Boeing, what a mob of losers

[flappist]

Originally Posted by old_mate

There has been controlled flight into terrain with Boeing's too, you know....

Not many with with expat tech crew.......

[Gammaboy]

Its funny, The Boeings will let you exceed their G-limits, will set off all sorts of buzzers and stuff to tell you you've just about pulled the wings off the plane... an Airbus won't... so a Boeing will let you dodge a mountain and an Airbus will fly you straight into it while saying "I'm sorry Dave, you know I can't do that...."

Oh, and the irony and comparisons to Fords and Holdens are not lost on me... :P

[flappist]

Originally Posted by Gammaboy

"I'm sorry Dave, you know I can't do that...."

Open the pod bay doors HAL....


love it.

[Dark Horse]

Originally Posted by Firefox7

Yeah...was a nasty....Incident.....but wasn't an accident.........! They were just testing the strength of the wings.....



Cheers...

Unfortunately a young boy died in that one, as well as a flight attendant and another adult. The young boys' sister tried to help unbuckle his seatbelt, he told her to get out of the aircraft for her own sake whilst he continued in vain to get the bloody thing undone before smoke inhalation got to him. A flight attendant had been overcome by smoke inhalation whilst initiating evacuation proceedures, and the third fatality resulted from the same in inability to get one of the overwing emergency exits open.

What actually happened with the A320 that flew into the trees was this:

The A320 was planned to fly along an airstrip at Habsheim firstly doing a high speed pass at 200' clean, and then a low speed, high alpha pass with flaps and undercarriage extended.

During the descent for the low speed pass, the pilots engaged Open Descent Idle Mode (ODIM) on the Flight Control Panel. Pretty self explanatory really, the engine power is reduced to flight idle, as the aircraft descends. The pilots align the A320 with the runway for the second pass.

Whilst in normal operational phases of flight there is a function within the Airbus flight control system called alpha floor. What this basically does is as soon as a stall is detected (angle that the wings cut the air become so steep, the airflow pattern to produce sufficient lift is disrupted), engine thrust is automatically increased to maximum continuous thrust. Positive pitch is also commanded automatically. This is to prevent controlled flight into terrain.

However, once the undercarriage and flaps are extended, alpha floor is overridden for obvious reasons. Combined with the ODIM selected, there is no controlled flight into terrain protection. From the outset the A320 flight control system was never designed to hold 200'.

Most air traffic control towers are about 200' high and they are used as a reference for most low altitude passes. However as Habsheim is a smaller airfield, the tower was only 40' in height. This was about the altitude that the pilots realised the aircraft was too low.

As the aircraft was still in ODIM, it took a long time for the engines to spool up again - something like 4 seconds from 29% N1 (fan speed at the front of the engine) to 50% N1 (just to counteract the decaying airspeed - which at this stage had dropped off to 121 knots and still decreasing). It takes another 7 seconds for the engines to spool up from 50% N1 to 104% N1 (firewalling to get the aircraft some speed and hopefully altitude). This delay is in part due to the electronic engine controls and also due to the nature of the modern turbo fan engine.

Unfortunately there was not enough room for the aircraft to recover. According to the digital flight data recorder, the A320 had just started to climb when it struck the trees. As per the automation with the flight deck, the cabin crew also operate automated systems such as announcements, fire alarms and so forth, which also assist with situational awareness in emergencies.

Unfortunately, all the automation proved valueless as all electrical power to run it was cut out in after the initial impact. (The engines also double as generators, and when they stop running, so do all electrics). The cabin crew reverted to loudhailers, in amongs the smoke, panic and confusion. Unfortunately, not all the doors could be opened due to spot fires, and the ones that could've been opened were difficult to operate.

Deemed the uncrashable plane, Airbus was slammed for providing pilots with the ease and use of the flight systems. It provided a level of overconfidence amongst the pilots, that was again to be seen in yet another A320 accident almost exactly 2 years later.

Air France management was slammed for poor flight planning and preparation for the flyover at Habsheim. One of the noteworthy items was the attention to detail such as the obstacles and control tower heights that were not briefed to the pilots. Air France was also slammed for executing such a stunt - a 200' low speed pass with passengers onboard is a considerable disregard for duty of care.

The pilots could also be apportioned blame, in allowing the A320 to fly as low as 40' with airspeed decaying beyond 121 knots. One of the comments made by the Captain was the delay between applying thrust and through the electronic engine controls the spoolup rate to maximum thrust. However, considering the circumstances placed on them, they were as much victims of the outcome as any onboard.