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A320 Runway Excursion - Jackson Hole
Forwarding a message from the NTSB
************************************************************ NTSB ADVISORY ************************************************************ National Transportation Safety Board Washington, DC 20594 February 27, 2008 ************************************************************ NTSB INVESTIGATES JETLINER RUNWAY EXCURSION IN JACKSON HOLE ************************************************************ The National Transportation Safety Board sent two investigators to Jackson Hole, Wyoming, to investigate an incident in which a United Airlines jet veered off the side of a runway. On February 25, 2008, at 9:16 p.m. MST, an Airbus A-320, registration N442UA, operated by United Airlines as flight 267, departed the right side of runway 19 during landing at Jackson Hole Airport. The captain, first officer, four flight attendants and 119 passengers evacuated the aircraft via the emergency slides. During the evacuation, one of the inflatable slides did not deploy. No serious injuries have been reported. The airplane departed Denver at 7:44 pm MST with the intended destination of Jackson Hole. Visual meteorological conditions prevailed during the nighttime landing. The reported weather at the airport about the time of the incident was wind calm, visibility of 10 miles, and overcast clouds at 3200 feet above the ground. The airplane came to rest on its landing gear at about a 90 degree angle to the runway in snow about three feet deep. An initial examination of the aircraft revealed no readily visible signs of structural damage or evidence of fire. The captain and first officer have both been interviewed by Safety Board investigators. The cockpit voice recorder (CVR) and flight data recorder (FDR) were removed from the aircraft and sent to the NTSB headquarters in Washington where they will be read out. Investigators are expected to remain on-scene for several days as they continue their documentation of the incident. |
Interestingly enought, one of my wife's friends was round the house the other night and told me about this. Her husband was travelling in the States and was one of the passengers - apparently it was all quite exciting! I searched high and low to find information for her, but this is the first information that has appeared. Good that everyone is safe.
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News report
Some of the best passenger quotes I've read in a while:
http://www.jacksonholenews.com/article.php?art_id=2799 |
further report
There is a further picture and report on www.jacdec.de/news
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pretty decent reporting. especially considering that the Jackson Hole News doesn't have quite the same operating budget as other news organizations that get about 97% of their facts wrong.
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Early thoughts
Full marks to the local newspaper, Jackson Hole News, and their reporter, Cory Hatch. I doubt even Flight International would have done better. And as for our "quality" newspapers in the UK, forget it!
Looks like IAE engines on this A320, rather than CFM. Reading the report, maybe it was the R/H overwing slide that failed, or wasn't used? The overwing slides on the A320 are 2-lane, as there are twin exits. There seems to be substantial fire damage to the R/H engine nacelle (composite material). Presumably, compressor stall resulted from using (fan-cascade) reverse to a standstill, and the snow being ingested. Quote: According to airport operations manager Chris Logan, officials conducted a friction test on the runway and came back with a rating of 65. “That’s basically bare asphalt,” said Logan. “Braking action was good.” [Unquote] Was the friction test done on the centreline only? If ATC was closed, was the airfield official who normally does the friction test instantly available? The report says one of the left tyres was flat. If that had happened early in the landing run, the effectiveness of L/H brakes would have been reduced. It is probably coincidental that the aircraft swung off to the right... |
Flat tire could be key to airplane accident
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Tyre underinflation theory
One might expect certain parties to suggest that the tyre was underinflated prior to touchdown... The QAR will quickly solve that problem, because A320 airplanes are, I believe, all fitted with TPIS (tyre-pressure indicating systems). [Certainly on the ones I flew.]
This system also triggers ECAM (system-monitoring) warnings of tyre low-pressure to the pilots in most flight-phases, including the approach to land. The pilots would receive a "Master Caution" audio/visual warning, with the L/G page displayed on the bottom-centre EIS display, and the offending tyre pressure colour-coded. However, the tyre could have been shredded during the previous departure, while remaining fully inflated. Hope this helps. |
TPIS is a chargeable option.
Also some operators have been removing the system due to reliability/cost of ownership concerns. |
Further details
"The airplane came to rest about 116 feet past the end of the runway and 140 feet to the right of the runway centerline. A heavy skid mark was found on the runway associated with the inboard tire of the left main landing gear. This tire was found deflated and showed wear consistent with a skid. Upon exiting the runway, both engines ingested snow and sustained internal damage.
Examination of the left main landing gear brake system revealed that the inboard and outboard wheel speed tachometer wires were cross-connected. Such a configuration would be likely to cause the antiskid system to use the inboard wheel speed to control the outboard braking, and vice versa. In such a situation, it would be likely that when the inboard tire began to skid, the antiskid system would release the pressure on the outboard brake instead of the inboard brake. Examination of maintenance records indicated that both main landing gear units were replaced on the incident airplane in early February 2008." |
Murphy strikes again
Thanks, ion,
Looks like "Murphy" is going to find his ears burning, yet again... At least it wasn't sidestick transducers (cross-wired) this time. |
So, can we assume that incident / possible accident could have happened the very first flight following early February maintenance, but also wait another full month, just waiting for the first heavy braking solicitation ...
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