Aloha Flight 243 - Air Disaster
History of the Flight
On April 28, 1988, an Aloha Airlines Boeing 737, N73711, based at the Honolulu International Airport, Hawaii, was scheduled for a series of Interisland flights to be conducted under Title 14 Code of Federal Regulations (CFR) Part 121. A captain and first officer were assigned for the first six flights of the day with a planned first officer change to complete the remainder of the daily schedule.
The first officer checked in with the dispatch office about 0500 Hawaiian standard time at the Aloha Airlines Operations Facility. After familiarizing himself with the flight operations paperwork, he proceeded to the Aloha Airlines parking apron and performed the preflight inspection required by company procedures before the first flight of the day. He stated that the airplane maintenance log release was signed and that there were no open discrepancies. He prepared the cockpit for the external portion of the preflight, exited the airplane In predawn darkness, and performed the visual exterior inspection on the lighted apron. He stated that he found nothing unusual and was satisfied that the airplane was ready for flight.
The captain checked in for duty about 0510; he completed his predeparture duties in the dispatch office and then proceeded to the airplane.
The crew flew three roundtrip flights, one each from Honolulu to Hilo, Maui, and Kaual. They reported that all six flights were uneventful and that all airplane systems performed in the normal and expected manner. Flightcrew visual exterior inspections between flights were not required by Federal Aviation Administration (FAA) accepted company procedures, and none were performed.
At 1100, a scheduled first officer change took place for the remainder of the day. The crew flew from Honolulu to Maui and then from Maui to Hilo. As with the previous flights of the day, no system, powerplant, or structural abnormalities were noted during these operations, and the flights were uneventful. Neither pilot left the airplane on arrival in Hilo, and the crew did not perform any visual exterior inspection nor were they required to do so.
At 1325, flight 243 departed Hilo Airport en route to Honolulu as part of the normal scheduled service. In addition to the two pilots, there were three flight attendants, an FAA air traffic controller, who was seated in the observer seat in the cockpit, and 89 passengers on board. Passenger boarding, engine start, taxi, and takeoff were uneventful.
The planned routing for Aloha flight 243 was from Hilo to Honolulu at flight level 240. Maui was listed as the alternate landing airport.
The first officer conducted the takeoff and en route climb from Hilo. The captain performed the nonflying pilot duties. The first officer did not recall using the autopilot.
The flight was conducted in visual meteorological conditions. There were no advisories for significant meteorological information (SIGMET) or airman's meteorological information (AIRMET) valid for the area along the planned route of flight.
No unusual occurrences were noted by either crewmember during the departure and climbout. As the airplane leveled at 24,000 feet, both pilots heard a loud "clap" or "whooshing" sound followed by a wind noise behind them. The first officer's head was jerked backward, and she stated that debris, including pieces of gray insulation, was floating in the cockpit. The captain observed that the cockpit entry door was missing and that there was blue sky where the first-class ceiling had been. The captain immediately took over the controls of the airplane. He described the airplane attitude as rolling slightly left and right and that the flight controls felt "loose."
Because of the decompression, both pilots and the air traffic controller in the observer seat donned their oxygen masks. The captain began an emergency descent. He stated that he extended the speed brakes and descended at an indicated airspeed (IAS) of 280 to 290 knots. Because of ambient noise, the pilots initially used hand signals to communicate. The first officer stated that she observed a rate of descent of 4,100 feet per minute at some point during the emergency descent. The captain also stated that he actuated the passenger oxygen switch. The passenger oxygen manual tee handle was not actuated.
When the decompression occurred, all the passengers were seated and the seat belt sign was illuminated. The No. 1 flight attendant reportedly was standing at seat row 5. According to passenger observations, the flight attendant was immediately swept out of the cabin through a hole in the left side of the fuselage. The No. 2 flight attendant, standing by row 15/16, was thrown to the floor and sustained minor bruises. She was subsequently able to crawl up and down the aisle to render assistance and calm the passengers. The No. 3 flight attendant, standing at row 2, was struck in the head by debris and thrown to the floor. She suffered serious injuries including a concussion and severe head lacerations.
The first officer said she tuned the transponder to emergency code 7700 and attempted to notify Honolulu Air Route Traffic Control Center (ARTCC) that the flight was diverting to Maui. Because of the cockpit noise level, she could not hear any radio transmissions, and she was not sure if the Honolulu ARTCC heard the communication.
Although Honolulu ARTCC did not receive the first officer's initial communication, the controller working flight 243 observed an emergency code 7700 transponder return about 23 nautical miles (nmi) south-southeast of the Kahului Airport, Maui. Starting at 1348:15, the controller attempted to communicate with the flight several times without success.
When the airplane descended through 14,000 feet, the first officer switched the radio to the Maui Tower frequency. At 1348:35, she informed the tower of the rapid decompression, declared an emergency, and stated the need for emergency equipment. Maui Tower acknowledged and began emergency notifications based on the first officer's report of decompression.
At the local controller's direction, the specialist working the Maui Tower clearance delivery position notified the airport's rescue and firefighting personnel, via the direct hot line, that a B-737 had declared an emergency, was inbound and that the nature of the emergency was a decompression. Rescue vehicles took up alert positions along the left side of the runway.
At the Maui Airport, ambulance service was available from the nearby community when notified by control tower personnel through the local "911" telephone number. Tower personnel did not consider it necessary at that time to call for an ambulance based on their understanding of the nature of the emergency.
The local controller instructed flight 243 to change to the Maui Sector transponder code to identify the flight and indicate to surrounding air traffic control (ATC) facilities that the flight was being handled by the Maui ATC facility. The first officer changed the transponder as requested.
The flight was operating beyond the local controller's area of radar authority of about 13 nmi. At 1350:58, the local controller requested the flight to switch to 119.5 MHz. (approach frequency) so that the approach controller could monitor the flight. Although the request was acknowledged, the flight was not heard on 119.5 MHz. Flight 243 continued to transmit on the local controller frequency.
At 1353:44, the first officer informed the local controller, "We're going to need assistance. We cannot communicate with the flight attendants. We'll need assistance for the passengers when we land." An ambulance request was not initiated as a result of this radio call. The first officer also provided the local controller with the flight's passenger count, but she did not indicate the fuel load. The local controller did not repeat the request for the fuel load even after a query from the chief of the emergency response team.
The captain stated that he began slowing the airplane as the flight approached 10,000 feet mean sea level (msl). This maneuver is required as a routine operations practice to comply with ATC speed limitations. He retracted the speed brakes, removed his oxygen mask, and began a gradual turn toward Maul's runway 02. At 210 knots IAS, the flightcrew could communicate verbally. The captain gave the command to lower the flaps. Initially flaps 1 were selected, then flaps 5. When attempting to extend beyond flaps 5, the airplane became less controllable, and the captain decided to return to flaps 5 for the landing.
Because the captain found the airplane becoming less controllable below 170 knots IAS, he elected to use 170 knots IAS for the approach and landing.
Using the public address (PA) system and on-board interphone, the first officer attempted to communicate with the flight attendants; however, there was no response.
At the command of the captain, the first officer lowered the landing gear at the normal point in the approach pattern. The main gear indicated down and locked; however, the nose gear position indicator light did not illuminate. Manual nose gear extension was selected and still the green indicator light did not illuminate; however, the red landing gear unsafe indicator light was not illuminated. After another manual attempt, the handle was placed down to complete the manual gear extension procedure. The captain said no attempt was made to use the nose gear downlock viewer because the center jumpseat was occupied and the captain believed it was urgent to land the airplane immediately.
At 1355:05, the first officer advised the tower, "We won't have a nose gear," and at 1356:14, the crew advised the tower, "We'll need all the equipment you've got."
While advancing the power levers to maneuver for the approach, the captain sensed a yawing motion and determined that the No. 1 (left) engine had failed. At 170 to 200 knots lAS, he placed the No. 1 engine start switch to the "flight" position in an attempt to start the engine; there was no response.
A normal descent profile was established 4 miles out on the final approach. The captain said that the airplane was "shaking a little, rocking slightly and felt springy."
Flight 243 landed on runway 02 at Maui's Kahului Airport at 1358:45. The captain said that he was able to make a normal touchdown and landing rollout. He used the No. 2 engine thrust reverser and brakes to stop the airplane. During the latter part of the rollout, the flaps were extended to 40 degrees as required for an evacuation. An emergency evacuation was then accomplished on the runway.
After the accident, a passenger stated that as she was boarding the airplane through the jet bridge at Hilo, she observed a longitudinal fuselage crack. The crack was in the upper row of rivets along the S-10L lap joint, about halfway between the cabin door and the edge of the jet bridge hood. She made no mention of the observation to the airline ground personnel or flight crew.
*Lost in flight; a sea search was unsuccessful.
**Air traffic controller seated in the observer seat in the cockpit.
Damage to Airplane
A major portion of the upper crown skin and structure of section 43 separated in flight causing an explosive decompression of the cabin. The damaged area extended from slightly aft of the main cabin entrance door, rear ward about 18 feet to the area just forward of the wings and from the left side of the cabin at the floor level to the right side window level.
The value of the airplane was estimated at about $5 million. As a result of the accident, the airplane was determined to be damaged beyond repair. It was dismantled on the site and sold for parts and scrap.
Excerpted from NTSB Accident Report
[Photos of Aloha Flight 243]
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