# NTSB LAX06LA017: North American T-39A, N39FS, Mojave, CA, October 17, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 17, 2005, 15:44 local (22:44 UTC) - Place: Mojave, CA - Coordinates: 35.059165, -118.151664 - Nearby events: https://openairdocs.org/map.md?lat=35.0592&lon=-118.1517&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 25, 2007 - Report: Approved by Office Director - Parties: Van Nuys FSDO - NTSB case key (mKey): 62734 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX06LA017 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62734/pdf - Page: https://openairdocs.org/ntsb/LAX06LA017 ## Probable cause The pilot's failure to maintain aircraft control during the landing roll. A wet runway surface was a factor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - aircraft control - not maintained, pilot in command (cause) - airport facilities,runway/landing area condition - wet (contributing factor) - Gear collapsed, landing - roll - terrain condition - soft ## Analysis Prior to departure, the pilot and copilot calculated takeoff and landing distances for a wet runway. The T39A departed for a test flight, but returned after a short time due to rain showers in the area. The landing runway was still wet from a previous rain shower. The crew selected an approach flap setting and crossed the runway threshold at 125 knots. The captain reported the touchdown was just past the runway numbers, and the crew experienced normal braking action until around the 3,000-foot remaining point. At that point, the braking "seemed ineffective." The flight crew selected antiskid off and normal braking was attempted with limited effect. The captain elected not to abort the landing due to the limited remaining runway and the time needed to spool up the engines. The copilot was calling out speeds and distance remaining, and the captain remembered the airspeed was 60 knots with 2,000 feet of runway remaining. The copilot called "nose wheel steering" a couple seconds later but the steering had little effect on the aircraft. He reported that the braking "became nil" as the aircraft slowed to about 30 knots. The airplane drifted to the right side of the runway and departed the runway surface. The landing gear dug into the soft ground, with the nose gear collapsing aft and the right main gear folding inward. No mechanical failures or malfunctions were found during post accident aircraft inspections. ## Factual narrative On October 17, 2005, at 1544 Pacific daylight time, a North American T-39A, N39FS, landed on runway 8 at the Mojave Airport (MHV), Mojave, California. During the landing roll the aircraft departed the runway and experienced a nose and right main landing gear collapse. The experimental certificated airplane was registered to, and operated by, BAE Systems Integrated Defense Solutions, Inc., Mojave, under the auspices of 14 CFR Part 91 as a test flight. The captain and copilot, who were both airline transport pilots, were not injured. The airplane sustained substantial damage. The flight departed MHV approximately 30 minutes prior to the accident for the local area test flight. Visual meteorological conditions prevailed and a flight plan was not filed. According to a statement provided by the captain, the flight was intended as a test flight after modifications were made to the nose, interior fittings, and ventral fin. He and the copilot calculated the takeoff and landing data based on weather at MHV. The captain indicated that the takeoff and landing criteria met the limits of runway 8 with a calculated landing distance over obstacles as 4,000 feet for a dry runway. Since the runway was wet they calculated a landing distance of 5,300 feet, and added a penalty due to the lack of speed brakes, which equated to 5,512 feet for no wind conditions. The crew estimated they had a 10-knot headwind, which they assumed would shorten the distance slightly. They briefed the project manager on their planned flight and departed after maintenance was completed on the aircraft. The flight crew conducted flight checks at or below 10,000 feet north of MHV. Due to rain showers in the area, they elected to return. They conducted a low pass and a touch-and-go landing to evaluate the winds and runway with no anomalies noted. The crew selected an approach flap setting and crossed the runway threshold at 125 knots. The captain reported the touchdown was just past the runway numbers, and the crew experienced normal braking action until around the 3,000-foot remaining point. At that point, the braking "seemed ineffective." The flight crew selected antiskid off and normal braking was attempted with limited effect. The captain elected not to abort the landing due to the limited remaining runway and the need to spool up the engines. The copilot was calling out speeds and distance remaining, and the captain remembered the airspeed was 60 knots with 2,000 feet of runway remaining. The copilot called "nose wheel steering" a couple seconds later but the steering had little effect on the aircraft. The pilot reported that the braking "became nil" as the aircraft slowed to about 30 knots. The airplane drifted to the right side of the runway and departed the runway surface. The nose wheel landing gear dug into the soft ground and folded aft, while the right main landing gear folded inward. The flight crew reported hydraulic fluid was visible throughout the cabin as they exited the airplane. The captain reported that there was no standing water on the runway; however, it was damp due to a rain shower that had moved past the airport about 15 minutes before landing. On September 27, 2005, the Mojave Spaceport General Manager issued an advisory notice informing operators that runway 8/26 would be NOTAM closed September 29th thru September 30th for Sealant Application and Remarking. The copilot's statement coincided with that of the captain's. The aircraft sustained substantial damage when the nose landing gear and right main gear collapsed. When the nose landing gear collapsed, it pushed the Nose Wheel Steering Control Valve through the floor of the cabin, leaving hydraulic fluid in the cabin and an 8-inch by 4-inch hole in the pressure vessel. In post accident examinations and tests of the accident aircraft, a Federal Aviation Administration Inspector from the Van Nuys, California, Flight Standards District Office noted no mechanical defects, correct instrument indications, and no indication of mechanical problems. During operational tests, the Inspector noted that there were no leaks in any hydraulic system and the brakes functioned properly using all systems. The Inspector also noted skid marks on the tires, but the depth did not go through the original grooves of the tire. ## Aircraft - Registration: [N39FS](https://openairdocs.org/aircraft/N39FS), registered now, S/N 62-4480, built 1963 (OpenAirDocs) - Reported make and model: North American T-39A - Registry model: [North American T-39A](https://openairdocs.org/model/north-american-t-39a) (registry code 6402509) (OpenAirDocs) - Registry engine: [Pratt & Whitney J-60-P3A](https://openairdocs.org/engine/pratt-whitney-j-60-p3a) (registry code 51762, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: 62-4480 - Airframe hours: 20444.1 - Engines: Pratt & Whitney J60-P3A 3000 lbs thrust turbo jet; Pratt & Whitney J60-P3A 3000 lbs thrust turbo jet - Damage: Substantial damage - Flight: Flight test, Part 91 - Registered owner: BAE Systems Integrated Defense Solutions Inc. - Airworthiness certificate: Special, Experimental (Special) - Last inspection: AAIP, July 1, 2005, 13.7 hours before - Departed: MHV, Mojave, CA - Airport: MHV, Mojave, runway 8, 7,050 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; airline transport, flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review September 1, 2004; seat: left; flight hours: 12,998 total, 722 in this make and model, 11,272 as pilot in command, 91 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours - Co-pilot; age 53; injuries: none; private, airline transport; airplane ratings: multi-engine land, single-engine land; medical: class 2, with waivers/limitations; last flight review June 1, 2005; seat: right; flight hours: 4,959 total, 230 in this make and model, 3,600 as pilot in command, 44 in the last 90 days, 17 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 10 knots - Visibility: 7 statute miles - Lowest ceiling: 4,000 ft overcast - Temperature: 64 °F, dew point 57 °F - Altimeter: 29.88 inHg - Observed at: PMD, 26 nm away ## 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 20051017027679A](https://openairdocs.org/incident/20051017027679A), Oct 17, 2005: Namer T39A, Mojave, CA, Substantial damage. (-23) On October 17, 2005, at approximately 1425 hours PDT, captain [privacy data omitted] acting as pilot in command of N39FS, a north American T39A, landed… 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.