Belleville, IL, USA
N77JL
Learjet 24D
!!THIS CASE WAS MODIFIED JANUARY 12, 2006!! The turbojet airplane was destroyed during a forced landing and post accident fire after a loss of power in both engines during takeoff climb. The pilot reported that both engines operated normally during taxi and pre-takeoff checks. He reported that, "We rotated positive rate gear up, V2 plus 30 flaps up, and at that point we struck birds taking No. 2 engine out. Upon losing No. 2 engine I advanced thrust levers forward and realized that the No. 1 engine was only producing approximately 70% RPM with EGT over read line." He executed a forced landing to a field and the crew and passengers evacuated the burning airplane. The copilot reported, "At approximately 500 to 1,000 ft. above ground level, I observed a large flock of birds straight ahead of us, and then passing just off our nose to the left side. I immediately heard an engine flameout. As I started to go to the checklist for single engine operations, I quickly realized that we were loosing airspeed and unable to maintain altitude. The PIC said we were going down and heading for the best emergency-landing stop." The Cockpit Voice Recorder (CVR) recorded the pilot stating, "We hit a bird," and the copilot stating, "Yep," immediately following the CVR recording a "sound similar to decrease in engine RPM." The inspection of the airplane's fuel system, pneumatic system, engines, fuel controls and fuel pumps revealed no pre-impact anomaly. No physical evidence of bird ingestion was found in either engine. A CVR sound spectrum plot and a flight profile analysis revealed that one engine flamed out almost immediately after the sound of a "thump" on the CVR. The other engine's speed decreased and experienced stalls until the engine speed was reduced to flight idle. The original engine certification tests indicated that compressor stalls occurred when a 2-4 ounce starling was shot ingested into the engine, but physical damage from bird ingestion was very slight due to the all steel construction and geometry of the engine. Engine flameouts, however, were not recorded during the certification tests. A wildlife specialist conducted a bird count at the accident airport two days after the accident occurred, and he reported counting a flock of about 800 European Starlings.
!!THIS CASE WAS MODIFIED JANUARY 12, 2006!! HISTORY OF FLIGHT On November 12, 2003, at 0645 central standard time, a Learjet 24D, N77JL, operated by Multi-Aero Inc. and piloted by an airline transport pilot, was destroyed during a forced landing and post accident fire after a loss of power in both engines. The flight departed runway 12R (6,997 feet by 100 feet, asphalt) at St. Louis Downtown Airport (CPS), near Cahokia, Illinois, at 0641. The business flight was operating under the provisions of 14 CFR Part 135 flight and was on an instrument flight rules (IFR) flight plan with North Platte, Nebraska, as the destination airport. Visual meteorological conditions prevailed at the time of the accident. The pilot and co-pilot sustained minor injuries. The two passengers reported no injuries. The pilot reported that the airplane was fueled with 300 gallons of jet A fuel with Prist, a fuel additive, from the local fixed base operator at CPS. The pilot reported that a ground power unit was used to start both engines and both engines started normally. The CPS tower was not open yet, so the flight received their departure weather from the CPS Automated Surface Observing System (ASOS), and received their takeoff clearance from St. Louis Approach Control. The pilot reported that after all the takeoff checks were accomplished, the proper "V" speeds set, and the flaps set to 10 flaps, the flight departed from runway 12R. The pilot reported, "I lined up on 12R and we proceeded with our takeoff roll. Co-pilot made standard calls, we rotated positive rate gear up, V2 plus 30 flaps up, and at that point we struck birds taking No. 2 engine out. Upon losing No. 2 engine I advanced thrust levers forward and realized that the No. 1 engine was only producing approximately 70% RPM with EGT over red line. I then realized time nor altitude was going to be enough for a restart or a return to landing. With only seconds remaining, I looked and found the best suitable landing spot to crash land the aircraft. Upon crash-landing aircraft wingtips departed and we came to a stop. Co-pilot assisted passengers out the emergency window exit away from the wreckage, and I escaped out of the main emergency exit and got away from the wreckage that had broken out into fire in the tail first, and then traveled though out the cabin and cockpit, destroying 95% of the aircraft with fire." The copilot reported, "The PIC was the 'Pilot Flying' and as the SIC, I was making the standard call outs. Everything was normal on the takeoff roll and I called out V1, rotate, V2, gear up, V2 plus 30, and flaps up. At approximately 500 to 1,000 ft. agl, I observed a large flock of birds straight ahead of us, and then passing just off our nose to the left side. I immediately heard an engine flameout. As I started to go to the checklist for single engine operations, I quickly realized that we were losing airspeed and unable to maintain altitude. The PIC said we were going down and heading for the best emergency-landing stop. I observed fire upon impact and as the aircraft slid to a stop. As I looked back to check on the passengers, I observed fire out both side fuselage windows. The passengers appeared to be uninjured. I attempted to open the top of the main cabin door but was unable. I then moved to the rear of the aircraft to open the emergency exit. I assisted the passengers out the emergency exit and got them away from the burning aircraft. I then observed the pilot coming from around the left side of the aircraft and we all moved away from the aircraft." One of the passengers reported hearing a "pop" on the left side of the aircraft shortly after takeoff. He reported that he did not remember hearing an increase in engine noise after hearing the "pop." It became obvious to the passenger that the airplane was losing power and the airplane started to descend. He checked his seat belt prior to impact. Once the airplane came to a stop, he had trouble finding the emergency exit until the copilot came back and opened the emergency exit. A witness on the ground reported seeing the airplane flying low and losing altitude. He reported that he could not tell by the sound if the engines were running. He reported that he did not see any smoke or flames coming from the airplane prior to impact. He reported that the tail of the airplane was on fire at first, but soon after the four people were out of the airplane, the whole airplane was on fire. The airplane was emitting a discrete transponder beacon code that the St. Louis approach radar recorded. The radar track data recorded six valid radar "hits" which indicated the airplane's heading, altitude, time, and position. The radar track data indicated the airplane climbed to about 900 feet pressure altitude (about 834 feet above mean sea level) at 0642:44. The elevation at CPS is 414 feet msl. During the next 28 seconds, five more radar hits indicated the airplane was on about a 120 magnetic bearing from CPS at an altitude of about 900 feet pressure altitude. The last recorded radar hit was at 0643:13. The airplane impacted the terrain on the down slope of a hill in a farm field that was recently planted. Local fire departments responded to the accident and used water and flame retardant to put out the fire. PERSONNEL INFORMATION The pilot held an airline transport pilot (ATP) certificate with single-engine and multi-engine land ratings. He also held a certified flight instructor certificate with single-engine airplane, multi-engine airplane, and instrument airplane ratings. He held a First Class medical certificate. The pilot had accumulated 9,054 total flight hours including 760 in the same make and model airplane as the accident airplane. Training records indicate that the pilot's most recent Airman Competency/Proficiency Check, as required by 14 CFR Part 135.299, was satisfactorily completed on January 8, 2003. The copilot held a commercial certificate with single-engine and multi-engine land ratings. He also held a certified flight instructor certificate with a single-engine airplane rating. He held a First Class medical certificate. The copilot had accumulated about 3,400 total flight hours including 150 in the same make and model airplane as the accident airplane. Training records indicate that the pilot's most recent Airman Competency/Proficiency Check, as required by 14 CFR Part 135.297, was satisfactorily completed on July 29, 2003. AIRCRAFT INFORMATION The airplane was a twin-engine Learjet 24D, serial number 286, manufactured in 1974. The airplane seated 8 and had a maximum gross takeoff weight of 13,000 pounds. The engines were GE CJ610-6 engines that produced 2,950 pounds of thrust each. The airframe had a total time of 6,653.4 hours with a total of 6,504 cycles. The last aircraft inspection was conducted on November 7, 2003, in accordance with Multi-Aero Inc's., Approved Airworthiness Inspection Program (AAIP) maintenance inspection program. The airplane had flown 2.3 hours since the last inspection. The left engine, serial number 251-518A, had accumulated 6,352.7 total hours. It underwent a 300-hour inspection on January 27, 2003, in accordance with Multi-Aero Inc's., AAIP. The right engine, serial number 251-517A, had accumulated 6,607.2 total hours. It was inspected on March 19, 2003, and an operational maintenance test flight was flown on April 18, 2003, to check that it operated within parameters. METEOROLOGICAL INFORMATION At 0653, the observed surface weather at CPS was: Winds variable at 5 knots; visibility 10 statute miles; sky clear; temperature 18 degrees C; dew point 16 degrees C; altimeter 29.85 inches of mercury. FLIGHT RECORDERS A Fairchild model A-100, cockpit voice recorder (CVR), was installed on the airplane. The CVR was inspected by the National Transportation Safety Board's (NTSB) Vehicle Performance Division. The inspection revealed that the recording consisted of four channels of fair to good quality audio information. The CVR recorded the following information: 0640:54 HOT-2 (Copilot's microphone): uuh, one **... one seven six six, set ... set, speed. *, twenty seven, thirty, thirty-four. There's uh ... 0641:28 CAM (Area microphone): [sound similar to increase in engine RPM] 0641:31 RDO-1 (Pilot's radio transmission): Downtown traffic, Webber two eighty six rolling on one two right. 0641.47 HOT-2: Speed's alive. 0641:50 HOT-2: eighty knot cross checked. 0642:00 HOT-2: V one. 0642:01 HOT-2: rotate. 0642:02 HOT-2: V two 0642:09 HOT-2: positive rate. 0642:10 HOT-2: gear's up. 0642:11 CAM: [sound of thump] 0642:12 HOT-2: plus thirty. 0642:14 HOT-2: comin' up. 0642:19 CAM: [sound similar to decrease in engine RPM] 0642:19 CAM: [sound of thump] 0642:24 HOT-1 (Pilot's microphone): hit a bird. 0642:25 HOT-2: yep 0642:30 HOT-2: plus thirty. 0642:46 HOT-1: call approach. 0642:48 CAM: [sound similar to landing gear warning horn] 0642:54 HOT-1: call approach, tell 'em. 0643:00 HOT-2: gear's up, flaps up, air's on. 0643:05 CAM: [sound similar to yaw damper disconnect tone] 0643:05 CAM: what's wrong with ... 0643:11 CAM-?: [sound of heavy breathing] 0643:16 CAM [sound similar to stick shaker starts and continues to end of recording] 0643:19 HOT-2: over here. 0643:24 CAM-?: going down. 0643:30 CAM: [sound of impact] 0643:31 End of Transcript End of Recording The NTSB's CVR "Specialist's Factual Report of Investigation" is in the docket material associated with this case. WRECKAGE AND IMPACT INFORMATION The aircraft contacted the terrain on the downward side of a shallow sloping hill located about 3 statute miles from CPS on a 120 degree magnetic bearing. The wreckage path was about 750 feet in length from the initial point of impact to the main wreckage on a 175 degree magnetic bearing. The main wreckage was located at coordinates 38 degrees 31.876 minutes North latitude, 90 degrees 05.689 minutes West longitude. The airplane was destroyed by impact and post-impact fire with most of the cabin and tailcone being consumed by fire. The cabin area above the center section on the wing was consumed by fire. The center section of the fuel tank remained structurally intact, although damaged by impact forces. All three landing gear were attached to the airplane and found in the retracted position. The nose of the airplane remained intact, but the cockpit received extensive fire and heat damage. Both windshields were melted and the upper skin was consumed. The instrument panel received impact damage and was covered with soot deposits. Both throttles were found in the cut off position. The thrust reverser levers were stowed. The fuel quantity indicator switch was in the right hand position. The fuel quantity gauge was fire damaged and the needle was in the 0 position. The left and right jet pump fuel switches were in the on position. The left and right boost pump switches were in the off position. The crossflow switch was in the closed position. The fuselage tank switch was in the off position. The fuel quantity indicator lights were destroyed. The outboard section of the left wing had separated from the airplane about 4-5 feet (Wing Station 70) outboard from the fuselage. The detached outboard section of the wing received fire and soot damage and was found about 325 feet from the initial impact point. The left flap was found near the outboard section of the wing. The left flap actuator was found in the attached inboard section of the wing and it measured 5 1/4 inches of extension, which corresponded to about 16.3 degrees of deployment. The left spoiler actuator measured about 3/4 inches of extension, which corresponded to 0 degrees of extension. The left wing fuel tip tank separated from the wing and was found in numerous pieces beginning near the start of the debris trail. The inboard section of the wing that was still attached to the fuselage was partially consumed by fire. The right wing remained attached to the forward fuselage section. The outboard section of the wing remained attached to the inboard wing section, but it was broken about mid-span and it was partially consumed by fire. The right flap and actuator remained attached to the wing. The right flap actuator was measured at 5 7/8 inches of extension, which corresponded to about 12.5 degrees of deployment. The right spoiler and actuator were still attached. The right spoiler actuator was measured at 8/10 inches of extension, which corresponded to 0 degrees of deployment. The right wing fuel tip tank separated from the wing and was found in numerous pieces along the wreckage path. The tailcone aft of the rear pressure bulkhead was consumed by fire. Both engines were found in place and attached to the aft fuselage. The vertical stabilizer, horizontal stabilizer, elevators, and rudder were found attached to the tailcone. The empennage section received fire damage and was covered with soot deposits. The horizontal stabilizer trim actuator nut screw assembly was measured at 16 11/16 inches total length, which equated to about -2.17 degrees nose down trim. All flight controls were accounted for at the accident site. The elevators and rudder remained attached to the tail section, but control continuity could not be established. The right aileron remained attached to the right wing, and the left aileron remained attached to the outboard section of the left wing. Aileron control continuity could not be established. The inspection of the inboard bays of the left and right wing center-section fuel tanks revealed that they received little or no fire damage. Internally, the inboard bays were clean and exhibited no effects from heat or mechanical damage. No contamination or corrosion was found in the inboard bays of the center-section fuel tanks, the jet pumps or boost pumps. The inboard fuel probes exhibited no anomalies. The left wing sump push-to-drain valve received impact damage. The left wing defuel valve was found undamaged and in the open position. The right wing sump push-to-drain valve received impact damage. The right wing defuel valve was found in the closed position. The pneumatic system of the aircraft was inspected and no pre-impact anomalies were evident. The inspection of the bleed air flow control valve assembly revealed that it had received fire damage. No outward bulging was associated with the cracks found on the assembly. A Federal Aviation Administration fire specialist inspector examined the airplane wreckage for evidence of an in-flight fire. He reported, "No evidence of an in-flight fire was observed on any area of the wreckage. The aft side of the vertical stabilizer had several production openings (small circular holes) adjacent to the leading edge of the rudder. An in-flight fire in the tail cone area would have likely produced soot trails from these openings and corresponding soot deposits on the leading edge of the rudder. These were not observed. The inside of the tail cone was sooted and much of the remaining aircraft structure was heavily damaged consistent with a post crash fuel fed fire." The inspection of the engines revealed that both engine inlets and nacelles had been consumed by fire. The bleed air valves were open on both engines. There was no evidence of uncontainment on either engine. The oil tanks were melted and empty on both engines. All accessory drive shafts were intact. Both compressor inlets showed some dirt and vegetation was ingested. Both compressor sections had dirt and vegetation in the first compressor stages, but no clogging was evident at the compressor outlet guide vanes (OGV). The compressor blades did not exhibit soft-body damage. There was no evidence of bird ingestion (feathers, tissue, bones) on the inlet guide vanes (IGV) or in the compressor, combustion, or turbine sections of the engines. Inspecting the compressor vanes under a black light showed traces of green colored luminescence (indicates organic material) on the 1st stage compressor rotor blades of the left engine, but not on the right e
The total loss of power to the right engine and the partial loss of power to the left engine after the airplane encountered a flock of birds during initial climb out, resulting in impeded ram induction airflow.
Source: NTSB Aviation Accident Database
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