LAX06LA017

NTSB accident investigation · North American T-39A · Mojave, CA · October 17, 2005

Accident · No injuriesLimited investigationFinal report
Date
October 17, 2005, 15:44 local (22:44 UTC)
Place
Mojave, CA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N39FSNorth American T-39A
Weather
Visual (VMC) · Day
Status
Completed · report July 25, 2007
Report
Approved by Office Director
Parties
Van Nuys FSDO
FAA report
20051017027679A
Case key
62734

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to maintain aircraft control during the landing roll. A wet runway surface was a factor.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - on ground/waterLanding - roll
Aircraft control - not maintainedPilot in commandCause
Airport facilities,runway/landing area condition - wetFactor
Gear collapsedLanding - 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
Reported as
North American T-39A
Category
Airplane
Serial number
62-4480
Airframe hours
20,444.1
Engines
Pratt & Whitney J60-P3A, 3,000 lbs thrust, turbo jetPratt & Whitney J60-P3A, 3,000 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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
57
Injuries
None
Certificates
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
Role
Co-pilot
Age
53
Injuries
None
Certificates
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.