Your opinion on an old controversial accident
 

I have recently read the accident report and petition for reconsideration concerning a TWA 727 that nearly crashed in 1979.

From the internet " while the plane was cruising at 39,000 feet, its #7 slat extended, initiating a sharp roll to the right. The roll continued despite the corrective measures taken by the autopilot and the human pilot. The aircraft went into a spiral dive, losing about 34,000 feet in 63 seconds. Control was regained at about 8,000 feet, by the decision of the Captain to extend the landing gear in an attempt to slow the aircraft, and following the #7 slat being torn off from the aircraft and symmetry of lift being re-established."

"The NTSB investigated the incident and established after eliminating all individual and combined sources of mechanical failure, that the extension of the slats was due to the flight crew manipulating the flap/slat controls in an inappropriate manner. The crew suggested instead that an actuator on the #7 slat had failed, causing its inadvertent deployment"

ALPA filed a petition for reconsideration in 1983 claiming the same as the crew. The NTSB dismissed this petition. ALPA claimed in a second and very detailed petition that a rudder hardover was the cause which the NTSB also dismissed.

All of which leaves me wondering if anyone out there has some thoughts on this whole incident.

http://en.wikipedia.org/wiki/TWA_Flight_841_(1979)

No Wikipedia Entry? Try Aviation Safety Network
 

Wikipedia entry exists... trailing ")" on URL was left off by original poster.

Link: TWA Flight 841 (1979) - Wikipedia, the free encyclopedia

:rolleyes:

ALPA claimed the possibility of a faulty CVR and that the NTSB should have investigated the recorder more thoroughly.

With so much adrenelin coursing through this crew, it is perhaps noteworthy that the Captain did not recall whether he had or had not followed his usual practice of erasing the flight recorder ?

Having narrowly survived such a potentially catastophic event, erasing one of the two primary sources of recorded evidence (the FDR couldn't be erased,) would be such a strange course of action, that you might reasonably think the Captain would remember either taking this course of action or not?

ALPA of course were present to advocate the position of one of their members.

the Captain stated that he usually activates the Bulk Erase feature at the conclusion of each flight

One needs to keep in mind that the underlying philosophy, if somewhat eroded by cases such at the Dash-8 in NZ etc., was that the CVR should only be used in cases where the crew were not available for the investigation (ie dead).

It was routine in Oz to bulk erase on chocks following all flights.

That's not to say that it might well have assisted the crew's situation at the enquiry had they chosen not to erase the CVR ?

Have I missed something? The reports seem to skate round what I was told actually happened.

On the B727, when at altitude, like FL390, is was not uncommon to pull the CB for the leading edge devices and then select Flap 1 with the lever, (which operated both slats and flaps), as Flap 1 did not change the camber of the wing, the flap went straight out and only increased the surface area thus giving a bit more lift and improving the Vs1.2 margin. Very non standard but OK if it worked. In the case of the TWA incident the wrong CB was pulled, the trailing edge flaps were inhibited and the slats started to deploy when the lever was moved to Flaps 1 causing the aircraft to go temporarily out of control.

If that has already been clearly stated somewhere and I have missed it, I apologise and will delete.

The first possible selection for flaps on the 727 is 2°. Are you aware of people actually performing this manouver on the 727 or any other aircraft through more than just long handed down rumours?

According to the NTSB, the flaps were intentionally selected to and did extend to 2°. The appropriate LED's extended as well for whatever reason, perhaps the wrong CB being pulled as you stated. The when the flaps were retracted, the #7 slat remained extended due to a pre-existing misalignment of that slat due to a failed bolt.

Sorry, my error, I should have said Flap 2,

Yes I do know 727 crew who regularly extended the trailing edge having first inhibited the leading edge devices.

The TWA crew would probably have got away with it if the #7 slat wasn't broken.

Was there much likelyhood of someone actually admitting to doing or attempting to do this sort of thing if they actually had tried?

Well I'm obviously not going to name names or airlines here am I? Whether they were telling the truth or not I have no idea but it seems strange that three senior B727 captains would make up the same story, they are all retired now and I doubt if they will be posting here either!

I have only repeated what I was told first hand, hardly gossip!

It certainly was quite the coincidence to have a rudder hardover(as claimed by petitioners) and a CVR bulk erase failure at almost exactly the same time on the same flight with a faulty slat retract mechanism.

Flying too high...
 

Back when I started airline flying, 1969, the big "concern" was "high altitude stall".
I recall captains taking airplanes well above a safe flight level.
As an example, overflying towering CBs in the USA Midwest...
I recall being at FL410 in a B-720 where chart maximum was FL370/380.
This captain "ace" got us 2 or 3 times in a stick shaker... Was about Mach .82.
xxx
As a flight engineer and first officer (727) some captains extended T/E flaps disabling leading edge devices.
The VFE speed limit on 727 (and 747) is directly related to leading edge VFE structural limit.
The "T/E Flaps 1 position" (747) or "T/E Flaps 2 position" (727) is not a VFE speed limit.
For these position, the trailing edge flaps extend the surface of the wing, not any drag increase.
But the VFE related to these positions is related to L/E flaps structure.
It is a certification limit. Maximum altitude for flaps 707-727-747 = 20,000 ft.
xxx
With the DC8-60/70 - there was a VFE and MFE limit.
Flaps 12 was 230 KIAS VFE or .46 Mach. OK to extend above FL 200.
Stall recovery procedure DC8...? Extend first notch of flaps, any level. Approved UAL procedure.
xxx
So - try to figure what "Hoot" Gibson did... I suspect he did...
Just was not an approved procedure. Never has been, but some did...
He probably wanted to be higher to avoid CAT, than flying 100 NM off his track...
xxx
The bulk erase...? Yes - in the "old days" I always did use that feature...
The last 15 years of my career, I no longer used that feature.
Every pilots bust at least "one limitation" (or regulation) per flight.
You never do...? - Shall I call you a liar...?
And now retired, I could not care less...
xxx
:*
Happy contrails

Based on the above post, it looks like it took minimal effort on my part to provide documentation.

"As a flight engineer and first officer (727) some captains extended T/E flaps disabling leading edge devices."

Not my area of expertise. I am only looking for, as the thread title suggests, opinions of others. However, I am quite glad to see that I was able to end a longstanding argument and add to the investigations failure to find a crewmember who had performed this flap operation manouver in cruise flight. It obviously is something that was done at the time.

I don't think the fact of military background or not has anything to do with whetther or not they would try something like this. Plenty of example in the civilian and military of crews doing things they shouldn't.

Flight tests did find according to the NTSB, when the so-called Boeing manouver was conducted, a similar FDR trace to the upset aircraft.

Recalling this old incident - forgot to mention another concern then often discussed.
Those of you familiar with 707-727-747, recall the outboard ailerons.
As soon as the outboard T/E flaps extend, the outboard ailerons are operating.
And you are familiar with the flex of the outer half of the wing... i.e. 727.
xxx
While everyone is preoccupied about the L/E panel extending, what happened with outboard ailerons.
Would it be possible that these outboard ailerons caused flight control reversal...
It is the reason Boeing locks the outboard ailerons for high altitude/high speed.
Could explain the complete loss of control of the aircraft... full roll, was it...?
xxx
:eek:
Happy contrails

Can't say for sure but at flaps 2°, while outboard ailerons are not locked any more, they are only partially available. Not sure how much but on a 200 series at 5° the big book says 80% outboard aileron deflection capability. So somewhat and perhaps significantly less is available at 2° flap.

2 rolls I believe.

B727 Flaps / Slats, my two cents.
 

Dear aviators,
The famous C/B is labelled as LE bypass valve. Just one scenario when it comes into play, like alternate flap use. First touch on the up/down swithc, will extend all LE, then will move the flap motor and by the torque tubes, will move the jackscrews attached to the wing rear spar, and so and so…
The LE slats will remain extended, then the speed limit of 230 kt. because this.
If we have normal hydraulics, we can retract again the LE flaps, using the above mentioned and famous C/B, after closing the red guarded switch to activate the alternate extension system, so now all fluid has access to LE lines an these can be retracted again.
Said that, each LE actuator has a locking device, initially electric, bult in each individual actuator. To unlock we need hyd. pressure in.
My opinion is that the mentioned idea of extending trailing edge flaps alone, was NOT an operating approved procedure at any airline as far as I know.
Inadvertent deployment???? for me it is very remote, however needs more study.

Thanks

TWA Flight 841 Hoot Gibson
 

I was a pilot for TWA and have over 10,000 flight hours in the B-727 and remember this incident very well.


The amazing thing about the Boeing suggestion about pulling CB's and extending 2 degrees of trailing edge flaps in cruise was never...I'm mean never discussed much less contemplated during any one of my 10,000 hours on the 727. We constantly discussed ways of saving fuel, but never talked about extending flaps in cruise. Where Boeing ever dug that one up is beyond me.


If Boeing knew such a procedure would save fuel, why didn't they design a procedure so we could use it? It sounds to me like a big, fat CYA red herring to distract any litigation away from Boeing.
Hipexec

A book has been published on the subject.

The Story Behind Scapegoat: A Flight Crew’s Journey From Heroes to Villains to Redemption by Emilio Corsetti III

The inspiration for this book came from a simple forum post. I had just watched the film Flight starring Denzel Washington. I’m a big fan of Robert Zemeckis. But he got so many things wrong in the first thirty minutes of that film that I wanted to throw something at the screen. I won’t go into detail, that would take too long, but I’ll give just one example. There is no magical lever that gives the pilot manual control. I still can’t understand how Zemeckis, who is a pilot, could make such a glaring, inexcusable error solely for what he thought would make for a dramatic moment. It’s sort of like a heart surgeon grabbing a pair of scissors to cut into a patient to begin a heart transplant.

So after sitting through one stupid scene after another, I decided to check out a pilot forum to see what other pilots thought of the film. That’s when I saw a post about TWA 841. The author of the post made a comment that the filmmakers should have told the real story of TWA 841 and how the crew got screwed over by Boeing and the NTSB.

Now I had heard of TWA 841. I remember thinking at the time that those pilots were toast. There’s no way they would be able to keep their jobs after the NTSB accused them of causing a near-fatal dive of close to 39,000 feet, and then attempting to cover up their actions by erasing the cockpit voice recorder. I assumed that the captain was selling real estate somewhere.

But I soon learned that not only was the crew not fired, but TWA and the pilot’s union fought for years to have the NTSB findings reversed. Now there’s a story.

So if Boeing and the NTSB got it wrong, what really happened? What connection is there between TWA 841 and a string of unexplained rollover accidents in 1990s?

As I dug deeper, a clear picture of what took place emerged. This story had all of the elements of a wrongful criminal conviction: erroneous eye witness testimony, false leads, investigator tunnel vision, manipulation of the evidence to fit a theory, etc. And at the very heart of the story was a conflict between the credibility of a flight crew against the integrity of the most popular aircraft in the world. Boeing and the NTSB won the first round. I hope this book sets the record straight and the crew is finally vindicated.

No different to the rubbish broadcast on the Staines crash where thanks to the master of the guild who never flew the Trident, the only other pilot was management safety and the second officers were promoted to senior first officers and first officers.
As the one time 747 fleet chief and later a safety auditor said to me ..none of their programs are accurate.

NTSB "investigation" : B-727 N840TW April 4th 1979
 

Glorify NTSB April 4th
You can write to ntsb [email protected] : ask ntsb to RETRACT AAR-81-8 .
Ask : ? Who inside or outside NTSB audits for Scientific Misconduct ?

The Boeing Scenario as of 1979
("a positive system command" for the "slat" system ) , pg 8 - Step #1
Boeing's Scenario was vague, non-specific , alluding to "Slats".
But all Seattle Engineers accepted it as truth
-- and many airline pilots joyed in spreading the rumor
[see the early part of this Pprune thread ] .

NTSB's second false assertion : There has long been an unofficial procedure ,
that none of us TWA-pilots had ever heard about .
Later, that nstb IIC admitted that
NTSB NEVER found any airline pilot who had done his fabled "unofficial procedure".

CBS Reports , July 14 1983 10pm :
decades later.

Just above (Scott's mention of their Voice Recorder) --
in 1977 & 1978, within four month, NTSB had found two other CVR's unreliable or inoperative

The NTSB report states that this incident began at about 21:48, whilst flying at FL 390, and control was regained at about 21:49, at about 8000 feet. The aircraft then landed at Detroit Metropolitan Airport, Michigan, at about 22:31.

The aircraft was fitted with a Fairchild Industries Model A-100 cockpit voice recorder, which only recorded up to 30 minutes. The allegations of CVR tampering aside, the NTSB was not going to find anything useful on the CVR given that 42 minutes passed between the start of the event and the landing (quite apart from any post-landing ground manoeuvring)! It's a largely moot point.