Aircraft Mishap Timeline

1. AIRCRAFT MISHAP TIMELINE

On 28 April 1988, Aloha Airlines Flight 243, a Boeing 747 based out of Honolulu International Airport, Hawaii, began operations on what was scheduled for six inter-island flights. The First Officer checked in with Aloha Airlines Flight Operations about 5:00am followed by the Captain shortly after. The aircraft log was signed off and released for flight with no open write-ups. They both completed pre-departure duties and proceeded to the aircraft. All pre-flight preparations were performed in the crew compartment and a visual external aircraft inspection was performed. The first officer was pleased with the aircraft after the walk-around and deemed it "Ready for flight".

The aircrew flew three round trip flights from Honolulu to Hilo, Maui, and Kauai. After each of these flights the aircrew reported that all aircraft systems were performing normal and that the flights were uneventful. During each of the stops no visual exterior inspections were performed. Visual exterior inspections were not required by the Federal Aviation Administration (FAA) standard Aloha Airlines company policies.

At 11:00am scheduled aircrew changes were performed for the remainder for the flights that day. This aircrew flew two legs from Honolulu to Maui, then from Maui to Hilo. All systems performed as advertised. The aircrew did not perform exterior visual inspection between these flights nor were they required as stated previously.

At approximately 1:25pm Aloha Airlines flight 243 began its journey from Hilo airport to Honolulu International Airport. Three cabin crewmembers and eighty-nine passengers were aboard the aircraft. Flight 234 reached its cruising altitude about twenty minutes into the flight. After the aircraft leveled off, there was a loud "clap and whooshing" sound followed by screaming and debris flying through the cockpit and cabin. The Captain immediately took the controls of the aircraft. All three flight crew members including the air traffic controller, put on their oxygen masks. As the aircrew looked back they could see that the cockpit door missing and they could see blue sky through the hole in the aircraft.

The aircraft was to some extent unstable and was responding to flight control inputs. Captain immediately began a rapid emergency descent towards Kahului airport on the island of Maui. The First Officer began calling Air Traffic Control (ATC) to report the flight divert and the state of emergency. The First Officer could not hear an ATC reply due to the high noise of air blowing through the crew compartment and cabin. On approach, the First Officer swapped over to the tower radio frequency and made contact with ATC.

The tower dispatched the emergency response to the runway. The aircraft continued to approach the airport at an appropriate and safe speed although the flight controls felt sluggish. The aircrew stated that the controls felt "loose" with the aircraft rolling left and right. The gear was selected down and the main gear down position light illuminated. The nose gear light did not illuminate. A manual extension of the nose gear was performed but the gear light did not illuminate. The gear unsafe light did not extinguish. Due to these indications the aircrew was given the impression that they would be landing without the nose gear. The tower then called and informed the Flight 243 aircrew that all of the landing gear was in the down position.

The Captain advanced the throttles to keep up the speed on final but he found that the #1 engine had failed. He attempted an engine restart but it was a "No-Go". The aircraft landed with one engine running on the runway and coasted to a stop. The aircrew and the passengers performed emergency egress of the aircraft. It was discovered the head flight attendant was missing. One confirmed fatality and 65 people injured.

2. FINDINGS

Due to the fact that the aircraft was safely landed it and the majority of it was still in tact, the NTSB was able to perform extensive research on the findings as to what caused the in-flight breakup. A total of 26 findings were discovered that led up to this mishap.

It was determined that weather was not a factor. The maintenance and quality inspection programs for Aloha Airlines were considered deficient. The flight crew was certificated and fully qualified with no flight restrictions.

According to the aircraft log, the Aloha Airlines Boeing 737 involved in this mishap was airworthy with no evidence of preexisting failures or malfunctions on all major flight systems. The Boeing 737 was 19 years old, and was with Aloha Airline since 1969. The aircraft had completed 89,680 flight cycles, which was second highest number in the entire of 737 aircraft worldwide.

Aloha Flight 243 suffered an explosive compression, tearing off a section of the forward fuselage. The leading edges of both wings and tail fins were dented from debris. The engine cowls and first stage fan blades showed foreign object damage caused by debris from the structural damage. Debris was lodged in the leading edge of the wing near the engine pylon. This prevented the slat from extending, causing the control problems when the crew tried to configure the aircraft for landing. Broken engine control cables, which ran through the damaged fuselage area, caused the loss of the engine.

The flight crew did not take in account the structural damage to the aircraft when they performed the emergency descent procedures. The aircrew knew there was structural damage when they looked back and noticed the section of the aircraft missing. If structural damage is in question a limited airspeed should be used as much as possible and high maneuvering turns should be circumvented.

The in flight breakup and fuselage failure originated in the lap joint near the S-10 rib area. Rivets were cracked allowing the "fail safe" tear strap to disbond and rip apart. This structural area as well as others on the skin of the 737, were cracking due to manufacturer defects during surface prep and bonding procedures. The lap joint disbonding and its lack of "environmental durability" were deemed the cause as to what happened.

Why did it happen? More findings concluded that Aloha Airlines neglected to adhere to Boeing Service Bulletin 737-53-1039 concerning lap joint disbonds and inspections required on the lap joint areas of the aircraft. Improper eddy current inspections were performed on the aircraft during its