# NTSB NYC01IA046: Mooney M20C, N942TB, Hazard, KY, November 30, 2000 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: November 30, 2000, 11:00 local (16:00 UTC) - Place: Hazard, KY - Coordinates: 37.249748, -83.189178 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.2497&lon=-83.1892&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor, 2 uninjured - Status: Completed, report July 10, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50707 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC01IA046 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50707/pdf - Page: https://openairdocs.org/ntsb/NYC01IA046 ## Probable cause The incorrect routing of the cabin air scat tubing by an unknown person, which resulted in a carbon monoxide leak into the cabin, and subsequent pilot incapacitation. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, cruise - air conditioning/heating/pressurization system(s) - incorrect, unknown (cause) - incapacitation(carbon monoxide), pilot in command ## Analysis During cruise flight, the pilot became incapacitated. The pilot rated passenger was able to fly the airplane toward an airport and wake the pilot. The pilot landed uneventfully, but suffered from toxic levels of carbon monoxide. Examination of the airplane revealed a hole in the cabin air scat tubing. The hole was in the vicinity of the joint that connected the number one cylinder to the exhaust manifold, and there was a visible gap in the joint. Further examination revealed that the sometime during the airplane's history, the scat tubing had been misrouted. ## Factual narrative On November 30, 2000, about 1100 Eastern Standard Time, a Mooney M20C, N942TB, was not damaged during a pilot incapacitation event near Hazard, Kentucky. The certificated private pilot and pilot rated passenger received minor injuries, and two passengers were not injured. Visual meteorological conditions prevailed for the flight that departed Lynchburg Regional Airport (LYH), Lynchburg, Virginia; destined for Kyle-Oakley Field (CEY), Murray, Kentucky. An instrument flight rules flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated that he was in cruise flight at 8,000 feet near Hazard, Kentucky. He began to feel ill, and requested a descent to 6,000 feet. The pilot then began to "go in and out of consciousness." The pilot rated passenger had not flown for over 25 years, but was able to fly the airplane to Big Sandy Regional Airport (K22), Prestonsburg, Kentucky. The pilot rated passenger successfully woke the pilot, and the pilot made an uneventful landing. The pilot stated that he remembered flying a left-hand traffic pattern at K22, but did not remember landing the airplane. The pilot further stated that hospital tests revealed he and the pilot rated passenger had toxic levels of carbon monoxide in their blood. Carbon monoxide was present in the rear seat passengers, but the levels were not toxic. Examination of the airplane revealed a hole in the cabin air scat tubing. The hole was next to the joint that connected the exhaust manifold to the exhaust from the number one cylinder. The joint was not secure, and a gap was visible. Photographs of the engine were forwarded to the airplane manufacturer. The manufacturer stated that sometime during the airplane's history, the scat tubing was misrouted. The tube with the hole, connected the air inlet to the cabin. A second tube connected the air inlet to a heater exchange. The tube with the hole was suppose to be routed underneath the second tube, however, it was resting on top of it. The manufacturer added that the scat tubing was not clamped, but the clamps would only help if the tube was correctly routed. The pilot stated that maintenance work was performed on his airplane prior to the day of the incident. Specifically, a fixed base operator replaced the alternator. However, a Federal Aviation Administration (FAA) inspector stated that the misrouting could have happened during any of several prior maintenance visits. The inspector could not confirm that the most recent maintenance work was the cause of the misrouting. Additionally, he could not confirm when the gap formed in the joint between the cylinder and exhaust manifold. The airplane's last annual inspection was performed on October 28, 2000. ## Aircraft - Registration: [N942TB](https://openairdocs.org/aircraft/N942TB), registered now, S/N 2587, built 1963 (OpenAirDocs) - Reported make and model: Mooney M20C - Registry model: [Mooney M20C](https://openairdocs.org/model/mooney-m20c) (registry code 5870208) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2587 - Airframe hours: 1404 - Engines: Lycoming O-360 180 horsepower reciprocating - Damage: No damage - Flight: Personal, Part 91 - Registered owner: Thomas R. Bailey - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 28, 2000, 49 hours before - Departed: LYH, LYNCHBURG, VA - Destination: CEY, MURRAY, KY - Flight plan: IFR - Airport: K22, Big Sandy Regional, runway 21, 5,000 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 751 total, 50 in this make and model, 711 as pilot in command, 56 in the last 90 days, 18 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 1,900 ft overcast - Temperature: 34 °F, dew point 25 °F - Altimeter: 30.00 inHg - Observed at: JKL, 12 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). - [Incident 20001130022099I](https://openairdocs.org/incident/20001130022099I), Nov 30, 2000: Mooney M20C, Prestonsburg, KY. (-23) On November 30, 2000, approx. 1630 UTC, a Mooney M-20C, N942TB, made an emergency landing at the big Sandy airport, prestonburg, KY. The a/c was operated… 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.