Incident Overview
On October 16, 2014, at approximately 1447 local time, Aloha Air Cargo flight 601, a Boeing 737-330 (registration N301KH), experienced a cargo shift shortly after takeoff from Lanai Airport (LNY) in Lanai City, Hawaii. The shift caused substantial damage to the aft pressure bulkhead, rendering the aircraft unable to pressurize. The flight continued to its intended destination and was subsequently towed to a hangar.
Flight Details
The flight operated under 14 Code of Federal Regulations Part 121 as a non-scheduled cargo service from LNY to Daniel K. Inouye International Airport (HNL) in Honolulu, Hawaii. There were no injuries to the two flight crew members and one onboard mechanic. The aircraft was chartered by Hawaii Island Air to transport lumber for an impending hurricane. LNY was not a station regularly served by Aloha Air Cargo, and no company employees were stationed there.
Cargo Loading
A flight mechanic and a load planner were initially scheduled to accompany the flight. However, due to weight and balance concerns on the return trip, dispatch decided that only one additional employee could travel; the load planner was left behind, and the mechanic served as the Additional Crew Member (ACM). This decision was contrary to company guidance.
Flight 600, the inbound leg, departed HNL at 1240 HST and arrived at LNY at 1253 HST. After unloading, empty cargo pallet cookie sheets were loaded for the return flight. These LD7 pallets consisted of a single-skinned pallet with edge rails, corner castings, and a center sheet section. The mechanic, first officer, and Island Air employees assisted in loading and verified that the locks were up and secured in all positions. Eight empty pallet cookie sheets were loaded; seven were strapped to the eighth sheet, which was locked in position 9 (the most aft cargo position, oriented lengthwise). This configuration was per dispatch's request for center of gravity considerations, despite the load planner having previously instructed that each pallet should be returned to its original position.
Incident and Aftermath
Flight 601 departed LNY at 1449 HST and arrived at HNL at 1514 HST. The crew noticed nothing unusual in the aircraft's handling or sounds. During climb, the auto fail light illuminated, and the crew followed the quick reference handbook (QRH). No door lights illuminated, and the outflow valve indicated closed. However, upon reaching 10,000 feet, the altitude alert horn activated, prompting the crew to level off at that altitude. No emergency was declared. The aircraft landed uneventfully. After landing, the flight crew notified dispatch of the pressurization issue and made a logbook entry. A new aircraft was assigned for continued operations. Dispatch notified maintenance.
Damage
Per company procedures, after arrival, Marshaller A performed a post-arrival check and discovered that all pallets were loaded into position 9, none of the locks between positions 8 and 9 were engaged, and the straps had allowed the sheets to shift aft, contacting the aft pressure bulkhead. Examination revealed substantial damage to the aft pressure bulkhead, damage to the left aft (L2) door panel, and detachment/torn right-hand forward and aft pop-up locking mechanism claws from their seat tracks.