Preliminary Report: MedEVAC Learjet 25C overrun
GATES LEARJET 25C, LEXINGTON, KY.,– AUG. 30, 2002–At 1:07 p.m. EDT Learjet 25C N24CP, on a Part 135 air-ambulance flight, overran Runway 4 while landing at Lexington (Ky.) Blue Grass Airport (LEX). The aircraft was destroyed, the patient was killed and the captain, first officer, flight nurse and another passenger were seriously injured.
The aircraft, which was operated by American Air Network dba Care Flight International, was on an IFR flight plan that originated at Marco Island (Fla.) Airport (MKY). According to FAA records, the airplane was owned by Henry Air. The flight nurse told investigators that the patient was en route to Lexington to receive medical treatment.
The Lexington tower controller testified that the airplane landed about 2,000 ft beyond the approach end of Runway 4. The nose touched down, then lifted as the pilot was apparently doing aerodynamic braking. A parking-garage camera helped investigators estimate the touchdown point as being between 1,500 and 2,500 ft from the approach end of 7,003-ft Runway 4.
After touchdown the airplane continued down the runway and over a 100-ft-long paved overrun area. It then crossed a 50-ft grassy area, went down a 50-ft, 60-deg sloped grassy hill and hit an ILS platform constructed of telephone poles and heavy crossbeams. The aircraft continued another 60 ft across a drainage ditch and a four-lane divided highway before coming to rest on the opposite shoulder. A review of tower transmissions revealed that shortly before the airplane went off the runway, one of the pilots keyed the microphone and shouted, “Brakes, brakes!”
No skid marks were found on the runway; however, light straight-line skid marks matching the width of the jet’s main landing gear were found on the last part of the paved overrun extending about 40 ft. The skid marks, along with a third set of marks matching the position of the jet’s nosewheel, continued through the grass to the edge of the dropoff. There were no tire tracks beyond the edge of the dropoff.
A debris and soot trail began at the ILS platform, crossed the drainage ditch and veered toward the right, across the highway to the main wreckage. A driver received minor injuries when parts of the airplane struck his coal truck, which was westbound on the highway. Two bystanders were also taken to hospitals after being overcome by smoke while trying to assist the airplane’s passengers.
Weather at the time was broken cloud layer at 4,300 ft, visibility 10 mi, wind 50 deg at seven knots and temperature 81 deg F.
The airplane had a Dee Howard XR conversion, which included thrust reversers. According to the XR maintenance manual, reverser deployment is hydraulically actuated and electrically controlled. There was also an accumulator that allowed deploy/stow cycling in the event of hydraulic system failure. The system would not have been armed unless the airplane was “firmly on the ground.” Investigators determined that the thrust reversers were out of the stowed position but were not deployed. The drag chute was also not deployed, and the flap position could not be determined due to ruptured hydraulic lines.
In the cockpit, the thrust levers were at idle and the flap handle was in the down position. The drag-chute handle and the emergency-brake handle were in the stowed position; however, the “emergency air” gauge indicated zero. The flap position indicator was up, and landing reference speeds were 123 kt on the captain’s side, and 121 kt on the first officer’s side. The brake calipers were tested with compressed air and operated normally. Brake disc pads were measured and found to be within limits. Neither the investigation nor a review of the cockpit voice recorder revealed any mechanical anomalies.
The captain held an airline transport pilot certificate with multi-engine and Learjet ratings, and his medical was current. During the accident the captain suffered head trauma, and subsequently could not remember any part of the accident flight after its departure from Florida.
The first officer held a commercial pilot certificate with multi-engine and instrument ratings. His medical was current, but the severity of his injuries prevented his being interviewed for the preliminary report.