# NTSB FTW94GA204: Hughes 269C, N7404F, London, TX, June 20, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Final report - Date: June 20, 1994, 18:30 local (23:30 UTC) - Place: London, TX - Coordinates: 30.669305, -99.569046 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.6693&lon=-99.5690&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report January 26, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 18931 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW94GA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18931/pdf - Page: https://openairdocs.org/ntsb/FTW94GA204 ## Probable cause THE PARTIAL POWER LOSS DUE TO A STICKING VALVE. FACTORS WERE THE REMAINING WORN LOBES ON THE CAMSHAFT AND THE LACK OF SUITABLE TERRAIN ONTO WHICH A SUCCESSFUL FORCED LANDING COULD BE EXECUTED. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, maneuvering - engine assembly,camshaft - worn (contributing factor) - engine assembly,valve,exhaust - open (cause) - Forced landing, descent - emergency - In flight collision with object, descent - emergency - object - tree(s) - terrain condition - none suitable (contributing factor) - In flight collision with terrain/water, descent - uncontrolled ## Analysis DURING A COYOTE ERADICATION FLIGHT, THE AIRCRAFT EXPERIENCED A PARTIAL POWER LOSS. THE PILOT STATED THAT WHILE HE WAS MANEUVERING AT LOW ALTITUDE AND AIRSPEED, HE FELT A VIBRATION THROUGH THE AIRFRAME, THE ENGINE AND MAIN ROTOR RPM BEGAN TO DECREASE, AND THE NEEDLES SPLIT. HE APPLIED FULL POWER, BUT THE ENGINE WOULD ONLY DEVELOP 2,000 RPM. WHILE THE PILOT WAS MANEUVERING TO A CLEAR AREA, THE MAIN ROTOR BLADES STRUCK TREES AND THE AIRCRAFT ROLLED TO THE RIGHT AND IMPACTED THE GROUND. FOLLOWING THE ACCIDENT, THE ENGINE WAS TEST RUN IN THE AIRFRAME AND FOUND TO BE RUNNING ROUGH. INVESTIGATION REVEALED THAT THE ENGINE CAMSHAFT LOBES WERE WORN BEYOND LIMITS AND THE #4 EXHAUST VALVE WAS HEAT DISCOLORED AND SHOWED SIGNS OF STICKING. ## Factual narrative On June 20, 1994, approximately 1830 central daylight time, a Hughes 269C, N7404F, was destroyed when it collided with trees and the ground near London, Texas. The helicopter, leased to and operated by the U. S. Department of Agriculture and flown by a commercial pilot, was on a local animal damage control flight. Company flight following was being utilized and visual meteorological conditions prevailed. The pilot and the one observer/gunner received minor injuries. According to the operator, the flight was part of a coyote eradication program. The flight had departed the Junction, Texas, Kimble County Airport at 1730, and flown to a local ranch, where the pilot and observer met with the ground search team. Shortly thereafter, the flight departed to the search area. The pilot stated that, due to the nature of the mission and the terrain cover, he was flying the search pattern at a height of 35 to 40 feet at about 30 knots. After searching the area for several minutes, the observed informed the pilot that he had spotted a target. Shortly after the gunner had spotted and opened fire on a coyote, the pilot felt what he described as a "short but violent" vibration in the anti- torque pedals. He said he initiated a right turn and began looking for a place to land. He then noticed that the engine RPM was dropping rapidly, the engine/rotor RPM needles were split, and the rotor RPM was bleeding off with the engine RPM. The pilot said he immediately applied full throttle, but the engine would only produce 2,000 RPM. At that point, he attempted to maneuver around some 10 foot high trees to a clear area. During the maneuver, the main rotor blades struck the trees and the aircraft rolled onto its right side and impacted the ground. Following recovery of the wreckage, the engine was run in the accident airframe with the main rotor and tail rotor drives disconnected. The engine started on the second attempt and was run at idle power and 2,000 RPM for a period of 25 minutes. The engine ran rough and there was a vibration through the airframe. Following the test run, the engine was removed from the airframe and disassembled. During the disassembly, wear was noted on all of the camshaft lobes, except the #2 cylinder exhaust valve lobe and the lobe for the #3 and #4 intake valves. It was also noted that the #4 exhaust valve was scored and had heat discoloration two thirds of the way down the valve stem. The #4 exhaust discharge ran cooler than the rest of the cylinders during the engine test run. ## Aircraft - Registration: [N7404F](https://openairdocs.org/deregistered/N7404F-2019-05-06), registration cancelled 2019-05-06, S/N 650414, built 1975 (OpenAirDocs) - Reported make and model: HUGHES 269C - Registry model: [Hughes 269C](https://openairdocs.org/model/hughes-269c) (registry code 4470504) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 650414 - Airframe hours: 7604 - Engines: LYCOMING HIO-360-D1A 220 horsepower reciprocating - Damage: Destroyed - Flight: Public aircraft, Part 91 - Operator: U. S. Dept. Of Agriculture - Registered owner: Miller Aero Service, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 6, 1994, 25 hours before - Departed: JCT, JUNCTION, TX - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; commercial; airplane ratings: single-engine land; medical: class 2, invalid medical for flight; seat: left; flight hours: 1,610 total, 1,516 in this make and model, 1,406 as pilot in command, 130 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 5 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 61 °F - Altimeter: 29.00 inHg ## 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 19940620015729A](https://openairdocs.org/incident/19940620015729A), Jun 20, 1994: Hughes 269C, London, TX, Destroyed. Coyote eradication flight. Rough engine low altitude. Needles split. Rotors hit trees. Camshaft lobes worn out. ## Other investigations on N7404F (2) 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. - [NTSB MIA77FKG78](https://openairdocs.org/ntsb/MIA77FKG78), Sep 10, 1977: Hughes 269 (N7404F), Montezuma, GA, substantial damage - [NTSB MIA77FKG69](https://openairdocs.org/ntsb/MIA77FKG69), Aug 19, 1977: Hughes 269C (N7404F), Montezuma, GA, substantial damage 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.