Learjet 35

The Learjet 35A received substantial damage on impact with airport property and terrain during a landing overrun on runway 19 (7,002 feet by 150 feet, grooved asphalt) at Charles B. Wheeler Downtown Airport (MKC), Kansas City, Missouri. The airplane was operated by a commercial operator as a positioning flight to Kansas City International Airport (MCI), Kansas City, Missouri, with a filed alternate destination of Lincoln Airport (LNK), Lincoln, Nebraska. Night instrument meteorological conditions prevailed at the time of the accident. LNK was a certificated airport with a snow removal plan and was served by runway 17R (12,901 feet by 200 feet, grooved asphalt and concrete). The flight was en route to MCI to pick up passengers and continue on as an on-demand charter but diverted to MKC following the closure of MCI. MCI was closed due to a McDonnell Douglas MD83 sliding off a taxiway during an after landing taxi on contaminated runway/taxiway conditions. MKC held a limited airport certificate that did not have a snow removal plan and was served by runway 19. Following a precision approach and landing on runway 19 at MKC, the Learjet 35A slid off the departure end of the runway and impacted airport property and terrain. The Learjet 35A was operated with inoperative thrust reversers as per the airplane's minimum equipment list at the time of the accident. About 1:05 hours before the accident, runway 19 Tapley values were recorded as 21-22-22 with 1/2 inch of wet snow. About 17 minutes before the accident, MKC began snow removal operations. About 7 minutes before the accident, the MKC air traffic control tower (TWR) instructed the snow removal vehicles to clear the runway for inbound traffic. TWR was advised by airport personnel that runway 19 was plowed and surface conditions were 1/4 inch of snow of snow; friction values were not taken or reported. While inbound, the Learjet 35A requested any braking action reports from TWR. The first airplane to land was a Cessna 210 Centurion, and the pilot reported braking action to the TWR as "moderate", which was then transmitted by TWR as "fair" from a Centurion in response to the Learjet 35A's query. The Cessna 210 Centurion pilot did not use brakes during landing and did not indicate this to TWR during his braking action report. The Aeronautical Information Manual states that no correlation has been established between MU values and the descriptive terms "good," fair," and "nil" used in braking action reports. The Airport Winter Safety and Operations advisory circular (AC) states that "pilot braking action reports oftentimes have been found to vary significantly, even when reported on the same frozen contaminant surface conditions." The AC also states, "It is generally accepted that friction surveys will be reliable as long as the depth of snow does not exceed 1 inch (2.5 cm) and/or depth of wet snow/slush does not exceed 1/8 inch (3mm). The Learjet 35A flightcrew calculated a landing distance 5,400 feet. Two of the cockpit voice recording channels, which normally contain the pilot and copilot audio panel information, were blank.

On October 24, 2004, about 0025 Pacific daylight time, a Learjet 35A twin-turbofan airplane, N30DK, registered to and operated by Med Flight Air Ambulance, Inc. (MFAA), collided into mountainous terrain shortly after takeoff from Brown Field Municipal Airport (SDM), near San Diego, California. The captain, the copilot, and the three medical crewmembers received fatal injuries, and the airplane was destroyed. The repositioning flight was operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91 with an instrument flight rules (IFR) flight plan filed. Night visual meteorological conditions prevailed. The flight, which was the fourth and final leg of a trip that originated the previous day, departed SDM at 0023.

The flightcrew stated that approximately 8 miles out on a visual approach for runway 10 they requested winds and altimeter setting from the control tower. They received altimeter setting 29.95 inches Hg., and winds from 090 degrees at 20 knots. About 5 miles out, in full landing configuration, they checked wind conditions again, and were told 090 at 16 knots. They were holding Vref of 125 knots plus 10 knots on final. The approach was normal until they got a downdraft on short final. The airplane sank and they reacted by immediately adding engine power and increasing pitch, but the airplane continued to sink. The airplane's main landing gear came in contact with the top of the barbwire fencing at the approach end of the runway. The airplane landed short of the threshold. The airplane was under control during the roll out and they taxied to the ramp. A special weather observation was taken at the Vance W. Amory International Airport at 1930, 10 minutes after the accident. The special weather observation was winds 090 at 15 knots, visibility 10 statute miles, scattered clouds at 2,000, temperature 27 degrees centigrade, dewpoint temperature 23 degrees centigrade, altimeter setting 29.95 inches hg.

The copilot was flying an ILS approach at an airspeed of Vref plus 10 knots, and the captain made visual contact with the runway about 350 feet agl. The airplane then drifted high on the glideslope, and the copilot decreased engine power. The sink rate subsequently became too great. By the time the captain called for a go-around, the airspeed had deteriorated, and the stick shaker activated. Although power was applied for the go-around, the airplane impacted the runway in a level attitude before the engines spooled up. The airplane came to rest in snow, about 20 feet off the left side of the runway, near mid-field.