York, NE, USA
N4380Q
CESSNA 172L
The flight instructor and student pilot were planning to do touch-and-go landings. A witness reported that the airplane took off on Runway 17, climbed about 100 feet, and then nosed down. The weather was clear and the wind was nearly straight down the runway. The flight instructor had logged nearly 3,000 hours of total flight time, with over 600 hours instruction and over 600 hours in the Cessna 172. Examination of the aircraft revealed no evidence of a preimpact mechanical malfunction. The flight instructor had a long history of diabetes, and had recently started a new injectable medication (exenatide, 10 micrograms twice a day) to help control his blood sugar. This medication can result in impairment due to low blood sugar, but he had not reported any adverse effects, and he was observed to be behaving normally the day prior to and the day of the accident. He was at extremely high risk of obstructive sleep apnea given his height (70 inches), weight (285 pounds), and poorly controlled blood pressure. Obstructive sleep apnea often results in impairment, but he was apparently not observed to snore while sleeping, a hallmark of the condition. Autopsy revealed an enlarged heart (it weighed 500 grams), but it was not thickened, suggesting an apparently unrecognized heart condition, dilated cardiomyopathy, that can result in sudden incapacitation. Given the failure of this experienced instructor pilot to either execute a normal climbout or appropriately oversee the climbout by his novice student, it is possible that he was incapacitated by a cardiac event. It is also possible, though less likely, that he was impaired either by unrecognized low blood sugar as a result of his new diabetes medication or by fatigue from unrecognized obstructive sleep apnea. However, the investigation could not conclusively determine if the instructor was impaired at the time of the accident.
HISTORY OF FLIGHT On September 19, 2008, approximately 1600 central daylight time, a Cessna 172L, N4380Q, registered to and operated by York Aviation, Inc., was substantially damaged when it struck the runway during an uncontrolled descent shortly after taking off from York Municipal Airport (JYR), York, Nebraska. Visual meteorological conditions (VMC) prevailed at the time of the accident. The instructional flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The flight instructor and student pilot on board the airplane were fatally injured. The local flight originated approximately 1545. According to the airport manager, the flight instructor and student pilot were planning to do touch-and-go landings, and he watched them taxi out to the runway. He said the time was approximately 1545. He then went back into the hangar. About 1620, he came out of the hangar and noticed the wreckage in the distance. He drove to the site and called 9-1-1. There was only one known witness to the accident. A citizen was driving on a gravel road west of the airport and noticed a single engine airplane on the runway, facing south. He watched it as it proceeded down the runway and lifted off. As it climbed approximately 100 feet, it suddenly nosed down. The witness' view was blocked by crops. Seeing no dust or smoke, he thought it may have been "an intentional move by the pilot," and he proceeded into town to run some errands. As he was driving home via the same route, he saw emergency equipment at the airport. Later, when he learned there had been no witnesses to the accident, he came forward. PERSONNEL INFORMATION The pilot-in-command, age 54, held a commercial pilot certificate, dated August 13, 2008, with airplane single-engine land and instrument ratings. He also held a flight instructor certificate, dated October 18, 2006, with an airplane single-engine land rating, and a ground instructor certificate, dated April 28, 2004, with advanced and instrument ratings. His second class airman medical certificate, dated November 1, 2007, contained the following restrictions and limitations: "Must wear corrective lenses and possess glasses for near/intermediate vision. Not valid for any class after November 30, 2008. A copy of the pilot's most recent logbook, containing entries from January 3 to September 18, 2008, was made available by his attorney. According to the logbook, his most recent biennial flight review was accomplished on August 3, 2008, in his own Beech A36. He had logged the following flight times (in hours): Total time, 2,945 Last 90 days, 62 As a flight instructor, 636 Last 90 days, 52 Cessna 172, 652 Last 90 days, 41 The student pilot, age 68, held a combination student pilot certificate/third class medical, dated September 18, 2008. It contained the restriction, "Must wear lenses for distant/possess glasses for near vision." The student's logbook contained entries from June 16 to September 18, 2008, and revealed that all of his flying had been done in the accident airplane and with the accident instructor. He had made four flights (June 16, 25, 27, July 13), totaling 3.4 hours, before returning home to San Diego. He returned to York and made two more flights (September 15, 18), totaling 1.6 hours before the accident flight. His total time was 5.0 hours. AIRCRAFT INFORMATION N4380Q (s.n. 17260280), a model 172L, was manufactured by the Cessna Aircraft Corporation in 1971. It was powered by a Lycoming O-320-E2D engine (s.n. L-39954-27E), rated at 150 horsepower, driving a Sensenich 2-blade, all-metal, fixed-pitch propeller (m.n. 74DM7S14-0-60, s.n. A 58981). According to the airplane maintenance records, the last annual inspection was performed on September 8, 2008. Total time on the airframe was 3,730.1 hours. The engine was overhauled by Lycoming on June 18, 2008, and installed in N4380Q on July 10, 2008, at a tachometer time of 3,897.4. At the time of overhaul, the engine had accumulated 6,518.3 hours time-in-service. At the time of the annual inspection, the engine had accrued 32.7 hours since major overhaul. The propeller was installed new on July 11, 2003. METEOROLOGICAL INFORMATION The following weather observations were recorded at York Municipal Airport at 1530 and 1630, respectively: Wind, 180 degrees at 9 knots; visibility, 10 statute miles; sky condition, clear; temperature, 27 degrees Celsius (C.); dew point, 11 degrees C.; altimeter setting, 30.14 inches of Mercury. Wind, 180 degrees at 14 knots, gusts to 18 knots; visibility, 10 statute miles; sky condition, clear; temperature, 27 degrees C.; dew point, 10 degrees C.; altimeter setting, 30.12 inches of Mercury. AERODROME INFORMATION York Municipal Airport (JYR) is located 1 mile north of York. It is situated at an elevation of 1,670 feet above mean sea level (msl). It is served by two runways: 17-35 (5,900 feet x 100 feet, concrete) and 05-23 (4,700 feet x 150 feet, turf). At the time of the accident, runway 17 was the active runway. The runway has a 798 foot displaced threshold. WRECKAGE AND IMPACT INFORMATION The on-scene examination revealed the airplane struck the runway to the left of centerline 2,841 feet from the displaced threshold of runway 17. Measurements indicate impact occurred in a left wing low, nose low attitude. The airplane then skidded 183 feet off the left side of the runway and into the grass, coming to rest upright. One frangible runway light was knocked off at the base. There were several gouges in the runway and a mark similar to a propeller strike. The flaps were up and the fuel selector was on both tanks. Control continuity was established from all flight control surfaces to their respective cockpit controls. The stall warning horn tested satisfactory. The front seats separated from the rails; the rails were distorted. Fire department personnel reported both occupants were wearing the seat belts and shoulder harnesses. The gascolator contained only a few drops of fuel because the bowl was broken. There was hydraulic bulging in the left wing tank. The right fuel tank was breached with the beginnings of fuel blighting in the grass. One propeller blade was twisted and the other blade was bent aft near the tip. Engine continuity and thumb compression was established. At the accident site, the Hobbs meter read 3037.1, and the tachometer read 3,945.2. When the airplane was signed out, the Hobbs meter read 3036.9, a difference of 0.3. MEDICAL AND PATHOLOGICAL INFORMATION According to rescue personnel, the student pilot was pronounced dead at the scene. The instructor was transported to the hospital where he expired. Autopsies were performed on both pilots. Both deaths were attributed to massive blunt trauma. Toxicology protocols were conducted by FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma. Azacyclonol and triamterene were detected in the instructor's blood and urine. NTSB's medical officer reviewed the instructor's FAA medical file and autopsy report, and the following are based on this review. The pilot had a long history of diabetes that was being treated by oral medications (metformin, 1000mg twice a day; rosiglitazone, 8mg a day, and glimepiride, 1 mg three times a day). Six weeks before the accident, he had been started on a new injectable medication (exenatide, 10 micrograms twice a day) to help control his blood sugar. No blood sugar measurements had been documented in FAA records since he began taking exenatide. The pilot had not reported any adverse effects from taking exenatide. Other flight students told an FAA inspector that the instructor's behavior was normal on the day prior to, and on the day of, the accident. The pilot's height was noted as 70 inches on his most recent application for an airman medical certificate, and his weight was noted as 285 pounds 10 days prior to the accident. FAA's medical file also noted that the pilot had high blood pressure. He was taking three different medications to control his blood pressure. Ten days before the accident, his blood pressure was 152/72. The records do not indicate any history of heart disease, and a treadmill stress test performed 12 years prior to the accident, as part of an evaluation for high blood pressure, was normal. According to the pilot's autopsy report, the heart was enlarged (it weighed 500 grams) but not thickened. The attorney representing the pilot's estate indicated that the pilot did not snore and had no family history of heart disease, congestive heart failure, or sudden cardiac death.
The student pilot's failure to maintain aircraft control, and the flight instructor's failure to take remedial action, for undetermined reasons.
Source: NTSB Aviation Accident Database
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