Another 737 down

[MiloMorai]

Boeing has admitted that there is problems with their simulators.

[Mister Fork]

Anyone else find it interesting that in both the MAX8 and the Air France 447 have a lot of similarities?

And then there is a pilot like Sully. Experienced to the max.  Was him switching on the APU moments after impact (without going to a checklist of both engines) was just an experience factor?

[Vraciu]

Anyone else find it interesting that in both the MAX8 and the Air France 447 have a lot of similarities?

And then there is a pilot like Sully. Experienced to the max.  Was him switching on the APU moments after impact (without going to a checklist of both engines) was just an experience factor?

I don’t know the emergency procedures on the Airbus (i.e. what is a memory item and what is not). That said they were likely outside the windmilling air start envelope so the only way to turn a motor in that case is with the APU. 

In the Legacy 600/650/ERJ I would have done the exact same thing—assuming my APU wasn’t still running as I make a habit to leave mine on for takeoff to run the bleed air system and give me a fifth generator for cases like this. 

[Vraciu]

Also, for an electric jet like the Bus I am sure it has a RAT but I would be much more comfortable with an APU running things.

[Toad]

Another little interesting bit is Sullenberger said the HAL 9000 also prevented him from flaring more at touchdown, resulting in a harder impact. This is in a talk he gave at Google which I think is on YouTube.

[Busher]

Another little interesting bit is Sullenberger said the HAL 9000 also prevented him from flaring more at touchdown, resulting in a harder impact. This is in a talk he gave at Google which I think is on YouTube.

I never chose to bid Airbus - there was always the issue of HAL deciding if my actions fit within it's intelligence before it let me do it.

But a question for my fellow pilots. You recall the A320 crash on June 26, 1988, it crashed while making a low pass over Mulhouse–Habsheim Airport as part of the Habsheim Air Show. We have all watched the video. While I appreciate he got way to deep into the back side of the drag curve, I always wondered, had he been in a conventional jet, could he have traded off a slight amount of angle of attack to gain enough lift to fly it out. I know the discussion is speculative as hell but the investigation never considered how Hal might have restricted pilot input in the recovery attempt.
And for the Airbus lovers, I'll concede he should not have put the 320 or any other airplane in that situation in the first place.

[Toad]

There is a LOT of controversy over that Mulhouse crash. A lot of different versions of what happened. Some pieces say the PIC disengaged the Alpha Floor protection, others say he did not.

There's conspiracy versions out there that say the FDR data was switched to protect Airbus. The official version denies that.

I think it's undeniable the PIC and SIC were highly experienced overall. I also think it's undeniable that finding fault with the HAL 9000 would probably have ended the A320 right there, so I think there's clearly a political aspect to the investigation.

Bottom line for me, a highly experience PIC realized he was too low. I think given the experience level, he probably DID push the power up and attempt a go-around. The PIC says he pulled back on the stick and the HAL 9000 nosed down to prevent a stall. Did that happen? Who knows?

Don't think we'll ever know exactly what happened.

[Vraciu]

That Bus crash was a seminal moment. 

The PIC insists he wanted to go around but the jet wouldn't let him. 

This leads back to Busher's point, namely the jet not letting you do more in extremis.

Now loop back to Air Chance 447.  An extreme AOA indication was dismissed and muted by HAL which utterly confused a crew that  wasn't familiar with old school flying, aka Pitch, Power, Performance.   I am hammering away at this with every class that comes through my schoolhouse.     This seems to be a lost art or something instead of a basic REQUIREMENT.   

[Vraciu]

Oh, and to specifically address the question of AOA, I guess it depends on the Normal Law stall margins.   In a raw mode I am sure you can coax a bit more out of the wing than what HAL allows, but I can't say for sure.   

A Falcon 900 even when stalled apparently isn't stalling.  At ~23° AOA the inboard slats automatically stow which lowers the nose to keep the wing flying.  It's pretty ingenious really.   

[Puma44]

And then there is a pilot like Sully. Experienced to the max.  Was him switching on the APU moments after impact (without going to a checklist of both engines) was just an experience factor?

A combination of experience, situational awareness, aircraft systems knowledge, and thinking outside the box.

[Puma44]

I never chose to bid Airbus - there was always the issue of HAL deciding if my actions fit within it's intelligence before it let me do it.

But a question for my fellow pilots. You recall the A320 crash on June 26, 1988, it crashed while making a low pass over Mulhouse–Habsheim Airport as part of the Habsheim Air Show. We have all watched the video. While I appreciate he got way to deep into the back side of the drag curve, I always wondered, had he been in a conventional jet, could he have traded off a slight amount of angle of attack to gain enough lift to fly it out. I know the discussion is speculative as hell but the investigation never considered how Hal might have restricted pilot input in the recovery attempt.
And for the Airbus lovers, I'll concede he should not have put the 320 or any other airplane in that situation in the first place.

I’m in agreement.  It falls back to the very basics of Private Pilot 101, no matter how complex the ride.

[DaveBB]

On an interesting note, the F-16's flight control computer will actually allow the pilot to get into an unrecoverable stall.  However, due to proper testing by Americas finest test pilots, a recovery procedure was developed.  The first thing the pilot is supposed to do is disengage the flight control computer, then rock the plane into a nose down attitude.

Flight control computers have a past and present history of not allowing 'private pilot 101'.

[Vraciu]

On an interesting note, the F-16's flight control computer will actually allow the pilot to get into an unrecoverable stall.  However, due to proper testing by Americas finest test pilots, a recovery procedure was developed.  The first thing the pilot is supposed to do is disengage the flight control computer, then rock the plane into a nose down attitude.

Sources please.   

If you disengage the FCC/FLCC (Flight Control Computer) on an F-16 you’re finished.  It’s statically (and probably dynamically) unstable, aka negatively stable, throughout most of its envelope requiring thousands of corrections a second to keep it flying.  Without the computer there is zero input to the flight controls.   #LawnDart

Flight control computers have a past and present history of not allowing 'private pilot 101'.

Really?   So a Viper Pilot is not permitted to fly pitch/power/performance?    I’m sure they’ll find that quite a surprise.   You better let them know, ASAP.

[Vraciu]

Here’s the real story vs. fiction from people who should know better.



https://m.youtube.com/watch?v=Rv9YC-gaNYo

The F-16 is not statically stable (that is why it is so maneuverable), so as you move through different AoA, the center of rotation moves relative to the center of gravity because the amount of lift changes over various parts of the airplane. These changes prevent the elevons from pushing the nose over enough to get the airplane to pitch down. At zero pitch rate (between 50-60 deg. AoA) the aircraft will just stay in that position and drop like a rock. So trying to lower the nose with the elevons will not work. However, there is a way out if altitude is available.

Although there is no nose down moment available to overcome the situation, there still is a nose up moment according to the graphs in the flight manual. By selecting the MPO (Manual Pitch Override) switch, overriding the FBW black boxes and pulling nose up there is enough moment available to move the nose further up. Once above 60 degrees AoA (you'll have to use your senses because the AoA indicater is pegged in the upper region), some nose down moment over the elevators becomes available again, enough to increase the pitch rate nose down through the critical 50 to 60 degrees AoA range and rock your way out of a deep stall.

- Starglider

https://www.airliners.net/forum/viewtopic.php?t=1022225


So they are not disabling the computer.   They are overriding its limits, essentially telling HAL 9000 he’s an idiot and to get out of the way so they can move the controls in a way he thinks unwise. 

Are you listening, Airbus?

[Puma44]

On an interesting note, the F-16's flight control computer will actually allow the pilot to get into an unrecoverable stall.  However, due to proper testing by Americas finest test pilots, a recovery procedure was developed.  The first thing the pilot is supposed to do is disengage the flight control computer, then rock the plane into a nose down attitude.

Flight control computers have a past and present history of not allowing 'private pilot 101'.

Got factual references for your theory?