# NTSB DEN00LA057: Learjet 60, N240FX, Jackson, WY, March 12, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 12, 2000, 08:40 local (15:40 UTC) - Place: Jackson, WY - Coordinates: 43.470123, -110.760261 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.4701&lon=-110.7603&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 2, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 48770 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN00LA057 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48770/pdf - Page: https://openairdocs.org/ntsb/DEN00LA057 ## Probable cause The pilot not following the airplane manufacturer's recommended landing procedures for a contaminated runway by landing with a tailwind. Factors were the pilot's inadvertent deactivation of the anti-skid protection, the ice contaminated runway, and the snow covered terrain beyond the runway. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Overrun, landing - roll - procedures/directives - not followed, pilot in command (cause) - weather condition - tailwind (contributing factor) - brakes,anti-skid - inadvertent deactivation, pilot in command (contributing factor) - airport facilities,runway/landing area condition - icy (contributing factor) - On ground/water encounter with terrain/water, landing - roll - terrain condition - snow covered (contributing factor) ## Analysis The airplane departed Provo, Utah, with its thrust reversers mechanically pinned in forward thrust. The ILS approach to runway 18 (6,299 x 150 feet, contaminated with ice, and -.611% gradient) at Jackson Hole Airport was performed with a 6.5 knot tailwind. During the landing roll, the captain used the emergency braking system, which deactivated the anti-skid protection. At mid-field, the airplane slid left, then slid right, and then left back to the runway centerline where the captain said he continued braking. The airplane continued beyond the end of the runway for 160 feet into snow approximately 2 feet deep. The manufacturer's Airplane Flight Manual indicates that when emergency braking is utilized, the anti-skid protection is deactivated. The CVR recorded a 'high pitch' sound at 0839:44, which was the high-pressure air of the emergency braking system being activated. The Airplane Flight Manual also limits landing on contaminated runways to the following: A. Winds must be zero or a headwind of less than 30 knots (i.e. no tailwind); B. The runway gradient must be between -1% and +2.2%; and C. The anti-skid system must be operational. ## Factual narrative On March 12, 2000, approximately 0840 mountain standard time, a Learjet 60, N240FX, was substantially damaged when it overran runway 18 during landing roll at Jackson Hole Airport, Jackson, Wyoming. The airline transport pilot and the airline transport copilot were not injured. The airplane was owned by Bombardier Aerospace Corp., of Dallas, Texas, and was being operated by FlexJet, also of Dallas, Texas, under Title 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident. The cross-country repositioning flight originated from Provo, Utah, approximately 43 minutes before the accident. An IFR flight plan had been filed. The pilots had spent the night in Provo, Utah, and they received this assignment on the morning of the accident. The captain said that they departed Provo with the airplane's thrust reversers mechanically pinned to the forward thrust position due to a maintenance discrepancy. As they approached Jackson, the airplane's cockpit voice recorder (CVR) documented that they planned to fly an Instrument Landing System (ILS) approach to runway 18 (6,299 x 150 feet, and -.611% gradient). The Automatic Weather Observation System (AWOS) recorded that the cloud ceiling was 1,200 feet above the ground and the wind was 030 degrees at 9 knots. Approximately 90 seconds before touchdown, the CVR recorded the AWOS wind as, 010 degrees at 7 knots (6.5 knot tailwind). The airport manager said that snow had fallen the night before the accident. He said that airport ground crews had plowed the runway and broomed it. The runway condition report prepared at 0516 indicated thin ice on the runway, and braking action was fair. The captain said that he was told that the braking action on the runway was fair. He flew the final approach at "Vref plus a couple of knots, continued the approach and made a normal touchdown approximately 800 to 1,000 feet down the runway." He said that he applied brakes approximately 500 to 800 feet after touchdown, and "noticed very little deceleration." The captain reported, on the National Transportation Safety Board's Pilot/Operator Aircraft Accident Report, that he used maximum braking effort to stop the airplane. The pilot reported to a FlexJet official, immediately after the accident, that he had used "emergency braking," because of the apparent lack of aircraft deceleration. Later, when interviewed by the NTSB Investigator-In-Charge, he could not remember if he had used emergency braking. According to the captain, at approximately runway midfield, the airplane began to slide left, then right, and then left back to centerline where "maximum braking continued." He said that they departed the end of the runway at approximately 40 knots, and continued forward (in an estimated 2 feet of snow) for approximately 160 feet. Subsequently, the nose landing gear separated and penetrated the airplane's pressure vessel. A manufacturer's representative said that if the emergency braking system were used, a very loud high pitched sound would be heard in the cockpit as the high-pressure air went into the brake lines. The CVR recorded a "high pitch" sound at 0839:44, and the pilots immediately began making verbal exclamations. The CVR documentation suggests that the airplane left the runway at 0840:00. The manufacturer's Airplane Flight Manual indicates that when emergency braking is utilized, the anti-skid protection is deactivated. The Airplane Flight Manual also limits landing on contaminated runways to the following: A. Winds must be zero or a headwind of less than 30 knots (i.e. no tailwind). B. The runway gradient must be between -1% and +2.2%. C. The anti-skid system must be operational. ## Aircraft - Registration: N240FX (not matched to a registry record) - Reported make and model: Learjet 60 - Category: Airplane - Serial number: 167 - Airframe hours: 320 - Engines: P&W PW-305A 4600 lbs thrust turbo fan - Damage: Substantial damage - Flight: Executive/Corporate, Part 91 - Registered owner: Bombardier Aerospace Corp - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, March 7, 2000, 9 hours before - Departed: PVU, PROVO, UT - Destination: JAC - Flight plan: IFR - Airport: JAC, Jackson Hole Airport, runway 18, 6,299 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 4,415 total, 1,389 in this make and model, 2,495 as pilot in command, 156 in the last 90 days, 96 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 1,200 ft overcast - Temperature: 16 °F, dew point 9 °F - Altimeter: 30.00 inHg - Observed at: JAC ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20000312006649A](https://openairdocs.org/incident/20000312006649A), Mar 12, 2000: Beech 60, Jackson, WY, No damage. (-23) Pilot failed to consider the following conditions for determining a proper landing distance during his preflight preparation: 1. Landing with a 6 knots… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.