AF 447 Thread No. 7

[roulishollandais]

@PJ2

Originally Posted by PJ2

I'm not sure what you mean by "effective aircraft

This excellent 1997 book that Machinbird advised me, shows 51 references of "Effective aircraft" to explicite the definition: Aviation safety and pilot control: understanding and preventing unfavorable Pilot-Vehicle Interactions isbn=0309056888...National Research Council (U.S.). Committee on the Effects of Aircraft-Pilot Coupling on Flight Safety - 1997 - Transportation - 208 pages
Implications for Design of the Effective Aircraft Dynamics Reduce time lags in the high-frequency effective aircraft dynamics. To reduce tendencies for ...

Originally Posted by PJ2

](no) unusual difficulties which require [...] (particular) skill or knowledge

These characteristics are required for certification, but have nothing to do with system "controllability"

Originally Posted by PJ2

eminently, (éminemment), "observable and controllable"

Observability and controllability don't have to be eminent, they just are mathematic.

Originally Posted by PJ2

Nor do the accident rates indicate a large difference between aircraft types

I assume you refer to A/B ? I have no royalties in any, nor in other manufacturer, nor in any insurance/aircraft financer. I am only involved in flying pleasure, pilot safety, and mathematic accuracy.

Originally Posted by PJ2

However, no aircraft, no design I know of is controllable or observable when it is taken into a full stall.

False :
1. In any pilot school over the world, stall is teached to get private pilot. Would this manoeuver be uncontrollable and the international civil aviation allow that ?
2. AF447's A330 finally seems to stall like many others aircrafts stalled : you just have to push to stop the stall .Gums quoted F-102, Concorde, Viper having analog stalls.Yourself said it is the case also with B777 and A330 D-sim. Is that uncontrollable if the pilot learned that ?
3.The french pilot school where Air France teached his young pilots (perhaps Bonin), IAAG/EPAG uses for VFR and IR learning the Socata TB20 Trinidad. This aircraft stalls in just descending, unstalls just with pushing... Would this manoeuver be uncontrollable and the french civil aviation allow that if it was ?
4. All the aerobatic pilots, including fight pilots regularly stall and spin, controlling perfectly their flights.. We like to look them and we could not imagine one second their flight is not controllable. Are they ?　

Originally Posted by PJ2

AF447 was recoverable even after entry into the stall but it required that the stick be pushed fully forward and held there until the wing began flying again. That would take between 15,000 and 22,000ft (I've flown this in the sim many times). This is Machinbird's "unloading of the wing" to which he referred some pages back.

Originally Posted by Machinbird

And Presto! we have some numbers and they show that

Originally Posted by Machinbird

If you do not mess it up you would do surprisingly well

Originally Posted by HN39

The "on the threshold of stall warning" trajectory with specific excess thrust (T-D)/W = 0.15 results in level off after 15 s (was 18s) at FL76, Mach 0.51, 295 kCAS, az=2,24 g.

The final loss of height is not your 22000 FT, nor FL200, nor 15000 FT,
but 5000 (max) +(FL100-FL76)=7400 FT

Originally Posted by PJ2

Said another way, a B777 pulled up in the same manner and handled the same way as this aircraft was would also crash

Are the B, C, D, etc pilots hammered with "B, C, D, etc. can't stall" ?

Originally Posted by PJ2

sidestick vs control column

Both may be tried, used. if correct. The problem of observability, governabillity, man-machine interface is not which actuator, but how it is connected to the effective system. I have no royalties in any manufacturer, and I choose to put philosophy in library not in aircraft.

Originally Posted by PJ2

This is the part that is very definitely not complicated

Originally Posted by TurbineD

However, it is more complicated when you can't interview a key person in the problem loop. When this happen, you have to make a list and go through the process

Originally Posted by PJ2

In the present system, 99.9% of flights work well with SOPs, CRM, appropriate use of automation (according to enlightened airline policies which permit hand-flying), but the loss of such skills is nevertheless no longer a blip but a trend

.

That is very dangerous ! Every sixty seven hours you have a four minutes crash ! I choose to fly with "these guys [...] (who) knew how to stay alive, (many of them are here, thank you !) and not in your "managed airlines" and their effective aircraft.

roulishollandais