Date:	Tuesday 4 November 2008
Time:	18:46
Type:	Learjet 45
Owner/operator:	Mexican Government
Registration:	XC-VMC
MSN:	45-028
Year of manufacture:	2000
Total airframe hrs:	2486 hours
Cycles:	2215 flights
Engine model:	Garrett TFE731-20AR-1B
Fatalities:	Fatalities: 9 / Occupants: 9
Other fatalities:	7
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	12 km W of Mexico City-Benito Juárez International Airport (MEX) -   Mexico
Phase:	Approach
Nature:	SF
Departure airport:	San Luis Potosí Airport (SLP/MMSP)
Destination airport:	Mexico City-Benito Juárez International Airport (MEX/MMMX)
Investigating agency:	DGCA Mexico
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The Learjet departed San Luis Potosí (SLP) at 18:04 on a flight to Mexico City (MEX). On board were a.o. Mexican Interior Minister Juan Camilo Mourino, Deputy Attorney General José Luis Santiago Vasconcelos and Miguel Monterrubio Cubas, the director of social communication.
The flight was uneventful and at 18:40 the flight was cleared direct to the MATEO VOR. The controller instructed the crew to increase their speed to 220 knots and cleared the flight for an ILS/DME approach to runway 05R.
The Learjet was trailing a Boeing 767-300 (Mexicana Flight 1692 from Buenos Aires), which was instructed to decrease speed to 160 knots to maintain separation with a preceding Airbus A318. At 18:41 a further instruction was given to slow down to an indicated airspeed of 150 knots.
At 18:42 the Boeing 767 crossed MATEO VOR at a ground speed of 224 knots. The Learjet was following at 8 nautical miles (NM) at a ground speed of 272 knots.
At 18:44 the controller instructed Mexicana Flight 1692 to slow down to the minimum approach speed. At that time, the Learjet 45
was crossing the MATEO VOR with a ground speed of 262 knots, approximately 5.7 NM behind.
The controller then instructed the Learjet crew to reduce their airspeed to 180 knots. This was acknowledged but it took 16 seconds for the crew to take action.
Separation between the Boeing 767 and Learjet had decreased to 3.8 NM and the Learjet entered the wake turbulence of the 767.
Control was lost and the aircraft entered an uncontrolled descent, impacting on the Monte Pelvoux and Ferrocarril de Cuernavaca Avenues. The aircraft disintegrated and a fire erupted. Several cars were destroyed and seven people on the ground were killed.

Probable cause (translated from original Spanish report): "Loss of control at low altitude and subsequent impact of the aircraft with the ground, encounter with wake turbulence caused by the aircraft that preceded it."

Contributing factors:
1. Lack of adequate training of the crew in the Lear Jet 45.
2. Delay of the flight crew in reducing speed.
3. Lack of Air Traffic Control to correct the excessive approach speed of the aircraft.
4. Likely fatigue accumulated by the air traffic controller.
5. Grant of flight capacity, administrative problems and probable corruption.
6. Insufficient monitoring of the aircraft operator to provide maintenance and operation.

Secretariá de Comunicaciones y Transportes (SCT)

photo (c) Harro Ranter; Genève-Cointrin Airport (GVA/LSGG); 06 August 2002

Date/time	Contributor	Updates