Atlas Air 767 down/Texas

[NSEU]

Are you saying that control column deflection was in fact an FDR parameter for the accident flight?

Column deflection is an input into the B767 DFDR (as well as control wheel and rudder pedal position).

There are two position transducers on the ends of the torque tube (which runs between the control columns) and, optionally, one force transducer (Ref AMM 31-31-08 and 31-31-19, 21-12-03). Also, reference Boeing Wiring Schematic 31-31-01 Page 101 Sheet 4 and Sheet 5.

Having said that, I cannot say that the DFDR records this data.

[MLHeliwrench]

would you be able to hear a jump seaters voice clearly on a CVR recording?

Do crews and /or jump seat pax go through security screening prior to boarding (I would think not)?

[niteflyr]

[QUOTE[left]Do crews and /or jump seat pax go through security screening prior to boarding (I would think not)?[/QUOTE]

Absolutely 100%

[jimjim1]

Vertical acceleration

Originally Posted by gums

it seemed improbable to push over and reach the extreme dive angle without bouncing off the top of the cockpit.

(Unusually) I am not certain that this has not been posted here earlier.

Vertical acceleration analysis I guess from the flightradar24 (or similar) data. Done a few days ago (27 Feb 2019) by Peter Lemme, satcom.guru. More than -1.5g. Quite a lot more seems likely. Presumably done by differentiating the altitude twice. Interesting discussion on Peter's page.

https://www.satcom.guru/2019/02/more...as-5y3591.html

[img]https://1.bp.********.com/-lrRaWb1ZZCM/XHdwq5__CwI/AAAAAAAAFaM/XUALij5OF-EVO9bzD9_iLB3fxibPhjuigCLcBGAs/s640/Screen%2BShot%2B2019-02-27%2Bat%2B9.24.24%2BPM.png(sic)

[Chu Chu]

I'm guessing something along the lines of the 737 rudder hardovers would move the column along with the elevators? So you'd need to know control force (or have other evidence) to rule it out?

[FIRESYSOK]

Originally Posted by Chu Chu

I'm guessing something along the lines of the 737 rudder hardovers would move the column along with the elevators? So you'd need to know control force (or have other evidence) to rule it out?

This isn’t a Microsoft joystick.

[tdracer]

Originally Posted by DaveReidUK

Are you saying that control column deflection was in fact an FDR parameter for the accident flight?

Short answer is I don't know for sure, but I'd be surprised if it's not.

[M2dude]

Originally Posted by MLHeliwrench

would you be able to hear a jump seaters voice clearly on a CVR recording?

Do crews and /or jump seat pax go through security screening prior to boarding (I would think not)?

Yes you would via the CVR Area Mic', and yes, crews DO have to go through security screening

[EDML]

Originally Posted by tdracer

Short answer is I don't know for sure, but I'd be surprised if it's not.

The NTSB reported that the DFDR stored 350 different parameters. That means it's using a comprehensive parameter set that will surely include each control position and TLA.

[Airbubba]

Originally Posted by DaveReidUK

Are you saying that control column deflection was in fact an FDR parameter for the accident flight?

Originally Posted by tdracer

Short answer is I don't know for sure, but I'd be surprised if it's not.

It looks like pitch control input was a required parameter on this 1992 model B-763:

§ 121.344 (d)(1):

(d) For all turbine-engine-powered transport category

airplanes that were manufactured after October 11, 1991 -

(1) The parameters listed in paragraph (a)(1) through (a)(34) of this section must be recorded within the ranges, accuracies, resolutions, and recording intervals specified in Appendix M of this part by August 20, 2001. Parameters listed in paragraphs (a)(12) through (a)(14) each may be recorded from a single source.
____________________

§ 121.344 (a)(12):

(12) Pitch control input;

https://www.law.cornell.edu/cfr/text/14/121.344

[MLHeliwrench]

Originally Posted by M2dude

Yes you would via the CVR Area Mic', and yes, crews DO have to go through security screening

OK, wasn’t sure that cargo crews got screened.

[Old Boeing Driver]

This is a fairly old 767. Does the FDR record column movements/positions, or are the FDR readings based on the position of the stabilizer/elevator.

Meaning if the stabilizer/elevator were moving, the columns actually may not be.

Apologies if this was asked/answered.

[Airbubba]

Originally Posted by Old Boeing Driver

This is a fairly old 767. Does the FDR record column movements/positions, or are the FDR readings based on the position of the stabilizer/elevator.

It should record both the pitch control input and the primary pitch control surface position according to the FAR I linked above.

[FIRESYSOK]

A thing called ‘startle factor’ is going to have played a huge role here, IMO. It doesn’t take but a bad instrument reading to precipitate an overwhelming, improper reaction.

[Intrance]

Originally Posted by Bravo Delta

No no no I can’t believe that.

Look up the CRJ200PF crash in Sweden from 2017. PF stopped watching instruments for a bit to do a briefing, when finished he looks back to the instruments and sees a 15 degree pitch up on the PFD attitude and practically instantly pushes column forward. PNF and standby instruments had normal pitch. Quick crosscheck would have most likely prevented that crash. But we are humans and are easily suprised/startled into action.

[BobbyHowie]

Originally Posted by ASRAAMTOO

Does full power on the 767 generate much pitch up. In other words if you had run out of ideas to raise the nose might you try it? Clutching at straws here......

The Turkish DC10 which crashed in France following explosive decompression used full power to near enough level off before getting shredded in a forest.

[Power]

Originally Posted by MLHeliwrench

Do crews and /or jump seat pax go through security screening prior to boarding (I would think not)?

no, not if they went through KCM entry

[GlueBall]

Originally Posted by pattern_is_full

This is not even speculation, just a "scenario" that might fit that reported throttle and control-input reading.

Massive incapacitation of PF (bird through the windscreen, medical, other), body pitches forward onto both column and (hand) throttle levers. Nose-over forces make it impossible for the other pilot and jumpseater to clear the controls until too late (that possible last-second attempt to get the nose up).

EDIT: I see I'm not alone - but it would certainly require a "Black Swan" event.

​​​​​​Below 10,000 feet the pilots would normally be strapped in by the shoulder harnesses, making a full slump-over into the control column less likely.

[suninmyeyes]

I agree with Glueball that with a standard 5 point Boeing seat harness and in turbulence an incapacitated pilot would not be able to make any forward control input let alone the hefty sustained input required to override an autopilot and pitch down 45 degrees. My only suggestion (and this is pretty remote) would be that someone could have been adjusting his seat and in turbulence it slid forward and jammed the control column forward. I hope it does not turn out to be a nefarious act as it would increase a lot of already inappropriate security restrictions on pilots.

[dgordon42]

Originally Posted by suninmyeyes

My only suggestion (and this is pretty remote) would be that someone could have been adjusting his seat and in turbulence it slid forward and jammed the control column forward

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

Dave.