Reflexion sur les incidents récents aux US

From an Airbus captain, about recent flight errors
24 Oct 2009 12:10 pm

A reader writes:

"I just thought you might like to know that while the airplane overflying Minneapolis received major headlines, the Delta airplane which landed on a taxiway in Atlanta earlier this week received minimal coverage. As you can imagine the taxiway landing is much more of a close call (that is a greater chance of casualties) than overflying an airport at altitude. As I've come to expect from the press there is no perspective on the relative danger of either incident. Somewhat similar to focusing on shark attacks while we kill approximately 40,000 every year on our roads.

"As an A-320 captain I don't mean to throw stones at either crew (there but for the grace of God...)... As to the Atlanta taxiway incident there were multiple factors including a long overnight flight, a sick check airman who was in the back, and a change of runway inside the marker [well into the plane's final descent, shortly before landing] to a runway without approach lighting... But it is interesting that one incident is totally ignored while the other gets major media play."

Google Earth view of approach to runway 27R at Atlanta. Where they should have landed is the runway at center of this view, with the chevron markers on black background pointing towards it. Where they actually landed was the taxiway just to its right. This happened in the dark. At night the taxiway would have blue lights and the runway white lights.

Why a taxiway landing is potentially much more dangerous: another airplane could theoretically be turning onto the taxiway just as the incoming plane was touching down, raising the prospect of a repeat of the deadliest accident in aviation history, the collision of two fully-loaded 747s on the runway at Tenerife, in the Canary Islands, in 1977. Why the current "overflight" incident, despite its safe conclusion, has gotten attention: for what it may show about pilot-fatigue and work-rule questions (plus the melodrama factor of passengers sitting, reading, dozing innocently while things in the cockpit are not as they should be; plus the melodrama factor of controllers, hearing nothing from the plane, not knowing whether it was another hijacking/terrorist episode). Why news coverage does not follow statistical risk of danger: this is life.

NTSB: Complex error chain preceded Delta 767 taxiway landing
By John Croft

A series of atypical circumstances preceded an early morning taxiway landing of a Delta Air Lines Boeing 767 at the Atlanta Hartsfield International airport from Rio de Janeirio on 19 October, according to a preliminary incident report published by the US National Transportation Safety Board (NTSB) on 23 December.

None of the 182 passengers or 11 crew on Delta Air Lines Flight 60 were injured in the incident, which occurred in pre-sunrise darkness and good weather at 06:05 EST that morning, nor was the aircraft damaged, according to the NTSB.

The chain of events that led to the incident appears to have begun during cruise flight, when a check airman in the cockpit became sick and was relocated to the main cabin.

While the nature of airman's medical problem was not identified, the NTSB says the crew notified Delta dispatchers of the situation "and a medical emergency was declared to air traffic control via the company". A decision was made to continue to Atlanta with the remaining two pilots, the NTSB continues.

Inbound to the airport, the air traffic controller handling the flight offered to switch the aircraft's landing runway from 27L to a parallel runway, 27R, via a "sidestep" manoeuvre in order to put the aircraft closer to the terminal for a planned medical evacuation of the sick check airman. The pilots accepted the modified clearance.


Runway layout at Atlanta


With a sidestep, pilots can fly the instrument approach to 27L, manoeuvring to the line up with 27R after sighting the runway visually on the approach.

The instrument landing system for 27R was not operating as it was not the baseline runway for the approach that night. Approach lights for runway 27R were also inoperative due to maintenance being performed.

"The crew landed on taxiway M, located 200ft north of runway 27R," says the NTSB. "After landing on the taxiway, the flight crew taxied to the ramp without further incident."