Incident Details
On April 10, 2011, at approximately 1145 eastern daylight time, a Beech Model 99, registered as N899AE, sustained substantial damage during landing at Polk County Airport (4A4) in Cedartown, Georgia. The aircraft was operated by Skydive Georgia under Part 91 of the Federal Aviation Regulations as a local sport-parachuting flight that had departed 4A4 about 1110. Visual meteorological conditions prevailed, and no flight plan was filed.
The pilot, returning to the airport after deploying parachutists, configured the airplane for landing. When he lowered the landing gear, only two of the three landing gear indicator lamps illuminated, indicating an unsafe condition with the left main landing gear. After activating the test switch, all three lamps illuminated, confirming the indicator lamps were functional. The pilot then retracted the gear and attempted to lower it again, but no lamps illuminated on this attempt. He subsequently lowered the gear manually, again receiving an unsafe left main gear indication. During the manual extension, the pressure required to pump the gear down increased until "something gave way."
The pilot completed the landing on the nose and right main landing gear, resulting in substantial damage to the left wing and fuselage.
Aircraft and Pilot Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine, multiengine, and instrument airplane, along with a flight instructor certificate with similar ratings. His most recent second-class medical certificate was issued on March 16, 2011. He reported 6,800 total flight hours, with 8 hours in the accident airplane make and model.
The aircraft, manufactured in 1968, had accrued 48,953 total flight hours. The most recent 100-hour inspection was completed on February 14, 2011, at 48,945 total aircraft hours.
Post-Accident Examination
Examination of the airplane by an FAA inspector revealed that the left main landing gear actuator showed evidence of wear or failure where the drive entered the actuator housing. The floor access panel to the landing gear motor was removed, the manual landing gear extend feature was found engaged, and the circuit breaker for the motor was in the "popped" position.
A further supervised examination of the left landing gear actuator on June 21, 2011, was conducted. The actuator had been overhauled and installed on August 31, 2008, at 48,575 aircraft hours and 66,518 cycles. Since overhaul, it had accumulated 377.5 hours and 285 cycles. Examination revealed that the actuator bearing supports lacked lubrication, and the bearings showed wear due to inadequate lubrication.
Due to the elapsed calendar months, aircraft hours, and cycles since installation, it could not be determined whether the lubrication was inadequate at installation or if subsequent inspections failed to detect the loss of grease. The Hawker-Beechcraft Model 99 Series Maintenance Manual prescribed repetitive lubrication of the retract actuator and actuator support bearings at intervals of 1,000 cycles or 30 months, whichever occurred first. Additionally, a caution in the manual advised against washing grease away from lubricated areas and recommended lubrication after washing wheel well areas with solvent to prevent premature wear.