Flight History
On November 20, 2013, at 1030 eastern standard time, a Beech C90A, registration N702DK, operated by Dominion Aviation Services Incorporated, departed Chesterfield County Airport (FCI) in Richmond, Virginia, on an IFR flight plan under 14 CFR Part 135. The flight was destined for Montgomery Executive Airport (BCB) in Blacksburg, Virginia. While on the downwind leg for runway 12 at BCB, the landing gear was lowered. The pilot noticed that the right main landing gear did not indicate down and locked; the annunciator panel showed the nose and left main gear in position, but the right main gear green light was not illuminated. The crew tested the light and found it functional. They cycled the gear handle with no change in indication and aborted the landing.
Attempts to extend the right main gear manually were unsuccessful. The pilot decided to divert to Roanoke Regional Airport (ROA) due to its longer runways. After performing the manual gear extension checklist, the flight crew conducted a low pass over runway 24 at ROA. The air traffic controller in the tower advised that the landing gear appeared to be down. The pilot then landed without flaps, shut down the right engine, and feathered the propeller to minimize damage if the gear collapsed. The touchdown was normal, but as the airplane exited the runway, the right main landing gear collapsed, causing substantial damage.
Crew Information
The pilot held an airline transport pilot certificate with multi-engine land and single-engine commercial privileges, type ratings for the CA-212 and DHC-6, and flight instructor ratings. He had 2,520 total flight hours, with 210 in the accident make and model. His most recent FAA first-class medical was issued on January 16, 2012.
The copilot held an airline transport pilot certificate with multi-engine land and single-engine commercial privileges, a type rating for the RA-390S, and flight instructor ratings. He had 4,783 total flight hours, with 2,664 in the accident make and model. His most recent FAA first-class medical was issued on August 20, 2012.
Aircraft Information
The accident airplane was a 1990 Beech C90A, a 6-seat, low-wing, pressurized twin-engine aircraft with retractable landing gear. It was powered by two Pratt & Whitney PT6-21 turboprop engines, each producing 550 shaft horsepower. The airplane had accrued approximately 5,086 total hours at the time of the accident. The most recent Approved Aircraft Inspection Program inspection was completed on March 29, 2012.
Meteorological Conditions
At 1054, weather at Roanoke Regional Airport recorded winds calm, visibility 10 miles, few clouds at 11,000 feet, temperature 8°C, dew point 3°C, and an altimeter setting of 30.17 inches of mercury.
Wreckage Examination
Examination revealed that the right main landing gear (MLG) collapse punctured the right nacelle fuel tank. Substantial damage was found to the right wing, right nacelle, and right wheel well. The right MLG Bearing Actuator Support Bracket was broken and separated from its mounting. Multiple cracks were visible, including a saw-tooth crack along the fasteners, and discoloration on the mounting surfaces. Optical and scanning electron microscope examination indicated abrasion and an overload region with a cloudy appearance.
Maintenance Records
On the day before the accident, the right main landing gear actuator was replaced due to a leak with an overhauled unit. Rigging, operational checks, and leak tests were performed, and the system was exercised to purge air. No leaks were detected, and the airplane was returned to service. Postaccident testing of the replaced actuator showed it performed per manufacturer specifications with no evidence of binding or preimpact failure. However, the aircraft had not incorporated Mandatory Service Bulletin (MSB) 32-3345, issued in December 2003, which required replacement of aluminum MLG actuator support brackets with steel brackets. The MSB was prompted by a similar incident on September 18, 2003, involving a Beech C90A (N200TR) that experienced a right main landing gear collapse after a low pass and landing at Piedmont Triad International Airport.
Service Bulletin and Safety Actions
Following reports of cracks in MLG bearing actuator support brackets, the manufacturer issued MSB 32-3345 to replace aluminum brackets with steel brackets for both main landing gears, specifying compliance as soon as possible but no later than the next inspection, 200 flight hours, or 24 months. At the time of the report, of 393 affected C90As, 305 had received steel brackets. In July 2014, Textron Aviation released Beechcraft King Air Series Communique 2014-01 to emphasize compliance. Dominion Aviation Services advised in August 2014 that they had reviewed all MSBs on their aircraft and would incorporate such reviews into their operations manual.