Fox Lake, IL, USA
N91381
Mooney M20J
The airplane was destroyed when it impacted a road following an uncontrolled descent. Examination of the airplane revealed no anomalies existed prior to impact. The pilot seated in the left seat had recently purchased the airplane. The pilot seated in the right seat was a certified flight instructor. According to the CFI's logbook, he had 2,401.4 hours total flight experience and 62.6 hours experience as a flight instructor. Radar track data showed the aircraft departed Palwaukee Airport, Wheeling, Illinois, and proceeded toward Fox Lake, Illinois. The last recorded radar return coincided with the time and location of the accident site. The radar data showed that during the 3 minutes prior to the last return, the airplane's groundspeed slowed from 158 knots to 70 knots while the altitude returns remained between 2,300 and 2,500 feet. The last two radar returns show the airplane descending through 2,200 feet and 1,700 feet pressure altitudes, respectively. The calculated ground speed during these last two radar returns was 63 knots and 42 knots, respectively. The Pilot's Operating Handbook for the airplane lists stall speeds with 0-degree bank angle between 48.5 knots and 59 knots calibrated airspeed (CAS) depending on weight and configuration. The gear-up, flaps-up stall speed at 2,300 pounds and 0-degree bank angle was listed at 54 knots CAS. The gear-down, flaps 33-degree stall speed for the same weight and bank angle was listed as 48.5 knots CAS.
HISTORY OF FLIGHT On July 28, 2004, at 1403 central daylight time, a Mooney M20J, N91381, piloted by a private pilot and a certified flight instructor (CFI), was destroyed on impact with a road near Fox Lake, Illinois. A postaccident explosion and fire ensued. The 14 CFR Part 91 flight was operating in visual meteorological conditions. The pilot and flight instructor were fatally injured. In addition, a law enforcement officer responding to the accident scene was seriously injured during the postaccident explosion and fire. The local training flight originated from the Palwaukee Municipal Airport (PWK), Wheeling, Illinois, at 1352. Radar data for the accident area was obtained from the Federal Aviation Administration (FAA). Using the accident location as a starting point and working backward, an aircraft track was found that originated from PWK and progressed to the accident site. The first radar return was at 13:52:40.23, and the last radar return was at 14:02:53.28. The location and time of the last radar return coincided with the accident location and time. The radar data was processed and plotted. The plots are included with the docket material associated with this report. The plot of the ground track shows the airplane departing PWK and continuing in northwesterly direction to the accident site. The ground track shows no appreciable change in heading after the departure from PWK. Altitude returns show the airplane at pressure altitudes between 2,100 and 2,500 feet for the majority of the flight. Between 13:58:02.85 and 14:02:39.39, the ground speed decreased from 158 knots to 70 knots. During this same time period, the pressure altitude returns varied from 2,300 feet at 13:58:02.85 to 2,500 feet and then back to 2,300 feet at 14:02:39.39. The last two radar returns at 14:02:44.01 and 14:02:53.28 show the airplane descending through 2,200 feet and 1,700 feet pressure altitudes, respectively. The calculated ground speed during these last two radar returns was 63 knots and 42 knots, respectively. PERSONNEL INFORMATION The pilot held a private pilot certificate with airplane single-engine land privileges. His third class medical certificate was issued on January 9, 2003. The pilot's flight logbook was found at the accident site. According to the recovered logbook, the pilot had accumulated 222.9 total flight hours as of the last entry dated July 20, 2004. A review of the logbook revealed that the pilot had accumulated 13.7 hours in Mooney M20J aircraft. According to the father-in-law of the pilot, the purpose of the flight was to be an instrument training flight. The CFI held a commercial pilot certificate with airplane single-engine land and instrument airplane ratings. He also held a flight instructor certificate with an airplane single-engine rating. His first class medical certificate was issued in May 2004. The medical certificate listed the limitation, "Must wear lenses for distant-possess glasses for near vision." The CFI's flight logbook was found at the accident site. According to the recovered logbook, the CFI had accumulated 2,401.4 hours of flight experience as of the last entry dated July 25, 2004. A review of the logbook revealed that the CFI had flown 58.2 hours in the last 90 days, 26.3 of which were in Mooney M20M aircraft. An acquaintance of the CFI reported that the CFI was the owner of a Mooney M20M. According to the CFI's logbook, he had given 62.6 hours of instruction prior to the last entry. AIRCRAFT INFORMATION The airplane was a Mooney model M20J, serial number 24-3237. It was a low-wing monoplane with retractable landing gear. A single Lycoming IO-360-A3B6D engine, serial number L-25673-51A, rated at 200 horsepower powered the airplane. METEOROLOGICAL INFORMATION At 1353, the recorded weather at PWK, located 19 nautical miles and 145 degrees from the accident site, was: wind calm; visibility - 10 statute miles; sky condition - few clouds at 6,000 feet above ground level; temperature - 25 degrees Celsius; dew point - 16 degrees Celsius; altimeter setting - 30.01 inches of mercury. At 1355, the recorded weather at the Waukegan regional airport, located 13 nautical miles and 080 degrees from the accident site, was: wind - 090 degrees at 7 knots; visibility - 10 statute miles; sky condition - few clouds at 7,000 feet above ground level; temperature - 26 degrees Celsius; dew point - 16 degrees Celsius; altimeter setting - 30.04 inches of mercury. COMMUNICATIONS No records of pertinent communications with the accident airplane were found. WRECKAGE AND IMPACT INFORMATION The National Transportation Safety Board on-scene investigation began about 1630 on the day of the accident. The accident site coordinates were determined to be 42 degrees 23.116 minutes north latitude, 88 degrees 9.619 minutes west longitude. The airplane impacted a paved road and all major structural and flight control assemblies were located in the immediate vicinity of the main wreckage. The cabin section of the fuselage and inboard wing surfaces exhibited extensive fire damage. Both the left and right wings were present and each was located adjacent to the fuselage. The inboard sections of both wings exhibited extensive fire damage. The left wing was examined and rearward crushing of the leading edge was noted. The aileron was intact and remained attached to the wing. The pushrod end that attached to the aileron was fractured. The fracture exhibited signatures consistent with overload. The left flap was separated from the wing. The second hinge from the outboard end was torn from the flap. All of the other flap hinges remained attached to the flap. The wing mounted portion of the outboard flap hinge was fractured and had signatures consistent with overload. The two inboard flap hinges were separated from the wing. The left main landing gear was separated from the wing structure. Aileron control continuity was established from the aileron bellcrank to the cockpit. The right wing was examined and rearward crushing of the leading edge was noted. The aileron was intact and remained attached to the wing. The right flap remained attached to the wing. The second flap hinge from the inboard end was melted. The outboard two hinges were intact. The right main landing gear was found within the wheel well in the retracted position. Aileron control continuity was established from the aileron to the cockpit. The tail surfaces remained attached to the fuselage. The left portion of the horizontal stabilizer was bent upward and rearward. The left outboard elevator hinge was fractured. All other tail surface hinges remained intact. Control surface continuity was established from the tail surfaces to the cockpit. The aluminum skins of the forward fuselage and cabin were consumed by fire. The cockpit interior, including the instrument panel was destroyed by fire. The steel tube substructure of the forward fuselage remained. The tail cone was bent upward at a point about 4 feet forward of the leading edge of the horizontal stabilizer. The engine was located at the accident scene. The crankcase was shattered and the number 1 engine cylinder was completely separated from the engine. Portions of the engine case remained attached to the cylinder. The number 1 piston and connecting rod remained attached to the crankshaft. The number 3 and number 4 cylinders were partially separated from the engine case. The number 2 cylinder remained attached to the engine case. The front third of the crankcase was missing exposing the crankshaft. The crankshaft was bent and the propeller flange was separated. The fuel servo was separated from its mounting flange and had impact damage. The propeller was found at the accident site. All three of the propeller blades remained attached to the hub. All three blades exhibited chordwise scratches and gouges. Each blade also had leading edge nicks, bending and twisting. The engine crankshaft flange remained attached to the hub. No defects were found with respect to the airframe, engine, or systems that could be determined to have existed prior to impact. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were performed on the pilot and CFI by the Lake County Coroner's Office in Waukegan, Illinois. A FAA "Final Forensic Toxicology Fatal Accident Report" for the CFI was negative for all tests performed. A FAA "Final Forensic Toxicology Fatal Accident Report" for the pilot listed Quinine detected in the Liver. Quinine is found in tonic water, and is also used to treat severe malaria. It is also commonly used to reduce the frequency of nocturnal leg cramps (a condition which may cause painful leg muscle spasm at night), and is available in an over-the-counter nutritional supplement marketed for this purpose. TESTS AND RESEARCH A pilot's operating handbook (POH) for the M20J was researched. The POH listed stall speeds with 0-degree bank angle between 48.5 knots and 59 knots calibrated airspeed (CAS). The stall speeds listed were dependent on the loaded weight of the airplane and the landing gear and flap configuration. The gear-up, flaps-up stall speed at 2,300 pounds and 0-degree bank angle was listed at 54 knots CAS. The gear-down, flaps 33-degree stall speed for the same weight and bank angle was listed as 48.5 knots CAS. ADDITIONAL INFORMATION According to a CFI that had previously given the pilot flight instruction, the pilot had recently purchased the airplane in Texas. This CFI stated that he had flown with the accident pilot on two previous occasions. One flight was a flight in the accident airplane from Flora, Illinois to PWK. The other flight was a training flight. This CFI stated that he would estimate the accident pilot's skill level as "average" for a pilot with 200 flight hours. He stated that during the training flight, he had to "help" the pilot with right rudder on takeoff. This CFI stated that he did not know the CFI that was in the airplane at the time of the accident. Textron Lycoming and the FAA were parties to the investigation.
The flight crew's failure to maintain airspeed which led to an inadvertent stall/spin. An additional cause was the flight instructor's unsuccessful remedial action during the course of the accident sequence. The slow flight performed was a factor.
Source: NTSB Aviation Accident Database
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