Investigation Summary
The aircraft, named 'City of Ottawa', was cruising at approximately 2,500 feet when the starboard engine failed approximately 15 miles out over the English Channel. The pilot, Captain Rudolf Brailli, broadcast a mayday and attempted to divert to Lympne Airport. However, the Handley Page W.10 was unable to maintain level flight on a single engine under its current load. As the aircraft descended toward the sea, Brailli executed a ditching approximately 12 miles offshore and 50 yards from the Belgian trawler Gaby. Upon contact with the water, the aircraft's nose submerged abruptly. This sudden deceleration threw forward-seated passengers from their seats, trapping them as the cabin flooded. The four passengers seated in the tail section and both crew members managed to escape the airframe and were picked up by the Gaby. The wreckage was later towed to Dungeness for inspection.
Final Conclusions
The Air Ministry investigation, led by Sir Arthur Colefax, concluded that the primary cause was the fatigue fracture of the big end bearing studs on the No. 4 connecting rod of the starboard engine. This failure caused the connecting rod to break, resulting in total power loss from that engine. The investigation noted that the engine had run for 126 hours since its last overhaul, well within the 300-hour permitted interval. The inquiry cleared both Imperial Airways and the engine manufacturer, Napier, of negligence, but the accident highlighted the danger of operating multi-engine aircraft that lacked the performance to maintain altitude following a single-engine failure.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Rudolf Paul David Brailli
Systems & Failure Modes
Napier Lion Engine
A 12-cylinder 'broad arrow' configuration engine. The failure of big end bearing studs in the No. 4 connecting rod led to the catastrophic failure of the starboard engine.
Wireless Radio
The crew successfully used the onboard radio to broadcast a mayday signal, which was received by coastal stations.
Interesting Facts
- 01The aircraft was a Handley Page W.10, a twin-engine biplane airliner.
- 02The starboard engine was a Napier Lion that had completed 126 hours since its last overhaul.
- 03The aircraft was loaded at 2,494 pounds, which was below its maximum permissible load of 2,946 pounds.
- 04The pilot, Captain Brailli, had 1,000 hours of flying experience.
- 05The investigation found that the W.10 could not maintain level flight on a single engine.
- 06Seven passengers died, all from drowning, while both crew members and four passengers survived.
Safety Actions & Advisories
Passenger Safety Equipment
The investigation recommended that all passengers should be provided with seatbelts.
Route Restrictions
The inquiry recommended that aircraft unable to maintain level flight with one engine inoperative and not designed for water landings be withdrawn from continental routes after July 1, 1930.
Location
APPROXIMATE POSITION · AIRPORT LEVEL · Coordinates are the estimate published in the wikipedia geotag. The ring shows the accuracy the record supports, not the point of impact.