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pwm2txlhopper
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How have autopilots evolved over the decades?

Sat Jan 12, 2019 3:36 am

I don’t have any instrument training, so my understanding of autopilots is fairly basic.

I know that these days autopilots on passenger airliners are connected to the FMS and GPS. Aside from that, how have autopilots evolved from the first generation of jet airliners up through modern times?

I’ve read about earlier autopilots in classic jets such as the 727 and DC-9 and how they had more limited capability than in later generations of aircraft, but I’m still confused about how they’ve evolved besides being connected to the FMS and GPS? What was the different innovations that came along over the decades with each new generation? Are there different features and functions that didn’t use to exist?

Also, I learned to fly in the late 1990s, right before glass cockpits and GPS were coming into GA. I learned instrument navigation using VOR/NDB/ defunct LORAN ( I’ve been inactive from flying for 19 years) I was wondering if modern commercial airlines even use VOR’s anymore when their flight plan shows one VOR to another? Do they even tune into them these days via VHF, or is the FMS and autopilot just navigating to the VOR using the GPS, but not the real VHF frequency for the said VOR?
 
GalaxyFlyer
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Re: How have autopilots evolved over the decades?

Sat Jan 12, 2019 4:14 am

The VOR is just a waypoint in the flight plan; most FMS auto-tunes the VOR-DME as a part of RNAV function backing up the GPS or IRS position. VOR navigation is pretty rare, perhaps only to show the navaid while flying an overlay approach or to do a nav check with a ground-based navaid prior to or exiting a Class II leg.

Autopilots are just a means of connecting muscles to the FMS navigation as presented to the pilots thru the Flight Director. The old autopilots could do most of the same basic functions today’s autopilots do—hold altitude, couple to a navigation input like VOR or ILS. The new ones just have loads more advanced functions—GPS nav, several vertical modes like Flight Path Angle, V/S, FLCH, VNAV, new approaches like LPV, RNP.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Sat Jan 12, 2019 10:21 am

You have to think in the wider context of the Autoflight System. Modern autopilots are integrated into a wider system of autoflight which includes autothrust, flight directors and FMS.

Some capabilities that have evolved:
- VNAV/LNAV from the FM.
- Soft cruise.
- Improved predictions with regards to climb and descent.
- Envelope protection, which is a massive subject by itself.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Faro
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Re: How have autopilots evolved over the decades?

Sat Jan 12, 2019 3:45 pm

GalaxyFlyer wrote:
The VOR is just a waypoint in the flight plan; most FMS auto-tunes the VOR-DME as a part of RNAV function backing up the GPS or IRS position. VOR navigation is pretty rare, perhaps only to show the navaid while flying an overlay approach or to do a nav check with a ground-based navaid prior to or exiting a Class II leg.

Autopilots are just a means of connecting muscles to the FMS navigation as presented to the pilots thru the Flight Director. The old autopilots could do most of the same basic functions today’s autopilots do—hold altitude, couple to a navigation input like VOR or ILS. The new ones just have loads more advanced functions—GPS nav, several vertical modes like Flight Path Angle, V/S, FLCH, VNAV, new approaches like LPV, RNP.



One wonders however, do pilots use all these modes or is it like with smartphones and computers where the vast majority of people use a limited number of functionalities?...


Faro
The chalice not my son
 
GalaxyFlyer
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Re: How have autopilots evolved over the decades?

Sat Jan 12, 2019 4:31 pm

Yeah, most are used depending on the situation. None are truly superfluous, but Collins has three ways to do most everything in a Fusion cockpit esp accessing data or modes and one is usually best for each specific task.

GF
 
VSMUT
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Re: How have autopilots evolved over the decades?

Sun Jan 13, 2019 5:09 pm

Faro wrote:
GalaxyFlyer wrote:
The VOR is just a waypoint in the flight plan; most FMS auto-tunes the VOR-DME as a part of RNAV function backing up the GPS or IRS position. VOR navigation is pretty rare, perhaps only to show the navaid while flying an overlay approach or to do a nav check with a ground-based navaid prior to or exiting a Class II leg.

Autopilots are just a means of connecting muscles to the FMS navigation as presented to the pilots thru the Flight Director. The old autopilots could do most of the same basic functions today’s autopilots do—hold altitude, couple to a navigation input like VOR or ILS. The new ones just have loads more advanced functions—GPS nav, several vertical modes like Flight Path Angle, V/S, FLCH, VNAV, new approaches like LPV, RNP.



One wonders however, do pilots use all these modes or is it like with smartphones and computers where the vast majority of people use a limited number of functionalities?...


Faro


I would say it depends entirely where you fly. If you were to fly up in Scandinavia and Germany, you would almost never use anything other than LNAV/RNAV (for cruise), HDG (for radar vectors) and ILS-Approach lateral modes. On the other hand, I just started in a new job in a country where there is only 1 instrument approach and barely any nav-aids in the entire country, meaning I never use anything other than HDG mode in conjunction with a GPS and a map.

So yes, it is entirely possible to never (or almost never) use many of the modes.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Sun Jan 13, 2019 10:56 pm

GalaxyFlyer wrote:
Yeah, most are used depending on the situation. None are truly superfluous, but Collins has three ways to do most everything in a Fusion cockpit esp accessing data or modes and one is usually best for each specific task.

GF


As an example, if you want to go direct to a fix in an A350 you can do it in the following ways:
- Click on the fix on the ND and select "From P.Pos direct to"
- Select the FM flight plan page, then click on the fix and select "From P.Pos direct to"
- Press the "Dir" key on the keyboard and select the fix from the dropdown menu, then "direct to".
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
GalaxyFlyer
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 1:14 am

Collins Fusion works the same way, depending situation each works well. We could press the DIR key and type in any fix in the flight plan or a random fix. We could click on the fix on the ND, all the airways associated with fix appeared and build a new route from the that fix. Graphical flight planning was a neat trick but not often used.

GF
 
747Whale
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 5:36 am

Faro wrote:

One wonders however, do pilots use all these modes or is it like with smartphones and computers where the vast majority of people use a limited number of functionalities?...


Faro


I have been in the cockpit with aviators who have two decades of time in that type aircraft, and they're still learning aspects of the system. It's rather humbling to witness. It's a call to look inwardly and ask "what it is that I don't know yet," and to constantly be searching.

Automation has progressed substantially in terms of capability and reliability, and certainly much of what's taken for granted today in vertical navigation was once a matter of rules of thumb.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 7:11 am

747Whale wrote:
Faro wrote:

One wonders however, do pilots use all these modes or is it like with smartphones and computers where the vast majority of people use a limited number of functionalities?...

Faro


I have been in the cockpit with aviators who have two decades of time in that type aircraft, and they're still learning aspects of the system. It's rather humbling to witness. It's a call to look inwardly and ask "what it is that I don't know yet," and to constantly be searching.

Automation has progressed substantially in terms of capability and reliability, and certainly much of what's taken for granted today in vertical navigation was once a matter of rules of thumb.


Quite so. Many functions are a bit obscure.

The other week, I learned how to set up a pseudo-waypoint based on the intersection of two radials, without storing it as a custom fix first. Why did I not know how to do this? Because getting an instruction based on two radials is pretty rare nowadays so I never had to learn...
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 5:13 pm

Faro wrote:
GalaxyFlyer wrote:
The VOR is just a waypoint in the flight plan; most FMS auto-tunes the VOR-DME as a part of RNAV function backing up the GPS or IRS position. VOR navigation is pretty rare, perhaps only to show the navaid while flying an overlay approach or to do a nav check with a ground-based navaid prior to or exiting a Class II leg.

Autopilots are just a means of connecting muscles to the FMS navigation as presented to the pilots thru the Flight Director. The old autopilots could do most of the same basic functions today’s autopilots do—hold altitude, couple to a navigation input like VOR or ILS. The new ones just have loads more advanced functions—GPS nav, several vertical modes like Flight Path Angle, V/S, FLCH, VNAV, new approaches like LPV, RNP.



One wonders however, do pilots use all these modes or is it like with smartphones and computers where the vast majority of people use a limited number of functionalities?...


Faro


There aren't that many Autpilot modes on Boeing airplanes. They all are used at one time or another.
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 5:21 pm

pwm2txlhopper wrote:
I don’t have any instrument training, so my understanding of autopilots is fairly basic.

I know that these days autopilots on passenger airliners are connected to the FMS and GPS. Aside from that, how have autopilots evolved from the first generation of jet airliners up through modern times?

I’ve read about earlier autopilots in classic jets such as the 727 and DC-9 and how they had more limited capability than in later generations of aircraft, but I’m still confused about how they’ve evolved besides being connected to the FMS and GPS? What was the different innovations that came along over the decades with each new generation? Are there different features and functions that didn’t use to exist?

Also, I learned to fly in the late 1990s, right before glass cockpits and GPS were coming into GA. I learned instrument navigation using VOR/NDB/ defunct LORAN ( I’ve been inactive from flying for 19 years) I was wondering if modern commercial airlines even use VOR’s anymore when their flight plan shows one VOR to another? Do they even tune into them these days via VHF, or is the FMS and autopilot just navigating to the VOR using the GPS, but not the real VHF frequency for the said VOR?


Boeing autopilots have modes that connect to the FMC and GPS and modes that do not. I think Airbus airplanes are similar.

You can connect to the FMC in the LNAV and VNAV modes and fly the FMC flight plan. Or you can directly tell the Autopilot to do stuff like fly a certain Heading or Track; climb to 10,000 feet, follow the Localizer and Glideslope, etc.

I'll list the modes that exist on the 777 and 787 for example. Other models are similar with minor differences or omissions that I could describe if anyone is interested:

Roll Modes:

Heading Select
Heading Hold
Track Select
Track Hold
LNAV (follows FMC flight path)
Localizer
Final Approach Course (not on legacy 777)
Rollout

Pitch Modes:

VNAV (follows vertical FMC flight path)
Altitude Hold
Flight Level Change
Vertical Speed
Flight Path Angle
Glideslope
Glidepath (not on legacy 777)
Flare

Autothrottle Modes:

Thrust Reference
Thrust
Speed
Idle
Hold
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Mon Jan 14, 2019 11:38 pm

Not that many more on Airbus. Taking the A350 as an example

AP Lateral modes:
RWY, RWY TRK
NAV
HDG, TRACK
LOC*, LOC
LOC B/C *, LOC B/C
F-LOC*, F-LOC
GA TRK
AP IN PROT

AP Vertical modes:
SRS
SRS TO
CLB
DES
OP CLB
OP DES
EMER DES
V/S, FPA
ALT*, ALT
ALT CST*, ALT CST
ALT CRZ* , ALT CRZ
G/S*, G/S
F-G/S*, F-G/S FLS-G/S
APP-DES
TCAS

AP Common modes:
LAND
FLARE
ROLL OUT

Autothrust thrust modes
THR CLB
THR MCT
THR LVR
THR DCLB
NOISE N1 xx%
THR DES
THR IDLE
A. FLOOR

Autothrust speed mode
SPEED, MACH

Autothrust RETARD mode
Not on FMA. Aural callout only

Autothrust soft mode
Not on FMA

BoeingGuy wrote:
Boeing autopilots have modes that connect to the FMC and GPS and modes that do not. I think Airbus airplanes are similar.


Indeed. On Airbus "FM-driven" modes are NAV mode in the lateral, and CLB/DES in the vertical (as opposed to OP CLB/OP DES), as well as ALT CSTR*/ALT CSTR.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 1:33 am

Ahhh, I forgot the Backcouse (B/CRS) roll mode on most models.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 1:36 am

And I forgot that F-GS*, F-GS, F-LOC* and F-LOC are "FM-driven" on Airbus.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Flighty
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 5:00 am

How about the final analog jets, DC-10, L-1011? Did their autopilot connect to navigation? I imagine them being advanced but no idea. Thx
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 5:09 am

Starlionblue wrote:
And I forgot that F-GS*, F-GS, F-LOC* and F-LOC are "FM-driven" on Airbus.


What are those modes? Are they the same as IAN on Boeing airplanes? ILS look-alike profiles built by the FMC? That would be FAC and G/P on Boeing models.
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 5:14 am

Starlionblue wrote:
Not that many more on Airbus. Taking the A350 as an example

AP Lateral modes:
RWY, RWY TRK
NAV
HDG, TRACK
LOC*, LOC
LOC B/C *, LOC B/C
F-LOC*, F-LOC
GA TRK
AP IN PROT

AP Vertical modes:
SRS
SRS TO
CLB
DES
OP CLB
OP DES
EMER DES
V/S, FPA
ALT*, ALT
ALT CST*, ALT CST
ALT CRZ* , ALT CRZ
G/S*, G/S
F-G/S*, F-G/S FLS-G/S
APP-DES
TCAS

AP Common modes:
LAND
FLARE
ROLL OUT

Autothrust thrust modes
THR CLB
THR MCT
THR LVR
THR DCLB
NOISE N1 xx%
THR DES
THR IDLE
A. FLOOR

Autothrust speed mode
SPEED, MACH

Autothrust RETARD mode
Not on FMA. Aural callout only

Autothrust soft mode
Not on FMA

BoeingGuy wrote:
Boeing autopilots have modes that connect to the FMC and GPS and modes that do not. I think Airbus airplanes are similar.


Indeed. On Airbus "FM-driven" modes are NAV mode in the lateral, and CLB/DES in the vertical (as opposed to OP CLB/OP DES), as well as ALT CSTR*/ALT CSTR.


Those seem a lot more complex than on Boeing airplanes. We don't have a separate emergency descent mode. You use FLCH and dial in Vmo as your speed. However, some models will pitch over more aggressively if the CABIN ALTITUDE warning is active.

I take it that the A350 autopilot will fly TCAS RAs?

I did forget to mention that VNAV has three modes: VNAV SPD, VNAV PTH and VNAV ALT.

I'd like to know what a lot of those Airbus modes do.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 5:34 am

BoeingGuy wrote:
Starlionblue wrote:
Not that many more on Airbus. Taking the A350 as an example

AP Lateral modes:
RWY, RWY TRK
NAV
HDG, TRACK
LOC*, LOC
LOC B/C *, LOC B/C
F-LOC*, F-LOC
GA TRK
AP IN PROT

AP Vertical modes:
SRS
SRS TO
CLB
DES
OP CLB
OP DES
EMER DES
V/S, FPA
ALT*, ALT
ALT CST*, ALT CST
ALT CRZ* , ALT CRZ
G/S*, G/S
F-G/S*, F-G/S FLS-G/S
APP-DES
TCAS

AP Common modes:
LAND
FLARE
ROLL OUT

Autothrust thrust modes
THR CLB
THR MCT
THR LVR
THR DCLB
NOISE N1 xx%
THR DES
THR IDLE
A. FLOOR

Autothrust speed mode
SPEED, MACH

Autothrust RETARD mode
Not on FMA. Aural callout only

Autothrust soft mode
Not on FMA

BoeingGuy wrote:
Boeing autopilots have modes that connect to the FMC and GPS and modes that do not. I think Airbus airplanes are similar.


Indeed. On Airbus "FM-driven" modes are NAV mode in the lateral, and CLB/DES in the vertical (as opposed to OP CLB/OP DES), as well as ALT CSTR*/ALT CSTR.


Those seem a lot more complex than on Boeing airplanes. We don't have a separate emergency descent mode. You use FLCH and dial in Vmo as your speed. However, some models will pitch over more aggressively if the CABIN ALTITUDE warning is active.

I take it that the A350 autopilot will fly TCAS RAs?

I did forget to mention that VNAV has three modes: VNAV SPD, VNAV PTH and VNAV ALT.

I'd like to know what a lot of those Airbus modes do.


Ask away and I'll try to answer. ;)


The A350 autopilot will fly a TCAS RA in TCAS mode. This feature is also available as an option on the A330.

EMER DES is only available on the A350 I think. To be fair, we do practice doing it manually. EMER DES seems a bit like a last ditch fallback to me. My guess is that most guys would fly it with selected modes (SPEED, OPEN DES, HDG) to maintain more active control of the situation, even if it entails a bit more workload.


On the FCU/ACP (MCP in Boeing-speak) you push a knob to "give" control to the FM. These are called managed modes. You pull a knob to "take" control from the FM. These are called selected modes. For example if you set a lower altitude and push, you get DES, which is an FM controlled descent mode that respects constraints and uses a calculated path to the next constraint. If you set a lower altitude and pull, you get OP DES, which rolls the engines back to flight idle and uses the stabiliser to descend at the current target speed.



BoeingGuy wrote:
Starlionblue wrote:
And I forgot that F-GS*, F-GS, F-LOC* and F-LOC are "FM-driven" on Airbus.


What are those modes? Are they the same as IAN on Boeing airplanes? ILS look-alike profiles built by the FMC? That would be FAC and G/P on Boeing models.


Yes. Synthetic FM generated glidepath and/or lateral guidance for LOC, VOR, RNAV and so on.

Any mode with a star, like LOC*, is the capture mode preceding certain modes. E.g. you go from HDG to LOC* to LOC, or CLB to ALT* to ALT.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
GalaxyFlyer
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 3:27 pm

starlionblue,

Is EMER DESCENT automatically engaged and flown on condition or is selectable by the pilot and then flown by the autopilot? Or both, I suppose?

GF
 
Flow2706
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Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 4:34 pm

GalaxyFlyer wrote:
starlionblue,

Is EMER DESCENT automatically engaged and flown on condition or is selectable by the pilot and then flown by the autopilot? Or both, I suppose?

GF


Here is a nice video of it: https://www.youtube.com/watch?v=t0-U0OqgHX4 In this video it looks like its selected manually, but maybe it can activate automatically as well (not sure since I'm not rated on 350s)
 
GalaxyFlyer
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Joined: Fri Jan 01, 2016 4:44 am

Re: How have autopilots evolved over the decades?

Tue Jan 15, 2019 5:30 pm

Thanks much. It is looks like the Collins system with a few added features—auto squawk of 7700; adds spoilers (speed brakes) and auto checklist. The Global didn’t do those items, but I think the Global 7500 added at least the squawk and checklist.

GF
 
Max Q
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 1:18 am

Flighty wrote:
How about the final analog jets, DC-10, L-1011? Did their autopilot connect to navigation? I imagine them being advanced but no idea. Thx



Yes, that generation of aircraft all had
the ability to connect the autopilot to whatever independent navigation device was being used such as Omega / INS etc..
The best contribution to safety is a competent Pilot.
 
BravoOne
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 11:09 am

Max Q wrote:
Flighty wrote:
How about the final analog jets, DC-10, L-1011? Did their autopilot connect to navigation? I imagine them being advanced but no idea. Thx



Yes, that generation of aircraft all had
the ability to connect the autopilot to whatever independent navigation device was being used such as Omega / INS etc..



Even the 707/727 and DC8 had a NAV function selector on the autopilot controller that could be engaged to track Doppler/INS/Omega signals. It also worked on VOR signals but was what could be described as wobbly when tracking a VOR course signal. The 727 had an upgraded autopilot
(Sperry SP150), that worked a little better than the early SP50 model autopilots. These autopilots were very primitive by today's standards or even early model 757/767 autopilots and I don't think anyone has even scratched the surface when Autoland is discussed.
 
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CARST
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 12:46 pm

BravoOne wrote:
... and I don't think anyone has even scratched the surface when Autoland is discussed.


Which was the first passenger aircraft to have autoland-capability?

And who did it evolve over the years?
 
Max Q
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 1:40 pm

CARST wrote:
BravoOne wrote:
... and I don't think anyone has even scratched the surface when Autoland is discussed.


Which was the first passenger aircraft to have autoland-capability?

And who did it evolve over the years?



Pretty sure that was the Hawker Siddeley
Trident in the early ‘60’s
The best contribution to safety is a competent Pilot.
 
Max Q
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 1:51 pm

Max Q wrote:
CARST wrote:
BravoOne wrote:
... and I don't think anyone has even scratched the surface when Autoland is discussed.


Which was the first passenger aircraft to have autoland-capability?

And who did it evolve over the years?



Pretty sure that was the Hawker Siddeley
Trident in the early ‘60’s



We had the ability to track a radial with the autopilot in the 727 but it wandered around a lot


We also had a few aircraft fitted with Omega, the aircraft would track from one waypoint to another in nav mode
The best contribution to safety is a competent Pilot.
 
CosmicCruiser
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 2:23 pm

As for autoland, I was always impressed at how dual autopilots "compare" each other on a CATIII app.
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 4:14 pm

Max Q wrote:
CARST wrote:
BravoOne wrote:
... and I don't think anyone has even scratched the surface when Autoland is discussed.


Which was the first passenger aircraft to have autoland-capability?

And who did it evolve over the years?



Pretty sure that was the Hawker Siddeley
Trident in the early ‘60’s


That’s my understanding also, Trident was first. Seems like in various sources I’ve also read that it was the DC-8 or L-1011.
 
747Whale
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 5:02 pm

CosmicCruiser wrote:
As for autoland, I was always impressed at how dual autopilots "compare" each other on a CATIII app.


Or triple autopilots.
 
BoeingGuy
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Re: How have autopilots evolved over the decades?

Wed Jan 16, 2019 5:54 pm

747Whale wrote:
CosmicCruiser wrote:
As for autoland, I was always impressed at how dual autopilots "compare" each other on a CATIII app.


Or triple autopilots.


The 777 and 787 fly-by-wire systems do a mid-point selection (a.k.a. "voting") of the three Autopilot commands. They are in effect always triple-channel.

The 747, 757, and 767 are only triple-channel and yaw engaged when coupled to the ILS or GLS (if equipped) during approach below 1500 feet. The autopilot servos do a mechanical mid-point selection of the autopilot commands.
 
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Starlionblue
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Re: How have autopilots evolved over the decades?

Fri Jan 18, 2019 2:50 am

Flow2706 wrote:
GalaxyFlyer wrote:
starlionblue,

Is EMER DESCENT automatically engaged and flown on condition or is selectable by the pilot and then flown by the autopilot? Or both, I suppose?

GF


Here is a nice video of it: https://www.youtube.com/watch?v=t0-U0OqgHX4 In this video it looks like its selected manually, but maybe it can activate automatically as well (not sure since I'm not rated on 350s)



It can be engaged by the pilot, or activate automatically, e.g. if both pilots have lost consciousness
- By pilot: By pressing the "Emergency Descent" button, which arms EMER DES, then pull fulling speedbrake to acttivate.
- Fully automatically: If cabin altitude is predicted to rise over 14000ft in the next 15 seconds, EMER DES will arm, and after a 15s countdown will activate.

In both scenarios, the descent will be flown automatically down to 10000ft or MORA, whichever is higher, including full speedbrake.

Additionally:
- AP/AT/FD will activate if not on when EMER DES activates.
- The squawk code will automatically change to 7700
- TCAS will be set to below.
- TCAS RA commands will be followed automatically. Once clear of conflict, EMER DES will reactivate.

You can of course still fly the emergency descent in the "tradtional way", by selecting an altitude and OPEN DSC, managing heading and speed as appropriate, and pulling full speedbrake.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
bhill
Posts: 1585
Joined: Thu Sep 13, 2001 8:28 am

Re: How have autopilots evolved over the decades?

Fri Jan 18, 2019 6:26 pm

Huh...all this smarts and not one "BRW COFF" button........
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