A 37-year-old McDonnell Douglas DC-9-14 was scheduled to operate a domestic passenger flight from Mexico City to Torreon, with an intermediate stop at Durango, in Mexico. 52 passengers and 4 crew were on board the aircraft for the first sector, leaving Mexico city ~30 minutes late.
The aircraft wreckage on the 7th of October 2009 (Source www.jetphotos.com © Iván Cabrero
After all flight preparations were completed both the Pratt & Whitney JT8D-7A engines were started and the aircraft headed out towards the runway. After take-off clearance was received the throttles were forwarded and the JT8D-7A engines accelerated the aircraft down the runway. The standard call-outs were made and at ~19.33 local time the aircraft rotated when it reached its rotation speed and lifted off the runway. Almost immediately after take-off, the aircraft encountered a windshear. It lost height and slammed back onto the runway, causing all three landing gears to be torn off. No longer under control, the aircraft veered off the runway. The right-hand wing was torn off before the aircraft came to a stop. There was no post-crash fire broke and an evacuation was initiated. All 56 occupants of the aircraft safely evacuated the aircraft.
The aircraft was damaged beyond repair.
The aircraft wreckage on the 7th of October 2009 (Source www.jetphotos.com © Iván Cabrero
What is Windshear? Wind shear is a change in wind speed and/or direction over a short distance. It can occur either horizontally or vertically and is most often associated with strong temperature inversions or density gradients. Wind shear can occur at high or low altitudes. Four common sources of low-level wind shear are:
1. Frontal activity
2. Thunderstorms
3. Temperature inversions
4. Surface obstructions The Federal Aviation Administration published an excellent safety publication with detailed information on low-level wind shear. You can access it by clicking on the file below.
Detailed weather information for the time of the accident is not available, nor is an accident investigation report available. Sources on the internet indicate that the probable cause is a low-level wind shear encounter on take-off. www.wunderground.com data for the day of the accident show a sudden drop in temperature and a wind speed increase and decrease around the time of the accident. A weather front moving or a temperature inversion may have caused a low-level windshear.
The weather for Mexico City International Airport on the 21st of July 2004,
the green vertical dotted line is the approximate take-off time of the accident aircraft
(Source: www.wunderground.com, amended by V2 Aviation - Training & Maintenance)
** Editorial note **
V2 Aviation - Training & Maintenance has not been able to obtain an investigation report on this accident. This blog is therefore based on several internet sources. Should there be an inconsistency in the blog don't hesitate to get in touch with us. There are two possibilities to do that, via the comments function at the bottom of this page or via the contact page of the website.
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