Air Asia Indonesia Lost Contact from Surabaya to Singapore

[Sorry Dog]

However this FlightGlobal article says BAE has no plans to offer it as a retrofit option:

It sorta stretches the imagination to see AB endorsing such an item that they don't offer "in house"....

...maybe one day after it is offered as a nextgen option to a neoneo model 350 then maybe the wheels might start turning for such a retrofit

[vilas]

https://www.faa.gov/training_testing...olume1/4d3.pdf


TERRAIN AVOIDANCE PROCEDURE


Applicable to FBW aircraft: A319, A320, A321, A330, A340 in NORMAL LAW


Immediately:


- THRUST LEVERS TOGA


I- A/P DISCONNECT
- SIDE-STICK* PULL UP, WINGS LEVEL


- SPD BRK Check retracted


[f necessary, use full back stick and maintain a max speed until terrain clearance is assured,


(GPWS warning ceased and radio altitude increasing).


When flight path is safe, decrease pitch and accelerate.

When speed above VLs and V/S positNe, retract flap and gear as required.




*In pitch alternate or direct law, pull up aggressively, wings level. if necessary, maintain speed at stall warning until terrain clearance assured.

[PDR1]

It sorta stretches the imagination to see AB endorsing such an item that they don't offer "in house"....

...maybe one day after it is offered as a nextgen option to a neoneo model 350 then maybe the wheels might start turning for such a retrofit

Not sure what you mean by "in house", but BAES hasn't been part of the AB consortium for many years. I'm sure that if approached by AB as a potential customer for this sidestick they'd be delighted to negotiate a sale of sidesticks for AB to integrate and certify on their aircraft.

PDR

[1201alarm]

You're not Buzz Aldrin, by any chance?!

Not at all, just a strong admirer of what these guys managed to pull of in the Apollo program. It seems I am not alone with that.

[gums]

C'mon CONF, as Vilas has posted, you only use full stick if you have to and you still have some "protections" ( tho I call them "limits").

Problem is we have ALT1 and then ALT2 and then DIRECT. Good grief!!!

I do not like DIRECT unless in a high-performance jet fighter that pilots can handle or a modified DIRECT that has given relations of stick displacement to control surface displacement, and then there's the rates/gains to consider.

Sheesh.

I do not see a lotta engineers here or pilots that went thru the birth of FBW and all the "laws". Many things to incorporate and many inputs to the computers. Human factors played a large role back in the 70's. The current discussion about not having sticks connected is a good example. Ditto for "pressure" versus "displacement" of the controls, be they yokes/wheels/sticks or touchpads.

[phylosocopter]

I still dont get this.

If the aircraft is not carrying persons who can fly it in alternate or direct law at cruise altitude how can it be certified to be there ?

Thats regulatory failure.

If it is not certified to fly at cruise except in normal law then how can it be certified whithout an agreed process for getting from cruise to some other altitude in event of law degredation.

[CONF iture]

So vilas, where does it say "Do not apply full back stick" ... ?
Make your own procedures as you like, but they're not from Airbus.

Originally Posted by gums

C'mon CONF, as Vilas has posted, you only use full stick if you have to and you still have some "protections" ( tho I call them "limits").

Not too sure why vilas choose to post a paper old of 20 years, but just opening the actual FCOM in the emergency procedures and GPWS ALERTS will put things straight :
"PULL UP"
Pull to full backstick and maintain in that position

No choice really - Maintain if you're fully protected in Normal law, but don't if you're only partially protected to respect the stall warning.
Alternate law in pitch is still a load factor demand with maneuver protection included, why wouldn't you take advantage of it if it can save you from hitting the ground ?

Vilas makes rules that are not in the books.

[QDMQDMQDM]

I've been a private pilot for years and I'm an emergency doctor with an interest in human factors.

Surely, there is a basic design flaw in a system which hands the aircraft back to the pilot in an emergency in one of a number of different control modes, all of which have different levels of protection and response to control inputs. The pilot, already stressed and faced with an emergency situation, cannot fly the aircraft automatically, but has to devote much of his higher cognitive function to trying to remember what he should and shouldn't be doing in this particular mode and what happens with different control deflections. For responses to be automatic and instinctive in this kind of situation, where there are so many different variables, seems to me like it would require a frequency of recurrent training and a level of basic handling skill which may be untenable.

Aircraft need to be designed to be flown by idiots, because some day one will.

[vilas]

Conf
What you are repeatedly saying is true only in normal law. You never pull full back stick in alternate. If you can quote any document stating you pull full back stick even in alternate law I will accept it. I don't make procedures but only keep quoting airbus documents unless there is a discussion where opinions are expressed. Even quoting airbus has irritated some people.

[_Phoenix]

Aircraft need to be designed to be flown by idiots, because some day one will.

"Manual flying" is just an illusion. Basically, pilot sends impulses to computer: up/down, left/right, the rudder is a footrest. So the aircraft is already designed to transform a pilot in idiot, but you need superman to fly the alternate laws.

[FDMII]

_Phoenix;

I'm sure what is said below will be familiar to you - just reiterating some of the characteristics of the Airbus system for the discussion. I don't intend here to be pedantic or instructive.

With that in mind..., "manual flying" has been an illusion for over fifty years.

The DC8 ailerons and rudder were hydraulically-powered with spring-tab backup while the elevator was cable-pulley & tab. Boeing had introduced hydraulic flight controls on the B707 in the late-50's.

Back then, it was fluid that sent the impulses - today it's electrons. Springs on control column/control wheel circuits & mechanisms provided feedback to the pilot.

The AB SS provides such feedback by the same method, (springs), so doing steep turns, for example, in either Normal, Alternate or Direct laws, the stick has to be held back more firmly when the bank angle is exceeds 33°.

What may be confusing to some, particularly when discussing the Airbus, is the difference between C* laws in FBW systems, and the various protections that may be built into EFCS systems. FBW in and of itself, offers no "protections"; FBW is just another way of moving flight control surfaces. "Protections" are possible because the system is digital and as we all know, anything that can be imagined can also be done with digital signals.

The rudder pedals have been, and should absolutely continue to be a footrest except in the usual circumstances with which pilots are familiar - crosswind landings and engine-out yaw control.

You do not need, "superman to fly the alternate laws", (an exaggeration I'm sure). What you actually need is a thorough understanding of the airplane and that comes, as always, with training, experience and continuous learning through staying in the books, (which is something I really wonder about in today's pilots, who seem to be discouraged by managements, (who are focussed entirely on slavishly following SOPs rather than encouraging airmanship and thinking), from deepening their knowledge of systems, high-altitude, high-speed, swept-wing flight by study, and reading accident reports.

Alternate Law circumstances are regularly-trained in the sim as a result of system failures which are in the script. Alternate law is a non-event; the airplane is conventional in the sense that one just flies the airplane normally, including respecting the stall warning. When actually flying the airplane, the change in laws is essentially transparent to the pilot. The cautions (and therefore the responsibility for knowledge of one's airplane), are related to loss of protections, not to any "special handling" requirements due to FBW.

I don't think you can say that computers have transformed pilots into "idiots" any more than hydraulics have.

Even as technology is never neutral or innocent, it is, in my view, the abuse of the tools that has done so because airline managements began assuming that "these airplanes fly themselves", and so require/mandate that the autoflight systems be engaged as soon as possible after takeoff and remain engaged until the landing rollout is completed. Asian carriers monitor this with FDM, a wholly inappropriate abuse of a safety technology, so disconnecting and doing something with the airplane is both an institutionalized fear as well as a safety problem. A more irresponsible mandate on the part of an air carrier could not perhaps be conceived/implemented, but there it is - a growing generation of "pilots" who can't fly and who are increasingly afraid to try.

[ExV238]

1201

Not at all, just a strong admirer of what these guys managed to pull of in the Apollo program. It seems I am not alone with that.

Correct!

[ExV238]

FDMII,

An excellent summary.



We also can trace flight envelope protection back to technology such as Q-feel systems, cracking struts and stick pushers; all features of pre-FBW flight control systems that limited a pilot's 'authority' to break an aircraft. Some were controversial when introduced, but are old hat now...

[_Phoenix]

@FDMII, neither me intend to be instructive or to initiate a polemic.

Back then, it was fluid that sent the impulses - today it's electrons.

The hydraulic fluid does not interpret the pilot inputs as flight computers determine the actuators movement

Springs on control column/control wheel circuits & mechanisms provided feedback to the pilot. The AB SS provides such feedback by the same method, (springs) ...

Maybe the active sidestick

What may be confusing to some.... FBW is just another way of moving flight control surfaces

If the pilot releases the stick, the aircraft keeps the pitch until the stick is moved again, then the flight computer moves the actuators without pilot input whatsoever. Also pitch control provides automatic elevator to compensate in turns "You just roll the aircraft and leave it alone"
Airbus said long time ago: "Flying the fly-by wire is similar to driving a stagecoach. Where the coach driver gives a command and the horses take care of the road, the A320 pilot makes a control input and the aircraft takes care of the flight-path. Having been educated in all the permissible speeds, attitudes, and manoeuvres, the A320 will never overspeed, overload, or stall"

[CONF iture]

Originally Posted by vilas

I don't make procedures but only keep quoting airbus documents

Unfortunately you have not been able to quote a single document to state :
"Never pull full back stick in alternate"

Why applying full back stick in Alternate law which has the same pitch control than Normal law ?
Because flight experience has revealed that an immediate 2.5 g reaction provides larger obstacle clearance, than a hesitant and delayed high G Load maneuver.

[FDMII]

_Phoenix;

Yes, agree - for FBW systems the computers determine actuator movement through both FBW & Airbus protections.

The action/result of the flight controls is transparent to flight crews in the sense that, (hopefully without conflating the description!), something like CWS, control-wheel-steering in Boeings and the Lockheed, the airplane stays in the last set position, albeit, for the Airbus, without the control surface movement to maintain 1g. Minor corrections to pitch & roll attitudes during manoeuvering are natural pilot inputs.

The feedback/feel of the SS would be the same for both sticks as a function of the design of the SS mechanism itself, which provides the required amount of pull to maintain altitude when bank-angle is > 33°.

To your third, again agreed, (same reasons as your first). But I would hasten to observe that informal, (marketing) remarks made by Airbus a "long time ago" are not in, or part of the AOM and FCTM, nor are they part of formal training curriculae. I would emphasize that understanding the EFCS of the airplane through the usual training & checking regimes is key, just as it is with any type and design.

The AOM and FCTM cautions when in Alternate or Direct law are abundant and clear: protections are degraded or lost: in all ways, fly the airplane as one would a conventional transport aircraft, respecting all airframe limitations, cautions and warnings.

[xcitation]

FBW

Surely the argument of computers being between pilot and control surfaces has long vanished from relevance. Many modern aircraft cannot be directly hand flown as they are aerodynically unstable by design e.g. f117. The days of real direct control are gone, transport pilots no longer require bulging biceps to execute emergency flight control inputs.

[FDMII]

@xcitation;

In my view the discussion regarding computers-flying-airplanes was over decades ago.

However, the subject keeps re-surfacing perhaps from those who don't fly transports or who do but haven't been trained on and haven't flown the Airbus.

Understanding is important and a collegial discussion on this forum may provide a way for all to gain an insight into FBW/automation issues.

Equally important is the reading and study of accidents, beginning with the reports. I think that makes a well-rounded airline pilot at a time when such well-roundedness, including airmanship is, in my perception, actively discouraged in favour of a box-ticking-for-audit-purposes culture and jammed-full simulator scripting.

[gums]

From excite:

Many modern aircraft cannot be directly hand flown as they are aerodynically unstable by design e.g. f117.

I must take exception, as I flew the first operational jet intentionally designed to have negative static stability belore 0.95M, and was fully FBW with zero mechanical anything connected to the control surfaces. You can see my bio on the info for we posters, unlike 99% of those who post here.

The Concorde prolly led us, but still had a few cables or whatever, maybe tabs controlled by cables.

Even the 'bus is not unstable, tho it does allow a cee gee back further than would be approved 40 years ago.

I cannot find a single commercial jet or more than one ot two military designs that cannot be flown with out cosmic computers, protections and such.

Although the computers or "boxes" shape the signals to the control surfaces, being hydraulic pressure or electronic waveforms, most jets fly today exactly as they did 60 years ago. So my jets 50 years ago used hydraulics, but the valves had shapes that did not provide a 1:1 pressure change for each pound/degree of displacement. Those early jets also had neat dampers that used gyros and/or rate sensors to dampen things. So dutch roll was not a biggie for we clueless jocks.

We even had "protections"!! No kidding. My Voodoo back in the 60's had an AoA limiter and then a 28 pound pusher on the stick if we exceeded 'X" Aoa or a certain pitch rate closse to the AoA limit. Sucker worked like a charm, although that beast provided awesome warning before the stall/pitchup - wing rock, hard buffet, etc. No roll protections, but what the hell. On other jets we had stick shakers or duddr vibrators or......

So the "manual" advocvate folks here have it close, but I am not convinced many of the nuggets have their basic skills burned-in by hours of practice and exposure to the dark side of things in their planes.

The practice of "engage otto" at 300 feet with gear up and the reverse when landing bugs me beyond anything. I don't feel all should be Chuck Yeager, but if we can't fly the profile without using otto, then we should not be flying at all. I used and expounded otto for a few thousand hours in single-seaters to reduce workload when wx or other problems arose. But I never flew a profile that I had to use otto versus my own skills/eperience, and remember that otto has ZERO experience.

out

[ExV238]

The hydraulic fluid does not interpret the pilot inputs as flight computers determine the actuators movement

If the pilot releases the stick, the aircraft keeps the pitch until the stick is moved again, then the flight computer moves the actuators without pilot input whatsoever.

Indeed!

Designers have used the best available means to make aircraft as easy as possible to handle, ever since the earliest days, whilst also allowing progressively higher performance. That's led successively to refinements in reversible (purely manual) control system with spring tabs, balance tabs, bob weights and the like; servo controls; and then the introduction of powered flight controls and associated artificial feel.

The nirvana is surely something such as described in the second quote above (although it's typically the flight path that's kept, not the pitch attitude as such), in which the pilot directs the flight path with the stick and the flight control system removes external and unwanted disturbances such as turbulence. This is what modern FBW seeks to achieve, but clearly it has to move the waggly bits on the wings and tail to do so, without a direct input from the pilot. This is nothing new; we've had yaw dampers moving the rudder without pilot command for over half a century!

FBW gives the opportunity to remove secondary effects such as (for example) roll due to sideslip, thus making tasks such as crosswind landings easier. Designers can now get much closer to providing pilots with handling qualities that they should have had decades ago, had the ability to provide them existed.

Turning to degraded modes; well, yes... If a Comet or 707 lost yaw damping, then the pilot had a very significantly greater problem on his/her hands than being in Alternate Law in an Airbus. And you'd better be careful not to reach the stall AoA in a VC-10, 1-11 or the like with a failed stick pusher.

FBW is still relatively new technology in the big scheme of things. There are rough edges still, to be sure, and it's being refined just as previous generations of flight control systems were. But the fundamental principles are right.

P.S. Sorry - some duplication with Gums' post, with which I agree completely.