# NTSB DFW07LA162: Aerospatiale SA-315, N5770F, Stuart, OK, July 14, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 14, 2007, 14:30 local (19:30 UTC) - Place: Stuart, OK - Coordinates: 34.902778, -96.077774 - Nearby events: https://openairdocs.org/map.md?lat=34.9028&lon=-96.0778&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 20, 2007 - Report: Approved by Office Director - Parties: NTSB, Turbomeca, FAA FSDO, Skydance Helicopters, Inc - NTSB case key (mKey): 66249 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW07LA162 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66249/pdf - Page: https://openairdocs.org/ntsb/DFW07LA162 ## Probable cause The loss of engine power due to a clogged fuel tube. A contributing factor was the lack of suitable terrain for the forced landing. ## Analysis The helicopter experienced a loss of engine power while hovering out of ground effect while performing external load operations. While moving a heavy load , the helicopter's fuel light was reported to have flickered. The company's mechanic drained the tank, purged the fuel lines, and replaced the fuel filter. The helicopter was then filled with "clean fuel" and test flown for approximately 30-minutes; with no problems noted. After moving 2 or 3 more loads, and while repositioning the next load, the pilot "felt the engine surge slightly". All engine instruments appeared to be in the normal range and the pilot elected to continue to move the external load. The engine then "cut back to ground idle' and the helicopter descended through the trees. The engine was removed from the airframe, and shipped to an engine overhaul facility for further investigation. An initial examination of the engine did not reveal any pre-impact anomalies. The engine was placed in a test cell for a full run-up. Two engine starts were attempted; however, the engine failed to start. After the first attempt, the idling device strainer was found clogged and was replaced. The engine was disassembled after the second failed attempt and the examination revealed that the fuel tube was clogged, and fuel was not getting to the fuel injection wheel in the engine. Fuel samples taken at the accident scene and at the engine examination, failed to find containments in the fuel. A lab test of the substance that was found in the fuel tube, failed to identify the foreign substance. ## Factual narrative On July 14, 2007, approximately 1430 central daylight time, a single-engine, turbine powered Aerospatiale SA-315 helicopter, N5770F, was substantially damaged during a forced landing following a loss of engine power while performing long-line external load operations near Stuart, Oklahoma. The commercial pilot, sole occupant of the helicopter, was not injured. The helicopter was owned and operated by Skydance Northwestern, Inc., of Minden, Nevada. Visual meteorological conditions prevailed, and a flight plan was not filed for the external load flight conducted under the provisions of 14 Code of Federal Regulations Part 133. The pilot stated in the accident report (NTSB Form 6120.1), that while moving a heavy load on the external load, he noticed the fuel light "flickering." The helicopter returned to the base and reported the event. The pilot reported that a mechanic drained the fuel tank, purged the fuel lines, and replaced the engine fuel filter. The helicopter was then filled with "clean fuel" and test flown for approximately 30-minutes; with no problems noted. The pilot then resumed moving drills, and after moving 2 or 3 additional drills, and while repositioning to pick-up the next load, he felt "the engine surge slightly" so he elected to set the load back on the ground to scan the engine instruments. The engine instruments appeared normal and the pilot continue to move his load. The pilot added that when he applied engine power, the engine "cut back to ground idle" and the helicopter descended through the trees. The Federal Aviation Administration inspector, who responded to the accident scene, reported the helicopter sustained structural damage during the forced landing. Fuel samples were taken by the operator and sent to a private lab for analysis. The engine was removed from the airframe, and shipped to Heli-Support, Inc., in Fort Collins, Colorado, for further investigation. An initial engine examination was conducted on 29 August 2007, with representatives from the operator, engine manufacturer, and the NTSB present. The initial examination of the engine did not reveal any pre-impact anomalies. Additional fuel samples were taken and sent to a second lab. The engine was then placed in a test cell for an engine run. Two engine starts were attempted; however, the engine failed to start. After the first attempt, the idling device strainer was found clogged and was replaced. The engine was disassembled after the second failed attempt and the examination revealed that the fuel tube was clogged, and fuel was not getting to the injection wheel in the engine. Results of the fuel samples taken, failed to find containments in the fuel. A lab test of the substance that was found in the fuel tube, failed to identify the substance. A source for the contamination was not found. At 1453, the automated weather observing system at MLC, located approximately 15 miles from the accident site, reported variable winds at 6 knots, 10 statute miles visibility, scattered clouds at 4,200 feet, temperature 86 degrees Fahrenheit, dew point 67 degrees Fahrenheit, and an altimeter setting of 29.94 inches of Mercury. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, hover - out of ground effect - fuel system - blocked(total) (cause) - Forced landing, descent - emergency - In flight collision with object, emergency landing - object - tree(s) - terrain condition - none suitable (contributing factor) ## Aircraft - Registration: [N5770F](https://openairdocs.org/deregistered/N5770F-2020-11-21), registration cancelled 2020-11-21, S/N 2593, built 1980 (OpenAirDocs) - Reported make and model: Aerospatiale SA-315 - Registry model: [Aerospatiale SA315B](https://openairdocs.org/model/aerospatiale-sa315b) (registry code 8680615) (OpenAirDocs) - Registry engine: [Turbomeca ASTAZOU series](https://openairdocs.org/engine/turbomeca-astazou-series) (registry code 60020, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2593 - Airframe hours: 12620 - Engines: Turbomeca Artouste III 858 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Skydance Operations Inc - Registered owner: Skydance Northwestern, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 1, 2007 - Departed: Stuart, OK - Destination: Stuart, OK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; commercial; medical: class 3, without waivers/limitations; last flight review September 1, 2006; seat: right; flight hours: 7,000 total, 250 in this make and model, 6,800 as pilot in command, 250 in the last 90 days, 20 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 66 °F - Altimeter: 29.94 inHg - Observed at: MLC ## 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 20070714012599A](https://openairdocs.org/incident/20070714012599A), Jul 14, 2007: Aerosp SA315B, Stuart, OK, Substantial damage. (-23) Aircraft was connected to a 120' longline and was just about to reposition a drill which weighed about 1,500 lbs. Just as he lifted the load a few… ## Other investigations on N5770F (1) 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 DEN83LA095](https://openairdocs.org/ntsb/DEN83LA095), Mar 30, 1983: Aerospatiale SA 315B (N5770F), Craig, CO, no 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.