# NTSB SEA96LA055: Cessna 172P, N96879, Salmon, ID, February 15, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 15, 1996, 13:00 local (20:00 UTC) - Place: Salmon, ID - Coordinates: 44.999298, -113.859977 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9993&lon=-113.8600&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 3, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 42333 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96LA055 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42333/pdf - Page: https://openairdocs.org/ntsb/SEA96LA055 ## Probable cause failure of the pilot to maintain directional control during the landing, which resulted in a ground swerve. A factor relating to the accident was: the rock pile to the left of the runway. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - flare/touchdown - directional control - not maintained, pilot in command (cause) - ground loop/swerve - inadvertent, pilot in command - On ground/water encounter with terrain/water, landing - roll - terrain condition - rock(s)/boulder(s) (contributing factor) - Nose over, landing ## Analysis The student pilot was landing on runway 17 in calm winds. He stated that he 'was on a decent approach, full flaps in, on centerline.' The pilot stated that in the flare, he 'noted a slight left yaw.' The airplane touched down with this left yaw and, according to the pilot, 'started a pronounced skid off the runway.' The pilot stated that although he attempted corrective action, the airplane departed the left edge of the 60-foot wide runway, struck a rock pile with its nosewheel, and nosed over. ## Factual narrative On February 15, 1996, approximately 1300 mountain standard time, a Cessna 172P, N96879, registered to and operated by Minuteman Aviation of Missoula, Montana, received substantial damage after it departed the runway following a loss of control on landing roll at Lemhi County Airport, Salmon, Idaho. The student pilot, who was on a 14 CFR 91 solo cross-country instructional flight from Missoula, was not injured. Visual meteorological conditions existed and a visual flight rules (VFR) flight plan had been filed. The pilot was landing on runway 17 at Salmon (5,150 by 60 feet, elevation 4,045 feet above sea level.) Winds at the time were calm. The pilot stated: "...I was on a decent approach, full flaps in, on centerline. As I was flaring in ground effect, I noted a slight left yaw. As I tried to correct for this, the right main touched down and I instantly started to jitter. I further tried to correct the problem. The airplane started a pronounced skid off the runway and I attempted an immediate go around, at which time the aircraft somehow flipped on its back side...." The FAA on-scene investigator reported that the airplane came to rest in an inverted position, with its nose pointed west, in an irrigation canal approximately 90 feet to the left of runway 17. Post-accident investigation revealed sidewise flat spots on both main tires. The right main wheel would not turn until the right main brake line was disconnected and fluid released. The right main brake torque plate was bent. Photographs taken at the accident scene showed the bottom of the forward part of the right main wheel fairing partially separated from the remainder of the fairing. The nosewheel was broken off at the fork and was located behind the airplane (with respect to its direction of travel) in a rock pile. The portion of the nose gear strut which remained attached to the aircraft was bent aft and cocked to the right. The left main wheel turned freely and no damage to the left main wheel or wheel fairing was visible in the photographs. The rudder and pedal position were slightly left of center in the photographs; the right rudder pedal was jammed into the firewall, which was shown buckled in this area. The control yokes were rotated about 50 degrees to the left. A control cable continuity check revealed no abnormalities. There was a skid mark on the runway approximately 90 feet long, starting at approximately the midpoint of the runway and arcing from the approximate runway centerline to the left edge of the runway. The aircraft was lying about 120 to 130 feet down the length of the runway from the end of the skid mark. The 1984 Cessna 172P pilot's operating handbook specifies a flaps-down landing airspeed of 60 to 70 knots indicated airspeed (KIAS) for a normal landing. Based on an airspeed of 60 KIAS, a density altitude of 4,000 feet, and no wind, the time for the airplane to travel 90 feet (the approximate length of the skid mark) was calculated to be 0.84 seconds. The straight-line distance from the end of the skid mark (at the left edge of the runway) to the aircraft wreckage was calculated to be approximately 158 feet, based on 90 feet laterally from the runway and 130 feet down the runway. The time for the aircraft to travel 158 feet at 60 KIAS, 4,000 feet density altitude and no wind was calculated to be 1.47 seconds. The angle off the runway centerline from the beginning point of the skid mark to the end point of the skid mark, based on a distance of 30 feet from the runway centerline to the runway edge and an approximate distance of 90 feet from the beginning of the mark to the end of the mark, was calculated to be 19.5 degrees. ## Aircraft - Registration: [N96879](https://openairdocs.org/aircraft/N96879), registered now, S/N 17276127, built 1984 (OpenAirDocs) - Reported make and model: Cessna 172P - Registry model: [Cessna 172P](https://openairdocs.org/model/cessna-172p) (registry code 2072436) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17276127 - Airframe hours: 4219 - Engines: Lycoming O-320-D2J 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Minuteman Aviation Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 5, 1996, 13 hours before - Departed: MSO, MISSOULA, MT - Flight plan: VFR - Airport: SMN, Lemhi County, runway 17, 5,150 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; student; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 31 total, 31 in this make and model, 8 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 41 °F, dew point 28 °F - Altimeter: 30.00 inHg - Observed at: SMN ## 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 19960215001809A](https://openairdocs.org/incident/19960215001809A), Feb 15, 1996: Cessna 172P, Salmon, ID, Substantial damage. While landing runway, departed on east side and overturned. 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.