Must read part two

[MikeBogh]

Asymmetric handling of the throttles could control bank.
>When the left engine alone was accelerated, the wings returned to
>the horizontal, similarly when the right engine only was retarded
>the same levelling effect could be achieved.
>
>This was a very difficult procedure to perform, especially
>when trying simultaneously to maintain horizontal flight and follow
>a heading:
>1) The response to thrust change appeared rapidly in pitch,
>but roll response was delayed, since the roll resulted from the
>sideslip induced by the asymmetric thrust, and there was a lag
>before this took effect
>2) Since the left wing was damaged, the degree of asymmetric
>thrust had to be found which was sufficient to compensate for the
>asymmetry of lift, and it had to be maintained while the thrust was
>adjusted to control the slope; easier said than done
>
>Eric was effectively flying an experimental aircraft and was
>continually gaining experience in manipulating the aircraft by the
>throttles. Steeve provided close assistance making some corrective
>inputs. There were a few rather alarming roll excursions beyond 30
>degrees during that time. The aircraft remained very difficult to
>control, however confidence was gained as the flight
>progressed.
>
>Eventually, they could consider navigation back to the field
>which had been lost from sight during the "training manoeuvres".
>Steeve took on the navigation. He suggested that a long final of at
>least 20 nautical miles was needed. The aircraft started a second
>360 degree orbit, this time under more control. Eric started a
>right turn to come back towards runway 33R, the longer of the two
>runways at Baghdad.
>
>The descent flight path then had to be established. That was
>not simple either: the descent angle selected by the average value
>of thrust was not easy to assess, since the whole process was
>subject to oscillation. It was thus an average descent angle that
>had to be judged, all the while maintaining the heading by
>asymmetric adjustment of the engines.
>
>To complicate matters further, the turbulence associated
>with a wind of 20 knots from 290 degrees (left crosswind component
>tended to excite natural oscillations, and in addition GPWS
>warnings associated with the abnormal landing configuration sounded
>repeatedly on short final.
>
>Eric concentrated on the essential, keeping the aircraft
>under control and reaching the airfield where the fire services
>could fight the fire on the left wing.
>
>Steeve assisted with efficient and timely call-outs,
>announcing distances and altitudes. He stressed the point that the
>power must not be completely reduced on touch-down; otherwise, the
>symmetrical thrust would induce a turn to the left, particularly
>undesirable just before ground contact.
>
>Mario, who, in addition to a close watch on all the systems,
>monitored the fuel remaining in the damaged left wing. It was vital
>that both engines were kept running by ensuring a positive supply
>of fuel and ignition. If one of the engines had lost power or
>failed, the aircraft and crew would have certainly been lost. He
>was therefore prepared to open the cross feed in case the left main
>tank emptied, but not too soon because the fuel in the right wing
>would then be lost through the leak on the left side. Furthermore,
>he was able to relieve both pilots by taking over all radio
>communication and made sure the aircraft was depressurised before
>touchdown to guarantee a successful emergency evacuation.
>
>Mario contacted ATC for an updated visual assessment to
>request if the aircraft was still on fire. A military helicopter
>replied that the left wing was on fire and that the flame was the
>length of the aircraft (50 metres). In spite of the extreme stress
>Mario had the courtesy to say "thank you" to the controller. He
>also requested that both runways 33L and 33R be kept free and that
>all emergency services be ready.
>
>The tension again increased as the ground approached. At
>250ft, the pitch attitude, still slowly oscillating, dropped
>towards a negative value, which was most alarming so close to the
>ground. It was restored nose-up by a large increase in the thrust
>on both engines.
>
>Towards 100ft, the aircraft was tracking to the runway
>threshold, but with a heading ten degrees less than the orientation
>of the runway. Eric made his final lateral control correction,
>reducing the right engine only. The aircraft banked to the right
>and the angle of convergence began to diminish.
>
>Twenty-five long minutes after impact of the missile, the
>A300 B4 finally landed on runway 33L, without further
>damage:
>1) At a positive pitch attitude
>2) With a moderate sink rate (less than 10ft/sec, far below
>the tolerances for the landing gear)
>3) At an angle of bank of ten degrees to the right, and
>heading diverging about eight degrees to the left of the runway
>axis
>
>Without any direct means of directional control, however,
>the aircraft rapidly went off the side of the runway. The throttles
>were retarded and selected to full reverse by Mario. The sandy
>ground provided a significant extra braking force and the aircraft,
>in spite of the high speed at touchdown, stopped after a landing
>run of the order of one kilometre, raising an impressive cloud of
>sand behind it.
>
>After engine shutdown the crew evacuated the aircraft from
>the right, inches away from a coil of razor wire. They ran a safe
>distance from the aircraft as the wing was still on fire only to be
>intercepted by some military emergency services personnel who
>warned them that they were standing in a possible mine field. Their
>incredible feat was almost spoiled after taking their first steps
>back on the ground.
>
>For their amazing and momentous actions in the saving of
>their aircraft, the Hugh Gordon-Burge Memorial Award is presented
>to each crewmember of the DHL flight.
>
>Aero-News Networks would like add our congratulations to
>Captain Gennotte, FO Michielsen and FE Rofail for winning
>this prestigious award.
>FMI: www.gapan.org, www.dhl.com





best to you all,
Mike

[Britbrat]

What an exciting & terrifying read. There are many pilots, but how many true aviators? My salutations to Captain Gennotte, First Officer Michielsen & Flight Engineer Rofail.

[Galvin]

These guys did an absolutely outstanding job of getting it on the ground without dying in the process and deserve every form of recognition anyone wants to send their way.

Having practiced total loss of control in the 727 simulator many times over the last twenty-one years I can appreciate a little of what they were faced with, absent the absolute cushion munching pucker factor that had to be going on. I am also acutely aware that not only skill but, to a very great degree, luck is involved in this kind of scenario.

I would estimate that we were able to land the simulator perhaps 60% of the time using only the pitch and bank responses to power changes, both symmetric and assymetric. This was of course complicated by the fact that the 727 was very nearly a centerline thrust airplane and having engines on the wings and a little farther outboard would have sped things up considerably in the yaw induced roll department.

The 727 had cable control tab backup to the ailerons and elevators in manual reversion as well as a manual trim backup. But it only had a hydraulic backup to the lower rudder and directional control was almost nil if this was disabled. The cable control fit made it highly unlikely we would have ever have to completely resort to pitch and roll control through power changes alone but after the first few thousand hours of training on manual reversion in the normal sense one wonders if they can control the aircraft without the cable backups too and thus we often simulated controlling the aircraft by thrust changes alone.

Conclusion: It's anything but a slam dunk and if you have the choice of being a better pilot or a luckier one, choose luckier.

This incident brings up a favorite subject of mine, that of the current practice of eliminating hard connections to the controls, like cable backup systems, from the cockpit in the interest of saving weight. The mechanical backups have disappeared in newer aircraft in favor of total reliance on pure hydraulic and (shudder) fly-by-wire interfaces. This current practice, while contributing to increased payloads and enabling the flying qualities wonks to tailor control response artificially by electronic means, is not an improvement in safety by my reckoning.

If I were military governor of the world I would force every engineer with a great idea to first fly his creation in the simulator and then require him to fly in the airplane throughout the test program, including the worst case scenarios in which his creation is totally disabled. Fear can change your focus as well as it can intensify it.