Investigation Summary
The flight was originally scheduled as a Boeing 707 jet service (Flight 601), but a cracked windshield forced the airline to substitute two propeller aircraft. Flight 2511 was the second of these substitutes. After a routine progress report at 02:31 EST, a dynamite explosion occurred in the passenger cabin. The blast originated near seat row 7 on the right side, causing a portion of the fuselage to fail and strike the number 3 propeller. The aircraft entered a wide, descending right-hand turn before breaking apart. Debris was found at Kure Beach and Snow's Marsh, miles away from the main wreckage site near Bolivia, North Carolina. Forensic analysis revealed sodium carbonate, sodium nitrate, and complex sulfur compounds, confirming the use of dynamite. Notably, several passengers were found wearing life jackets, leading investigators to consider theories that the cabin remained somewhat controlled for a period after the initial blast, allowing time for emergency preparations before the final in-flight disintegration.
Final Conclusions
The Civil Aeronautics Board concluded that the probable cause was the detonation of dynamite within the passenger cabin. The board referred the criminal aspects of the case to the Department of Justice and the FBI. Although the investigation highlighted passenger Julian Frank, who had recently purchased nearly $900,000 in life insurance and was under investigation for fraud, the FBI never officially named a perpetrator or filed charges.
Photographic Evidence (1)
Video Analysis
Memorial honors victims of unsolved 1960 plane crash — A memorial at the Bolivia Fire Department recognizes the 34 people killed when National Airlines Flight 2511 exploded over North Carolina.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Systems & Failure Modes
Fuselage Structure
The dynamite blast severely impaired the structural integrity, leading to in-flight disintegration.
Propeller No. 3
A portion of the fuselage that broke away during the explosion struck this propeller.
Interesting Facts
- 01The aircraft was a substitute for a Boeing 707 that was grounded due to a cracked cockpit windshield.
- 02Investigators recovered approximately 90% of the fuselage and reassembled it on a wood and chicken-wire frame.
- 03The explosive device was determined to have been powered by dry cell batteries.
- 04One victim, Julian Frank, had purchased nearly $900,000 in life insurance in the six months prior to the crash.
- 05Vice Admiral Edward Orrick McDonnell, a Medal of Honor recipient, was among the fatalities.
Safety Actions & Advisories
Criminal Referral
The Civil Aeronautics Board referred the case to the Department of Justice and the FBI for criminal investigation after determining the cause was a deliberate explosion.
Security Surveillance Enhancement
Following this and other early 1960s bombings, the FAA increased surveillance of airport terminals and encouraged the development of technology to detect explosives in checked and carry-on luggage.
Known Controversies & Unanswered Questions
Unsolved Perpetrator Identity
Reference ↗While Julian Frank is widely suspected of a suicide bombing due to his financial troubles and proximity to the blast, the FBI never officially closed the case or named him as the perpetrator.