# NTSB CHI97LA222: Morgan MINI-500, N500XM, Ava, MO, July 19, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 19, 1997, 14:30 local (19:30 UTC) - Place: Ava, MO - Coordinates: 36.949077, -92.659812 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.9491&lon=-92.6598&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 28, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 10638 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI97LA222 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10638/pdf - Page: https://openairdocs.org/ntsb/CHI97LA222 ## Probable cause Loss of engine power due to loss of engine cooling fluid. Related factors were maintenance service bulletin not complied with by the owner/pilot mechanic resulting in low output of the carburetor, and unsuitable terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, descent - powerplant - seized (contributing factor) - maintenance,service bulletin/letter - not complied with, owner/pilot mechanic (contributing factor) - fuel system,carburetor - output low (contributing factor) - cooling system,lines - leak (cause) - Forced landing, emergency descent/landing - Roll over, emergency landing - terrain condition - none suitable (cause) ## Analysis The pilot was completing a series of flight tests that involved transitions from cruise flight into a hover. The pilot reported the exhaust gas temperature (EGT) was higher in cruise flight than when hovering and that the EGT cooled rapidly when the helicopter went from cruise flight into the hovering maneuver. The pilot stated that approximately two miles from his destination, at 2,500 feet mean sea level (msl), he began a 200 to 300 foot/min descent to reach the airport's traffic pattern altitude. He said that as soon as the descent was initiated he experienced unusual engine noises and an abrupt loss of engine power. He lowered the collective and applied full power, but received no indication of engine power. He then initiated an autorotation to landing on a field with a 30-degree slope. Upon landing, the aircraft rolled over and came to rest on its port side causing the rotor to impact the tail boom. Examination of the engine showed evidence that the engine had seized during flight. Inspection of the fuel metering system showed that the accident airplane had not complied with Revolution Helicopter Service Information Letter number 042696, which requires the original factory carburetor jet setting to be adjusted to insure that the EGT be between 1,000 and 1,150 degrees Fahrenheit. No engine coolant was found in the coolant tank and the coolant hose tee was found to be deformed and leaking fluid. ## Factual narrative On July 19, 1997, at 1430 central daylight time, a Morgan Mini-500 helicopter, N500XM, was substantially damaged during a forced landing following a loss of engine power, near Ava, Missouri. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot reported no injuries. The flight departed Cabool Memorial Airport, Cabool, Missouri at 1305 and was en route to Ava/Bill Martin Memorial Airport (AOV), Ava, Missouri, at the time of the accident. According to the pilot's written statement, the pilot was completing a series of flight tests that involved transitions from cruise flight into a hover. The pilot reported the exhaust gas temperature (EGT) was higher in cruise flight than when hovering and that the EGT cooled rapidly when the helicopter went from cruise flight into the hovering maneuver. The pilot stated that approximately two miles from AOV, at 2,500 feet mean sea level (msl), he began a 200 to 300 foot/min descent to reach the airport's traffic pattern altitude. The pilot reported that as soon as the descent was initiated he experienced unusual engine noises and an abrupt loss of engine power. The pilot stated that he lowered the collective and applied full power but received no indication of engine power. The pilot then initiated an autorotation to landing on a field with a 30-degree slope. The pilot stated that upon landing the aircraft rolled over and came to rest on its port side causing the rotor to impact the tail boom. Examination of the accident aircraft was conducted by the Investigator-in-Charge and representatives from Revolution Helicopter Corporation, INC., on August 18, 1997. Examination of the engine showed evidence that the engine had seized during flight. Inspection of the fuel metering system showed that the accident airplane had not complied with Revolution Helicopter Service Information Letter Number 042696, which requires the original factory carburetor jet setting to be adjusted to insure that the EGT be between 1,000 and 1,150 degrees Fahrenheit. No engine coolant was found in the coolant tank and the coolant hose tee was found to be deformed and leaking fluid. ## Aircraft - Registration: [N500XM](https://openairdocs.org/aircraft/N500XM), registered now, S/N 180, built 1997 (OpenAirDocs) - Reported make and model: Morgan MINI-500 - Registry model: [Morgan John Wayne MINI 500 HELI](https://openairdocs.org/model/morgan-john-wayne-mini-500-heli) (registry code 05604O4) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: 180 - Airframe hours: 23 - Engines: Rotax 582 67 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: John Wayn Morgan - Airworthiness certificate: Special, Experimental (Special) - Last inspection: AAIP, May 20, 1997, 20 hours before - Departed: TVB, CABOOL, MO - Destination: AOV, MO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: center; flight hours: 2,808 total, 23 in this make and model, 2,637 as pilot in command, 65 in the last 90 days, 46 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 6 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 70 °F - Altimeter: 30.00 inHg - Observed at: SGS, 37 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 19970719039809A](https://openairdocs.org/incident/19970719039809A), Jul 19, 1997: Amtr MINI500, Ava, MO, Substantial damage. Lost power at cruise. Hard forced landing. Landed hillside. Rolled. Coolant leaked. Overheated. SD on carb overdue. 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.