Investigation Summary
Flight 199 was a multi-leg cargo operation that began in Detroit and proceeded to Hamilton, Ontario, to load automotive parts. After a stop in Shreveport for customs and refueling, the aircraft departed for Saltillo at 23:48 CDT. As the flight approached Saltillo in the early morning hours, the crew encountered adverse weather including fog banks. The investigation revealed a series of operational failures: the crew attempted an ILS/DME approach despite the captain's command bars and one DME unit being inoperative. CVR transcripts revealed the crew shared a single set of Jeppesen approach charts; the captain asked for the 'number one book' during descent, and the first officer later asked if there were 'extra approaches' available. Because his own DME was inoperative, the first officer explicitly stated, 'I got to look at yours because I can't—I don't have a DME over here,' forcing him to divide his attention between the captain's instruments and his own. The approach became unstable, but the crew did not initiate a go-around until they were at a very low altitude and lacked visual contact with the runway. During the attempt to climb away, the aircraft struck wires and crashed near the Libramiento José López Portillo, coming to rest near DHL and Mercury Cargo hangars.
Final Conclusions
The DGCA Mexico (ACC 34/08) concluded the probable cause was the continuation of an unstable final approach without the runway in sight and the subsequent loss of control during the go-around at low altitude. Contributing factors included pilot fatigue, the first officer's lack of experience, failure to follow standard operating procedures, and the use of inoperative equipment (DME #2 and captain's command bars). CVR data highlighted the crew's deteriorating situational awareness; at 01:09:00, the First Officer reported his DME was 'going flaky' but noted he was 'starting to see the outside' just seconds before EGPWS 'sink rate' alerts began. The report also cited a lack of supervision by the authority and communication saturation at the Monterrey Control Center, which delayed critical weather updates and approach clearances.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
DME (Distance Measuring Equipment)
The #2 DME unit was inoperative, complicating the DME arc and ILS/DME approach procedures required for Saltillo.
Flight Director Command Bars
The captain's command bars were inoperative, depriving the pilot flying of primary visual guidance during the instrument approach.
Interesting Facts
- 01The aircraft was manufactured in 1967 and had previously served with Continental Airlines.
- 02The crew was operating with only one set of Jeppesen approach charts between them.
- 03The captain's flight director command bars and the #2 DME were inoperative at the time of the accident.
- 04The aircraft struck power lines during the attempted go-around.
- 05The crash site was located approximately 200 meters from DHL and Mercury Cargo hangars.
Safety Actions & Advisories
Operational Oversight and Fatigue Management
Source ↗The investigation highlighted the need for better supervision by aviation authorities and stricter adherence to standard operating procedures (SOPs), particularly regarding the requirement for each pilot to have their own set of approach charts and the prohibition of continuing approaches with critical navigation equipment inoperative.