WRECKAGE AND IMPACT INFORMATION
The airplane impacted the top of a light pole about 198 feet above the ground. Pieces of the right wing inboard leading edge were found embedded in the joint that attaches the light fixture to the pole. Numerous pieces of the right wing inboard leading edge, upper and lower right wing skin, and the right main landing gear door were found between the light pole and the initial ground impact mark, which was about 790 feet northeast of the light pole.
The initial portion of the ground impact mark extended about 110 feet along a magnetic heading of 035°. Numerous pieces of the left wing outboard leading edge were found embedded in the ground along the gouge mark. The left wing tip was found near the gouge mark about 50 feet from the initial ground impact mark. The airplane‘s main wreckage, which contained the majority of the airplane‘s forward fuselage and cockpit, was found beyond the ground impact mark. All of the airplane structure, including the fuselage, wings, and empennage, were found along the wreckage path.
Both engines were found separated from the airplane. The engines showed no indications of uncontainment, case rupture, or in-flight fire. The left engine low pressure compressor blades were found in place and bent opposite the direction of rotation. The right engine low pressure compressor blades were found in place and straight, with no circumferential rub marks. Postaccident disassembly of the engines revealed no preexisting defects or malfunctions, and testing of both engines‘ fuel controls showed that they were functioning normally.
MEDICAL AND PATHOLOGICAL INFORMATION
Tissue and fluid specimens from both pilots tested negative for a wide range of drugs, including major drugs of abuse. The captain‘s specimen tested positive for ethanol, but the analysis indicated that the detected ethanol most likely resulted from postmortem formation.
TESTS AND RESEARCH
Flight simulations were conducted to determine whether any GPWS alerts would have been expected during the flight with parameters, such as altitude, airspeed, and glideslope deviation, set to approximate the conditions of the accident flight profile. The simulations showed that the airplane penetrated the descent-below-glideslope alert envelope at an altitude of about 925 feet, by which time, the ILS frequency had been selected by the first officer and the landing gear commanded down. The airplane penetrated the insufficient terrain clearance alert envelope at an altitude of about 255 feet. Therefore, the —glideslope“ and —too low terrain“ alerts, respectively, should have activated. The simulations also showed that the —500“ and —200“ feet aural alerts should have activated.
Postaccident tests using an engineering bench test unit were also conducted to verify whether GPWS alerts would be generated with parameters set to approximate the accident flight profile. The tests showed that, at an altitude about 915 feet, the —glideslope“ alert sounded and repeated. During the tests, the altitude was continually reduced, and the following was noted: about 500 feet, the —500“ foot alert sounded; about 300 feet, the —glideslope“ alert got louder; about 272 feet, the —too low terrain“ alert sounded and repeated; about 244 feet, the —minimums“ alert sounded; and, about 200 feet, the —200“ foot alert sounded.
ORGANIZATIONAL AND MANAGEMENT INFORMATION
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本文鏈接地址：Crash During Approach to Landing Gulfstream G-1159A (G-III),(10)
