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DALLAS - On April 28, 1988, Aloha Airlines (AQ) flight 243 suffered an explosive decompression. The incident would have far-reaching consequences for aviation safety policies and procedures.
During the explosion, the ceiling of the AQ Boeing 737-200 was torn open. The Captain was able to land the damaged jet safely at Kahului Airport (OGG) on Maui with 65 passengers and crew on board. Sadly, there was one fatality, Clarabelle Lansing. The jettisoned Flight Attendant would never be found.
Mayday Chronology
Prior to the flight from Hilo to Honolulu, the Boeing 737-200 aircraft had undergone a normal walkaround pre-flight inspection by the First Officer, who did not find anything unusual. At 13:25, flight 243 departed for the capital that it would never reach on that day.
When the airplane climbed to 24,000 feet, an explosive decompression took place. At that moment, the roof flew off of the aircraft, and the 58-year-old flight attendant, Clarabelle Lansing, who was in row 5, was ejected into the void.
Co-pilot Tompkins was flying the aircraft when the incident occurred; 44-year-old Captain Robert Schornstheimer took over and steered the aircraft to begin an emergency descent to Maui, managing to land the aircraft safely without taking any more lives.
In addition to Lansing's fatality, seven passengers and another FA had serious injuries.
Prior to the day of the incident, the Boeing 737-200 aircraft had accumulated 89,680 flight cycles and 35,496 flight hours. It was later known that just before departure, damage to the aircraft was reported by a passenger who, at that moment, did not mention it to the crew.
The Investigation
The anomaly found by the initial investigation was a longitudinal fuselage crack, which, after checks, turned out to be a fissure in the upper row of rivets along the stringer S-10L lap joint. The approximate location of the failure was found between the cabin door and the jet bridge hood.
The Boeing 737-200 was damaged beyond repair and was dismantled on site. Additional damage to the airplane included damaged and dented horizontal stabilizers, both of which had been struck by flying debris.
Further investigations disclosed that the primary damage was caused by the total separation of the upper crown skin and other fuselage structures. According to videos taken during and after the landing, the failure extended from the small aft of the main cabin to the entrance door aft, running 18 feet.
Due to the findings, the National Transportation Safety Board (NTSB) determined that the failure of the AQ maintenance program to detect the presence of significant disbonding and fatigue damage was the probable cause of the accident.
As fuselage examinations of the aircraft were scheduled during the night, this made it more difficult to carry out an adequate inspection of its outer skin.
Aloha Airlines Maintenance Program
Before the incident, AQ used a maintenance program based on a D-check (heavy maintenance and inspection check) interval of 15,000 flight hours, according to the Federal Aviation Administration (FAA). At the time of the incident, however, Boeing recommended a 20,000 flight-hour interval.
While Boeing's Maintenance Planning Document proposed a D-check a few weeks apart, AQ separated the check into 52 separate work packages. Parts of D-check items were included in the overnight B-checks.
Regarding these procedures, the NTSB stated that this practice was inappropriate to assess the overall condition of an airplane, outlining that "the maintenance and inspection personnel that each airplane would need to have fully operational status to meet the next day's flying schedule."
As AQ had unusually short flights in its schedule, flight cycles doubled the accumulated flight cycle rate that Boeing considered in its maintenance recommendations.
Consequently, the accumulation of flight cycles produced the initiation of fatigue cracks and the following rate of crack growth in the pressurized fuselage structure; as a result, the conclusion was reached that the damage was not caused by the number of flight hours.
https://youtu.be/QBOcTX6-OrE
Legacy of Flight 243 on Aircraft Maintenance
Back in the 80s, these circumstances were not sufficiently regarded during the release of the AQ maintenance program and its approval by the FAA.
The NTSB concluded in its final report on the accident:
"The National Transportation Safety Board determines that the probable cause of this accident was the failure of the Aloha Airlines maintenance program to detect the presence of significant disbonding and fatigue damage, which ultimately led to the failure of the lap joint at S-10L and the separation of the fuselage upper lobe."
"Contributing to the accident were: the failure of Aloha Airlines management to supervise properly its maintenance force; the failure of the FAA to require Airworthiness Directive 87-21-08 inspection of all the lap joints proposed by Boeing Alert Service Bulletin SB 737-53A1039; and the lack of a complete terminating action (neither generated by Boeing nor required by the FAA) after the discovery of early production difficulties in the B-737 cold bond lap joint, which resulted in low bond durability, corrosion, and premature fatigue cracking."
One board member dissented, arguing that the fatigue cracking was clearly the probable cause, but that the airline's maintenance should not be singled out because failures by the FAA, Boeing, and AQ maintenance each were contributing factors to the disaster
The safe landing at Maui established the incident as a significant event in the history of aviation, with far-reaching effects on aviation safety policies and procedures for years to come.
A memorial garden was opened in 1995 to honor Lansing at Honolulu International Airport (HNL).
Featured image: Accident aircraft photo taken in 1973. Photo: By Charles O'Rear, 1941-, Photographer (NARA record: 3403717)This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Colors adjusted. - U.S. National Archives and Records Administration, Public Domain
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