA if alpha goes above a certain value between alpha prot and alpha max..
- High alpha protection (flight envelope function). If Alpha goes above Alpha prot, pitch commands give an alpha, not a load factor. Pulling back to the stop means you get max possible lift, which is at an alpha very close to stall. So you can just hold the stick full back. Easy. Once at Alpha Max, the flight envelope function gives automatic pitch down to protect from stall and automatically retracts the speedbrakes.
- SRS pitch orders on the flight director (flight guidance function) during initial climb or go around. Follow SRS orders for best climb performance.
- Ground speed mini on approach (autothrust function) protects against speed decay.







Wow ! I have researched the "Laws" built in protection in Airbus's but this thread makes it easier to understand in actual application.

We cannot go back in time, but I do wander if Delta 188 that crashed at DFW had been a A330 would the result been much different.

Thank you again for taking the time to answer my questions.


You mean Delta flight 191 in 1985? The outcome today would probably have been different, but not necessarily thanks to Airbus control laws.

Regardless of aircraft, the decision to continue the approach through a thunderstorm contributed to the crash. However, at the time windshear awareness was not what it is today. Windshear is the "big bad" nowadays. Airports and aircraft have windshear detection systems, SOPs are different and recurrent windshear training is mandatory. In fact, one of the regulation changes after Delta 191 was mandating onboard windshear detection systems.

In a modern aircraft regardless of manufacturer, the crew would have been aware of the windshear earlier, probably even before entering it. The response would be an immediate go around with TOGA thrust. At this point the features listed above would assist the pilots, but the important action (going around) is already done.


Yes, Delta 191, thank you for the correction. This crash always bothers me because of my familiarity with DFW Airport (as a FF, always connecting through DFW) . Reassuring to know technology today alerts the pilot to TOGA the "autothrust" and get out of there instead sticking to the approach.


That's a different subject, but at that time there was no real industry awareness of windshear and the appropriate escape maneuvers. When the speed started dropping in the windshear, the DL 191 crew put the nose down in an attempt to regain airspeed. That's the worst thing you can do.

The DL 191 windshear profile is loaded in the simulators of the company I work for. We fly that and other windshear profiles to test the reactive windshear system and autoflight systems for windshear guidance. Even without Predictive Windshear alerting you in advance, we fly out of the scenario with no difficulty at all. Same with Eastern at JFK and Pan Am at MSY. No sweat on a modern day airplane, even with only reactive windshear alerting.

Boeing has logic in the TO/GA mode for the autopilot and autothrottle that assists in windshear recovery. Among other things, the thrust levers are limited to forward movement only in this mode, even if you overshoot your IAS or V/S targets.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 6:11 pm

Starlionblue wrote:
Technology certainly helps but I think windshear awareness is the biggest part. There's just more awareness of the dangers nowadays compared to 30-40 years ago.

If you go to TOGA you're just asking for everything the engines have to giv
e. Autothrust is not involved.


If I was a pilot, I would find that detent very reassuring.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 6:20 pm

BoeingGuy wrote:
william wrote:
Starlionblue wrote:

You mean Delta flight 191 in 1985? The outcome today would probably have been different, but not necessarily thanks to Airbus control laws.

Regardless of aircraft, the decision to continue the approach through a thunderstorm contributed to the crash. However, at the time windshear awareness was not what it is today. Windshear is the "big bad" nowadays. Airports and aircraft have windshear detection systems, SOPs are different and recurrent windshear training is mandatory. In fact, one of the regulation changes after Delta 191 was mandating onboard windshear detection systems.

In a modern aircraft regardless of manufacturer, the crew would have been aware of the windshear earlier, probably even before entering it. The response would be an immediate go around with TOGA thrust. At this point the features listed above would assist the pilots, but the important action (going around) is already done.


Yes, Delta 191, thank you for the correction. This crash always bothers me because of my familiarity with DFW Airport (as a FF, always connecting through DFW) . Reassuring to know technology today alerts the pilot to TOGA the "autothrust" and get out of there instead sticking to the approach.


That's a different subject, but at that time there was no real industry awareness of windshear and the appropriate escape maneuvers. When the speed started dropping in the windshear, the DL 191 crew put the nose down in an attempt to regain airspeed. That's the worst thing you can do.

The DL 191 windshear profile is loaded in the simulators of the company I work for. We fly that and other windshear profiles to test the reactive windshear system and autoflight systems for windshear guidance. Even without Predictive Windshear alerting you in advance, we fly out of the scenario with no difficulty at all. Same with Eastern at JFK and Pan Am at MSY. No sweat on a modern day airplane, even with only reactive windshear alerting.

Boeing has logic in the TO/GA mode for the autopilot and autothrottle that assists in windshear recovery. Among other things, the thrust levers are limited to forward movement only in this mode, even if you overshoot your IAS or V/S targets.


Wind shear is dangerous and to be avoided, lets get that out of the way. However, that paragraph is profound and shatters a lot of media hyped fear (or ignorance) regarding wind shear, and to be frank "common think" even among aviation enthusiasts that these three flights were doomed upon entering the wind shear event. Wow, really profound.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 7:49 pm

my 2¢, from what I remember reading on the DL crash they continued to keep the thrust levers in A/T and therefore everytime they got back "on speed" the thrust levers came back. This happened all the way to the ground. The F/O & S/O hinted at their concern but no actions were taken. They were a little over confident that they were following a Lear Jet that landed safely. The Capt took no corrective action. They barely missed the Fedex ramp.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 11:00 pm

CosmicCruiser wrote:
my 2¢, from what I remember reading on the DL crash they continued to keep the thrust levers in A/T and therefore everytime they got back "on speed" the thrust levers came back. This happened all the way to the ground. The F/O & S/O hinted at their concern but no actions were taken. They were a little over confident that they were following a Lear Jet that landed safely. The Capt took no corrective action. They barely missed the Fedex ramp.


The DL 191 windshear scenario in our engineering simulators is nasty. It starts at about 800 feet and really rocks you around too. Sometimes the Reactive Windshear alert will occur three different times. It is manageable though if you perform the proper maneuver when getting the alert.

The JFK and MSY scenarios seem a bit tame so sometimes I wonder if they are modeled correctly. However, we have the benefit of getting the reactive windshear warning and now having a published procedure for windshear escape. The crews encountering them did not have that luxury. Maybe they seem tame for that reason, and because we have a reset switch in the simulator if you crash. An even better luxury would be Predictive Windshear, which alerts you to go around before you even get into it.
 
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Re: A320, autopilot soon after takeoff

Wed Nov 22, 2017 11:28 pm

BoeingGuy wrote:
william wrote:
Starlionblue wrote:

You mean Delta flight 191 in 1985? The outcome today would probably have been different, but not necessarily thanks to Airbus control laws.

Regardless of aircraft, the decision to continue the approach through a thunderstorm contributed to the crash. However, at the time windshear awareness was not what it is today. Windshear is the "big bad" nowadays. Airports and aircraft have windshear detection systems, SOPs are different and recurrent windshear training is mandatory. In fact, one of the regulation changes after Delta 191 was mandating onboard windshear detection systems.

In a modern aircraft regardless of manufacturer, the crew would have been aware of the windshear earlier, probably even before entering it. The response would be an immediate go around with TOGA thrust. At this point the features listed above would assist the pilots, but the important action (going around) is already done.


Yes, Delta 191, thank you for the correction. This crash always bothers me because of my familiarity with DFW Airport (as a FF, always connecting through DFW) . Reassuring to know technology today alerts the pilot to TOGA the "autothrust" and get out of there instead sticking to the approach.


That's a different subject, but at that time there was no real industry awareness of windshear and the appropriate escape maneuvers. When the speed started dropping in the windshear, the DL 191 crew put the nose down in an attempt to regain airspeed. That's the worst thing you can do.

The DL 191 windshear profile is loaded in the simulators of the company I work for. We fly that and other windshear profiles to test the reactive windshear system and autoflight systems for windshear guidance. Even without Predictive Windshear alerting you in advance, we fly out of the scenario with no difficulty at all. Same with Eastern at JFK and Pan Am at MSY. No sweat on a modern day airplane, even with only reactive windshear alerting.

Boeing has logic in the TO/GA mode for the autopilot and autothrottle that assists in windshear recovery. Among other things, the thrust levers are limited to forward movement only in this mode, even if you overshoot your IAS or V/S targets.


Correct on all counts. Windshear today is a known risk that is trained for, with systems and procedures to deal with it.

The autothrottle mode you describe on Boeing seems to have a similar function to Alpha Floor, which automatically sets TOGA thrust if the airspeed decays below a certain target. Alpha Floor is armed at any speed up to around Mach 0.5 (type dependent) as long as the autothrust is engaged.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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longhauler
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Re: A320, autopilot soon after takeoff

Thu Nov 23, 2017 2:22 am

A couple minor corrections....
Starlionblue wrote:
As mentioned by Flow2706, with the autothrust on, the thrust levers stay in the CLB detent from acceleration altitude to the flare. On the 330, you'd pull back to IDLE around 30 feet. If doing an autoland you wait for the "RETARD" command from the system, so the thrust stays in a bit longer.

With the autopilot engaged, the thrust is commanded to idle automatically starting at 40' by the "retard mode". The "retard" call at 10' is to remind the pilot to match the thrust levers with the already commanded idle thrust setting. With the autopilot disconnected, the thrust levers must be retarded for thrust to return to idle, otherwise they would advance thrust in the flare to maintain Vapp.

But you are correct, manually retarding the thrust levers in a manual landing will normally be quicker (if done correctly) than automatically in an autoland.
Starlionblue wrote:
The autothrottle mode you describe on Boeing seems to have a similar function to Alpha Floor, which automatically sets TOGA thrust if the airspeed decays below a certain target. Alpha Floor is armed at any speed up to around Mach 0.5 (type dependent) as long as the autothrust is engaged.


The autothrust does not have to be enganged for Alpha Floor to work. In fact, Alpha Floor activation is one of the methods that engages the autothrust when not already engaged.

This safety quirk goes right back to the A300 designed in the 1970s. I'll never forget the demonstration of Alpha Floor in the A300. Autothrust off, clean aircraft, thrust back to idle then maintain altitdude. We were all anxiously waiting for it to stall ... but no, authrothust engaged then went to TOGA and we "hung around" nose high at an impossibly low speed!
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Re: A320, autopilot soon after takeoff

Thu Nov 23, 2017 3:30 am

Thx for the corrections Longhauler. The details matter! The RETARD thing is similar to a lot of Airbus stuff, as in "Let's have the monkey set the control to the correct position after the aircraft has already performed the action."

Thanks for clarifying that wrinkle of Alpha Floor. Looking into the FCOM:

"The Autothrust system, when active...
...Uses ALPHA FLOOR mode to set maximum thrust when the aircraft angle of attack exceeds a specific threshold."


This seems to imply that Alpha Floor is only armed with autothrust active. Which is why it was a bit unclear to me. But further on...

"When ALPHA FLOOR is activated, regardless of the initial A/THR status and position of the thrust levers, the A/THR activates."

Aha! Alpha Floor activates autothrust if it wasn't already active. The only way to kill Alpha Floor completely is to disengage AT for the remainder of the flight by holding the instinctive disconnect pushbutton.
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Re: A320, autopilot soon after takeoff

Thu Nov 23, 2017 10:40 am

Severe Windshear is rare. We train for it in the simulator every year or so, but I'm not sure if an actual windshear can actually be that strong. In the simulator the wind shifts from the previous wind to around 60 or 70kts tailwind over a few seconds and then slowly comes back to the previous wind. Its very easy to over speed the flaps if you are not quick to retract them after the windshear encounter (you should not change configuration while in windshear, so flaps and gear may still be extended when leaving the shear). The Windshears I have encountered in reality were far more benign - I never got an actual windshear warning but the speed dropped a good bit (or increased in one case). But all very manageable by performing a go around. Until now, I got two predictive windshear warnings (Go Around, Windshear ahead - one of them yesterday on a ferry flight to Amsterdam - Wind was 180/12 Gusting 22, it was a bit bumpy but we didn't get a windshear for real). In both cases we concluded that they were spurious and decided to continue the approach (which is allowable as per the FCOM as long as there are not other indications of Windshear and the reactive Windshear Warning system ist working).
 
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Re: A320, autopilot soon after takeoff

Mon Nov 27, 2017 6:38 am

Thank you again to all who answered my question. I see how though flying an Airbus is very automated, the benefits of sharing the flying SOPs between Airbus aircraft. Its interesting that an A320 and A330 pilot were able to speak on SOP on flying an Airbus. I see a pilot could quickly learn how to fly any Airbus family in short time and the benefits that would be to an airline.
 
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Starlionblue
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Re: A320, autopilot soon after takeoff

Mon Nov 27, 2017 7:47 am

william wrote:
Thank you again to all who answered my question. I see how though flying an Airbus is very automated, the benefits of sharing the flying SOPs between Airbus aircraft. Its interesting that an A320 and A330 pilot were able to speak on SOP on flying an Airbus. I see a pilot could quickly learn how to fly any Airbus family in short time and the benefits that would be to an airline.


This is true. The family feel is definitely there. The cockpits are almost identical. (The landing gear indicator light arrangement and the APU fire button location are giveaways.) There are some significant system differences, e.g. the hydraulic systems, but they make normal procedures too different.

Moving to 350 and 380, there are bigger differences but the same 320/330 philosophy shines through strongly.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Re: A320, autopilot soon after takeoff

Mon Nov 27, 2017 8:58 am

DocLightning wrote:
Well, there are still throttles. It's just that the thrust levers do not directly control the throttles.


Well,
<nitpic mode=on>
a "throttle" is a distinct feature on petrol engines that "throttles airflow" and thus reduces power produced.
the unthrottled engine would produce full power. ( carburettor adds fuel proportional to airflow.)
<nitpic mode=off>

on a diesel you control fuel flow. ( actually its RPM, you control a governor that then controls fuel flow.)
on a jet engine ( oldstyle ) you control fuel flow.
on a modern FADEC style engine you control thrust commanded and the FADEC software moves all its available
girlygigs to achieve its masters command.

older MB diesels used to have a butterfly valve looking like a throttle too.
Used for providing motor braking ( instead of an exhaust braking valve like on trucks )
and vacuum for the hydraulic brakes servo assist.
Murphy is an optimist
 
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longhauler
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Re: A320, autopilot soon after takeoff

Mon Nov 27, 2017 11:29 pm

Starlionblue wrote:
The family feel is definitely there. The cockpits are almost identical. (The landing gear indicator light arrangement and the APU fire button location are giveaways.) There are some significant system differences, e.g. the hydraulic systems, but they make normal procedures too different.

Moving to 350 and 380, there are bigger differences but the same 320/330 philosophy shines through strongly.


It's funny you should say that, as I have been saying exactly that for decades. I have flown the A300B4-203, A310-304, A320 series, A330-300 and A340-300. (It's not hard to tell my airline career merger path!) The family lines are definitely there.

Today, a lot of "why" is left out of our present procedures, we just follow SOPs/drills/checklists. But having flown the A300 30 years ago, the reason for a lot of what we do is apparent.

For example the flows and procedures of the "Smoke/Fumes/Avncs Smoke" QRH procedure is rooted in the old A300, where the Flight Engineer used the "sniffer fan and tube" (I'm not kidding) to tell if there was smoke in the Essential Bus. You either kept the Ess Bus powered and shut everything else off, or shut down the Ess Bus and did the reverse. Today's procedure follows the same logic.

Sadly, we did not choose the A350 and I read descriptions of it enviously.
Just because I stopped arguing, doesn't mean I think you are right. It just means I gave up!
 
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william
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Re: A320, autopilot soon after takeoff

Wed Nov 29, 2017 2:49 pm

longhauler wrote:
Starlionblue wrote:
The family feel is definitely there. The cockpits are almost identical. (The landing gear indicator light arrangement and the APU fire button location are giveaways.) There are some significant system differences, e.g. the hydraulic systems, but they make normal procedures too different.

Moving to 350 and 380, there are bigger differences but the same 320/330 philosophy shines through strongly.


It's funny you should say that, as I have been saying exactly that for decades. I have flown the A300B4-203, A310-304, A320 series, A330-300 and A340-300. (It's not hard to tell my airline career merger path!) The family lines are definitely there.

Today, a lot of "why" is left out of our present procedures, we just follow SOPs/drills/checklists. But having flown the A300 30 years ago, the reason for a lot of what we do is apparent.

For example the flows and procedures of the "Smoke/Fumes/Avncs Smoke" QRH procedure is rooted in the old A300, where the Flight Engineer used the "sniffer fan and tube" (I'm not kidding) to tell if there was smoke in the Essential Bus. You either kept the Ess Bus powered and shut everything else off, or shut down the Ess Bus and did the reverse. Today's procedure follows the same logic.

Sadly, we did not choose the A350 and I read descriptions of it enviously.


Maybe Zeke will chime in on this thread, I believe he flies the A350.
 
Chaostheory
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Re: A320, autopilot soon after takeoff

Wed Nov 29, 2017 10:27 pm

As fantastic as the airbus setup is in the context of windshear recovery, it's important to remember that windshear avoidance is still key. Sometimes the weather is too dynamic for the protections to keep up and prevent stall. There has been at least one documented a319/320 stall during a windshear episode in China. Fortunately for the crew, alpha protection kicked in and the aircraft recovered with about 1000ft to spare. If I recall from the moment of ap disconnect, both pilots held their side sticks fully aft through the entire process.
 
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rjsampson
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 12:21 am

BoeingGuy wrote:
The DL 191 windshear scenario in our engineering simulators is nasty. It starts at about 800 feet and really rocks you around too. Sometimes the Reactive Windshear alert will occur three different times. It is manageable though if you perform the proper maneuver when getting the alert.



DL 191. This began my studies in aviation accidents. The PF was the FO. This wasn't just a windshear, but a Microburst which is probably the most evil weather phenomenon that can happen on approach. What bothered me from the CVR was the captain saying "you're gonna lose it all of a sudden," and then saying "there is is."
The Captain then gradually commanded the PF to "push it up, , push it up, way up!" before he finally commanded 30 seconds later "TOGA!" before the crash. Granted, this was before WSAD was on the aircraft, and subsequently was required on all 121 flights as a result of this accident.

I suppose a Learjet had successfully landed prior to the ill-fated L-1011. But when the experienced Captain told the PF that "you're gonna lose it all of a sudden... There it is:" Should TOGA have not been commanded immediately?
"..your eyes will be forever turned skyward, for there.." yeah we know the DaVinci quote. But GA is so dang expensive these days! :(
 
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767333ER
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 12:48 am

longhauler wrote:
Starlionblue wrote:
The family feel is definitely there. The cockpits are almost identical. (The landing gear indicator light arrangement and the APU fire button location are giveaways.) There are some significant system differences, e.g. the hydraulic systems, but they make normal procedures too different.

Moving to 350 and 380, there are bigger differences but the same 320/330 philosophy shines through strongly.


It's funny you should say that, as I have been saying exactly that for decades. I have flown the A300B4-203, A310-304, A320 series, A330-300 and A340-300. (It's not hard to tell my airline career merger path!) The family lines are definitely there.

Today, a lot of "why" is left out of our present procedures, we just follow SOPs/drills/checklists. But having flown the A300 30 years ago, the reason for a lot of what we do is apparent.

For example the flows and procedures of the "Smoke/Fumes/Avncs Smoke" QRH procedure is rooted in the old A300, where the Flight Engineer used the "sniffer fan and tube" (I'm not kidding) to tell if there was smoke in the Essential Bus. You either kept the Ess Bus powered and shut everything else off, or shut down the Ess Bus and did the reverse. Today's procedure follows the same logic.

Sadly, we did not choose the A350 and I read descriptions of it enviously.

And this as described here is the natural course improvement/innovation in a nutshell. Airbus looked at their existing products and took a look at what was already really good and what they could improve and created a new product. This involves learning from mistakes, using new knowledge to improve older ideas, and using years of use to see what did and didn’t need changed. Of course we see this everywhere, not just at Airbus. Boeing has done this too though in less of a neat and organized way due to many factors, it just seems the 737 either got forgotten about somehow or is just an exception just because.

This turned into a very informative and interesting discussion. To add to longhauler’s last remark, sadly, on December 11 AC137 won’t be departing as the first revenue flight of a brand new A320.
Been on: 732 733 734 73G 738 752 763 A319 A320 A321 CRJ CR7 CRA/CR9 E145 E175 E190 F28 MD-82 MD-83 C172R C172S P2006T
 
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william
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 2:55 pm

rjsampson wrote:
BoeingGuy wrote:
The DL 191 windshear scenario in our engineering simulators is nasty. It starts at about 800 feet and really rocks you around too. Sometimes the Reactive Windshear alert will occur three different times. It is manageable though if you perform the proper maneuver when getting the alert.



DL 191. This began my studies in aviation accidents. The PF was the FO. This wasn't just a windshear, but a Microburst which is probably the most evil weather phenomenon that can happen on approach. What bothered me from the CVR was the captain saying "you're gonna lose it all of a sudden," and then saying "there is is."
The Captain then gradually commanded the PF to "push it up, , push it up, way up!" before he finally commanded 30 seconds later "TOGA!" before the crash. Granted, this was before WSAD was on the aircraft, and subsequently was required on all 121 flights as a result of this accident.

I suppose a Learjet had successfully landed prior to the ill-fated L-1011. But when the experienced Captain told the PF that "you're gonna lose it all of a sudden... There it is:" Should TOGA have not been commanded immediately?



This has bother me too, expecially since the media portrays the aircraft as being doomed once in the windshear. Why didn't the FO "firewall the throttles" instead of continued the approach? I think the point the pilots on this thread have made is that today radar would have warned off the approached and if the approached would have continued as soon as the pilot saw a sudden increase in headwind, simulator training would kick in and TOGA would be initiated. And if one is flying an Airbus product then the "law" protections would kick in to "try" to compensate for the windshear.

Thats why you read my earlier post asking what would of happen if the DL191 was an A330 and not a TriStar.
 
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william
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 3:04 pm

Chaostheory wrote:
As fantastic as the airbus setup is in the context of windshear recovery, it's important to remember that windshear avoidance is still key. Sometimes the weather is too dynamic for the protections to keep up and prevent stall. There has been at least one documented a319/320 stall during a windshear episode in China. Fortunately for the crew, alpha protection kicked in and the aircraft recovered with about 1000ft to spare. If I recall from the moment of ap disconnect, both pilots held their side sticks fully aft through the entire process.


I whole heatedly agree and thanks for the interesting experience in China.
 
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longhauler
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 4:04 pm

Chaostheory wrote:
As fantastic as the airbus setup is in the context of windshear recovery, it's important to remember that windshear avoidance is still key. Sometimes the weather is too dynamic for the protections to keep up and prevent stall. There has been at least one documented a319/320 stall during a windshear episode in China. Fortunately for the crew, alpha protection kicked in and the aircraft recovered with about 1000ft to spare. If I recall from the moment of ap disconnect, both pilots held their side sticks fully aft through the entire process.

That recovery ... sidestick full aft, TOGA thrust ... is current Airbus windshear recovery technique. It puts the aircraft in the best possible condition. FADEC giving all the engines have to give and fly-by-wire keeping the aircraft at maximum angle of attack.

Do you have a reference for this incident? I would be curious to read it. Not just the windshear encounter, but actually stalling an A320 while still in Normal Law. As far as I know, I didn't think it was possible.

To date (touching wood here) there has never been an Airbus lost in a windshear. While some may think that is elegant French engineering design and to a point, it is. But I agree with your first comment. Today, education and avoidance combined with ground based detection equipment has likely made the best advances with regard to surviving a windshear.

william wrote:
Thats why you read my earlier post asking what would of happen if the DL191 was an A330 and not a TriStar.


I would guess that had it been an A330, it would not have crashed had windshear recovery techniques been followed.
Just because I stopped arguing, doesn't mean I think you are right. It just means I gave up!
 
Flow2706
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 4:54 pm

longhauler wrote:
Do you have a reference for this incident? I would be curious to read it. Not just the windshear encounter, but actually stalling an A320 while still in Normal Law. As far as I know, I didn't think it was possible.

I heard about that incident as well. An interesting incident indeed, but the crew did not follow procedures and brought themselves into a very dangerous situation. You can find the report here: https://www.bea.aero/docspa/2010/b-5410 ... 914.en.pdf
 
Chaostheory
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Re: A320, autopilot soon after takeoff

Thu Nov 30, 2017 8:44 pm

longhauler wrote:
That recovery ... sidestick full aft, TOGA thrust ... is current Airbus windshear recovery technique. It puts the aircraft in the best possible condition. FADEC giving all the engines have to give and fly-by-wire keeping the aircraft at maximum angle of attack.

Do you have a reference for this incident? I would be curious to read it. Not just the windshear encounter, but actually stalling an A320 while still in Normal Law. As far as I know, I didn't think it was possible.

To date (touching wood here) there has never been an Airbus lost in a windshear. While some may think that is elegant French engineering design and to a point, it is. But I agree with your first comment. Today, education and avoidance combined with ground based detection equipment has likely made the best advances with regard to surviving a windshear.


As far as I know, this is the only incident where an airbus fbw aircraft has stalled in normal law. As you rightly state, full back stick and toga is the stated procedure and the aircraft will give you close to max performance. Without looking at my notes, I recall alpha max will hold you to within 3 or 4 degrees of clmax on the A320. I'm grateful for flow2706 doing the leg work and finding the link as I had forgotten most of the details. There is an additional report out there put together by the BEA or Airbus which includes side stick input traces from the fdr though I can't find it. This stall event is always in the back of mind as it was covered during my 320 instructor training course in Toulouse many years ago.

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