# NTSB DEN05CA052: Hughes 269C, N9688F, Englewood, CO, January 29, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: January 29, 2005, 11:35 local (18:35 UTC) - Place: Englewood, CO - Coordinates: 39.569999, -104.849166 - Nearby events: https://openairdocs.org/map.md?lat=39.5700&lon=-104.8492&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 28, 2005 - Report: Approved by Office Director - Parties: Denver, Colorado - NTSB case key (mKey): 60930 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN05CA052 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/60930/pdf - Page: https://openairdocs.org/ntsb/DEN05CA052 ## Probable cause the student pilot's failure to maintain control of the helicopter and the instructor's inadequate supervision of the flight. Contributing factors were low rotor rpm, low airspeed, and the instructor's delay in taking remedial action. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - turn to reverse direction - emergency procedure - simulated - autorotation - initiated, pilot in command - aircraft control - not maintained, pilot in command (cause) - rotor rpm - low (contributing factor) - airspeed - low (contributing factor) - terrain condition - ground - supervision - inadequate, pilot in command(cfi) (cause) - In flight collision with terrain/water, descent - uncontrolled - remedial action - delayed, pilot in command(cfi) (contributing factor) - Gear collapsed, descent - uncontrolled ## Analysis The instructor and student pilot were practicing autorotations. The instructor demonstrated a "360 degree autorotation" and returned to an altitude of 600 feet agl. The student then executed the same maneuver. After he had turned approximately 270 degrees, the instructor noticed that the airspeed had dropped to 40 knots and a high rate of descent had developed. The instructor applied power and attempted to arrest the descent, but the helicopter made a hard landing on the right skid. The skid collapsed, all three rotor blade tips were bent, and the right side of the airframe was damaged as a result of the ground strike. ## Factual narrative On January 29, 2005, approximately 1135 mountain standard time, a Hughes 269C helicopter, N9688F, piloted by a commercial certificated flight instructor, was substantially damaged when it made a hard landing at Centennial Airport (APA), Englewood, Colorado. Visual meteorological conditions prevailed at the time of the accident. The local instructional flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The flight instructor and student pilot reported no injuries. The flight originated at Centennial Airport approximately 1040. The following is based on a telephone interview with, and written statement from, the flight instructor: The instructor and his student were practicing autorotations. The instructor demonstrated a "360 degree autorotation" to the student from an altitude of 600 feet agl with a power recovery. He then returned to an altitude of 600 feet agl, where he, "rolled off the throttle to initiate the maneuver [for the student]." The student lowered the collective and began a right turn. As he was completing the first 180 degrees of turn, the instructor noticed that the "rotor rpm was at the top of the green arc, so [he] applied collective to maintain rotor rpm." Approximately 270 degrees into the turn, rotor rpm had decayed and the instructor lowered the collective in an attempt to maintain rotor rpm. He then noticed that the airspeed had dropped to 40 knots and a high rate of descent had developed. The instructor applied power, then, rolled out of the turn and leveled the aircraft for a run-on landing. The instructor could not arrest the descent rate, and the helicopter touched down on the right skid. The skid collapsed and the helicopter skidded to a stop. All three main rotor blade tips were bent and the airframe was damaged on the right side as a result of the ground strike. ## Aircraft - Registration: [N9688F](https://openairdocs.org/deregistered/N9688F-2013-09-19), registration cancelled 2013-09-19, S/N 320133, built 1972 (OpenAirDocs) - Reported make and model: Hughes 269C - Registry model: [Hughes 269C](https://openairdocs.org/model/hughes-269c) (registry code 4470504) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 320133 - Engines: Lycoming H10-360-DIA reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Mile High Helicopter Company, doing business as Mile High Helicopter Company - Registered owner: Mile High Helicopter Company - Airworthiness certificate: Standard, Normal - Departed: APA, Englewood, CO - Destination: APA, Englewood, CO - Airport: APA, Centennial Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 39; injuries: none; flight instructor, commercial; medical: class 2; flight hours: 725 total, 179 in this make and model, 35 in the last 90 days, 13 in the last 30 days - Pilot; injuries: none ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 8,000 ft overcast - Temperature: 41 °F, dew point 30 °F - Altimeter: 30.07 inHg - Observed at: APA ## 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 20050129001539A](https://openairdocs.org/incident/20050129001539A), Jan 29, 2005: Hughes 269C, Denver, CO, Destroyed. (-23) On Saturday, January 29, 2005, at approximately 1845 UTC, N9688F, a Hughes helicopter model 269C impacted the ground during autorotation training at… 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.