# NTSB LAX00LA034: Hawker Siddeley Hunter T MK 7, N576NL, Mesa, AZ, November 17, 1999 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 17, 1999, 16:49 local (23:49 UTC) - Place: Mesa, AZ - Coordinates: 33.329875, -111.630607 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.3299&lon=-111.6306&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report May 9, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47790 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA034 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47790/pdf - Page: https://openairdocs.org/ntsb/LAX00LA034 ## Probable cause The fatigue failure and separation the stage 3 compressor blades due to corrosion pitting of the blade retention lug bores. A factor in the accident was the failure of the various post military surplus operators of this engine to incorporate the manufacturer's recommended modifications to prevent such failures. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, takeoff - initial climb - compressor assembly,blade - corroded (cause) - maintenance,service bulletin/letter - not performed, other maintenance personnel (contributing factor) - compressor assembly,blade - fatigue (cause) - compressor assembly,blade - separation - Forced landing, emergency landing after takeoff - On ground/water encounter with terrain/water, landing - roll - object - fence - terrain condition - berm ## Analysis Following a loss of engine power on the ex-British military jet fighter just after liftoff, the pilot aborted the takeoff on the runway but could not stop prior to over-running the departure end and colliding with a fence and a berm. The pilot and crew chief said that about 5-10 seconds after takeoff a significant compressor stall happened with a loud explosion, followed by engine spool down. The airplane is a two-seat ex-military jet fighter produced in the 1950's and early 1960's by Hawker for service in the British Royal Air Force. Following the airplane's surplus from the RAF, it was imported into the United States and was being flown under a FAA special airworthiness certificate in the experimental category for the purpose of exhibition and racing. According to records at Rolls-Royce, the engine was manufactured in 1954 and sent to the RAF as part of a spares contract. The engine was last in the factory overhaul facility on March 26, 1981, for overhaul at 251 hours TSO. The engine is life limited to 450 hours between overhauls. The last manufacturer's records on this engine documented its installation in another Hawker Hunter by the RAF in 1983, with 392 hours TSO. The operator's engine maintenance records began on June 27, 1990, and documented its installation in the accident airframe at a maintenance facility in Wisconsin. An unsigned handwritten note preceded this entry and stated that the engine had a total run time since overhaul of 436 hours, with 265 hours remaining to overhaul. No documentation was available to support the engine history between leaving RAF service and the installation in the accident airframe. The last entry in the records was dated July 2, 1999, and consisted of an annual inspection at a time of 548 hours since last overhaul. A partial engine disassembly revealed that three third stage compressor blades had fractured from their root fixing lugs and separated. All compressor blades from stages 5 through 10 had fractured through their airfoil sections just outboard of the root. The root lugs from the failed third stage were removed and submitted for metallurgical analysis. All three blades failed due to high cycle fatigue failures, which initiated in the bores of the lug fixing pins. Energy Dispersive X-ray revealed corrosion cracks and pits at the crack initiation site. This engine has a history of high cycle fatigue failures of stage 3 compressor blades due to corrosion pits. Two modifications were introduced by the manufacturer, which incorporated a strengthened lug and a silicon rubber sealant to the bore interface to prevent the corrosion induced fatigue failures. The modifications were performed by the RAF between 1983 and 1986 to in-service and spares stock engines. This engine did not have these modifications incorporated. ## Factual narrative On November 17, 1999, at 1649 hours mountain standard time, a Hawker Siddeley Hunter T MK 7 jet, N576NL, collided with a ditch following a complete power loss on initial takeoff at Williams-Gateway Airport, Mesa, Arizona. The airplane, owned by Mach Two Inc. and operated by Advanced Training Systems International, Inc., sustained substantial damage. The commercial pilot sustained serious injuries and his passenger received minor injuries. The flight was being conducted under 14 CFR Part 91 when the accident occurred. The purpose of the flight was to reposition the aircraft to California for training purposes. Visual meteorological conditions prevailed at the time of the accident and the airplane was on an IFR flight plan. The flight originated at the airport moments before the accident. The pilot said that the airplane was prepared for flight and serviced by his crew chief before he did a preflight on the airplane. He stated that everything appeared ok and the airplane appeared ready for flight. The pilot said the engine start was uneventful, "nice and cool," with temperatures staying below 500 degrees as the engine spooled up to idle power in less than 20 seconds. He requested and received an IFR clearance to NAS Pt. Mugu from ground control, went through the post start and taxi checks, and taxied out to runway 30C. After they reached the hold short line, they completed the takeoff checklist and called for takeoff. They were cleared for takeoff with a right turnout after departure. The pilot said they taxied out on the runway and ran the engine up to 7,200 rpm and checked the instruments and flight controls. The engine temperature, oil pressure, hydraulic pressure, and boosted flight controls were working well. He then released the brakes, pushed the throttle up to the "military power detent," and checked the instruments again as they began the takeoff roll. He stated that rpm was 8,100, temperature was 650 degrees, and oil and hydraulic pressure was good. He said the airplane accelerated nicely and he rotated at 130 knots and flew off at 140 knots after using about 3,000 feet of take-off roll. About 5-10 seconds after takeoff, the pilot said he experienced a significant compressor stall with the engine "chug" and a loud explosion. He notified the crew chief that they had just lost the engine, and that he was going to set the airplane back down. He lowered the landing gear and set up for a normal touchdown back on the runway. He extended the drag chute just before touchdown and said he felt a "good tug." Once back on the ground, he immediately began applying the brakes in an attempt to stop the airplane before they reached the flood control ditch at the end of the runway. He was unable to stop the airplane before it hit the ditch and they went into the ditch and back out the other side. When the airplane came to rest, the pilot said he told his crew chief that he had broken his back and asked him to blow the canopy for him to get them out of the airplane. The crew chief, positioned in the right seat, stated that the preflight, start-up, run-up, and takeoff were "normal," and he did not realize that there was a problem until the pilot informed him that the engine had quit. He said he did not recall seeing any panel lights or hearing any aural warnings. An eyewitness to the crash said he was located on the south ramp at the airport and that the ramp was approximately 45-degrees to the runway. His line-of-sight had him watching the middle of the takeoff run. He said he heard a "bang" which sounded like a compressor stall and then the airplane was out of his sight. He said he heard two more compressor stalls at close to the same magnitude. He said he would estimate the airplane was at 100 feet agl when he first noticed the takeoff. A witness, who was a pilot in an airplane behind the accident airplane, was interviewed. He stated he observed a 30-foot flame exit the engine when it was about 200 feet above the ground on the initial takeoff climb. The pilot said that he did not observe any catastrophic failure of the engine or any parts depart the engine as he observed the flames. One eyewitness who watched the airplane takeoff stated he heard a "bang" that sounded like a compressor stall after the airplane had climbed to approximately 100 feet agl. He said the airplane continued out of his sight but that he heard at least two other loud noises very similar to the first noise after the airplane disappeared from his sight. AIRCRAFT INFORMATION The airplane is a two-seat ex-military jet fighter produced in the 1950's and early 1960's by Hawker for service in the United Kingdom Royal Air Force. Following the airplane's surplus from the RAF, it was imported into the United States and was being flown under a Federal Aviation Administration (FAA) special airworthiness certificate in the experimental category for the purpose of exhibition and racing. The airworthiness certificate was issued on December 12, 1994, by the Minneapolis, Minnesota, Flight Standards District Office. The airplane's logbook shows three recent flights including the ferry flight from Minnesota to Williams Gateway on November 9, 1999, for a total of 3.5 hours. The pilot of the ferry flights was also the pilot on the accident flight. According to Rolls-Royce, a review of their records indicated that the engine, serial number 5919, was manufactured in 1954 and sent to the RAF as part of a spares contract. The engine was last dispatched from their overhaul facility on March 26, 1981, following part life rework (overhaul) at 251 hours technical service order (TSO). According to Rolls-Royce, the engine is life limited (overhaul requirement) at 450 hours from parts rework and it would be life expired at 701 hours TSO. The last records on this engine documented its installation in another Hawker Hunter, serial number XL617, by the RAF on September 28, 1983, with 392 hours TSO. The engine maintenance records presented by the operator at the request of Safety Board investigators began on June 27, 1990, and documented its installation in the accident airframe at Volk Field, Wisconsin. An unsigned handwritten note preceded this entry and stated that the engine had a total run time since overhaul of 436 hours, with 265 hours remaining to life limit. No documentation was available to support the engine history between leaving RAF service and the installation in the accident airframe. The last entry in the records was dated July 2, 1999, and consisted of an annual inspection at a time of 548 hours since overhaul. WRECKAGE INSPECTION Safety Board investigators and technical representatives of Rolls-Royce examined the airplane on January 11-12, 2000. The salvage operator who recovered the airplane reported that the main fuselage fuel tanks and 100-gallon tip tanks were full of fuel, with just in excess of 400 gallons pumped into barrels at the crash site. The wings were removed by the salvage operator to assist in the recovery of the airplane. The nose gear was collapsed and the nose bay was damaged. Impact damage was observed to the forward section of the fuselage. Inspection of the intake prior to the engine removal showed that the intake ducting contained a moderate amount of dirt, with heavier concentrations present in the right duct. The starter fairing was intact with no apparent damage. The left portion of the instrument panel just above the avionics rack was buckled. All circuit breakers were in. The LP and HP throttle cocks were in the aft (cutoff) position. The fuel isolation switch was guarded and in the normal position. The engine remained contained within the engine bay during the impact sequence. Further examination of the engine revealed that the forward roller track was fractured. The bottom of the exhaust duct showed upward bending. The aft portion of the tail cone contained evidence of fi ## Aircraft - Registration: [N576NL](https://openairdocs.org/deregistered/N576NL-2013-06-18), registration cancelled 2013-06-18, S/N XL576 (OpenAirDocs) - Reported make and model: Hawker Siddeley HUNTER T MK 7 (HUNTER T M) - Registry model: [Hawker HUNTER T MK 7](https://openairdocs.org/model/hawker-hunter-t-mk-7) (registry code 4230122) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 41H003314 - Airframe hours: 4731 - Engines: Rolls-Royce AVON MK 12201 7600 lbs thrust turbo jet - Damage: Substantial damage - Flight: Business, Part 91 - Operator: Advanced Training Systems Int. - Registered owner: Mach Two Inc - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, July 2, 1999 - Departed: IWA - Destination: NTD, NAS POINT MUGU, CA - Flight plan: IFR - Airport: IWA, Williams Gateway Airport, runway 30C, 10,300 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 7,540 total, 41 in this make and model, 7,250 as pilot in command, 63 in the last 90 days, 35 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 4 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 41 °F - Altimeter: 29.00 inHg - Observed at: IWA, 1 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19991117046639A](https://openairdocs.org/incident/19991117046639A), Nov 17, 1999: Phoenix, AZ, No damage. (-23)Engine failure immediately after takeoff from rwy 30C. Aircraft impacted terrain 700 feet past end of runway and came to a stop approx. 2000 feet beyond… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.