NTSB investigate UK B737 nose dive in flight . . .

Non-revenue easyJet B737-700 G-EZJK flight being investigated by AAIB and NTSB after the aircraft experienced a violent ‘pitch-down’ on Monday. The aircraft is report as losing 10,000 feet and exceeding the VMO by 100 knots. No injuries reported among the 4 person crew - only persons on board.

FlightGlobal news

Photo of G-EZJK

So what do the armchair speculators think of this? I don’t know much about the 737-700… could this be a computer malfunction, or some sort of weird weather anomaly? Is there any sort of incident like this that has been investigated before? If I’m not mistaken, the air canada flight that had some pitch issues was unofficially unsolved but categorized as severe turbulence.

Maybe just MAYBE, could there have been a breach in cabin pressure which caused rapid depressurization and loss of altitude?

I vote for shenanigans in the cockpit.

It could be a situation like this:
Thankfully it ended better.

Read the CVR transcripts from WIKI link, poor bastards really screwed the pooch on this one.

A brief summary of which would be “Dude, watch this!”.

Very Darwinian event overall and very sad for the families involved.

I second that vote

The only thing that transcript was missing … BARELY!!! … was, “Hold my beer. Watch this.”

While the ultimate fate is rather severe, I’m glad that neither of these guys is flying anymore. They kicked waaaaaaaay beyond their punt coverage on that one.

Here is a link to the CVR transcript:


It is a PDF file, about 384 KB. It may be down; I got into it using Google
Chrome a minute ago, but now it won’t let me in. Good luck.

Did they ever release a CVR or anything like that on the Air Canada flight? I mean they declared an emergency, so you’d think that may come up.

I guess my question is a dangerous one because it could open up a huge argument… but I’m going to ask anyway for the sake of info since I don’t know.

Do the newer “ultra computerized” aircraft (from airbus and boeing) have some flaws that have to do with that advanced technology? I know the computers used on board are much more sophisticated than the one I use, but when I hear computer, I think technical difficulties.

First thing that comes to my mind is “a sudden malfunction of the rudder power control unit (PCU)” as in the cases of US Airways 427 and United 585! United 585 was a 737-200 and US 427 was a 737-300. Eastwind 517, a 737-200, also experienced sudden and violent loss of control going into Richmond, Virginia, but the pilots managed to regain control and land safely. That flight led to the discovery of the cause of the two fatal crashes. All three planes were descending on approach to their destinations. In this EasyJet case, it appears the plane was closer to it’s departure point as it diverted to it’s point of origin. Probably not related in this case, but worth looking into…

The CVR transcript from the Pinnacle flight mentioned above… man! Every phrase transcibed early in the flight contained “[Sound of Laughing]”. I just get the image of Beavis and Butthead at the controls.

“Dude… Huh… huh-huh… huh…!”

I’m sure the investigators got the same image in their minds when they heard the tapes too.

While the rudder PCU theory was validated by the fact that the plane had been up to FL410 and had descended prior to the incident, this case appears to have a different cause.

EasyJet 8010 Preliminary Report released

“…the balance tabs, attached to the elevators of the aircraft, being adjusted in the opposite sense to that identified as necessary by the flight test. The aircraft was therefore significantly out of trim during the post-maintenance test flight, and it was that which initiated the pitch-down incident during the manual reversion test.”

Aviation Herald news article:

By Simon Hradecky, created Wednesday, Mar 4th 2009 10:37Z, last updated Wednesday, Mar 4th 2009 10:37Z

The AAIB reported in their preliminary report, that the airplane nosedived as the result of elevator balance tabs being adjusted the wrong way during maintenance and therefore the elevator trim being out of limits.

The commander of the test flight had done a “shakedown” test on the preceding ferry flight to Southend and found, that the manual stabiliser trim wheel adjustment was within, but very close to the approved maintenance manual limits. He therefore requested verbally to address that issue, but did not produce an entry in the tech log of the airplane as the trim had been within limits. The AAIB stated: “The absence of a formal post‑flight debrief and formal written record resulted in the balance tabs, attached to the elevators of the aircraft, being adjusted in the opposite sense to that identified as necessary by the flight test. The aircraft was therefore significantly out of trim during the post-maintenance test flight, and it was that which initiated the pitch-down incident during the manual reversion test.”

The aircraft was at the end of its lease and had undergone maintenance, before it was to be handed over to another operator.

The airplane therefore departed Southend for a combined maintenance check and customer demonstration flight. The test schedule was loosely based on Boeing’s new aircraft delivery test schedule. The commander was pilot flying.

The airplane climbed up to FL410 and performed several tests up there, then descended to FL150 about 45 minutes into the flight to do further tests (the radar track, that The Aviation Herald used for the initial report did not contain that descend and showed the airplane still at FL410 for unknown reasons). At FL150 the crew performed an APU bleed test, then configured the airplane for the manual reversion test, which required the airplane to be flown at FL150, 250 KIAS, fuel in balance, autopilot and autothrust off, STAB TRIM MAIN ELEC and AUTOPILOT switches to CUTOUT and the aircraft in trim. The customer demonstration manual also requested the spoilers A and B switches to be selected off. The crew configured the airplane according to the customer demonstration manual and not the maintenance manual extracts. The manual reversion test was further prepared by selecting the FLT Control switches A to off, checking normal operation of the flight controls on the remaining B system, then reinstating system A and now turning system B off checking normal operation on a single flight control system. The operation was found satisfactory.

The commander then released the controls, the first officer turned both FLT Control switches A and B off simultaneously removing all hydraulics assistance from the flight controls. The airplane immediately pitched down 2.81 degrees nose down and began a descend of 3100 fpm although the commander pulled the yoke back with considerable force. The commander therefore abandoned the test, but did not wish to reengage hydraulics with significant back pressure on the yoke.

Accordng to his training the commander rolled the airplane to a 90 degrees left bank to unload the pressure on the elevator and release controls before reinstating hydraulics. The commander believed he had released controls when he called the first officer to re-engage hydraulics. However, the cockpit voice recorder shows, that there was confusion between the two pilots resulting that the FLT Control switches were not moved, the commander however believed hydraulics was reengaged.

The commander rolled the wings level again and attempted to arrest the sink rate, which peaked at around 21000 fpm. The control forces remained high, but the commander thought that was due to the high speed in excess of 440KIAS. The commander pulled thrust levers to idle and deployed spoilers, however the spoilers had been selected off as well in the preparation of the test. The commander maintained back pressure which issuing a PAN call to ATC. The airplane eventually recovered at 5600 feet. The pilots reviewed the situation and selected the FLT Control switches back on, which restored normal control forces.

The flight was aborted, suspecting possible structural damage the commander kept the speed below 250 KIAS and configured early for the landing, which went without further incident.

Three immediate safety actions have been taken:

The operator has suspended further check flights until a review of maintenance procedures, check pilot procedures and flight check schedules has been completed.

The CAA is reviewing the check flight handbook to ensure, that guidance to flying control checks are not open to misinterpretation.

The CAA intends to publish an Airworthiness Commmunication regarding coordination of check flights between operators and maintenance organisations.

Holy crap. That was a really close call. The 90-degree bank was a thing of brilliance, IMHO.

Thanks for the update, NeedleNose.