OSF AVIATION LLC
Also recorded as: OSF AVIATION LLC
Accident & enforcement record
Events that happened, regardless of the operator's own reporting. Each links to its public source.
NTSB accidents & incidents
Operated by OSF AVIATION LLC. (per NTSB report)
The flight instructor's incorrect cyclic control during a hover, which resulted in a hard landing.
Operated by OSF AVIATION LLC (per NTSB report)
The loss of the number one hydraulic system fluid and hydraulic pressure during cruise due to the failure of the bolts that secure the hydraulic pump's cover.
FAA enforcement actions
No FAA enforcement actions linked to this operator.
Maintenance disclosure history
Service Difficulty Reports are self-reported maintenance findings. The NUMBER of reports is not a measure of reliability — diligent operators file more, not fewer. These are shown for transparency, not as a negative signal. To verify a report, search its control number at the FAA SDRS site.
Reports span 2007–2026. Most-reported systems: Electrical power (24) — 8; Tail rotor drive (65) — 6; Engine (72) — 5; Engine indicating (77) — 5; Air conditioning & press. (21) — 3 (top 5 of 18 systems, covering 27 of 51 coded reports). Most-common natures of condition, as filed: WARNING INDICATION — 21; FALSE WARNING — 8; OTHER — 6; OVER TEMP — 3; SMOKE/FUMES/ODORS/SPARKS — 3 (top 5 of 12 conditions, covering 41 of 51 coded reports).
51 reports on file — showing most recent 50.
Part: BLOWER MOTOR — BROKEN (ZONE 200) · airframe 9,713 hrs · 26,745 cycles
UNUSUAL NOISE FROM THE PASSENGER BLOWER MOTOR.
Part: BLOWER — FAULTY (ZONE 200) · airframe 9,682 hrs · 26,652 cycles
DURING TAKEOFF IT WAS NOTED AN UNUSUAL NOISE WAS HEARD IN THE CABIN OVERHEAD FOLLOWED BY AN ODOR. ABORTED TAKEOFF AND SHUT DOWN AIRCRAFT.
Part: GCU — FAILED (ZONE 200) · airframe 9,683 hrs · 26,628 cycles
NR 1 GENERATOR DISCONNECT ON THE CAD. RESET ATTEMPTED AND STILL DISCONNECTED. PATIENT FLIGHT ABORTED DUE TO MEL RESTRICTION OF DAY VFR ONLY.
Part: GCU — FAILED (ZONE 200) · airframe 9,683 hrs · 26,628 cycles
NR 1 GENERATOR DISCONNECT ON THE CAD. RESET ATTEMPTED AND STILL DISCONNECTED. PATIENT FLIGHT ABORTED DUE TO MEL RESTRICTION OF DAY VFR ONLY.
Part: GCU — FAILED (ZONE 200) · airframe 9,683 hrs · 26,628 cycles
NR 1 GENERATOR DISCONNECT ON THE CAD. RESET ATTEMPTED AND STILL DISCONNECTED. PATIENT FLIGHT ABORTED DUE TO MEL RESTRICTION OF DAY VFR ONLY.
Part: GCU — FAILED (ZONE 200) · airframe 9,685 hrs · 26,628 cycles
NR 1 GENERATOR DISCONNECT DISPLAYED ON THE CAD. RESET GENERATOR TO NO AVIAL. DUE TO MEL RESTRICTIONS OF DAY VFR ONLY FLIGHT WAS ABORTED.
Part: GCU — FAILED (ZONE 200) · airframe 9,683 hrs · 26,628 cycles
#1 GENERATOR DISCONNECT LIGHT DISPLAYED ON CAD. CONFIRMED LOSS OF GENERATOR. RESET ATTEMPTS FAILED. ABORTED FLIGHT AS MEL ONLY ALLOWED DAY VFR AND COULD NOT COMPLETE THE PATIENT TRANSFER BEFORE SUNSET.
Part: ELEC CONNECTOR — DIRTY (ZONE 300) · airframe 9,068 hrs · 25,076 cycles
YAW ACTUATOR LIGHT ILLUMINATED ON AUTO PILOT TEST. INSPECTED, CLEANED, AND RESEATED THE YAW SEMA CANNON PLUG PROBLEM WENT AWAY.
Part: PROBE — FAULTED (ENGINE TEMP) · airframe 9,029 hrs · 24,976 cycles
DURING START UP PILOT REPORTED POSSIBLE OVER TEMP OF ENGINE. AFTER FURTHER INSPECTION FOUND A BAD TEMP PROBE.
Part: WIRE — CHAFED (TAIL ROTOR) · airframe 9,235 hrs · 25,440 cycles
PILOT REPORTED TR CHIP CT ON WARNING UNIT DURING STARTUP. FLIGHT WAS THEN ABORTED. MX FOUND A CHAFED WIRE ON THE TAIL SECTION THAT CAUSED CONTINUITY TEST TO FAIL. WIRE WAS REPAIRED AND AIRCRAFT WENT BACK IN SERVICE.
Part: PROBE — FAULTY (ENG BAY) · airframe 9,044 hrs · 25,445 cycles
DURING START UP THE PILOT NOTED A HIGH RISE IN TEMP WHICH EXCEEDED ALLOWABLE TEMP FOR START. IMMEDIATELY SHUT THE ENGINE DOWN. CONTACTED MX. PER THE MX MANUAL NO TEMPS WERE EXCEEDED PER THE MX MANUAL ONLY THE "ALLOWABLE" LIMIT FOR PILOT START. FURTHER TROUBLESHOOTING FOUND A FAULTY TEMP PROBE WHICH WOULD HAVE CAUSED A HIGHER THAN NORMAL TEMP DURING THE START. CHANGED THE TEMP PROBE AND ENGINE STARTED NORMAL.
Part: VARTOMS — FAULTED · airframe 9,144 hrs · 25,211 cycles
VARTOMS SYSTEM KICKED INTO MANUAL MODE AS ENGINES COULDN'T HOLD TORQUE MATCHING AT THE SPECIFIC POWER SETTING. SYSTEM WAS TROUBLESHOT AND FOUND TO BE WITHIN ALL PARAMETERS. NO DEFECTS NOTED DURING TEST FLIGHTS.
Part: ENGINE — FAULTED · airframe 8,764 hrs
ENGINE WOULD NOT START. THE ENGINE WAS FLOODED WITH FUEL
Part: TERMINAL BLOCK — FAILED (NR 2 ENGINE) · airframe 8,695 hrs · 24,572 cycles
PATIENT ONBOARD FOR DEPARTURE #2 ENGINE WOULD NOT START. FOUND A BAD TERMINAL BOARD AND BUS TIE RELAY.
Part: CONTROL BOX — DISENGAGED (VARTOMS) · airframe 8,483 hrs · 23,596 cycles
DURING DECENT THE VARTOMS SYSTEM DISENGAGED. CAUSING THE NUMBER 1 ENGINE TORQUE TO DECREASE. THE PILOT WAS UNABLE TO GET THE TORQUES MATCHED MANUALLY. ABORTED THE LANDING AND PROCEEDED TO AN AIRPORT TO PERFORM A PRECAUTIONARY LANDING. AFTER EXTENSIVE TROUBLESHOOTING AND CONTACT WITH TECH SUPPORT, WE COULD NOT DUPLICATE THE ISSUE OR FIND ANY FAULTS WITH THE SYSTEM.
Part: STATIC INVERTER — FAILED · airframe 8,414 hrs · 23,868 cycles
LOSS OF ALL MED CREW LIGHTING AND POWER RECEPTACLES
Part: WARNING MESSAGE — FALSE ACTIVATION · airframe 8,393 hrs · 23,810 cycles
ON APPROACH PILOT OBSERVED CAUTION ON THE CAD FOR AP1 ACTUATOR WITH A P ON THE PFD. THIS WAS DURING EXTREME COLD TEMPERATURES. COULD NOT DUPLICATE.
Part: MOTOR — DISENGAGED (VARTOMS) · airframe 8,620 hrs
ON APPROACH THE VARTOMS SYSTEM DISENGAGED AND TORQUE MATCHING HAD TO BE PERFORMED MANUALLY
Part: COLL PITCH CNTR — ABNORMAL · airframe 8,350 hrs
COLLECTIVE FRICTION WAS TOO LIGHT ALLOWING COLLECTIVE TO FALL WHEN HANDS OFF CONTROLS. FOUND THE COLLECTIVE FRICTION KNOB FULLY LOOSENED AND NOT TIGHTENED TO INPUT COLLECTIVE FRICTION ON THE COLLECTIVE ALLOWING THE CONSTANT POWER TO BE MAINTAINED.
Part: ROD END — WORN (UNKNOWN) · airframe 7,882 hrs · 21,934 cycles
VIBRATION FELT IN A HOOVER. FOUND ROD END BEARING WORN ON MAIN ROTOR PITCH LINK.
Part: UNKNOWN — UNKNOWN (UNKNOWN) · airframe 7,838 hrs
PILOT PFD AND ND WENT BLANK WITH AHRS INDICATION. CLEANED CONNECTOR PLUG GOING INTO MODE SELECT PANEL COULD NOT DUPLICATE THE ISSUE.
Part: GAUGE — DEBONDED (ZONE 200) · airframe 7,811 hrs
MAST MOMENT WAS EXCEEDED IN A HOVER. LANDED THE AIRCRAFT WITH NO ISSUES. AFTER TROUBLESHOOTING FOUND THE STRAIN GAUGE IN THE MAST HAD DEBONDED CAUSING A FALSE INDICATION IN THE COCKPIT.
Part: ENGINE — ABNORMAL (UNKNOWN) · airframe 7,413 hrs
#2 ENGINE CHIP LIGHT AFTER START. BURNT CHIP AND IT CAME BACK. SHUTDOWN AND CALLED MX
Part: ENGINE — MAKING METAL (#1) · airframe 7,216 hrs
DURING CRUISE #1 ENGINE WARNING. AFTER 2 ATTEMPTS TO BURN THE LIGHT REMAINED ON. POWER WAS REDUCED AND PLANNING FOR A PRECAUTIONARY LANDING BEGAN. THE ENGINE WAS THEN SHUT DOWN AND A RUN-ON LANDING WAS PERFORMED WITH NO FURTHER INCIDENT. AFTER INSPECTION THE ENGINE WAS DETERMINED UNAIRWORTHY AND WAS REMOVED AND REPLACED.
Part: ENGINE — MAKING METAL (#1) · airframe 7,371 hrs
DURING CRUISE FLIGHT THE #1 ENGINE CHIP LIGHT ILLUMINATED. AFTER 2 ATTEMPTS TO BURN THE LIGHT REMAINED ON. THE ENGINE POWER WAS REDUCED AND PLANNING FOR PRECAUTIONARY LANDING BEGAN. THE ENGINE WAS THEN SHUT DOWN AND A RUN-ON LANDING WAS PERFORMED WITH NO FURTHER INCIDENTS. THE CHIP PLUG WAS INSPECTED REF MM AND TECH SUPPORT. PLUGS CLEANED AND GROUND RUNS WERE PERFORMED, THE AIRCRAFT WAS RETURNED TO SERVICE.
Part: ENGINE — ABNORMAL · airframe 7,136 hrs
ENGINE OVER TEMP ON START. T4 CIRCUIT BOARD TT UNKNOWN
Part: PRESSURE SENSOR — ABNORMAL (#1 ENGINE) · airframe 6,702 hrs
FUEL PRESSURE SENSOR FAILED
Part: TACHOMETER — FAILED · airframe 6,511 hrs
TRIPLE TACH WOULDN'T PASS SELF TEST ON START UP
Part: TACHOMETER — FAILED (MAIN ROTOR) · airframe 6,466 hrs
1&2 NP AND ROTOR RPM INDICATOR (TRIPLE TAC) WAS INOP DURING THE START SEQUENCE.
Part: GEARBOX — MAKING METAL (TAIL ROTOR) · airframe 6,370 hrs
RECEIVE T\R CHIP WARNING. ON SHORT FINAL TO LANDING SO NO TIME TO BURN. FOUND A SMALL SLIVER ON THE 90 DEGREE G\B. FOLLOWED MANUFACTURES RECOMMENDED PROCEDURES. NO FURTHER ISSUES
Part: CONNECTOR — DIRTY (ENGINE) · airframe 6,315 hrs
FLIGHT # 03766 - RIGHT AFTER LIFT OFF FROM GBG BASE APRON, ANALOG TRIPLE TACH GAVE ERRATIC INDICATIONS SHOWING #1 NEEDLE DROPPING TO 80-83 RANGE AND BOUNCING BACK UP TO MATCH ROTOR AND NUMBER 2. SIMULTANEOUSLY, VARTOMS DROPPED TO MANUAL MODE AND NG1 SPLIT TO HIGH SIDE, GIVING APPEARANCE OF TRYING TO DRAG THE NG2 UP. TURNED THE AIRCRAFT BACK TO THE APRON AND LANDED PROMPTLY WITHOUT FURTHER INCIDENT.
Part: OIL SYSTEM — LEAKING (NR 1 ENGINE)
IN CRUISE FLIGHT #1 ENGINE OIL PRESSURE LIGHT CAME ON ENGINE OIL TEMP STARTED TO RISE FOLLOWED BY DEC4REASING ENGINE TORQUE INDICATION. PILOT SHUTDOWN #1 ENGINE AND PERFORMED A RUNNING LANDING AT KYVS. INVESTIGATION SHOWED LOSS OF OIL IN ENGINE RESERVOIR AND AND BURNT OI AT THE POWER TURBINE WHEEL AT THE BACK OF THE ENGINE. ENGINE WAS REPLACED AND THE SUSPECT ENGINE WILL BE SENT TO THE MANUFACTURER FOR FURTHER INVESTIGATION.
Part: WARNING MESSAGE — FALSE ACTIVATION (ACTUATOR) · airframe 4,732 hrs · 13,991 cycles
DURING FLIGHT, ACTUATOR CAUTION APPEARED ON CAD. PILOT DECIDED TO LAND AT BMI AIRPORT INSTEAD OF HIS DESTINATION AT HOSPITAL. COULD NOT DUPLICATE FAULT AFTER A POWER CYCLE.
Part: INDICATOR — INOPERATIVE (LOW ROTOR) · airframe 4,722 hrs · 13,938 cycles
AIRCRAFT WAS PULLED INTO A HOVER AND THE LOW ROTOR WARNING SOUNDED AND THE ROTOR RPM READ ZERO. AIRCRAFT LANDED AND FLIGHT WAS CANCELLED.
Part: CHIP DETECTOR — CONTAMINATED (MR GEARBOX) · airframe 3,836 hrs · 11,298 cycles
M/R GEARBOX CHIP LIGHT ILLUMINATED DURING HOVER. MECHANIC INSPECTED CHIP PLUGS AND FOUND NORMAL FUZZ PER MM. CLEANED CHIP PLUGS AND PERFORMED 10 MINUTE HOVER CHECK AND FOUND NO DEBRIS ON CHIP PLUGS. RETURNED AIRCRAFT TO SERVICE.
Part: WARNING MESSAGE — ILLUMINATED (FUEL PUMP) · airframe 3,665 hrs · 10,717 cycles
DURING CRUISE FLIGHT F PUMP AFT WARNING APPEARED ON THE CAD. ABORTED FLIGHT AND RETURNED TO BASE AT KPIA.
Part: WIRE — PINCHED (BACKLIGHTING) · airframe 3,075 hrs · 9,149 cycles
ENROUTE TO HOSPITAL, THERE WAS A BRIGHT FLASH IN COCKPIT AND A BURNED ELECTRICAL ODOR. AIRCRAFT TURNED BACK TO BASE AND CONTACTED FLIGHT COM. AFTER A FEW MOMENTS THE SMELL CEASED SO THEY CONTINUED BACK TO BASE. BOUT I MINUTE FROM LANDING ANOTHER FLASH APPEARED IN THE COCKPIT FROM THE OVERHEAD CIRCUIT BREAKER PANEL AND THEY LANDED AT THE AIRPORT AND CONTACTED MAINTENANCE. MAINTENANCE FOUND THE WIRING FOR THE CIRCUIT PANEL BACKLIGHTING WAS PINCHED BETWEEN THE PANEL AND THE AIRFRAME CAUSED BY WORK BEING DONE IN THAT AREA EARLIER THAT DAY. THE WIRING WAS REPAIRED AND REROUTED TO PREVENT THIS FROM HAPPENING AGAIN. THE AIRCRAFT WAS RETURNED TO SERVICE.
Part: SWITCH — STICKING (THROTTLE) · airframe 2,927 hrs · 8,823 cycles
DURING STARTUP, THE NR 1 ENGINE TWIST GRIP LIGHT REMAINED ILLUMINATED. THE AIRCRAFT WAS SHUTDOWN AND MAINTENANCE WAS NOTIFIED. FOUND THE SWITCH WAS STICKING AND OUT OF ADJUSTMENT. THE SWITCH WAS CLEANED AND ADJUSTED AND THE AIRCRAFT WAS RETURNED TO SERVICE.
Part: WARNING LIGHT — FALSE ACTIVATION (COCKPIT) · airframe 1,795 hrs · 5,277 cycles
TAIL ROTOR GEARBOX CHIP LIGHT OCCURRED OVER AIRPORT, MADE PRECAUTIONARY LANDING. FINISHED PATIENT TRANSPORT BY GND AMBULANCE.
Part: WIRE — BROKEN (NR 1 GENERATOR) · airframe 1,326 hrs · 3,989 cycles
ON FINAL APPROACH, NR 1 GEN DISCONNECT APPEARED ON CAD. AFTER SEVERAL ATTEMPTS TO RESET GENERATOR, IT REMAINED OFFLINE. THE ACFT LANDED AND MAINTENACE WAS CONTACTED. A MECHANIC WENT TO ACFT AND DEFERRED THE DISCREPANCY AND THE ACFT WAS FLOWN TO THE MAIN MAINTENACE FACILITY. THE NEXT DAY A BROKEN WIRE WAS DISCOVERED AT THE NR 1 GENERATOR.
Part: ACTUATOR — FAULTY (TAIL BOOM) · airframe 1,483 hrs · 4,444 cycles
AS AIRCRAFT WAS PICKED UP INTO A HOVER CAD WARNING ACTUATOR APPEARED WITH THE ASSOCIATED Y ON THE PILOTS PRIMARY FLIGHT DISPLAY. AIRCRAFT WAS LANDED, SYSTEM WAS RESET AND PICKED UP INTO A HOVER WITH THE SAME RESULT. AIRCRAFT LANDED, FLIGHT DISCONTINUED AND MAINTENANCE WAS CALLED.
Part: UNKNOWN — ODOR (COCKPIT) · airframe 1,406 hrs · 4,164 cycles
ON LEVEL OFF AND INTO CRUISE FLIGHT, MED CREW DETECTED A STRONG FUEL ODOR IN CABIN. ODOR THEN SPREAD TO COCKPIT. FLIGHT ABORTED AND RETURNED TO PAD. ACFT INSPECTED FOR FUEL LEAKS NONE FOUND. TOOK TWO ATTEMPTS TO START NR 2 ENGINE AND ODOR IS BELIEVED TO BE EXCESS FUEL FROM THE ABORTED FIRST START.
Part: GEARBOX — MAKING METAL (TAIL ROTOR) · airframe 1,380 hrs · 4,083 cycles
DURING APPROACH, TAIL ROTOR CHIP LIGHT ILLUMINATED, ATTEMPT TO BURN THE CHIP WAS UNSUCCESSFUL AND A LANDING WAS MADE. DUE TO METAL IN THE TAIL ROTOR GEARBOX THE UNIT WAS REPLACED.
Part: ENGINE — POWER LOSS · airframe 1,089 hrs · 3,235 cycles
BRIEFLY BEFORE ENTERING CRUISE FLIGHT, BOTH ENGINE CAD DISPLAYS SHOWED ENG PA DIS. ALSO ROTOR RPM DROPPED TO THE POINT OF WP LIGHT AND HORN. PILOT LOWERD POWER AND ATTEMPTED TO BEEP UP RPM. LOWERING POWER BROUGHT UP ROTOR RPM. AFTER CONSULTING CHECKLIST FOR WARNINGS, PILOT DECIDED TO ATTEMPT RUNWAY LANDING IN CASE THERE WAS NOT ENOUGH POWER TP HOVER. AT 5 FEET THERE THERE WAS SUFFICIENT POWER AND ROTOR RPM TO HOVER SO PILOT OPTED TO HOVER OVER TO HANGAR TO LAND. ACFT WAS TAKEN OUT OF SERVICE AND MAINTENANCE CONTACTED.
Part: VALVE — BYPASSING (NR 1 OVERSPEED)
NR 1 ENGINE WAS LOW. TROUBLESHOT AND FOUND NR 1 OVERSPEED VALVE BYPASSING AIR. PART HAD BEEN INSTALLED FOR 115.4 HRS SINCE O/H.
Part: STARTER GEN — MALFUNCTIONED (ENGINE)
GENERATOR WOULD NOT GO ON-LINE AFTER ENGINE START FOR RETURN FLIGHT BACK TO HOME BASE FROM HELIPAD AFTER PATIENT DROP-OFF.
Part: FUEL CONTROL — UNSERVICEABLE (NR1 ENGINE) · airframe 5,884 hrs
COMPONENT HAS A HISTORY OF CAUSING ENG TO MOMENTARILY DECELERATE AS THROTTLE IS ADVANCED PAST THE IDLE STOP TO FLIGHT. DECELERATION CAN BE OVERCOME BY CONTINUING TO ADVANCE THROTTLE THROUGH THE DECELERATION. ONCE THROUGH DECELERATION A MAXIMUM OF ONLY 90 PERCENT OF MAIN ROTOR RPM COULD BE ACHIEVED. ALL ENGINE INDICATING INSTRUMENTS ARE WITH IN LIMITS AT FULL OPEN THROTTLE AS WELL AS AT IDLE ABOVE AND BELOW IDLE STOP.
Part: BOLT — SHEARED (HYDRAULIC PUMP)
2 BOLTS HOLDING THE BACK PUMP COVER ON, SHEARED AND ALLOWED ALL OF THE FLUID IN THE SYSTEM TO BE PUMPED OVERBOARD CAUSING A LOSS OF THE NR 1 HYD SYS. (K)
Part: HANGER ASSY — WORN (TAIL ROTOR DRIVE) · airframe 4,225 hrs
FWD TAIL ROTOR HANGER BEARING FAILED. SAFETY STRAP WAS THE ONLY THING HOLDING DRIVESHAFT IN PLACE. PILOT AND CREW NOTICED A MOMENTARY KNOCKING NOISE AFTER NR 1 ENGINE AT IDLE ONLY. CONTACTED BELL PRODUCT SUPPORT AND REPLACED HANGER BEARING ASSY. AFTER INSPECTION.
Linked aircraft
| N-number | Make / model | Year | Status | Link basis |
|---|---|---|---|---|
| N140SF | EUROCOPTER DEUTSCHLAND GMBH MBB-BK 117 C-2 | 2010 | Valid Registration | Matched by certificate designatorOperator named in NTSB report |
| N240SF | EUROCOPTER DEUTSCHLAND GMBH MBB-BK 117 C-2 | 2010 | Valid Registration | Matched by certificate designator |
| N340SF | EUROCOPTER DEUTSCHLAND GMBH MBB-BK 117 C-2 | 2010 | Valid Registration | Matched by certificate designator |
| N440SF | EUROCOPTER DEUTSCHLAND GMBH MBB-BK 117 C-2 | 2011 | Valid Registration | Matched by certificate designator |
| N880SF | BELL 230 | — | Valid Registration | Operator named in NTSB report |
Aircraft with earlier records under this certificate
Maintenance and accident records on this page also cover aircraft that are not in this operator's current FAA fleet list. Charter and management fleets change — owners switch management companies, sell, or export aircraft. Where the registry shows what became of a tail, it is noted below.