Investigation Summary
The aircraft, nicknamed the Flying Pig due to its bulky fuselage, was the last of the Vickers Vulcans still in operation. G-EBLB (MSN 9, built in 1925) was the final of nine Type 74 variants built. On the day of the accident, Captain John Spafford was tasked with testing a newly installed engine. Although it was a technical test flight, Imperial Airways staff were permitted to join for air experience. The occupants included the pilot, an Air Ministry inspector (who survived), and four airline employees: Emily Joan Benjafield, William Edward Quinnell Halstead, Andrew Hall, and Phyllis Amelia Smith. After reaching approximately 700 to 800 feet, Spafford noticed the aircraft began to sink despite maintaining a nose-down attitude to preserve airspeed. He increased the throttle, but the engine failed to respond effectively. The water temperature surged past 100 degrees Celsius, and steam began escaping from the left-hand engine cowling. Faced with a densely populated area of trees and houses, Spafford identified a market garden as the only viable landing site. The aircraft impacted the ground at a 45-degree angle. Spafford was initially trapped by his foot but managed to free himself just as the engine caught fire. He was able to rescue the inspector, but the intensity of the fire prevented further rescue efforts. An inquest later revealed that while one passenger died from the impact, the others were likely unconscious when the fire consumed the cabin.
Final Conclusions
The inquest concluded with a verdict of accidental death. The primary technical factor was the failure of the newly installed engine, evidenced by overheating and a critical loss of power during the initial climb. The coroner and the jury strongly criticized the airline's policy of allowing non-essential personnel on test flights, leading to a formal recommendation that the practice be discontinued.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Engine Cooling System
The engine water temperature rose above 100 degrees Celsius, resulting in steam escaping the cowling and a subsequent total loss of power.
Vickers Vulcan Airframe
A single-engine biplane designed for eight passengers; it was noted for being underpowered and having a corpulent fuselage design.
Interesting Facts
- 01The Vickers Vulcan G-EBLB was the last of its type still in operation at the time of the crash.
- 02The aircraft was nicknamed 'The Flying Pig' by locals due to its unusual appearance.
- 03The engine had been replaced just one day prior to the accident flight.
- 04The four fatalities were Imperial Airways employees: Emily Joan Benjafield (18), William Edward Quinnell Halstead (44), Andrew Hall (39), and Phyllis Amelia Smith (19).
- 05The pilot survived the crash after being ejected or clambering clear of the open cockpit.
- 06The aircraft was Manufacturer Serial Number (MSN) 9 and was manufactured in 1925.
Safety Actions & Advisories
Prohibition of Passengers on Test Flights
Following the coroner's recommendation, Imperial Airways agreed to discontinue the practice of allowing employees or other non-essential passengers to fly on technical engine test flights.