Incident Overview
On November 22, 2010, at approximately 0929 mountain standard time, an Israel Aircraft Industries Gulfstream 200, registration N718QS, overran runway 19 at Jackson Hole Airport (JAC) in Jackson, Wyoming. The airplane was undamaged. The flight crew, consisting of an airline transport rated captain and first officer, were not injured. Instrument meteorological conditions prevailed, and the flight operated under an instrument flight rules (IFR) flight plan. The repositioning flight originated from Bozeman, Montana, at 0837.
Flight Crew Reports
According to the captain's written statement, the flight was delayed earlier due to weather and low runway surface friction report values (MU) in the 20s at JAC. About an hour later, the crew received company clearance after MU values rose to the 40s. During the approach, the crew obtained weather conditions from the airport's automated terminal information service (ATIS) and deemed them acceptable. A previous aircraft reported breaking out of clouds about 1.5 miles from the airport and assessed braking action as fair.
Upon landing on runway 19, the captain deployed thrust reversers and observed green ground/air slat indication lights and anti-skid system pulsing, but the airplane did not decelerate as expected. Maximum thrust reverse was applied without effect. Approaching the departure end, the captain initiated a slight right turn to avoid approach lighting. The airplane came to rest about 25 feet beyond a 338-foot long blast pad.
The first officer stated that the flight received delayed vectors for traffic sequencing and obtained MU values of 41, 37, and 36. About 10 minutes before landing, the tower reported MU readings of 40, 42, and 40 with braking action fair. Despite deploying ground airbrakes, thrust reversers, and brakes, deceleration was slow. After the overrun, the crew conducted post-landing checklists and exited. The first officer observed no damage and noted the runway appeared covered by clear ice. No mechanical malfunctions were reported.
Airport Conditions
Jackson Hole Airport features a single 6,300-foot long, 150-foot wide runway paved with porous friction course (PFC) asphalt. Runway 19 is equipped with an instrument landing system (ILS), high-intensity edge lighting, precision markings, medium intensity approach lighting (MALS), and precision approach path indicators (PAPI) set at 3 degrees. Runway safety areas of 500 by 1,000 feet extend beyond both thresholds, with 300-foot concrete blast pads. The runway slopes -0.6 percent from north to south, dropping 38 feet over its length.
Runway friction values are assessed using a Saab 9-5 SFT vehicle and Tapley decelerometer. Notices to Airmen (NOTAMs) issued at 0630 reported MU values of 41, 37, 36 with patchy thin snow over patchy thin packed snow and ice. At 0920, MU values were 40, 42, 40 with similar surface conditions. A Saab SFT printout at 0936 recorded MU values of 34, 33, and 23.
Weather and Runway Conditions
Air traffic control (ATC) recordings revealed that about 5 minutes 47 seconds before the overrun, the airport friction measurement vehicle operator reported MU values 40, 42, 40 with patchy thin snow over patchy thin packed snow and ice. The flight crew contacted ATC 54 seconds later. About 3 minutes 48 seconds before the overrun, a Piper Meridian pilot reported the runway as “a little bit slick” with poor to fair braking action. The Gulfstream crew acknowledged this report. About 1 minute 23 seconds before the overrun, the controller informed the crew that MU values were in the 40s but braking action reports did not reflect that.
The flight crew reported visual contact about 1.8 miles from the runway at 7,000 feet msl. During the overrun, they reported braking action nil to poor.
Cockpit voice recorder data showed the crew discussed conditions and verified sufficient landing distance, estimating a worst-case landing distance of 5,877 feet with 40 degrees flaps and de-ice/anti-ice on.
Regulatory and Company Procedures
The FAA Aeronautical Information Manual defines MU as a friction value from 0 to 100; values of 40 or less indicate deteriorating braking performance. No correlation has been established between MU values and descriptive braking action terms (good, fair, poor, nil).
The company’s Flight Operations Manual requires flight crews to recalculate landing distance if conditions worsen significantly and add a 15% safety margin. It also specifies that braking action reports used for landing decisions must be from similar aircraft (turbojet or turboprop of comparable size).