“We Are Gliding in IMC”: The Final Minutes of N5626D
A Beech Bonanza lost all engine power near Norwood, Massachusetts, leaving the pilot to attempt an emergency landing through low cloud.
Accident Facts
- Incident date
- June 28, 2015
- Registration
- N5626D
- Aircraft
- Beech A36 Bonanza
- Location
- Plainville, Massachusetts
- Operation
- Part 91 personal flight
- Category
- Fatal crash — total loss of engine power
- NTSB probable cause
- The total loss of engine power due to the failure of the alternator drive coupling
- NTSB report
- ERA15FA254
- Reconstruction
- ATC audio reconstruction
The Flight Toward Norwood
The Beech A36 departed Lancaster at about 16:12 with Norwood as the destination. The flight was IFR, and the weather near the accident site was instrument conditions. At 17:35, an observation about eight miles southwest reported an overcast ceiling at 800 ft with nine miles visibility.
The Final Radio Calls
The pilot then reported a severe vibration and that they were losing the engine. ATC told him about a highway approximately 2.5 miles away. The pilot replied that they had no engine, were in IMC and needed help. The controller provided vectors toward the highway, which the pilot acknowledged. Soon afterward he said, “we're gliding.”
What Failed Inside the Engine
The NTSB found that the alternator drive coupling had failed. Debris from the failed coupling damaged other engine components and ultimately resulted in catastrophic engine failure because of loss of oil lubrication. The investigation identified two possible conditions that could lead to coupling failure, including out-of-tolerance components and improper assembly or torque procedures. It could not determine which condition was responsible in this case.
The Final Radar Track
The last radar return showed the aircraft in a right turn at about 700 ft and 66 knots, only about 0.1 mile from the accident site. The airplane impacted the corner of a residence and backyard deck and was consumed by a post-crash fire. Three people aboard were killed; the residents of the house escaped without fatal injury.
Conclusion
N5626D reached the emergency phase close to its destination, but the engine failure occurred in weather that severely limited the pilot's ability to see or select a landing area. The investigation established the mechanical failure inside the engine and separately established how the low cloud ceiling reduced the available emergency options.
Primary Source / Investigation Record
Investigation reference: ERA15FA254