Pitot Tube Failure

[3WE]

To the crew of AF447, there was no memorized procedure to maintain safe pitch and power vs regain altitude or arrest vertical rate.

I firmly believe there are all sorts of memory procedures to climb, descend, level, speed up, slow down, go left, go right...

AS WELL AS TO CONTINUE STRAIGHT AHEAD IN LEVEL, FAT, DUMB AND HAPPY FLIGHT.

And, I firmly believe there is a reasonable memory procedure on how to stall a plane...unfortunately that was the memory procedure that was chosen.

[Evan]

Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. My point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.

Still waiting for you to read my words and respond to my actual concern. I've already said that I don't doubt that you know what pitch and power settings are safe. This is about doing that vs doing something else, such as attempting to regain flight level after an upset or attempting to transit to a higher one. To the crew of AF447, there was no memorized procedure to maintain safe pitch and power vs regain altitude or arrest vertical rate. There was only a written procedure (never pulled out) to level off with prescribed pitch and power settings. Therefore, everything in that moment was left to personal pilot judgment and improvisation in a deceptive environment. And look what happened.

AFAIK, procedurally, nothing has changed as a result.

[Gabriel]

Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. Our point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.

Fixed, and I guess you can start with whatever you had at that time and work from there. 12 degrees higher is possibly not a good target.

[ATLcrew]

Certainly, as this is not a memory procedure, if the pilots have been too lax to learn the QRH procedure, they will have to do something before this procedure is called and followed, and that something is what I'm getting at. It shouldn't be left to personal improvisation. It should also be a memorized procedure (even if it instructs them to remain at the current or typical pitch and power but not their current flight level).

Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. My point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.

[3WE]

I’ll try to remember all that next time I ride a bike.

[Evan]

Which is why that's what Airbus actually preaches...

Wait a tick ATL... This IS the procedure from the BEA report that AF447 had onboard.



There are two options:

1) Memory items 'if the safe conduct of the flight is impacted'
2) Instructions to level off if 'the safe conduct of the flight' is not impacted.

There is no 'do nothing' here. Option 2 still instructs pilots to use 'PITCH/THRUST FOR INITIAL LEVEL OFF' by following a reference table with specific values. That is a procedure involving a pilot doing A instead of B (improvising).

Certainly, as this is not a memory procedure, if the pilots have been too lax to learn the QRH procedure, they will have to do something before this procedure is called and followed, and that something is what I'm getting at. It shouldn't be left to personal improvisation. It should also be a memorized procedure (even if it instructs them to remain at the current or typical pitch and power but not their current flight level).

Case in point AF447:

Pitch 5 secs before the autopilot disconnect (2h 10min 00) : 1.8 deg (let's consider this 'typical pitch' for this phase of flight).
Altitude 5 secs before the autopilot disconnect (2h 10 min 00): 35,024.
Vertical Speed 5 secs before the autopilot disconnect (2h 10 min 00): 0 +/-.
Normal Acceleration 5 secs before the autopilot disconnect (2h 10 min 00): 1G +/-.

Pitch at the time of the autopilot disconnect (2h 10min 05): 0 deg.
Altitude reading just after autopilot disconnect (2h 10min 09): 34,664.
Vertical Speed reading just after autopilot disconnect (2h 10min 07): -400 fpm (estimated from the FDR).
Normal Acceleration just after autopilot disconnect (2h 10min 05): .7G +/-.

Now, If your improvised airmanship goal was to 'level off', given the apparent descent depicted by your instruments (along with 8.4 deg of roll and turbulence), and you consider level flight to be FL350 with approximately 2 deg of pitch, wouldn't leveling off lead you to pull up slightly?

If so, now you've added pitch that wasn't needed (due to deception from misleading instrument readings) and this will result in you leaving level flight and slowing down.

Now, let's say you aren't skilled with manual flight at this speed/flight level. Isn't it possible to overcontrol a bit there?

Maximum Normal Acceleration during the first 5 secs after autopilot disconnect: 1.25G.
Pitch attitude 5 seconds after the loss of autopilot (2h 10mins 10): 4-5 deg .
Stall warning threshold: 4 deg +/- AoA

The thing you must keep in mind is that I'm ONLY talking about the intial actions needed to stabilize long enough to get to the QRH. Those critical moments when a memory procedure would be very helpful...

(At about 2h 10min 10, I suspect the intention to ascend took hold. That's another matter.)

[3WE]

If you want to get higher you have to climb so "climb" has to be at least related with an intermediary goal. But "climb" by itself is insufficient (as a goal or as a mean to achieve it).

If you are driving North and want to go West, you just turn West? (and bump into a fence for not doing it in a corner or lose control for applying just 1/8 of the steering wheel travel at 100 MPH?).

C-172M Memory Checklist for Climb

-AIRSPEED, ATTITUDE AND ALTITUDE APPROPRIATE FOR FLIGHT AND CLIMB...CONFIRM
-SIMULTANEIOUSLY ADJUST POWER, ATTITUDE AND AIRSPEED TO VALUES KNOWN FOR CLIMB
-MAINTAIN ATTITUDE AND AIRSPEED TO COUNTERACT DREADED PHUGOID BEHAVIOR
-ADJUST MIXTURE WHEN ABOVE 3000 FEET AGL[/SIZE]

I suppose that 172 S and A300 memory checklist might suggest an aggressive 1.5G 6000 ft pull ups with no attention to airspeed at all whatsoever. But I dunno, in my cowboy improvisational mind, significant attitude adjustments with unreliable airspeed seems like a bad idea.

[Evan]

"We" are never going to get anywhere period, but that's beside the point. I agree with you re the first minute. If Bonin did absolutely nothing in that first minute, the rest would not have happened. To me, that's the best memory item of all, do nothing. It's kind of hard to screw up.

I couldn't agree more, in theory. But, in a deceptive and unrehearsed situation, a few things DO need to be done and a few things DO need to be made clear to prevent a pilot from doing something wrong. In other words, to ensure that, in terms of flight control, a pilot does nothing. The DO NOTS are needed here.

Which is why that's what Airbus actually preaches, as does every other manufacturer. If a procedure calls for doing A, there is at least some chance a fella might do B instead. But if it calls for doing nothing, that one's pretty easy.

That's a false assumption. If you give no instruction for A, there is a greater chance that a pilot will do B. It's called improvisation. From what I can tell, there is no 'do nothing' procedure.

[ATLcrew]

But it is the first minute of this event that matters. If it's handled correctly, the rest else will never happen.

That would lead to a logical conclusion that we should do whatever we can to thwart such improvised intentions in the future.

But we're never going to get anywhere if you keep misrepresenting what actually happened.

"We" are never going to get anywhere period, but that's beside the point. I agree with you re the first minute. If Bonin did absolutely nothing in that first minute, the rest would not have happened. To me, that's the best memory item of all, do nothing. It's kind of hard to screw up. Which is why that's what Airbus actually preaches, as does every other manufacturer. If a procedure calls for doing A, there is at least some chance a fella might do B instead. But if it calls for doing nothing, that one's pretty easy.

When is that open mind of yours scheduled to arrive?

[Evan]

Does the 172 have a G-on-stick stick? This plot shows that the pilot was actively commanding more than 1 G almost 100% of the time, and quite more than 1G most of the time..

Yes, it is an excellent way to stall.

Then why didn't it stall? The truth is, the sidestick plot shows BOTH increases and decreases in load factor command, which have the effect of either increasing or maintaining pitch up to a maximum of 12deg over a span of 21 seconds, followed by a series of mostly-less-than-1G commands that have the effect of reducing pitch back down to 6deg over a similar time period. This is all done with the assumption of full climb thrust. This is all done without stalling.

Is that what you did when your instructors said, "Ok, let's practice stalls"? If so, then you failed.

Look, OBVIOUSLY I'm not arguing with you that what Bonin did was very, very wrong. I'm refuting your argument that it was comparable to turning north in your car where there is no intersection--I'm refuting the idea that it was 'unbelievable and crazy" (your description) or 'relentless" (3WE's decription). If either were the case (as appears to be the case with Renslow), he would have stalled within seconds, not after a full minute of varying control inputs. It bears the signs of a sane but confused pilot acting intentionally with flawed judgment and unpracticed skills. It led to a seemingly crazy sustained pull to 17deg and a stall, but only after the first minute, after the climb to 37,000, when he seems to have became desperately confused. But it is the first minute of this event that matters. If it's handled correctly, the rest else will never happen.

That would lead to a logical conclusion that we should do whatever we can to thwart such improvised intentions in the future.

But we're never going to get anywhere if you keep misrepresenting what actually happened.

[Gabriel]

Is this what you did when your instructors said, "Ok, let's practice stalls"?

[ATTACH=CONFIG]27329[/ATTACH]

Does the 172 have a G-on-stick stick? This plot shows that the pilot was actively commanding more than 1 G almost 100% of the time, and quite more than 1G most of the time..

Yes, it is an excellent way to stall.

[Evan]

But still enough to burn all excess airspeed, stall the thing and no doubt register on numerous LSSSGAs.

But he didn't stall it in the initial pull-up and climb to 37,000ft. He certainly could have, Renslow style, if he had no sense left in his head, by pulling up relentlessly, but he did. not. do. that.

And not_unlike what I did when instructors said, "Ok, let's practice stalls"

Is this what you did when your instructors said, "Ok, let's practice stalls"?

[Evan]

Or you could try this:

You:

If you want to get higher you have to climb so "climb" has to be at least related with an intermediary goal. But "climb" by itself is insufficient (as a goal or as a mean to achieve it).
If you are driving North and want to go West, you just turn West? (and bump into a fence for not doing it in a corner or lose control for applying just 1/8 of the steering wheel travel at 100 MPH?)
"Climb" NEEDS to be associated with performance goals. When you want to climb, you don't just pull up. That's NOT how flying a plane works. Do we need a "climb" QRH procedure with memory items?

The Official BEA Report:

The excessive amplitude of these inputs made them unsuitable and incompatible with the recommended aeroplane handling practices for high altitude flight. This nose-up input may initially have been a response to the perception of the aeroplane’s movements (in particular the reduction in pitch angle of 2° associated with the variation in load factor) just before the AP disconnection in turbulence. This response may have been associated with a desire to regain cruise level: the PF may have detected on his PFD the loss of altitude of about 300 ft and loss of vertical speed of the order of 600 ft/min in descent. The excessive nature of the PF’s inputs can be explained by the startle effect and the emotional shock at the autopilot disconnection, amplified by the lack of practical training for crews in flight at high altitude, together with unusual flight control laws.

and...

There remain a number of possible explanations:
- The crew’s attention being focused on roll, speed or on the ECAM;
- The initiation, more or less consciously due to the effects of surprise and stress,of the action plan (climb) desired by the PF prior to the autopilot disconnection;
- The attraction of “clear sky”, since the aeroplane was flying at the edge of the cloud layer;
- A saturation of the mental resources needed to make sense of the situation, to the detriment of aeroplane handling;
- The presence of turbulence that may have altered perception of aeroplane movements in response to his inputs.

MIssing on that list is:

- A complete absence of fundamental airmanship [fact]

And I know why. The people who analyse these things for a living tend to keep an open mind.

[Evan]

Me:

Maybe this was a case of failed supplemental airmanship and we need to focus of providing better procedural (memorized) training for this scenario.

You:

Do we need a "climb" QRH procedure with memory items?

You just seem intent of ridiculing my position.

Regarding a procedure, here's what I'm getting at: There is no standardized Sudden Autopilot Failure at Cruise Level Flight memory procedure that I know of but if there were, I imagine it would go something like:

- AP/AT ..... OFF
- FD's ...... OFF
- Maintain level flight at current altitude and airspeed.
- THRUST LEVERS (MOVE)
- QRH

However, if the scenario includes unreliable airspeeds (ADR 1 + 2 + 3 Fault due to ice contamination), I imagine it should go something like:

- AP/AT ..... OFF
- FD's ..... OFF
- Establish and maintain standard pitch and power settings for level flight. (5°/CL or first hashmark above horizon and CL or whatever is deemed easiest to memorize).
- ALTIMETER AND VSI ARE UNRELIABLE - DO NOT ATTEMPT TO MAINTAIN OR CHANGE ALTITUDE
- THRUST LEVERS (MOVE)
- QRH

You see the difference? The difference lies in doing something differently than you would normally do it, in defending against stealth, deceptions and erroneous improvisation. If he learned it properly in supplemental upset recovery training, I expect Bonin would follow it as faithfully as he would donning his oxygen mask in a decompression event or pulling the thrust levers back in a rejected takeoff. These are simple, memorable. focused tasks to be done without requiring any mental deliberation. They are not foolproof, nothing is, but they are significant defenses nonetheless.

Neither do I think that. But you didn't get that yet, did you?

I get that you don't think anything was intentional. But you don't seem to get what I think was intentional.

[Gabriel]

Proof of your confirmation bias:

Me:

If you want to get higher you have to climb so "climb" has to be at least related with an intermediary goal. But "climb" by itself is insufficient (as a goal or as a mean to achieve it).
If you are driving North and want to go West, you just turn West? (and bump into a fence for not doing it in a corner or lose control for applying just 1/8 of the steering wheel travel at 100 MPH?)
"Climb" NEEDS to be associated with performance goals. When you want to climb, you don't just pull up. That's NOT how flying a plane works. Do we need a "climb" QRH procedure with memory items?

You:

When you want to climb, you don't just pull up. That's NOT how flying a plane works.

AFAIK, you climb by increasing speed and/or AoA. The pilot assumes the thrust is already at full CL (100% N1). The pilot assumes the plane is slowly descending. If he intended to climb, why wouldn't he pull up?

Ok, Evan, when you want to turn left, just turn your steering wheel counterclockwise. Nothing else is needed.

Again, I don't think he intended to achieve 7000fpm of 1.5G.

Neither do I think that. But you didn't get that yet, did you?