Guam Hazard Mitigation Plan - Western States Seismic Policy Council

SECTIONFIVERisk AssessmentLocationMarine and air transit locations and routes, through Apra Harbor and GIAA, are shown onFigures D-24 and D-25. As shown on this figure, many residential and commercial land uses arelocated near the airport. An accident where a plane misses a runway could mean a large area ofdamage and devastation in these areas of intensive land use. The GIAA is also located close tothe populated areas of the Agana, Agana Heights, Barrigada, Chalan Pago-Ordot, Mangilao,Mongmong-Toto-Maite, and Tamuning villages. An aircraft crash into any of these areas couldalso have a very large impact.Previous OccurrencesTwo aircraft transportation accidents have occurred on Guam involving large commercialairlines. On August 6, 1997, a Boeing 747 operated by Korean Air, struck Nimitz Hill andcrashed 3 miles short of the GIAA. Of the 254 persons on-board the airplane, only 29 survivedthe accident. The investigation conducted by the National Transportation Safety Board (NTSB)concluded that the probable cause of the accident was “the captain’s failure to adequately briefand execute the nonprecision approach and the first officer’s and flight engineer’s failure toeffectively monitor and cross-check the captain’s execution of the approach. Contributing tothese failures were the captain’s fatigue and Korean Air’s inadequate flight crew training. Also,contributing to the accident was the Federal Aviation Administration’s (FAA’s) intentionalinhibition of the minimum safe altitude warning (MSAW) system at Guam and the agency’sfailure to adequately manage the system.” The combination of this aviation accident and ageneral economic recession in South Korea resulted in an 87 percent decline in the number ofKorean tourists that visited Guam between 1997 and 1998. The available records did notdescribe the effects to the uninhabited area where the plane crashed.On December 17, 2002, a Philippine Airlines Airbus A330 struck the power lines on top ofNimitz Hill. This accident resulted in no injuries or fatalities. Although the investigation by theNTSB was not as thorough as the investigation for the Korean Air accident, the NTSB has statedthat the probable cause of this incident was “the pilot’s initiation of a premature descent that wasboth below the nominal glideslope and steeper than normal. Contributing to the incident was theair traffic controller’s failure to respond to the MSAW warning and issue a safety alert asrequired by FAA order.”No documentation of a marine vessel accident resulting in a blockage of Apra Harbor is readilyavailable. Historical records show several marine vessel accidents during tropical cyclones thathave resulted in large property damage. As discussed in Section 5.3.15 (Tropical Cyclone),tropical cyclones generally have very high winds, high surf, and elevated sea levels, all of whichcan affect marine vessels. During Super Typhoon Karen in 1962, three ships sank, and twotugboats and a huge floating crane were pulled off their moorings and driven ashore. No recordsof the financial losses for these accidents were available. During Tropical Storm Mary in 1974,high winds caused the Caribia, a 40,000-ton passenger liner being towed to Taiwan for salvage,to be cut loose from its tugboat at the entrance to Apra Harbor. As a result, the ship ran agroundon the breakwater of the harbor and sank. This accident resulted in a $3.3 million loss. DuringSuper Typhoon Pamela in 1976, ten ships and tugboats sank or ran aground in Apra Harbor. Norecords of the financial losses for these accidents were available. During Typhoon Russ in 1990,two ships broke from their moorings in Apra Harbor and went aground on the harbor breakwater.No records of the financial losses for this accident were available. Although not directly stated in5-46