Investigation Summary
The aircraft, named 'Star of Severn', was climbing through 11,000 feet in turbulent weather when it disintegrated. The Italian Board of Inquiry focused on the fuel system, specifically the vent outlets of the reserve tanks. They determined that a lightning strike likely created a 'streamer corona' (static discharge) at the vent outlets. This discharge ignited gasoline vapors being expelled from the vents due to the climb and atmospheric conditions. The resulting flame front traveled back through the vent pipes into tank number 7, causing an initial explosion that immediately triggered a secondary explosion in tank number 6, leading to the total structural failure of the wing.
Final Conclusions
The breaking-up in flight was due to the explosion of fuel vapors in tank number 7, followed by an explosion in tank number 6. The ignition was caused by static electricity discharges (streamer corona) at the vent outlets, set off by the stormy weather and frequent electric discharges in the area.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Paul S. Grade
Co-pilot
Harry L. Stanton
First Officer
Frank W. Ellis
Flight Engineer
John V. Powell
Flight Engineer
Donald Leuke
Systems & Failure Modes
Fuel Tank Vent System
The pipes designed to equalize pressure in the fuel tanks allowed lightning-induced sparks to ignite exiting vapors.
Reserve Fuel Tanks
Tanks 6 and 7 were the primary sites of the internal explosions that destroyed the wing structure.
Interesting Facts
- 01The accident was the first fatal crash involving the Lockheed L-1649 Starliner.
- 02It was the deadliest aviation accident of 1959.
- 03The aircraft had flown only 71 hours since its last upkeep and line inspection.
- 04The investigation was conducted by an Italian Board of Inquiry with a U.S. CAB representative.
- 05The aircraft was carrying 59 passengers and 9 crew members.
Safety Actions & Advisories
Fuel Vent Flame Arrestors
The investigation recommended the installation of flame arrestors in fuel vent systems to prevent external ignition sources, such as lightning-induced streamer coronas, from reaching and igniting fuel vapors within the tanks.