OpenAirDocs.org

19970606016789A

Accident · Destroyed
Open the Markdown

FAA accident report · Bell 206L-1 · Highland, CA · June 6, 1997

FAA Aviation Safety Information PortalNTSB investigation search

© OpenStreetMap
Date
June 6, 1997 · 17:03 local
Place
Highland, CA
Phase of flight
Low Level Operations
Operating rules
General operating rules (Part 91)
Damage
Destroyed
Aircraft
N27591
Reported as
Bell 206L1
Reported engine
Allison 250C30P
People aboard
1
Fatal injuries
1
Pilot’s flight hours
11,000 total2,900 in this make and model61 in the last 90 days
N27591Registration cancelled May 15, 2013 · Bell Helicopter Textron 206L-1S/N 45273Airframe modelBell Helicopter Textron 206L-1

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

Helicopter crashed during fire suppression operations, unable to radio mayday, engine flamed out. (.4) after a water drop, the aircraft made an abrupt pull up and turn. An inspection revealed that the lines from the engine fuel nozzle to the fuel control and the airframe fuel filter contained fuel. Both fuel boost pump circuit breakers were in the set position; however, the engine was not equipped with auto ignition. The lines and in-line filters contained both fuel and particulate matter in the botton of both filter housings. Testing revealed that the manifold check valve leaked from both inlet ports. When the valves were disassembled additional foreign material was found. Additional testing revealed that the valves installed at theinlet connection also leaked due to similar contamination. Leaking valves can reduce the motive volumn of fuel to the aft fuel cell resulting in an abnormally low fuel level in the aft fuel cell. If the operating boost pumps are unported, such as through an intentionally abrupt maneuver, air can be 'sucked' into the engine by the engine-driven fuel pump resulting in the extinction of the ingnition flame. The pilot monitored his remaining fuel with a cl ock rather than by low fuel lights or fuel gauge.

As the FAA filed it

HELICOPTER CRASHED DURING FIRE SUPPRESSION OPERATIONS, UNABLE TO RADIO MAYDAY, ENGINE FLAMED OUT. (.4) AFTER A WATER DROP, THE AIRCRAFT MADE AN ABRUPT PULL UP AND TURN. AN INSPECTION REVEALED THAT THE LINES FROM THE ENGINE FUEL NOZZLE TO THE FUEL CONTROL AND THE AIRFRAME FUEL FILTER CONTAINED FUEL. BOTH FUEL BOOST PUMP CIRCUIT BREAKERS WERE IN THE SET POSITION; HOWEVER, THE ENGINE WAS NOT EQUIPPED WITH AUTO IGNITION. THE LINES AND IN-LINE FILTERS CONTAINED BOTH FUEL AND PARTICULATE MATTER IN THE BOTTON OF BOTH FILTER HOUSINGS. TESTING REVEALED THAT THE MANIFOLD CHECK VALVE LEAKED FROM BOTH INLET PORTS. WHEN THE VALVES WERE DISASSEMBLED ADDITIONAL FOREIGN MATERIAL WAS FOUND. ADDITIONAL TESTING REVEALED THAT THE VALVES INSTALLED AT THEINLET CONNECTION ALSO LEAKED DUE TO SIMILAR CONTAMINATION. LEAKING VALVES CAN REDUCE THE MOTIVE VOLUMN OF FUEL TO THE AFT FUEL CELL RESULTING IN AN ABNORMALLY LOW FUEL LEVEL IN THE AFT FUEL CELL. IF THE OPERATING BOOST PUMPS ARE UNPORTED, SUCH AS THROUGH AN INTENTIONALLY ABRUPT MANEUVER, AIR CAN BE 'SUCKED' INTO THE ENGINE BY THE ENGINE-DRIVEN FUEL PUMP RESULTING IN THE EXTINCTION OF THE INGNITION FLAME. THE PILOT MONITORED HIS REMAINING FUEL WITH A CL OCK RATHER THAN BY LOW FUEL LIGHTS OR FUEL GAUGE.