On Tuesday, September 29, 1959, exactly 63 years ago today, Braniff Flight 542 disintegrated midair 41 minutes into a flight between Houston and Dallas.The aircraft involved in the incident was an 11-day-old
Lockheed L-188A Electra powered by Allison 501-D13 engines.
The plane with the registration number N9705C was being flown by two pilots and a flight engineer with minimal experience in flying the Electra as they had just completed their transition training.
Braniff Flight 542 was a scheduled domestic flight from Houston to New York
Braniff Flight 542 was a regularly scheduled flight between Houston and New York with stops in Dallas and Washington, D.C. Originally scheduled to depart Houston for Dallas at 22:15 Central Standard Time (CST), the plane left 22 minutes late due to a mechanical issue with the number three generator.
Once the plane was airborne, Houston control handed it over to San Antonio, who the pilots reported to the controller, saying they were flying over the Gulf Coast at an altitude of 9,000 feet. At 22:52, the plane was now flying at 15,000 feet and six minutes later reported that they had just passed the Leona Omnidirectional Navigation Radio (omni).
Then via the Braniff company radio, they said maintenance would be required on the number three generator, believing it had not been sufficiently insulated in Houston. At 23:09, en route to the Trinidad Intersection, the left wing and number one (left outboard) engine separated from the plane. Pieces of the broken wing then struck and dislodged the horizontal stabilizer. The aircraft’s right wing then broke away, causing structural damage to the fuselage and the plane’s breakup.
All 34 passengers and crew died
Those passengers and crew who were not killed during the initial breakup of the plane were either ejected from the aircraft or trapped within it as it fell out of the sky. All 34 passengers and crew died as the wreckage came down in a potato field near Buffalo, Texas.
Civil aviation investigators arrived at the crash site the following day and found the left wing a mile away from the wreckage in the potato field. It was soon evident that the series of events had begun with the left wing, but they could not figure out how it had happened. Engineers at NASA, Boeing, Convair, and the FAA also failed to find out what caused the wing to break off.
Two Lockheed Electra’s belonging to VARIG. Photo: JetPhoto.com
Now dumbfounded as to the cause, the interest in the case stalled for six months until another Electra, this time belonging to North West Orient Airlines, disintegrated in flight near Tell City, Indiana. Following the second crash, CAB Chief Safety Investigator Phillip Goldstein was reported as saying:
“The structure was subjected to forces greater than it was designed for. We have definite evidence of a wing failure. Why this wing failure occurred, I don’t know.”
Again investigators were scratching their heads to come up with an answer and finally concluded that the plane’s wings were too stiff. Vibrations in the wing and harmonic coupling caused increased vibrations until a part of the structure eventually failed.
The conclusion of the investigation
The probability was that the Braniff International Airways Flight 542 accident was caused by the following:
- As far as was known, the plane was flying straight and level at a normal cruise speed with no mechanical problems.
- The plane had structural damage compatible with the oscillatory motion of the number one engine and left wing.
#OTD in 1959: Braniff Flight 542, an L-188 Electra, disintegrated over Texas (US), killing all 34 on board. Cause was initially undetermined, but after a similar later crash, it was established that forces generated by undampened propeller whirl caused structural wing failure. pic.twitter.com/LJq7qv7uOq
— Air Safety #OTD by Francisco Cunha (@OnDisasters) September 28, 2020
All the investigative teams concluded that the probable cause of the accident was the failure of the left-wing due to an undampened propeller.