Investigation Summary
The flight encountered a squall line of severe thunderstorms while cruising at FL200. Although Air Traffic Control advised that other aircraft were deviating to the east, the crew elected to deviate west based on their onboard weather radar. As they descended toward 5,000 feet, they encountered heavy hail and extreme turbulence. Realizing the severity of the conditions, the Captain initiated a steep right-hand 180-degree turn to exit the storm. During this maneuver, the aircraft rolled past 90 degrees and pitched down 40 degrees. In the desperate attempt to pull out of the resulting dive, the crew applied control inputs that generated high load factors. The final structural failure was triggered when the already stressed airframe encountered a massive vertical gust, calculated at approximately 83 knots. This combination of pilot-induced stress and environmental forces caused the right wing to fail at approximately 6,750 feet, leading to a total loss of control and an in-flight fire.
Final Conclusions
The NTSB determined the probable cause was the stressing of the aircraft structure beyond its ultimate strength during an attempted recovery from an unusual attitude induced by thunderstorm turbulence. The investigation highlighted the captain's decision to penetrate an area of known severe weather and the subsequent execution of a high-bank turn in a high-turbulence environment as critical errors.
Video Analysis
Braniff International Airways 352 - [In-flight breakup] — A detailed breakdown of the structural failure and pilot decision-making that led to the mid-air breakup of Braniff Flight 352 over Texas.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain John R. Phillips
Phillips was 46 years old; he had just completed his Electra captain currency check on May 2, 1968, one day before the accident.
First Officer John F. Foster
Flight Engineer James M. Hillix
Systems & Failure Modes
Weather Radar
The crew relied on onboard radar to pick a path through the storm, which proved less effective than the ground-based radar used by ATC.
Airframe Structure
The Lockheed L-188A Electra was designed to withstand significant loads, but the 4.35g pull-up exceeded its ultimate design limits.
Interesting Facts
- 01The aircraft experienced a load factor of 4.35g during the recovery attempt.
- 02The Captain had only returned to the Electra as a captain one day prior to the accident.
- 03All 85 people on board, including Texas State Representative Joseph Lockridge, were killed.
- 04The right wing failed due to upward overstressing.
Safety Actions & Advisories
Thunderstorm Avoidance Training
The accident served as a case study for pilot training regarding the dangers of 'tight' turns in severe turbulence and the limitations of airborne weather radar.