LAX99LA023
1998-11-04 · MAMMOTH, California, United States · Serious · 1 aircraft · Status: Completed
Airport MMH
N50JG has since been reassigned. It is now registered to a different aircraft (JUNKERS FLUGZEUGWERKE GMBH JUNKERS A50 JUNIOR, built 2023), which was not involved in this event.
Aircraft involved
Probable cause & findings
The pilot's failure to ensure that the autopilot was off prior to takeoff, and, his failure to maintain pitch control during the resultant pitch trim excursion during the takeoff ground roll.
Factual narrative
On November 4, 1998, at 1045 hours Pacific standard time, a Piper PA-46-350P, N50JG, crashed during takeoff from runway 09 at the Mammoth, California, airport. The aircraft, owned and operated by the pilot under 14 CFR Part 91, was substantially damaged. The private pilot and one passenger received serious injuries. The other two passengers received minor injuries. Visual meteorological conditions existed at the time and no flight plan was filed for the personal VFR flight to Las Vegas, Nevada. According to the airport manager, the aircraft took off prematurely and over rotated to a nose high attitude. Shortly thereafter, the aircraft hit the ground tail first then the nose. The aircraft veered off the side of the 7,000-foot-long runway and came to rest on a taxiway. The winds were reported as calm at the time. The pilot told the manager that he "stalled on takeoff." At the request of the Safety Board, the airport manager documented the position of the elevator trim tab and the cockpit elevator trim indicator in the full nose up trim positions. In his written report to the Safety Board, the pilot said that the aircraft had a dead battery and required external power for the start. During this process, the autopilot "cycled twice." The pilot stated that he performed a normal run-up and trimmed the aircraft for takeoff. At 62 knots, the aircraft pitched prematurely to a nose high attitude and lifted off the ground. The pilot retracted the landing gear and the airplane settled back to the ground. The pilot told Federal Aviation Administration inspectors from the Reno, Nevada, Flight Standards District Office that the autopilot ran the pitch trim to the full nose up position just prior to rotation speed. The aircraft lifted off and immediately "felt mushy." The pilot said the left wing dropped and the airplane settled back onto the runway. According to the autopilot manufacturer, the autopilot pitch servo capstans are designed with a clutch that will slip at 25 pounds of control wheel force. Flight test data was supplied by Piper Aircraft concerning control wheel force versus pitch trim tab position. The two speeds for which data points were supplied were 110 KCAS and 200 KCAS. The control wheel force required to hold speed at full trim tab deflection was 48 and 71 pounds, respectively. Witnesses said the aircraft took off prematurely and over rotated to a nose high attitude. Shortly thereafter, the aircraft hit the ground tail first then the nose. The aircraft veered off the side runway and came to rest on a taxiway. The winds were reported as calm at the time. The pilot told the witness that he stalled on takeoff. Immediately after the accident, the position of the elevator trim tab and the cockpit elevator trim indicator were found in the full nose up trim positions. The pilot reported that the aircraft had a dead battery and required external power for the start. During this process, the autopilot cycled twice. The pilot stated that he performed a normal run-up and trimmed the aircraft for takeoff. He said that at 62 knots the autopilot ran the pitch trim to the full nose up position and the aircraft pitched prematurely to a nose high attitude and lifted off the ground. The pilot then retracted the landing gear. The left wing dropped and the airplane settled back to the ground. According to the auto pilot manufacturer, the pitch servo capstans are designed with a clutch that will slip at 25 pounds of control wheel force. According to flight test data supplied by Piper, the control wheel force required to hold 62-knot speed at full trim tab deflection would be less than 40 pounds. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1998_LAX99LA023.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Search this event elsewhere
External sources are reported, not agency: signal that something happened, not fact about what happened.
- TallyAero Live Wire Aviation press
- NTSB CAROL Agency ↗
- NTSB Docket Agency ↗
- Aviation Safety Network Aviation press ↗
- Kathryn's Report Aviation press ↗
- Aviation Herald Aviation press ↗
- AVweb Aviation press ↗
- Pilots of America Community ↗
- Reddit /r/flying Community ↗
- FlightAware Aviation press ↗
- AOPA accident database Aviation press ↗
- Google News News ↗
- DuckDuckGo News ↗
Related research
Matched on aircraft type or causal vocabulary (stall, autopilot). All research papers
- NASA NTRS 2026 · Conference Paper Computational Analysis of Steady State Aerodynamics of Transonic Truss-Braced Wing Configuration in Deep Stall
This study presents a computational investigation of steady state aerodynamics of the Subsonic Ultra-Green Aircraft Research (SUGAR) Transonic Truss-Braced Wing (TTBW) configuration over a wide range …
- arXiv 2025 · arXiv preprint ROSflight 2.0: Lean ROS 2-Based Autopilot for Unmanned Aerial Vehicles
ROSflight is a lean, open-source autopilot ecosystem for unmanned aerial vehicles (UAVs). Designed by researchers for researchers, it is built to lower the barrier to entry to UAV research and acceler…
- arXiv 2025 · arXiv preprint ROSplane 2.0: A Fixed-Wing Autopilot for Research
Unmanned aerial vehicle (UAV) research requires the integration of cutting-edge technology into existing autopilot frameworks.
- arXiv 2024 · arXiv preprint A Data-Driven Autopilot for Fixed-Wing Aircraft Based on Model Predictive Control
Autopilots for fixed-wing aircraft are typically designed based on linearized aerodynamic models consisting of stability and control derivatives obtained from wind-tunnel testing.
- arXiv 2023 · arXiv preprint Automating Bird Diverter Installation through Multi-Aerial Robots and Signal Temporal Logic Specifications
This paper tackles the task assignment and trajectory generation problem for bird diverter installation using a fleet of multi-rotors.
- arXiv 2023 · arXiv preprint Variation of Critical Crystallization Pressure for the Formation of Square Ice in Graphene Nanocapillaries
Two-dimensional square ice in graphene nanocapillaries at room temperature is a fascinating phenomenon and has been confirmed experimentally.