# NTSB FTW98LA183: Enstrom 280C, N5693D, Castle Rock, CO, April 16, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 16, 1998, 15:45 local (21:45 UTC) - Place: Castle Rock, CO - Coordinates: 39.370376, -104.850097 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.3704&lon=-104.8501&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 20580 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA183 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20580/pdf - Page: https://openairdocs.org/ntsb/FTW98LA183 ## Probable cause Malfunction of the engine-driven fuel pump. Factors were unsuitable terrain, soft ground, and a berm. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, maneuvering - fuel system,pump - malfunction (cause) - Forced landing, descent - emergency - terrain condition - soft - In flight collision with terrain/water, emergency descent/landing - terrain condition - soft (contributing factor) - terrain condition - ground (contributing factor) - terrain condition - berm (contributing factor) - terrain condition - none suitable (contributing factor) ## Analysis The flight instructor was conducting an introductory flight with a new student. While demonstrating emergency procedures at approximately 400 feet above the ground, the helicopter lost engine power. Determining the ground unsuitable for landing, he turned south and aimed for a flat area of terrain. He cushioned the landing with the collective, then sank 6 inches into the ground. Examination of the engine disclosed no abnormalities, however a postaccident functional test of the engine revealed a malfunction in the engine-driven fuel pump. When the electrically-driven boost pump was switched to the OFF position, power fluctuations were noted. All three rotor blades were bent, and the tail boom was severed. ## Factual narrative On April 16, 1998, at 1545 mountain daylight time, an Enstrom 280C helicopter, N5693D, sustained substantial damage during an emergency landing while on an instructional flight near Castle Rock, Colorado. The certified flight instructor and student were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for this local area flight which originated at Centennial Airport, Englewood, Colorado, at 1530. The flight was operating under Title 14 CFR Part 91 when the accident occurred. According to the flight instructor, he was conducting an introductory flight with a new student. Fifteen minutes after departure, he began demonstrating emergency procedures. While approximately 400 feet above the ground, he reduced the throttle to 2000 rpm. After scanning the instrument panel, he noted the rotor rpm was indicating 350, and the engine rpm was indicating 0. He "lowered the collective to [the] stop, rolled the throttle back and forth, and depressed the starter for approximately 300 feet - 9 seconds." Determining that the ground was unsuitable for landing, he turned south and aimed for a "flat place in [a] gully." He cushioned the landing with the collective, then sank 6 inches into the ground. The helicopter stopped abruptly, then rolled forward. The main rotor struck a berm, causing "rotor torque to be transferred to [the] fuselage, twisting it to [the] left." In a nose down attitude of approximately 20 degrees, the fuselage turned 180 degrees with a nose high attitude of about 70 degrees. Examination of the engine disclosed no abnormalities; however, a postaccident functional test of the engine revealed a malfunction in the engine-driven fuel pump. After a normal start, the engine ran for approximately two minutes and the throttle was advanced to 2,900 rpm. After five minutes of operation, the engine sounded steady and normal indications were present. When the electrically-driven boost pump was switched to the OFF position, power fluctuations were noted with the engine-driven fuel pump operating. The engine was shut off for approximately five minutes, then restarted. The engine was operated with both the electric fuel pump ON and OFF. During periods with the electrically-driven boost pump OFF, the engine rpm indications on the tachometer fluctuated approximately 700 rpm. All three rotor blades were bent, and the tail boom was severed. ## Aircraft - Registration: N5693D (not matched to a registry record) - Reported make and model: Enstrom 280C - Category: Helicopter - Serial number: 1192 - Airframe hours: 3048 - Engines: Lycoming HIO-360-E1AD 205 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Robert B. Welch - Registered owner: Denver Helicopters Services - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 31, 1998, 15 hours before - Departed: APA, ENGLEWOOD, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 1, expired; seat: left; flight hours: 1,093 total, 45 in this make and model, 949 as pilot in command, 72 in the last 90 days, 16 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 37 °F - Altimeter: 29.00 inHg - Observed at: APA, 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). - [Accident 19980416006929A](https://openairdocs.org/incident/19980416006929A), Apr 16, 1998: Enstrm 280C, Castle Rock, CO, Substantial damage. Demo flight for prospective student. Entered a autorotation flared. Noticed engine quit. Hit hard. Fuel pump defect (.4)the flight instructor was conducting an… 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.