History of Flight
On October 1, 2009, at approximately 1400 eastern daylight time, a Butler Aircraft Aerostar 601, registration N81FW, was substantially damaged when the nose gear collapsed upon landing at Hernando County Airport (BKV), Brooksville, Florida. The certificated private pilot, who owned the airplane and was the sole occupant, was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed.
The pilot reported departing from Albert Whitted Airport (SPG) in St. Petersburg, Florida, en route to BKV, a non-towered airport. He prepared to land on runway 3, which had a concrete surface measuring 5,015 feet long and 150 feet wide. The airplane was equipped with three green indicator lights corresponding to each landing gear leg; these lights were designed to illuminate when all three gears were properly extended. The pilot stated that after selecting the landing gear down, all three green lights were illuminated.
During landing, the airplane touched down "normally" on the main landing gear. However, when the pilot lowered the nose to bring the nose gear onto the runway, the airplane continued pitching down until the nose structure contacted the runway surface. The propeller tips struck the runway, and the airplane slid to a stop on its main landing gear and nose structure. The airplane remained on the paved runway and no fire occurred.
Personnel Information
FAA records indicated the pilot held a private pilot certificate with single-engine and multi-engine land ratings, and an instrument rating. He had approximately 1,847 total hours of flight experience, including 51 hours in the accident make and model and about 8 hours in that specific airplane. His most recent flight review was in August 2008, and his most recent third-class medical certificate was issued in September 2008.
Aircraft Information
According to FAA records, the airplane was manufactured in 1970 and powered by two Lycoming IO-540 series piston engines. Previous registrations included N7482S and N31FW. The pilot purchased the airplane in June 2009. Its most recent annual inspection was completed in January 2009, at which time the total time in service was 4,232 hours. At the time of the accident, the airplane had accumulated 4,255 total hours.
Meteorological Information
The recorded weather observation at BKV at 1353 included wind from 010 degrees at 5 knots, visibility 10 miles, clear skies, temperature 28°C, dew point 9°C, and an altimeter setting of 29.99 inches of mercury.
Wreckage and Impact Information
An FAA inspector who examined the airplane noted crush and abrasion damage to the nose gear doors, lower forward nose skins, and underlying structure from runway contact.
Post-accident discussions with the pilot revealed that an amber light, normally illuminated to indicate the landing gear was in transit, did not illuminate during the gear extension on the accident flight. The airplane was also equipped with a warning horn intended to sound when throttles were retarded and gear was not extended. The pilot stated that no pre-takeoff check of the horn was performed and that the horn did not sound during the approach and landing.
Additional Information
FAA records from 1989 showed a major repair to the lower nose section, which included replacement of webs, skins, and nose landing gear door assemblies. The reason for that repair was not determined.
Maintenance records from the January 2009 annual inspection listed several discrepancies. Discrepancy number 15 noted that "Nose gear doors hang open about 4 inches," with corrective action stating that rigging was incorrect and an incorrect attach bracket had been installed; a correct bracket (part number 5462014-1) was installed and the doors were rigged and adjusted. Subsequent discussion with the maintenance technician indicated that the nose gear doors were operated by mechanical sequencing links driven by gear retraction/extension, and that one of these links was the component referred to as the "attach bracket."
Discrepancy number 16 reported a leaking nose gear oleo strut, which was resealed and serviced. Discrepancy number 31 noted a hydraulic leak from the belly, with sources identified as the landing gear actuating valve and the flap actuating valve, both of which were removed and resealed.
After the accident, the airplane was partially hoisted, the nose gear was manually extended and locked, and the airplane was placed in a hangar on its gear. The FAA inspector reported that when electrical power was applied, the three green landing gear lights on the instrument panel illuminated normally. The amber "gear in transit/unsafe" light had a push-to-test feature and illuminated when pressed.
As of January 2011, the pilot stated that the airplane was scheduled for repair but that lack of available replacement parts had prevented maintenance. Consequently, certain investigative activities—including functional checks of the landing gear aural warning system and the retraction/extension system—had not been accomplished. No failure mechanisms or component failures, including the items repaired during the most recent annual inspection, were identified as contributory or causal to the accident sequence.