Loss of control Accident Learjet 24D N997TD,

ASN Wikibase Occurrence # 323160

Date:	Monday 10 December 2001
Time:	18:21
Type:	Learjet 24D
Owner/operator:	Air Cargo Express
Registration:	N997TD
MSN:	24-247
Year of manufacture:	1972
Total airframe hrs:	7966 hours
Engine model:	General Electric CJ610-6
Fatalities:	Fatalities: 2 / Occupants: 2
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	near Sierra Blanca, TX - United States of America
Phase:	En route
Nature:	Ferry/positioning
Departure airport:	Harlingen-Valley International Airport, TX (HRL/KHRL)
Destination airport:	El Paso International Airport, TX (ELP/KELP)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Learjet N997TD, operating as Turbodog 36, departed Harlingen at 17:00 for a positioning flight to El Paso. At 18:09 Albuquerque ARTCC cleared the pilot to descend "at pilot's discretion" from FL390 to 10,000 feet. Ten minutes later the flight was cleared direct to El Paso. At 1821:06, while the plane was descending through FL219, Albuquerque instructed the pilot to contact El Paso approach control. The pilot acknowledged with an incorrect frequency and uttered an unintelligible sound. The controller attempted to correct the readback, but no response was received and the pilot never contacted El Paso approach control. During this exchange the transponder's mode C function indicated the airplane climbed to FL225. The airplane continued to climb to FL231 and at 1821:20 no mode C was received from the airplane. The Learjet had entered an uncontrolled descent and crashed.

PROBABLE CAUSE: "Loss of control during descent for undetermined reasons."

Accident investigation: