Jump Seat pax getting out of a 'front seat' after sampling the B767 perhaps?
(See post #327 in this thread)

Dave.

I seem to remember that ATC offered a vector around weather when the crew said which way they wanted to go they were told to descend Expedishly to 3000 could've been hooking up straps jump seater leaning forward to watch the approach thrown onto pedestal and throttle.

Not likely in my experience, and why would they swap seats down low approaching a line of weather?

But, most of the other scenarios including an intentional crash don't seem likely either.

There was an infamous incident in 1994 where a crewmember tried to crash a freighter:

https://en.wikipedia.org/wiki/Federa...ess_Flight_705

Sounds plausible - and remember the Voyager
 

This scenario sounds to me the most plausible explanation for this tragedy. There is a possible similarity to the RAF Voyager incident over Turkey, which was recovered because that occurred at high altitude.

The possibility of a deliberate act seems less likely when details are compared with Germanwings; in that case the pilot was alone in the cockpit, his colleague unable to return because of the security door, and, in retrospect, the pilot had a clear history of mental illness. In this case there is no suggestion that one pilot had left the cockpit, and in addition there was, exceptionally, a third person very close by, making this flight the least likely one during which to commit suicide. Of course we do not know if any of the three individuals had any relevant medical history, and that could tilt the balance of probabilities...

On a freighter? I doubt it.

I flew the 200/300 20 years ago and I'm pretty sure ours were all manually adjusted (I'm not saying that it wasn't a possible option, though..).

The shoulder portions of the five point harnesses on the 767 are the inertia type - so depending on the 'rate' it's quite feasible for a pilot to 'pitch' forward into the controls. Besides, he didn't need to suddenly 'pitch' forward - slumping forward would be sufficient and is unlikely to be fast enough to trigger the inertia reels.
Airbubba - I don't know if it was basic or an option - but as I recall the 767s I did flight tests on over the last 15 years all had electric seat adjusts - and most were new build freighters.

The airframe in question was a passenger aircraft until a few years ago.

Has any determination/guesstimation been made about the ceiling at the time and location of the accident? Or, the likelihood if they were IMC at the time of the "upset"?

Not from my jumpseat experience. Maybe 30% of the pilots do actually use them.
Having some poor weather ahead with a lot of red on the radar however, I would expect most of them to strap in properly.

Two of ours have electric adjustment and all the other have manual adjustment. All built originally as freighters. I guess it must be a customer option.

This particular 767 had manual seats.

Saludos,

SEQU

Predictive Windshear alerts from the weather radar should still function. Airbubba is right, reactive windshear alerts from the EGPWS are inhibited above 1500 feet AGL. So if they were responding to a WS alert at that altitude, it was from the WXR.

Might want to check your manual on that one.

Don't know if it's true, but I saw an article yesterday saying that Grieg Feith (former NTSB "Mud Stud") mentioned that "the autopilot was still engaged when the aircraft was on its rapid descent, meaning that the pilots were fighting the automation". As an old timer, I can't imagine sitting there below 10,000, watching the throttles go to 100% and the nose dropping to 49 degrees nose low without disconnecting the automation, throttles to idle, deploying the spoilers, and pulling for all I'm worth.

"Disconnecting" the autopilot on a 767 is trivial - just push or pull with a few pounds of force and it disconnects (with an aural alert in case it's inadvertent). Similarly it takes about 2 lbs. force to move a throttle (4 lbs for both throttles) regardless of what the autothrottle is doing. It's also pretty easy to differentiate an autothrottle movement from a manual movement on the DFDR. There is a max A/T rate (six degrees/second at the throttle lever IIRC) so about ten seconds to go from idle to full forward (obviously less if the throttle is at an intermediate setting).

One of the things that may need to be looked into on this is how the 767 control system responds if the pilot pushes the column while the autopilot is engaged. More recent models recognize pilot intervention via significant controller displacement as time to disconnect the autopilot. On older models the autopilot does not immediately disengage in response to pilot input. There may have been a period of time where both Hal and Row 0 were providing significant control inputs. Learning that the autopilot remained engaged would not necessarily mean that Hal was at fault.

This event was going on for 18 seconds. I would assume that one or both pilots had hold of the yoke.

I can't imagine that either did dot push the A/P disconnect on the yoke.

Note: I am assuming there is an A/P disconnect on the yoke as on previous Boeing's.

There is an autopilot disconnect button on the yoke and a disconnect bar on the glareshield Mode Control Panel on the classic B-763.

Also, the NTSB release said the throttles went to full power before the pitch over.

I also can't imagine not pulling the throttles and speedbrake lever back with the nose pointed down for whatever reason.

No, I'm sure they were trying everything humanly possible, exactly the way we all would have been. But if the darn automation wouldn't relinquish control, that would be a horrible feeling.

When you"re 49 degrees pitch down and going thru redline?

Also read that their speed increased from their assigned 230 kts to 430 kts in the descent, and that at impact it was close to 500 kts.

Deliberate act possible. Examination of pilots' histories needed.

This possible cause should be evaluated in the same way as a technical issue. Methodically and objectively.

Well, in fact, almost anything is possible until we hear differently!

They move the lift distribution outboard, so if you're pulling 2g with the speedbrakes out the root bending moment will be higher compared to a 2g manouevre with a clean wing.
In any case I doubt you'd still be accelerating if you're pulling 2g+ as the drag would be significantly higher

Yes, there is. The 767 doesn't have "high tech" computer "augmentations." It's a straight-forward, easy airliner to fly. A/T easy to disconnect or override. Autoflight easy to turn off.

Cornering Speed
 

Written from a fighter pilot viewpoint. When applying to a transport, there are going to be additional factors to consider such as control hinge moments, wing bending moment, and control system design. (For Airbus FBW, all such decisions have been already made for you.)

With the nose buried downward, and with concern about hitting the ground, you would like to achieve a minimum radius turn, but without tearing the aircraft apart.
The minimum radius turn is generally achieved where max AOA and max allowable G meet on the performance curves.

You can consider using up some of your safety margin when planning what G level to attain. Then look up the performance curves and determine a cornering velocity based upon your most probable gross weight.
Below cornering velocity, you can slightly improve performance by accelerating slightly and pulling into buffet. Above cornering velocity, you must slow down to improve turn performance and meanwhile avoid going beyond your max acceptable G (without a G meter).

Knowing your cornering speed is strictly emergency knowledge and would be used solely to ensure you are not completely out of the ballpark in your pull out efforts.
No doubt, the test pilots and aerodynamics guys can flesh this out better. As I recall, the F-4 cornering velocity was 420 knots. You definitely will not want to be anywhere near that speed when you pull out in your transport.

Correct. Less lift less load. That is how gust load relief via the ailerons works on the bus.

The interesting question would be, how the speed brakes influence the cornering radius pulling out of the dive. However, even here they won't make things worse I would guess.