WPvsMW
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Autopilots and reverse thrust

Fri Dec 01, 2017 9:49 am

Given that autopilots can handle landing and rollout (with deceleration using brakes) at CAT III(B) runways... do any current autopilots also control reverse thrust during landing on a/p?

For a case in point... could autopilot-controlled reverse thrust have saved the landing of DL1086 at LGA in 2015?
https://en.wikipedia.org/wiki/Delta_Air ... light_1086

Related topic... any thoughts on when CAT III(C) (landing and rollout, in zero visibility) will be operational?

IMO, CAT III(C) would need some sort of Ground/Cockpit integration to get the a/c off the runway to parking.
 
BravoOne
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 2:58 pm

It's all a matter of $$. Does the cost justify the results? Airlines, manufactures and airports have obviously deemed it not cost efffective at this time.
 
Flow2706
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 3:08 pm

I don't know any type that gives you auto reverse. However, there is a feature that was introduced by Airbus on the A350 and A380 (and as far as I know it is also available as on option on A320, however I have never flown an A320 that had it installed) which is called ROPS (Runway Overrun Prevention System). It will compare the computed landing distance and with remaining runway length during rollout (there is also an airborne warning provided if the system senses that the runway length is insufficient prior to touchdown) and if it senses a risk of an overrun automatically apply maximum brakes and generate an audio message "MAX Reverse" (and if the threat still exists at 70kts an other audio message "Keep MAX Reverse"). While the reverser is not automatically actuated the system advises the pilot to do so.
 
BoeingGuy
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 3:51 pm

Flow2706 wrote:
I don't know any type that gives you auto reverse. However, there is a feature that was introduced by Airbus on the A350 and A380 (and as far as I know it is also available as on option on A320, however I have never flown an A320 that had it installed) which is called ROPS (Runway Overrun Prevention System). It will compare the computed landing distance and with remaining runway length during rollout (there is also an airborne warning provided if the system senses that the runway length is insufficient prior to touchdown) and if it senses a risk of an overrun automatically apply maximum brakes and generate an audio message "MAX Reverse" (and if the threat still exists at 70kts an other audio message "Keep MAX Reverse"). While the reverser is not automatically actuated the system advises the pilot to do so.


Some Boeing airplanes have a very similar feature that tells you MAX REVERSE and MAX BRAKES if on the ground; tells you to go around if in the air and it calculates you won't be able to stop on the runway. I think it's available on the 737 and will be on the 777X.

Not only is Reverse Thrust manually controlled on Boeing airplanes, but the Autothrottle will disconnect when you raise the reverse thrust levers.
 
BravoOne
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 4:25 pm

I'm pretty sure that the ILS, be it CAT 1, 2, or 3abc, is on the way out with the evolution of NEXTGEN. Airports will only have an ILS as a backup approach. All other appproaches will be WAAS iterations.

EK had a STC's system on the 777 that had the accident in DBX that warned of a long landing. I don't think it served the crew well in this case.
 
WPvsMW
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 6:49 pm

How are B6 and WN doing with their onboard NEXTGEN installations?
The irony is that MLS was (is) more accurate and simpler than ILS, but airport operators and airlines didn't want to bear the upgrade cost.
NEXTGEN still doesn't have the H and V accuracy that ILS provides (much less that of MLS) for landing. "Ionospheric billows" and deviation updates every 5 seconds ... sensor to satellite to hub to satellite to a/c. I'm sure WAAS/LAAS and the rest of NEXTGEN will eventually work, then there's six competing national/regional systems. I can see WAAS for everything but landing, and the revival of MLS as LAAS for landing.
 
BravoOne
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 9:41 pm

I haven't a clue what either of these airlines are doing regarding NEXTGEN. SWA in particular has not been a leader in this field and until just recently they were at the back of the pack in just about all issues regrading advanced technology. In their defense foot dragging is common throughout the US airline industry.
 
WPvsMW
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Re: Autopilots and reverse thrust

Fri Dec 01, 2017 10:23 pm

In 2011, B6 and WN were the guinea pigs in a beta test of the initial phase (ADS-B OUT) of NEXTGEN. 5X was probably the first adopter, in 1997.
https://www.flightglobal.com/news/artic ... al-352774/

B6 and 5X (but not WN) are adding the space-based component of ADS-B.
https://www.ainonline.com/aviation-news ... ased-ads-b
http://interactive.aviationtoday.com/av ... d-jetblue/
 
achutchison
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Re: Autopilots and reverse thrust

Sat Dec 02, 2017 3:53 pm

The autopilot doesn’t control deceleration or spoiler deployment. These are all different systems we’re talking about here that work in tandem.
 
WPvsMW
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Re: Autopilots and reverse thrust

Sat Dec 02, 2017 6:54 pm

If the autopilot doesn't land the plane (including control surfaces and brakes) in a Cat III(B) landing, what does?
https://www.easa.europa.eu/system/files ... -019-R.pdf, see section on CAT III operations.
 
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7BOEING7
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Re: Autopilots and reverse thrust

Sat Dec 02, 2017 11:31 pm

WPvsMW wrote:
If the autopilot doesn't land the plane (including control surfaces and brakes) in a Cat III(B) landing, what does?
https://www.easa.europa.eu/system/files ... -019-R.pdf, see section on CAT III operations.


Not sure if this is what you're asking for, but on Boeing airplanes the autopilot/autothrottle get the airplane on the ground where the autobrake system if armed slows the airplane and the speedbrakes are deployed if armed or with reverse selection if not armed.
 
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Starlionblue
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 1:23 am

7BOEING7 wrote:
WPvsMW wrote:
If the autopilot doesn't land the plane (including control surfaces and brakes) in a Cat III(B) landing, what does?
https://www.easa.europa.eu/system/files ... -019-R.pdf, see section on CAT III operations.


Not sure if this is what you're asking for, but on Boeing airplanes the autopilot/autothrottle get the airplane on the ground where the autobrake system if armed slows the airplane and the speedbrakes are deployed if armed or with reverse selection if not armed.


Same on Airbus.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
WPvsMW
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 4:58 am

Thanks for the clarification... "deceleration" and "spoilers" apply equally to airborne and touchdown/rollout, which confused me. Broadly speaking, autobrake begins when autopilot/autothrottle stops, which leads me to DL1086 and whether reverse thrust can be automated. Given improvements in inertial sensors (is the a/c rollout down the middle of the runway? sensed a thousand times a seconds and brake/reverse thrust corrections made) and computing power, isn't integration of reverse thrust not only possible, but required for CAT III(C)? CAT III(C), now only a vision, requires landing in zero visibility... which would mean computer control through full rollout ... in zero visibility.
 
26point2
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 6:04 am

Interesting thread. Reverse Thrust is not included in stopping distance certification. ..Neither rejected takeoff or landing distance. Why automate it?
 
WPvsMW
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 6:41 am

Why?.... DL 1086.
 
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Starlionblue
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 6:45 am

WPvsMW wrote:
Why?.... DL 1086.


The Delta 1086 investigation concluded that the probable cause was the pilot flying's "inability to maintain directional control of the airplane due to his application of excessive reverse thrust, which degraded the effectiveness of the rudder in controlling the airplane’s heading". In other words, reverse thrust made things worse.

If you can't maintain directional control on rollout, you should cancel reverse.

Besides, if there's one thing that will kill you quickly it is reverse in the air. Lauda Air 004 is a prime example. I'd rather not have automation controlling such a thing.

Let's please not automate reverse.

26point2 wrote:
Interesting thread. Reverse Thrust is not included in stopping distance certification. ..Neither rejected takeoff or landing distance. Why automate it?


Indeed.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
greg85
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 10:18 am

I don't know any type that gives you auto reverse. However, there is a feature that was introduced by Airbus on the A350 and A380 (and as far as I know it is also available as on option on A320, however I have never flown an A320 that had it installed) which is called ROPS (Runway Overrun Prevention System). It will compare the computed landing distance and with remaining runway length during rollout (there is also an airborne warning provided if the system senses that the runway length is insufficient prior to touchdown) and if it senses a risk of an overrun automatically apply maximum brakes and generate an audio message "MAX Reverse" (and if the threat still exists at 70kts an other audio message "Keep MAX Reverse"). While the reverser is not automatically actuated the system advises the pilot to do so.


ROW/ROP does not automatically apply braking. It simply displays messages on the PFD, and in certain cases has aural alerts. It can say handy things like "runway to short" or "max braking", it's then up to the pilot to act on these alerts if appropriate. (A320)
 
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Starlionblue
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 12:36 pm

greg85 wrote:
I don't know any type that gives you auto reverse. However, there is a feature that was introduced by Airbus on the A350 and A380 (and as far as I know it is also available as on option on A320, however I have never flown an A320 that had it installed) which is called ROPS (Runway Overrun Prevention System). It will compare the computed landing distance and with remaining runway length during rollout (there is also an airborne warning provided if the system senses that the runway length is insufficient prior to touchdown) and if it senses a risk of an overrun automatically apply maximum brakes and generate an audio message "MAX Reverse" (and if the threat still exists at 70kts an other audio message "Keep MAX Reverse"). While the reverser is not automatically actuated the system advises the pilot to do so.


ROW/ROP does not automatically apply braking. It simply displays messages on the PFD, and in certain cases has aural alerts. It can say handy things like "runway to short" or "max braking", it's then up to the pilot to act on these alerts if appropriate. (A320)


Same on the 350. The ROW/ROP warnings are bloody loud though! :D
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
barney captain
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Re: Autopilots and reverse thrust

Sun Dec 03, 2017 9:40 pm

26point2 wrote:
Interesting thread. Reverse Thrust is not included in stopping distance certification. ..Neither rejected takeoff or landing distance. Why automate it?


We found out after the fact that indeed, the 700 was certified using reverse for landing calculations.
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