# NTSB ANC94LA007: Helio H-391-B, N173K, Beaver Creek, AK, October 8, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 7, 1993, 17:35 local (Oct 8, 1993, 01:35 UTC) - Place: Beaver Creek, AK - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 2, 1994 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2465 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC94LA007 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2465/pdf - Page: https://openairdocs.org/ntsb/ANC94LA007 ## Probable cause THE PILOT'S FAILURE TO MAINTAIN THE REQUIRED AIRSPEED DURING THE EMERGENCY DESCENT AS PUBLISHED IN THE PILOT'S MANUAL. A FACTOR IS THE LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - reason for occurrence undetermined (cause) - Forced landing, descent - emergency - In flight collision with terrain/water, landing - airspeed - not maintained, pilot in command (cause) ## Analysis THE PILOT STATED THAT THE AIRPLANE LOST POWER. HE ALSO STATED THAT HE HAD 10 GALLONS OF FUEL IN THE RIGHT TANK AND 15 GALLONS OF FUEL IN THE LEFT AND THAT THE AIRPLANE DID NOT RUN OUT OF FUEL. DURING HIS ENGINE OUT DESCENT, HE ALLOWED THE AIRSPEED TO DISSIPATE BELOW 65 KNOTS. THE PILOT'S MANUAL STATES THAT BELOW 65 KNOTS, THE SLATS AUTOMATICALLY DEPLOY AND THE GLIDE PATH STEEPENS CONSIDERABLY. THE PILOT MISSED THE INTENDED FORCED LANDING AREA. ## Factual narrative On October 7, 1993, at approximately 1735 Alaska daylight time, a wheel equipped Helio Courier H-391-B airplane, N173K, crashed in Beaver Creek while attempting an engine-out emergency landing on a gravel bar. Beaver Creek is 60 miles magnetic north of Fairbanks, Alaska. The airplane, operated by Transporter Alaska, Inc., had departed Fort Yukon at 1700 while on a positioning flight operating under 14 CFR Part 91 on a VFR flight plan in visual meteorological conditions. The commercial pilot, the sole occupant, was not injured and the airplane sustained substantial damage. The pilot was rescued by an Alaska Air National Guard Pavehawk 60 helicopter and was flown to Fairbanks, Alaska. He told the NTSB that while en route to Fairbanks at 2,000 feet mean sea level (msl), the engine lost fuel pressure and then lost power. The pilot said that he attempted an emergency landing on a gravel bar; however, he could not stretch the glide "once the propeller stopped turning." He said he "completely missed" the touchdown point and crash landed in the creek. The aircraft remained upright and sustained substantial damage. He said that the flight was carrying only personal survival equipment at the time and was returning from a revenue flight to Fort Yukon. The Pilot/Operator did not submit an NTSB 6120.1/2. According to Brian Staurseth, FAA Inspector for FSDO 01, Fairbanks, Alaska, the Pilot stated he had 10 gallons of fuel in the left tank and 15 gallons of fuel in the right tank. the Pilot stated the airplane did not run out of fuel. He did state that during his glide he allowed the airspeed to dissipate below 65 knots. Once below 65 knots, the slats automatically extend. The Pilot/Operator's manual warns about reducing the airspeed below 65 knots in an engine out operation. It states that once below 65 knots and the slats extended, the airplane's glide path steepens considerably. The airplane wreckage was not inspected and the amount of fuel could not be determined because the airplane landed in a river. Before anyone could reach the wreckage, the river rose and submerged the airplane completely. This accident was investigated by Douglas Herlihy, who has left the Agency and compiled by George Kobelnyk of the Northwest Field Office. ## Aircraft - Registration: [N173K](https://openairdocs.org/aircraft/N173K), registered now, S/N 074 (OpenAirDocs) - Reported make and model: Helio H-391-B - Registry model: [Helio H-391B](https://openairdocs.org/model/helio-h-391b) (registry code 4300106) (OpenAirDocs) - Registry engine: [Lycoming GO-435](https://openairdocs.org/engine/lycoming-go-435) (registry code 41520, reciprocating) (OpenAirDocs) - Category: Airplane - Engines: UNKNOWN UNKNOWN reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: Porter, Steven H., doing business as Transporter Alaska Inc. - Airworthiness certificate: Standard, Utility - Departed: FYU, FORT YUKON, AK - Destination: FAI, FAIRBANKS, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 4,500 total ## Weather - Conditions: Visual (VMC), Not reported - Visibility: 40 statute miles - Lowest ceiling: none - Temperature: 37 °F ## 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 19931007039779A](https://openairdocs.org/incident/19931007039779A), Oct 7, 1993: Helio H391B, Beaver Creek, AK, Substantial damage. Lost power en route. Crashed in a Creek trying for a sandbar. Too slow slats extended. Shortened glide. ## Other investigations on N173K (3) 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 ANC80FAA15](https://openairdocs.org/ntsb/ANC80FAA15), Jun 28, 1980: Helio Acft H-250 (N173K), Northway, AK, substantial damage - [NTSB LAX67F0059](https://openairdocs.org/ntsb/LAX67F0059), Aug 2, 1966: Helio H-391B (N173K), Van Nuys, CA, substantial damage - [NTSB UNK65X0217](https://openairdocs.org/ntsb/UNK65X0217), Oct 10, 1964: Helio 391B (N173K), Perry, FL, 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.