Engineering design Vs Pilots perception
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John Maris of Marinvent has patented Dynamic Non-Linear Display formats that provide information about the complete altitude and airspeed range of the aircraft (as just two examples) on tape instruments. Ideal for unusual attitudes and dynamic maneuvers like emergency descents. Anyone want to try them in an R&D setting can send me a PM.
AI design
The Flash Airlines B737 accident at Sharm el Sheikh on 3 Jan 2004 was partially attributed to spatial disorientation of the Commander and one of the factors was allegedly his Air Force background (Mig 21). Note that the Egyptian CAA report and the NTSB and BEA comments do not fully agree. See:
BEA
and go to Reports/Search 2004.
BEA
and go to Reports/Search 2004.
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F-111 correction
The story regarding the wing sweep lever for the F-111, in that it was originally designed with the function of lever forward-wings sweep forward, lever back-wings sweep back, perfect one to one mapping, engineers logical solution. However pilots perception is lever forward=go faster, lever back=go slower, along with the other controls in the cockpit that meant something went faster if you pushed it forward and vice versa. So as the pilot wanted to slow down for landing, the wing sweep lever was moved aft and the wings swept back, which was obviously not very nice. The wing sweep lever was subsequently re-designed to stop any potential confusion for the pilots.
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Bentstick
Interesting update/correction on the wing sweep lever. It is contradictory to the HMI thesis I read but it sounds like you have first hand knowledge of the lever and its operation, so I'm not really in a position to dispute with any real strength.
Whats the story with the park brake and hook handles?
Interesting update/correction on the wing sweep lever. It is contradictory to the HMI thesis I read but it sounds like you have first hand knowledge of the lever and its operation, so I'm not really in a position to dispute with any real strength.
Whats the story with the park brake and hook handles?
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You can confirm it for yourself by looking at cockpit photos of F111s (any model, any era) when parked on the ramp. You'll notice that the wing sweep lever is always fully forward (16 deg).
The Hook and park Brake handles were of similar(ish) shape and size and mounted about 10cm apart, just fwd of the wing sweep lever(Park break was grey, hook handle was yellow) . Many a Pig driver blew the hook down while attempting to engage the park brake.
The Hook and park Brake handles were of similar(ish) shape and size and mounted about 10cm apart, just fwd of the wing sweep lever(Park break was grey, hook handle was yellow) . Many a Pig driver blew the hook down while attempting to engage the park brake.
Hi
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Engineers and pilots
hello
I think it is a wrong approach to want to change instruments. We've saddly lost the first SF34 in ZRH because of this you're trying to tell me?
I think that you're trying to solve the "how" this happened while you should try to fix the "why".
But for heck of it ...I hate this in cockpits:
A) Clicking. Easy,787, 380, 777, E145,E170...Never heard about touch screens like in jet fighters? Why do I need to see Windows like menu in an aircraft.
B) FAULT lights with partial system working. Is this thing working or not????
C) Poor audio radio quality. Should be digital (less fatigue) with auto frequency switching
D) Control laws: Too complicated and there are always exceptions. Why? The engineer will give you 10x10000 reasons why, but he's not flying the thing.
E) Virtual MCDU keyboards.
F) Limitations. Do not operate the gear if pressure is below 1450 PSI. Do I care? No, I need to raise of lower the drag generator. End of story. Fadec can compute several parameters per second but I still need to keep an eye on the oil pressure when starting the engines. Thanks automation.
G) Switches versus push buttons. I prefer flush, pushed in for normal, LED bulbs. Green= Works ON. Red = failed stopped operation. Not lit = OFF.
H) Flap handle. Should be kept for backup only and a new logic incorporated in speed modes allowing flaps extension for slowing down. EGPWS will yell at you TOO LOOW GEAR/FLAPS but no piece of automation here...still manually have to lower the gear. Even 3 radio altimeters not sufficent to tell that we can safely raise the gear automatically. We have auto slats but no auto flaps.
I) Garmin 1000 on VFR (mainly) machines. So you have to operate VFR while spending most of your time punching buttons head down on the displays of a single pilot operated machine? Watch the other guy.
J) 0/0 capabilities. Engineering dream. How do I taxi if I cannot legally rely on the moving map of my EFB?
K) Airbus controls (stick and throttles) not showing movements.
L) Pure engineering concepts. 'Kmon have you ever seen a concept car commercially available? No, that's why it is called a concept. Concept and practical don't go along (use is practical but manufacturing is nightmare).
If you're french and born in Blagnac then you can understand Crew Operating Manual. (How to operate the crew right?). If you're from KBFI then you can understand Aircraft Operating Manual (How to operate the ship).
M) Vertical speed mode. This thing is on since 800 BC on ships and no one came up with something smooth.
N) HF radio. Yeah, I still have my 56k modem for surfing the web!
I love:
A) EVS, HUD
B) EICAS/ECAM message auto arrange
C) OEI auto pop up for SID, Climb...
D) TAC on 777
E) Antiskid (everybody thinks it is granted like on cars. Remember 40 years ago...)
F) Wx radar mapping by FL.
G) FANS, ADS, Satcom...
H) Electronic checklist
I) EFBs vs laptops.
To conclude:
The why vs the how...
It is very complicated for a pilot to write down a robust spec to an engineer.
It is very easy for the engineer to implement the IF ...CONDITION then ACTION from the spec, but it is awfully complicated to write a ELSE if nothing is given in the spec. Most of the problems are coming for this missing statement (unspecified). And it is getting worse because of commercial pressure( shorter coding, testing, integration, robustness test time), more and more combination of conditions are remaining untested or deliberately put into the class "unlikely to occur".
"This failed because these conditions where never tested". "This plane crashed because pilot was tired". You would like to design something that will tell a tired pilot he's making a mistake but next thing management will ask is to have our flight duty extended and fly with more fatigue.
I do beleive that making these 2 worlds (Engineers/Pilots) "talking" together is an art. I love to write sequencers in C versus "Cool" realtime applications in Java with embedded windows XP. But between you and me: KISS (Keep It Stupid & Simple).
I think it is a wrong approach to want to change instruments. We've saddly lost the first SF34 in ZRH because of this you're trying to tell me?
I think that you're trying to solve the "how" this happened while you should try to fix the "why".
But for heck of it ...I hate this in cockpits:
A) Clicking. Easy,787, 380, 777, E145,E170...Never heard about touch screens like in jet fighters? Why do I need to see Windows like menu in an aircraft.
B) FAULT lights with partial system working. Is this thing working or not????
C) Poor audio radio quality. Should be digital (less fatigue) with auto frequency switching
D) Control laws: Too complicated and there are always exceptions. Why? The engineer will give you 10x10000 reasons why, but he's not flying the thing.
E) Virtual MCDU keyboards.
F) Limitations. Do not operate the gear if pressure is below 1450 PSI. Do I care? No, I need to raise of lower the drag generator. End of story. Fadec can compute several parameters per second but I still need to keep an eye on the oil pressure when starting the engines. Thanks automation.
G) Switches versus push buttons. I prefer flush, pushed in for normal, LED bulbs. Green= Works ON. Red = failed stopped operation. Not lit = OFF.
H) Flap handle. Should be kept for backup only and a new logic incorporated in speed modes allowing flaps extension for slowing down. EGPWS will yell at you TOO LOOW GEAR/FLAPS but no piece of automation here...still manually have to lower the gear. Even 3 radio altimeters not sufficent to tell that we can safely raise the gear automatically. We have auto slats but no auto flaps.
I) Garmin 1000 on VFR (mainly) machines. So you have to operate VFR while spending most of your time punching buttons head down on the displays of a single pilot operated machine? Watch the other guy.
J) 0/0 capabilities. Engineering dream. How do I taxi if I cannot legally rely on the moving map of my EFB?
K) Airbus controls (stick and throttles) not showing movements.
L) Pure engineering concepts. 'Kmon have you ever seen a concept car commercially available? No, that's why it is called a concept. Concept and practical don't go along (use is practical but manufacturing is nightmare).
If you're french and born in Blagnac then you can understand Crew Operating Manual. (How to operate the crew right?). If you're from KBFI then you can understand Aircraft Operating Manual (How to operate the ship).
M) Vertical speed mode. This thing is on since 800 BC on ships and no one came up with something smooth.
N) HF radio. Yeah, I still have my 56k modem for surfing the web!
I love:
A) EVS, HUD
B) EICAS/ECAM message auto arrange
C) OEI auto pop up for SID, Climb...
D) TAC on 777
E) Antiskid (everybody thinks it is granted like on cars. Remember 40 years ago...)
F) Wx radar mapping by FL.
G) FANS, ADS, Satcom...
H) Electronic checklist
I) EFBs vs laptops.
To conclude:
The why vs the how...
It is very complicated for a pilot to write down a robust spec to an engineer.
It is very easy for the engineer to implement the IF ...CONDITION then ACTION from the spec, but it is awfully complicated to write a ELSE if nothing is given in the spec. Most of the problems are coming for this missing statement (unspecified). And it is getting worse because of commercial pressure( shorter coding, testing, integration, robustness test time), more and more combination of conditions are remaining untested or deliberately put into the class "unlikely to occur".
"This failed because these conditions where never tested". "This plane crashed because pilot was tired". You would like to design something that will tell a tired pilot he's making a mistake but next thing management will ask is to have our flight duty extended and fly with more fatigue.
I do beleive that making these 2 worlds (Engineers/Pilots) "talking" together is an art. I love to write sequencers in C versus "Cool" realtime applications in Java with embedded windows XP. But between you and me: KISS (Keep It Stupid & Simple).
Last edited by bauduin_alex; 26th Feb 2009 at 19:50.
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Flap handle. Should be kept for backup only and a new logic incorporated in speed modes allowing flaps extension for slowing down. EGPWS will yell at you TOO LOOW GEAR/FLAPS but no piece of automation here...still manually have to lower the gear. Even 3 radio altimeters not sufficent to tell that we can safely raise the gear automatically. We have auto slats but no auto flaps.
The important thing is to avoid latent failures. It is very difficult to establish the impact of partial loss of inputs to a complex system, in order to allow continued operation. Which functionality of the equipment is still OK ? It is safer to declare the unit non-functional and switch to an alternative. So I agree a “partially failed” indication as mentioned elsewhere in your post is not very helpful !
It is very complicated for a pilot to write down a robust spec to an engineer.
It is very easy for the engineer to implement the IF ...CONDITION then ACTION from the spec, but it is awfully complicated to write a ELSE if nothing is given in the spec.
Most of the problems are coming for this missing statement (unspecified). And it is getting worse because of commercial pressure( shorter coding, testing, integration, robustness test time), more and more combination of conditions are remaining untested or deliberately put into the class "unlikely to occur".
It is very easy for the engineer to implement the IF ...CONDITION then ACTION from the spec, but it is awfully complicated to write a ELSE if nothing is given in the spec.
Most of the problems are coming for this missing statement (unspecified). And it is getting worse because of commercial pressure( shorter coding, testing, integration, robustness test time), more and more combination of conditions are remaining untested or deliberately put into the class "unlikely to occur".
Getting users, even highly trained and intelligent-ones like pilots (!) to express their requirements is difficult and is often based on “I want it like this - but better”. It needs to be related to a specific aspect of an existing system of an available prototype to demonstrate the concept.
I would be interested to know your views of data-fusion, and integration of equipmnet displays and data sources.
hugel
Only half a speed-brake
The BROWN-UP instrument
I understand the thread moved past this particular item, but perhaps someone may still find little info on the horizon interesting. The part number is LUN 1202, electrically powered through voltage changer. Best picture I could find is here:
http://pwdt.virtualskies.net/images/lun1202.jpg
Used on 70's design eastern trainers (Zlins), simple design now obsolete. I completed my initial instrument and night training with these.
The mechanical principles are:
Aircraft symbol is fixed in bank. The left knob serves for adjustments in pitch designed to fine tune the vertical position of the aircraft symbol so that in level flight with different speeds pilot could "zero" the indicated pitch and maintain precise reference. I was told not to use it, nor felt it would be required.
The coloured ball inside (not the side-slip indicator) maintains position in 3D with the vertical divider aligned to true horizon.
How to read:
The picture shows a slight nose down attitude, for basic recognition the upper part over which the aircraft symbol is now portrayed is painted brown with a label "descends". Suppose you would like to return to neutral pitch: look at the ball's vertical divider and "pick" it up to align with (fixed) aircraft symbol. The ball's divider needs to go up - pull back on the stick.
Bank is read by comparing the top-down line on the ball to the scales at bottom. The gyro-ball is again stabilised and the whole instrument (and aeroplane) revolves around it. For a right 15 deg bank situation, the scales would turn clockwise over the stabilised background gyro ball. I.e. you need to pull the top-down line drawn on the gyro-ball out from the neutral position behind the scales to the first mark on the right side. As you apply right rudder to keep the sideslip indicator centred you will see the turn coordinator located right in between these to sway to right, all conveniently located at one spot. So once we had banked to the right you would see the top-down line on the reference ball aligned behind the right side of the (fixed) scales on the bottom of the instrument. To return wings level, you push the top-down line back to centre with a left input on the stick. Or, as I was told on the first day of the training "kick" the gyro back to neutral position - with your knee kick the stick.
Maybe different teaching would be required with yoke equipped aircraft, but for Zlins this worked seamlessly.
Yours,
FD (the un-real)
http://pwdt.virtualskies.net/images/lun1202.jpg
Used on 70's design eastern trainers (Zlins), simple design now obsolete. I completed my initial instrument and night training with these.
The mechanical principles are:
Aircraft symbol is fixed in bank. The left knob serves for adjustments in pitch designed to fine tune the vertical position of the aircraft symbol so that in level flight with different speeds pilot could "zero" the indicated pitch and maintain precise reference. I was told not to use it, nor felt it would be required.
The coloured ball inside (not the side-slip indicator) maintains position in 3D with the vertical divider aligned to true horizon.
How to read:
The picture shows a slight nose down attitude, for basic recognition the upper part over which the aircraft symbol is now portrayed is painted brown with a label "descends". Suppose you would like to return to neutral pitch: look at the ball's vertical divider and "pick" it up to align with (fixed) aircraft symbol. The ball's divider needs to go up - pull back on the stick.
Bank is read by comparing the top-down line on the ball to the scales at bottom. The gyro-ball is again stabilised and the whole instrument (and aeroplane) revolves around it. For a right 15 deg bank situation, the scales would turn clockwise over the stabilised background gyro ball. I.e. you need to pull the top-down line drawn on the gyro-ball out from the neutral position behind the scales to the first mark on the right side. As you apply right rudder to keep the sideslip indicator centred you will see the turn coordinator located right in between these to sway to right, all conveniently located at one spot. So once we had banked to the right you would see the top-down line on the reference ball aligned behind the right side of the (fixed) scales on the bottom of the instrument. To return wings level, you push the top-down line back to centre with a left input on the stick. Or, as I was told on the first day of the training "kick" the gyro back to neutral position - with your knee kick the stick.
Maybe different teaching would be required with yoke equipped aircraft, but for Zlins this worked seamlessly.
Yours,
FD (the un-real)
