Rotorcraft systems
Main and tail rotors, the transmissions and shafts that drive them, and the rotor controls. Helicopters carry more FAA orders per aircraft than any other kind.
Operators and repair shops have filed 17,867 failure reports about this system since 1995, 1,496 of them in the last ten years. The FAA has issued 1,348 airworthiness directives on it, the most recent November 27, 2026. The part most often named in the reports is the blade. Among model families, the Messerschmitt-Bolkow-Blohm BK 117 appears most often in the last ten years; taking fleet size into account, the Robinson R22 has the highest rate among sizeable fleets, about 2.7 reports a year for every 100 aircraft.
Failure reports by year as filed with the FAA
Failure reports by year, as a table
| reports | |
|---|---|
| 95 | 1,558 |
| 96 | 1,523 |
| 97 | 1,627 |
| 98 | 1,681 |
| 99 | 1,487 |
| 00 | 796 |
| 01 | 1,292 |
| 02 | 1,326 |
| 03 | 1,665 |
| 04 | 587 |
| 05 | 403 |
| 06 | 264 |
| 07 | 249 |
| 08 | 247 |
| 09 | 185 |
| 10 | 187 |
| 11 | 218 |
| 12 | 373 |
| 13 | 217 |
| 14 | 169 |
| 15 | 174 |
| 16 | 143 |
| 17 | 132 |
| 18 | 110 |
| 19 | 256 |
| 20 | 223 |
| 21 | 156 |
| 22 | 115 |
| 23 | 151 |
| 24 | 117 |
| 25 | 145 |
| 26 | 91 |
Models most often named last ten years
Messerschmitt-Bolkow-Blohm BK 117334Robinson R44235Robinson R22217Bell 407147Airbus Helicopters EC-135 now H13583Bell 206 JetRanger and LongRanger75Agusta Aerospace Corp AW13965Airbus Helicopters AS350 AStar (Écureuil), now H12553Sikorsky S-9239Hughes 369 500 series helicopters36Agusta Aerospace Corp AW11932Airbus Helicopters EC 130 now H13030
Model families most named, as a table
Highest rate, fleets of 500 or more reports a year per 100 aircraft registered
Parts most often named
Blade156Bearing151Actuator142Tachometer104Gearbox81Dual Tachometer56Transmission52V-Belt47Bolt42Servo38Chip Detector37Fitting23
Parts most reported, as a table
| reports | |
|---|---|
| Blade | 156 |
| Bearing | 151 |
| Actuator | 142 |
| Tachometer | 104 |
| Gearbox | 81 |
| Dual Tachometer | 56 |
| Transmission | 52 |
| V-Belt | 47 |
| Bolt | 42 |
| Servo | 38 |
| Chip Detector | 37 |
| Fitting | 23 |
Who made the parts named last ten years, as the reports code them
Robinson Helicopter CO INC424Group Economique Airbus Industrie227Bell Helicopter CO. Div. Textron INC148Messerschmitt-Bolkow-Blohm91Agusta-Bell S.P.A.78Sikorsky Aircraft53Eurocopter46The Boeing CO32S.N.I.A.S.27Douglas A/C CO Mcdonnel Douglas CORP9
Part makers most named, as a table
| reports | |
|---|---|
| Robinson Helicopter CO INC | 424 |
| Group Economique Airbus Industrie | 227 |
| Bell Helicopter CO. Div. Textron INC | 148 |
| Messerschmitt-Bolkow-Blohm | 91 |
| Agusta-Bell S.P.A. | 78 |
| Sikorsky Aircraft | 53 |
| Eurocopter | 46 |
| The Boeing CO | 32 |
| S.N.I.A.S. | 27 |
| Douglas A/C CO Mcdonnel Douglas CORP | 9 |
What was wrong with them the condition reported
Cracked269Defective177Failed112Making Metal75Worn70Corroded64Damaged55Inoperative52Brinelled47Leaking45
Conditions most reported, as a table
| reports | |
|---|---|
| Cracked | 269 |
| Defective | 177 |
| Failed | 112 |
| Making Metal | 75 |
| Worn | 70 |
| Corroded | 64 |
| Damaged | 55 |
| Inoperative | 52 |
| Brinelled | 47 |
| Leaking | 45 |
Where in the system the FAA's codes
Main rotor 204Main rotor drive 195Main rotor drive 184Main rotor 160Main rotor 128Rotors flight control 124Tail rotor 68Main rotor 60Tail rotor drive 60Main rotor drive 57Rotors flight control 52Main rotor 51
What was wrong last ten years · share of 1,639 reports that say
a warning light or message211 (13%)flight controls affected141 (9%)vibration or buffeting107 (7%)a false warning29 (2%)poor quality control14 (0.9%)came apart in flight10 (0.6%)significant failure8 (0.5%)no warning when there should have been7 (0.4%)
As a table
| reports | share | |
|---|---|---|
| a warning light or message | 211 | 13% |
| flight controls affected | 141 | 9% |
| vibration or buffeting | 107 | 7% |
| a false warning | 29 | 2% |
| poor quality control | 14 | 0.9% |
| came apart in flight | 10 | 0.6% |
| significant failure | 8 | 0.5% |
| no warning when there should have been | 7 | 0.4% |
When it was found last ten years · share of 1,639 reports that say
inspection or maintenance583 (36%)cruise187 (11%)taxiing or ground handling76 (5%)air ambulance work73 (4%)hovering52 (3%)climb36 (2%)landing25 (2%)take-off24 (1%)
As a table
| reports | share | |
|---|---|---|
| inspection or maintenance | 583 | 36% |
| cruise | 187 | 11% |
| taxiing or ground handling | 76 | 5% |
| air ambulance work | 73 | 4% |
| hovering | 52 | 3% |
| climb | 36 | 2% |
| landing | 25 | 2% |
| take-off | 24 | 1% |
What the crew did last ten years · share of 1,639 reports that say
an unscheduled landing266 (16%)an aborted take-off100 (6%)a return to the gate23 (1%)an emergency descent19 (1%)an engine shut down11 (0.7%)an autorotation3 (0.2%)
As a table
| reports | share | |
|---|---|---|
| an unscheduled landing | 266 | 16% |
| an aborted take-off | 100 | 6% |
| a return to the gate | 23 | 1% |
| an emergency descent | 19 | 1% |
| an engine shut down | 11 | 0.7% |
| an autorotation | 3 | 0.2% |
Who filed the report last ten years · share of 1,639 reports that say
a repair station (Part 145)899 (55%)a charter or commuter operator (Part 135)569 (35%)a non-certificated international operator65 (4%)a mechanic37 (2%)a private or corporate operator (Part 91)21 (1%)a foreign carrier (Part 129)19 (1%)an airline (Part 121)9 (0.5%)the FAA7 (0.4%)
As a table
| reports | share | |
|---|---|---|
| a repair station (Part 145) | 899 | 55% |
| a charter or commuter operator (Part 135) | 569 | 35% |
| a non-certificated international operator | 65 | 4% |
| a mechanic | 37 | 2% |
| a private or corporate operator (Part 91) | 21 | 1% |
| a foreign carrier (Part 129) | 19 | 1% |
| an airline (Part 121) | 9 | 0.5% |
| the FAA | 7 | 0.4% |
How it was found last ten years · share of 1,639 reports that say
a visual inspection598 (36%)magnetic particle39 (2%)a functional check26 (2%)borescope12 (0.7%)dye penetrant11 (0.7%)eddy current8 (0.5%)ultrasound1 (0.1%)a magnified visual inspection1 (0.1%)
As a table
| reports | share | |
|---|---|---|
| a visual inspection | 598 | 36% |
| magnetic particle | 39 | 2% |
| a functional check | 26 | 2% |
| borescope | 12 | 0.7% |
| dye penetrant | 11 | 0.7% |
| eddy current | 8 | 0.5% |
| ultrasound | 1 | 0.1% |
| a magnified visual inspection | 1 | 0.1% |
FAA orders 1,348 airworthiness directives · newest first
2026-11-272026-21-05 · Engine/transmission coupling
2026-11-122026-21-10 · Tail rotor gearbox
2026-11-052026-20-08 · Tail rotor drive system
2026-11-022026-19-02 · Main rotor blades
2026-10-222026-18-10 · Rotorcraft tail boom
2026-10-162026-20-07 · Engine exhaust system
2026-10-132026-20-06 · Main rotor gearbox
2026-10-022026-17-07 · Main rotor mast/swashplate
2026-09-182026-16-10 · Tail rotor drive shaft
2026-09-172026-16-03 · Tail Rotor Drive System
2026-09-102026-15-17 · Main Rotor Gearbox
2026-09-102026-16-02 · Tail rotor system
All 1,348 orders on this system
Orders by decade
Who makes and modifies it
Approved modifications 238 · the companies holding the most
Pratt & Whitney Engine Services INC. 19American Eurocopter Corporation 14Devore Aviation Corporation of America, A New Mexico Corporation 12Columbia Helicopters INC 10Aerometals 9Bell Helicopter Textron INC. 9Scott'S Bell 47 INC 8Van Horn Aviation LLC 7Croman Corporation 6Helicopter Technology CO 6
Engine series most often named last ten years
Lycoming O-360-J2A 153Lycoming IO-540-AE1A5 126Lycoming O-540-F1B5 85Allison (Rolls-Royce) 250-C47B 34Turbomeca (Safran) ARRIEL 2B1 22Allison (Rolls-Royce) 250-C20B 17Turbomeca (Safran) ARRIEL 2D 16Lycoming O-320-B2C 11Pratt & Whitney Canada PW207D 11Turbomeca (Safran) ARRIEL 1E2 11Allison (Rolls-Royce) 250-C30P 10Pratt & Whitney Canada PT6B-37A 9
Safety bulletins 20 · advice, not orders
2024-10-292024-05 · Engine/Transmission Coupling, Gearmotor Assembly
2023-02-142023-01 · MAIN ROTOR BLADES; Brinelled Main Rotor Blade Spindle Bearing
2022-04-11AIR-22-08 · MAIN ROTOR DRIVE SYSTEM,TAIL ROTOR DRIVE SYSTEM
2019-04-04SW-19-05 · Tail Rotor Drive System, Spline Damage
2019-02-19SW-18-29R1 · Rotorcraft Tail Boom, Attach Structure Failure
2018-10-01SW-18-29 · Rotorcraft Tail Boom, Attach Structure Failure
Sources: FAA service difficulty reports (yearly files since 1995, grouped by the FAA's four-digit system code into this site's fourteen systems), airworthiness directives, supplemental type certificates, technical standard order authorisations and special conditions from the FAA's Dynamic Regulatory System. Rates per 100 aircraft use today's register as the fleet; they show reporting as much as reliability, and commercial fleets report more. Connections as data: /graph/system/rotorcraft.json.