Getting your Trinity Audio player ready...
4 min read

Editor’s Note: TWA Flight 841, a Boeing 727-31 (N840TW), operated as a scheduled passenger flight from John F. Kennedy International Airport, New York (JFK) to Minneapolis-St. Paul International Airport, Minnesota (MSP) on Wednesday, April 4, 1979. Flight 841  departed JFK with 82 passengers and seven crew members at 20:25. The following description of what took place is from the final NTSB Report (DCA79AA016).

About 21:48 eastern, on April 4, 1979, a Trans World Airlines, Inc., Boeing 727, operating as Flight 841, entered an uncontrolled maneuver at 39,000 feet pressure altitude near Saginaw, Michigan. The aircraft descended to about 5,000 feet in about 63 seconds before the flightcrew regained control. About 22:31, the flightcrew made an emergency landing at Metropolitan Airport, Detroit, Michigan (DTW). Of the 89 persons aboard, eight passengers received minor injuries. The aircraft was damaged substantially.

The Safety Board determines that the probable cause of this accident was the isolation of the No, 7 leading slat in the fully or partially extended position after an extension of the Nos. 2, 3, 6, and 7 leading edge slats and the subsequent retraction of the Nos. 2, 3, and 6 slats, and the captain’s untimely flight control inputs to counter the roll resulting from the slat asymmetry. Contributing to the cause was a preexisting misalignment of the No. 7 slat which, when combined with the cruise condition airloads, precluded retraction of that slat. After eliminating all probable individual or combined mechanical failures, or malfunctions which could lead to slat extension, the Safety Board determined that the extension of the slats was the result of the flightcrew’s manipulation of the flap/slat controls. Contributing to the captain’s untimely use of the flight controls was distraction due probably to his efforts to rectify the source of the control problem.


B-727

Flight 841 operated as a scheduled passenger flight from New York (JFK) to Minneapolis (MSP) on April 4, 1979 when it entered a spiraling dive.

As a retired B-727 captain, this is why I believe the NTSB got it wrong on TWA 841 and Captain Hoot Gibson and his crew. On April 4, 1979, TWA 841 was involved in an out-of-control spin over Michigan. At that time, I was the ALPA Captain Representative of the Chicago-based pilots and was flying the B-727 from the Chicago O’Hare (ORD) domicile.

Early in the morning of April 5, 1979, I received a phone call from ORD Chief Pilot, Harry Jacobsen, asking me to join him on a flight to Detroit to meet with Captain Hoot Gibson and his crew that were involved in an incident. On arrival in Detroit, besides interviewing the pilots, Captain Jacobsen asked me to speak for TWA in dealing with the media.

After arriving at the hotel where the crew was staying, I called Hoot and asked to see him in his room. Hoot and I have been friends for many years. In his room, Hoot detailed the event in great detail. I was flabbergasted as Hoot described the terrifying event. Next, I visited First Officer, Scott Kennedy, whose description of the event was the same as Hoot’s but a little less detailed.

Finally, I visited with Flight Engineer Gary Banks. Gary detailed how hopeless he felt watching the event from the flight engineer seat. There was going to be an initial hearing at the hotel later that day and I advised Hoot, Scott, and Gary to tell the truth since the Federal Government would be involved in the hearing and not telling the truth was a federal offense. I totally believed Hoot, Scott, and Gary that day, and I totally believe their story today. The NTSB claimed the flight crew caused the incident. The flight crew DID NOT cause the event as described by the NTSB.

As a TWA captain currently flying the B-727 at the  time of the incident, I was well aware that most pilots flying the 727 did not like the way it handled at higher altitudes like FL 390. Also, I am sure that if any crew member in the cockpit suggested lowering the flaps at 39,000 feet to improve performance, they would have been laughed out of the cockpit. That was not the TWA culture.

Ok, this is at the heart of the matter as to why I do not believe the NTSB.  For the event described by the NTSB to have happened, the wing flaps had to be extended at 39,000 feet. This takes hydraulic power which creates a substantial amount of noise from the hydraulic operating pumps. Most passengers  have heard this when the flaps are extended during ground taxi. The noise is just as noticeable at high altitude.  So, did the NTSB get testimony from either the crew or the passengers about hearing an unusual noise just prior to the upset? No, because that would not fit their narrative.

Later evidence shows that the lower rudder on TWA 841 may have failed and started the upset. The NTSB refused to hear any new evidence. I rest my case.


Postscript:  A number of programs have been produced over the years describing the events and subsequent investgation of TWA 841 including from the Smithsonian Channel.

The flap and slat extension sequence on the B-727:

Jerry Lawler
Latest posts by Jerry Lawler (see all)
23 replies
  1. Captain Grampa Gumpy Bear
    Captain Grampa Gumpy Bear says:

    The flaps on the B-727 are powered by Hydraulic System “A”, which are engine driven pumps attached to Engines 1 & 2. The noise passengers hear is a “motor” mounted on the aft Wheel Well Wall, powered by Hydraulic System “A”. Through a transmission, connected to two tubes, for a lack of actual terms, to the trailing edge flap transmissions connected to jack screws on both wings. When Flaps 2 are selected, the wing area increases, as the Trailing Edge Flaps extend almost straight back with very little droop. The increase in camber occurs when Leading Edges Devices (LEDs) are extended. As flaps extend, LEADING EDGE FLAPS and SLATS (LEFAS) Valves open and close. Controlled by the Outboard Flaps position 2 Leading Edge Slats 2,3 and 6,7, only, are extended. Flaps selected to 5 will cause remaining LEDs to extend. On the F/E’s panel is “LEFAS” Valve Circuit Breaker. When pulled the LEFAS valves will not open in concert with Flap extension. It was, and still is, unwritten tribal knowledge and urban legend, and ONLY in THEORY, that to increase lift and stability the LEFAS Valve C/B could be pulled to prevent LEDs 2,3 and 6,7 from extending. If the C/B is reset, with the Flaps at 2 the LEFAS valve opens and slats 2,3 and 6,7 extend. While rare, a LED hydraulic actuator would blow causing both asymmetry and a loss of Hydraulic System “A”a fluid. This was due to weak actuators, fighting wind resistance. While configuring for landing, I experienced this a couple of times, only on the -100 series. The weaker were eventually replaced with more substantial actuators. Never had issues with the -200 series. Anyway… I’ll leave it at that.

    Reply
  2. Captain Grampa Grumpy Bear
    Captain Grampa Grumpy Bear says:

    Quick note about the Lower Rudder.

    The Lower Rudder is powered by Hydraulic System “A” and the Standby System, when selected, when there is a loss of System “A” or by QRH procedure. There is a Rudder Load Limiter associated with with both upper and lower rudders. Flaps extended results in high pressure available and full rudder travel being available as in the case with an engine failure during takeoff or go-around. With the flaps retracted reduced hydraulic pressure is available. There is a RUDDER LOAD LIMITER light, associated with pressure to the lower rudder. This light illuminates if the pressure to the lower rudder is in disagreement with flap position.

    Reply
  3. Carter Fairchild
    Carter Fairchild says:

    I’m a retired American Airlines pilot. I flew for Lloyd Aero Bolivia Airlines of Bolivia in 1978 as a copilot. I was there to speak English in countries that require it. We would pull the circuit breaker for the leading edge devices and move the flap handle to 2 degrees. You could now take the 727-100 to Fl 390. After this incident the FAA made Boeing remove the circuit breaker so you can’t do it again. They think the FE got the wrong circuit breaker. When they went to flaps 2 and the leading edge devices went out. They put the flaps back up and on one wing the devices went back in. The other wing got jammed out. In a big upset like that with the airplane almost going straight down you put the landing gear down to recover the airplane and they did that. At that time I had a type rating and FE on the B-727. I flew the B-727 for 4 airliners. American was the last one. I have type ratings in DC-9, B-727, B-757, B-767, B-777.

    Reply
    • Paul Havis
      Paul Havis says:

      Hi Carter. I too worked for Boliviano as an American 727 FO (to speak English for them) in 1978 and part of ‘79 and I’m trying to remember you? (I lived at “gringo house” with a few of the other expats. Does that jog your memory?) I got a 727 FO job at Singapore next, followed by another FO job for Air Guinee until I landed permanent employment at PEOPLExpress and then merged with Continental and United. I’m typed in the 737 727 747 and 777 with the DC10 and A300 type ratings thrown in along the way for good measure. For the life of me, I cannot remember “pulling the circuit breaker” and extending the flaps on any Bolivian airline 727 flight I worked on. And for the record, it was never done at any airline I flew for afterward…. HOWEVER, just prior to my employment with Bolivano I worked for Scenic Airlines flying Cessna 402’s through Grand Canyon and I became aware, at that time, that the infamous Hoot Gibson worked for Scenic (while flying for TWA) and he ground looped one of their precious and rare Ford Trimotor airplanes either before, or just after, his 727 high-dive. Interesting stuff. Party on, Garth. HAVIS

      Reply
  4. Wayne
    Wayne says:

    Five years, 3500 hours spent on the 727. It was a good design, but the 757 and 767 were better designs. First time I rode jump seat on a fully loaded 767-200 we climbed quickly and comfortably to FL390 and the plane had plenty of performance margin and handled very nicely. Couldn’t have done that in the 727. It would have required a step climb after an hour or two and even then only if it was very smooth up there. I never saw the flaps being monkeyed around with at altitude. It was a plane that required a high level of skill by the pilots from takeoff all the way until the landing rollout and the steam gauges would now seem impossibly hard to use in piloting such a high performance aircraft. No ground speed readout, no wind information, no traffic display, hardly any system automation, nav charts spread across a pilot’s lap with the planned route highlighted, small instrument gauges, etc. But I also remember some older (55 or older) pilots who retired early rather than face the seemingly daunting task of transitioning to the 757/67 and the glass cockpit environment. Seems weird now, but they were very comfortable with the old technology of the 727.

    Reply
    • Mike
      Mike says:

      I flew all 3 seats at UPS on the 727 for 11 years, didn’t wanna leave but had too when they retired the fleet. My first automation FMS a/c was the A300, the finally the the wonderful 757/767 and in my last final years it was upgraded with Large Display Screens ( LDS). I fully understand the reluctance to fly an FMS aircraft and loosing a flight engineer but one either adapts to change and its new way of doing things or else.

      Reply
  5. Terry Simpson
    Terry Simpson says:

    I have seen the NTSB investigation report. I believe it is correct. Hoot Gibson lied. His FO and FE lied too. He erased the Cockpit Voice Recorder to cover his dishonesty and unprofessional conduct. He should have been ashamed of himself. The corrupted pilot union backed him in his dangerous lies. He should have been fired on the spot. He was a corrupted man and pilot who put his plane and passengers in danger for no good reason. TWA no longer exists due to poor management and out of control, greedy Union pilots and employees. Other airlines no longer exist for the same reasons. These are the facts.

    Reply
    • Rich Pauly
      Rich Pauly says:

      What BS. I was an FE on the 727 at Republic Airlines and Northwest Airlines. At neither airline did I meet or hear of a crew that tried any configuration of the aircraft other than that called for by the Approved Flight Manual. As a member of the ALPA Safety structure (I investigated 2 accidents and 2 less serious incidents) we always told the crews to tell the truth. Our goal was to find the truth and fix whatever issue caused the event. ALPA Safety is well regarded by the NTSB that it has always been granted participant status on any investigation it requests to be part of.
      Think about it. Protecting 1 pilot’s career with falsehoods puts all other pilots in jeopardy.
      As a Line Check Airman at Delta Air Lines, we only taught professionalism and adherence to SOP and the Approved Flght Manual. The old Cockpit Voice recorder could be erased, but not the Flight Data Recorder.

      Reply
  6. george andre
    george andre says:

    As the TWA Director of Flt Ops Engineering and a current 727 Capt. I became intimate with the details of this incident. After the aircraft was repaired, myself and a Boeing Engineering test pilot test flew the airplane to evaluate this so-called story of crews isolating partial trailing edge flaps for a performance gain at high altitude. Everybody seemed to know someone who used this unapproved scheme but no one ever surfaced. Performance at just one degree of trailing edge flaps resulted in immediate loss of performance, noticable airframe vibration and increased drag. It was apparent that this so-called unapproved procedure was not readily used. My test flight along with Boeing indicated that this so-called performance “trick” was mostly and unfounded tale. Evidence remaining on the airplane showed that the slat failed from airloads and only after it departed the wing was Hoot able to effect recovery. There were a number of uncommanded leading edge extentions in the 727 fleet.

    Reply
    • Daniel Harrah
      Daniel Harrah says:

      Thanks for the clarification. It’s like Gus Grissom and the hatch blowing on Freedom 7. A lot of people think he lied, but he didn’t which was proved when the capsule was found. I only met Hoot briefly, but I believe he is a man of integrity.

      Reply
      • wade russell
        wade russell says:

        Met Hoot couple times at Reno Air Races. Very impressive, and- inmho- very honest. To say he was talented pilot- understatement ! Sinc., Wade

        Reply
    • LD Jeffries
      LD Jeffries says:

      I flew the 727 as an FE for 1800 hours for Continental 1998-2000. If that procedure would have been an option that worked I would have heard about it. That fleet was full of Captain SCABs that knew every dirty trick in the book. I saw lots of other crap but never saw that, thankfully!

      Reply
      • LD Jeffries
        LD Jeffries says:

        I also had met Hoot several years ago at the Oshkosh Ace Ducey Bar . For a guy with his resume and background he was pretty laid back and down to earth. We shared a beer and talked airplanes, airlines and military stuff.

        Reply
  7. Steve Green
    Steve Green says:

    I had a conversation with Hoot years later, probably around 1990, at the ALPA office in Herndon. I was working on an NTSB petition for reconsideration associated with the AVAir 3378 accident. Hoot was working on his own NTSB petition for reconsideration. We discussed many aspects of both cases, but particularly the mechanics of NTSB petitions and process. He was knowledgeable about the process, engaging, and interested in the work, beyond his own case. I remember walking away thinking, nobody can be that engaged and thoughtful, and be putting so much effort into developing a petition, so many years later…to cover up a lie.

    But I’m probably biased. I was working on the 3378 petition because the Board had conveniently overlooked a rather persuasive piece of physical evidence…the stall avoidance system switch had been selected off prior to impact…in order to perseverate on the first officer’s difficulties in training. In that case, there were no recorders to erase, and much we will never know. But the Board, in those days, had quite the habit of smoking out inconsistencies in their perception of the Right Stuff.

    Reply
  8. Scott
    Scott says:

    IMHO the NTSB, once it makes its mind up, will NEVER reconsider its determination (ok, I will allow they did reconsider the UAL 737 at COS).

    While at Business Express, we lost a 1900 during training. The NTSB was quick to blame the instructor. Several years later, both the instructors father and ALPA uncovered scientific evidence that the plane most likely had a failure of the right engine truss, resulting in the engine departing the airplane and taking out the elevator.

    ALPA petitioned to reopen the investigation. The NTSB has never considered this request.

    Reply
    • Steve Green
      Steve Green says:

      Scott, indeed. Myself and Stu Updike of Atlantic Express were the investigators who developed the BusEx petition. To be fair, the Board did change the probable cause of the AVAir 3378 accident, in response to our petition…16 years after we submitted it…

      Reply
  9. Chuck
    Chuck says:

    The NTSB is unfortunately drunk with power. And although portrayed as being infinitely knowledgeable, they are about as competent as the investigative journalists on the evening news. The combination of these leads to biased determinations and an unwillingness to look at facts or expert knowledge that are contrary to their biased opinion because they must at all costs remain superior and infallible. Let’s praise Hoot & crew for the save that seems to be glossed over.

    Reply
    • Hop
      Hop says:

      The only NTSB inspector I ever knew personally couldn’t handle an engine out in an empty DC-3, during a PC. (Scared the crap outta me). He left and went to work as an accident investigator.

      Reply
  10. Larry Smith
    Larry Smith says:

    Great story. Reminds me of my time on the 727, great plane, but was glad to get to the other Boeings where I could land the darn thing.

    Reply
  11. Dan Marotta
    Dan Marotta says:

    Pulling the wrong circuit breaker would allow the LEDs to extend “accidentally”. I’ve always believed that is what happened.

    Reply

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *