# NTSB ANC93LA158: Hughes 369D, N5074R, Mount Iliamna, AK, August 28, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 27, 1993, 19:20 local (Aug 28, 1993, 03:20 UTC) - Place: Mount Iliamna, AK - Coordinates: 59.850627, -154.560974 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=59.8506&lon=-154.5610&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report June 30, 1994 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2414 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC93LA158 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2414/pdf - Page: https://openairdocs.org/ntsb/ANC93LA158 ## Probable cause THE PILOT'S IMPROPER IN-FLIGHT PLANNING/DECISION, AND HIS DELAY IN TAKING REMEDIAL ACTION. FACTORS WERE THE MOUNTAINOUS TERRAIN AND GUSTY WINDS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - turn to reverse direction - terrain condition - mountainous/hilly (contributing factor) - in-flight planning/decision - improper, pilot in command (cause) - weather condition - gusts (contributing factor) - remedial action - delayed, pilot in command (cause) ## Analysis AFTER MAKING A LOW PASS OVER A MOUNTAINOUS WORK SITE THE HELICOPTER STARTED A RIGHT TURN. THE PILOT SAID HE SOON REALIZED THAT THE HELICOPTER WOULD NOT BE ABLE TO OUT CLIMB THE STEEP TERRAIN, SO HE STARTED A TURN BACK TO THE LEFT. THEN THE RIGHT SKID HIT THE MOUNTAINSIDE, CAUSING THE SKID AND THE RIGHT HALF OF THE CROSSTUBES TO BE TORN FROM THE AIRFRAME. SOME ADDITIONAL DAMAGE WAS ALSO SUSTAINED BY THE FUSELAGE. THE HELICOPTER RETURNED TO ITS NEARBY BASE CAMP AND LANDED ON A MAKESHIFT SUPPORT STRUCTURE. THE PILOT SAID HE MIGHT HAVE ENCOUNTERED A DOWNDRAFT. THE PILOT AND FOUR PASSENGERS SAID THE WINDS WERE GUSTY AT THE TIME OF THE ACCIDENT. ## Factual narrative On August 27, 1993, at 1920 Alaska daylight time, a skid equipped Hughes 369D helicopter, N5074R, operated by Soloy Helicopters, Inc., of Wasilla, Alaska, collided with the terrain while maneuvering just northeast of Mount Iliamna, Alaska. The commercial pilot and 4 passengers were not injured, and the helicopter sustained substantial damage. The unscheduled domestic passenger flight, operating under 14 CFR Part 135, departed a remote camp in the area about 5 minutes before the accident. Visual meteorological conditions existed, and a company VFR flight plan was filed. Shortly after the accident, during a telephone interview, the pilot stated the following in part: "I had just taken off from the driller's base camp, and had made a low pass over the drill rig about 2 miles away to see if anyone there needed us for anything. I started a right turn then realized that I wouldn't be able to out climb the steep mountain, so turned back to the left. Then the right skid hit the mountainside causing the skid and crosstubes to be separated from the helicopter. The fuselage belly was also damaged. I flew back to the base camp where I landed on a makeshift support structure. I could have encountered a downdraft that caused the helicopter to settle down and hit the mountainside." ## Aircraft - Registration: N5074R (not matched to a registry record) - Reported make and model: HUGHES 369D - Category: Helicopter - Serial number: 1151D - Airframe hours: 6624 - Engines: ALLISON 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Soloy Helicopters, Inc. - Registered owner: Soloy Helicopters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 11, 1993, 81 hours before - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; commercial, private; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 5,650 total, 3,600 in this make and model, 5,540 as pilot in command, 270 in the last 90 days, 110 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 10 knots, gusting 15 - Visibility: 20 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 61 °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 19930827031619A](https://openairdocs.org/incident/19930827031619A), Aug 27, 1993: Hughes 369D, Mount Iliamna, AK, Substantial damage. Made low pass over drill rig. Skid hit mountain side on pullup. Landed safely at base on makeshift rig. 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.