19980113000289A

Acft lost radio and radar contact on 2 mile final to rwy 26 and crashed und unk circ. Houston, TX. (.19) on January 13, 1998, at 0810 central standard time, a gates Lear jet 25B, N627WS, registered to first star, inc., of wilmington, Delaware, and operated by American corporate aviation, inc., of Houston, Texas collided with terrain during an ILS approach to runway 26 at george bush Intercontinental airport (iah) Houston, Texas. The airplane was destroyed by impact damage and post-crash fire. The two occupants the airline transport rated captain and the commercial rated first officer, were fatally injured. The title 14 CFR part 91 positioning flight departed from Houston's hobby airport (hou) at 0745 for the flight to fargo, north dakota. Instrument meteorological conditions prevailed and an IFR flight plan was filed. According to FAA air traffic control personnel, the flight departed from hou at 0745 and was provided radar vectors by approach control for the ILS 26 approach at iah. At 0755, the first officer declared a missed approach, and at 0756, in response to a question from the controller as to whether there was a problem with the airplane, she replied "just the compass we're working on it." At 0800, the first officer requested a second approach to iah, and the flight was again given radar vectors to the ILS 26 approach. At 0806, the flight was cleared for the approach by the approach controller, and at 0808, the flight was cleared to land by the local (tower) controller. At 0810, radio and radar contact with the airplane were lost. A search was begun and the wreckage was located by a us coast guard helicopter at 1040 in a heavily wooded area approx. 2 nautical miles from the threshold of runway 26. Examination of the accident site revealed that wreckage was scattered along a linear path on a measured magnetic heading of approx. 263 degrees. The airplane's first contact with the 75 to 80 foot tall trees was evidenced by 1/2INCH diameter fresh cut pine branches lying on the ground. Both outboard main gear doors were found approx. 350 feet from initial tree contact with the left door 24 feet left and the right door 36 feet right of the centerline of the wreckage path and 840 feet from initial tree contact. Flight control continuity could not be established due to the extent of fragmentation of the airplane; however all flight controls were accounted for along the wreckage path. The fuselage with the vertical stabilizer attached came to rest about 1000 feet from initial tree contact and was 90% consumed by post-crash fire. All the cockpit instruments, gauges, circuit breakers and flight controls were destroyed by fire. The airplane was equipped with a cockpit voice recorder (CVR) which was found approx. 20 feet to the left of the cockpit. The CVR has been forwarded to NTSB headquarters in Washington, DC, for readout. The right engine was located near the centerline of the wreckage path about 890 feet from initial tree contact. The outboard two-thirds of each stage 1 compressor rotor blade was bent approx. 45 to 60 degrees opposite the direction of rotation. Upon removal of the left combustor borescope cover, compressed wood particles were found adhering to the forward facing steps along the aft edges of the port. The left engine was located approx. 6 feet forward and to the right of the cockpit. The tips of the stage 1 compressor rotor blades exhibited leading edge tip curling and tearing opposite the direction of rotation. Upon removal of both combustor borescope covers, compressed wood particles were found adhering to the forward facing steps along the aft edges of the ports. (.4)the flight crew was positioning the airplane in preparation for a revenue flight when it crashed 2 nautical miles (NM) short of the runway during a second instrument landing system approach in instrument meteorological conditions. Except for the final 48 seconds of the 25-minute flight, the captain was the flying pilot, and the first officer was the nonflying pilot. When the airplane was about 0.5 NM inside the outer marker on the first approach, the compass warning flag on the captain's course deviation indicator appeared, indicating that the heading display was unreliable. The airplane deviated from the localizer centerline to the left but continued to descend. After about 1 minute, during which time the airplane's track continued to diverge from the localizer centerline, the flight crew executed a missed approach. The flight crew then unsuccessfully attempted to clear the compass flag by resetting circuit breakers. The captain directed the first officer to request a second approach. Contrary to company crew coordination procedures, the flight crew did not conduct an approach briefing or make al titude callouts for either approach. Although accurate heading information was available to the captain on his radio magnetic indicator, he experienced difficulty tracking the localizer course as the airplane proceeded past the outer marker on the second approach. The captain transferred control to the first officer when the airplane was 1.9 NM inside the outer marker. The airplane then began to deviate below the glideslope. The descent continued through the published decision height of 200 feet above ground level, and the airplane struck 80 foot-tall trees. Postaccidnet testing revealed that the first officer's instrument were displaying a false full fly-down glisdeslope indication because of a failed amplifier in the navigation receiver. The glideslope deficiency was discovered 2 months before the accident by another flight crew. An FAA repair station attempted to resolve the problem and misdiagnosed it as 'sticking' needles in the cockpit instrument. The operator was immediately advised to the problem. The operator's minimum equipment list for the airplane required that the problem be repaired within 10 days, but the operator improperly deferred maintenance on it for 60 days and allowed the unairworthy airplane to be flown by the accident flight crew. The airplane was not equipped with, nor was it required to be equipped with, a ground proximity warning system, which would have sounded 40 seconds before impact. (-23) on January 13, 1998 a Lear jet 25B operating as a part 91 positioning flight from Houston hobby airport (hou) to Houston Intercontinental Airport (iah) crashed while on approach to Intercontinental. The pilot and copilot received fatal injuries and the aircraft was destroyed by impact and post crash fire. See narrative #FTW98FA0096