# Franklin 6V4 series

- Type: Engine model (FAA registry)
- Registry code: 27033
- Manufacturer (registry): FRANKLIN
- Model: 6V4 SERIES
- Engine type: Reciprocating
- Power: 210 hp
- Data sheet: [TCDS E-244](https://openairdocs.org/tcds/E-244) (OpenAirDocs)
- Holder: Franklin Sp. z.o.o.
- Installed in: 84 registered aircraft
- Page: https://openairdocs.org/engine/franklin-6v4-series

The registry names only the engine series, so ADs for every model in the series are matched.

## ADs that may apply (OpenAirDocs)

Matched to this engine model by model name and maker. Each AD's applicability may narrow it by serial number, part number or equipment.

- [AD 69-09-01](https://openairdocs.org/ad/69-09-01): Eisemann Magnetos · Eisemann Magnetos, 2A4-45-B2, 2A4-49-B2 and 158 more
- [AD 51-28-02](https://openairdocs.org/ad/51-28-02): Oil Pump Gears · Wytwornia Sprzetu Komunikacyjnego 6V4-178-B3, 6V4-178-B31, 6V4-178-B32 and 3 more

## Registered aircraft (84, first 50)

- [N10195](https://openairdocs.org/aircraft/N10195): [Deuchar Hillary](https://openairdocs.org/faa-owner/DEUCHAR%20HILLARY), [Brookings, OR](https://openairdocs.org/faa-place/OR/Brookings), S/N 562
- [N1101V](https://openairdocs.org/aircraft/N1101V): [Clement Walter F](https://openairdocs.org/faa-owner/CLEMENT%20WALTER%20F), [Enfield, NC](https://openairdocs.org/faa-place/NC/Enfield), built 1947, S/N 18
- [N12888](https://openairdocs.org/aircraft/N12888): [Suess Robert D](https://openairdocs.org/faa-owner/SUESS%20ROBERT%20D), [San Jose, CA](https://openairdocs.org/faa-place/CA/San%20Jose), built 1947, S/N 20
- [N1348Z](https://openairdocs.org/aircraft/N1348Z): [Pockrus Pat B](https://openairdocs.org/faa-owner/POCKRUS%20PAT%20B), [Mineral Wells, TX](https://openairdocs.org/faa-place/TX/Mineral%20Wells), built 1958, S/N 1043
- [N153B](https://openairdocs.org/aircraft/N153B): [Scotts Helicopter Service](https://openairdocs.org/faa-owner/SCOTTS%20HELICOPTER%20SERVICE), [Le Sueur, MN](https://openairdocs.org/faa-place/MN/Le%20Sueur), built 1947, S/N 7
- [N155JN](https://openairdocs.org/aircraft/N155JN): [Aero-Mobil Inc](https://openairdocs.org/faa-owner/AERO-MOBIL%20INC), [Wilmington, DE](https://openairdocs.org/faa-place/DE/Wilmington), built 1955, S/N 1445
- [N157B](https://openairdocs.org/aircraft/N157B): [Lewis Gerald K](https://openairdocs.org/faa-owner/LEWIS%20GERALD%20K), [Bakersfield, CA](https://openairdocs.org/faa-place/CA/Bakersfield), built 1947, S/N 11
- [N160B](https://openairdocs.org/aircraft/N160B): [James David R](https://openairdocs.org/faa-owner/JAMES%20DAVID%20R), [Wayne, MI](https://openairdocs.org/faa-place/MI/Wayne), built 1947, S/N 14
- [N162M](https://openairdocs.org/aircraft/N162M): [Costa James Joseph](https://openairdocs.org/faa-owner/COSTA%20JAMES%20JOSEPH), [Tulare, CA](https://openairdocs.org/faa-place/CA/Tulare), built 1962, S/N 238
- [N16356](https://openairdocs.org/aircraft/N16356): [Modern American Warrior Inc](https://openairdocs.org/faa-owner/MODERN%20AMERICAN%20WARRIOR%20INC), [Spring, TX](https://openairdocs.org/faa-place/TX/Spring), built 1951, S/N 536
- [N172SM](https://openairdocs.org/aircraft/N172SM): [Sedeyn Thomas Sr](https://openairdocs.org/faa-owner/SEDEYN%20THOMAS%20SR), [Salem, NJ](https://openairdocs.org/faa-place/NJ/Salem), built 1950, S/N 317
- [N1773](https://openairdocs.org/aircraft/N1773): [Aircraft Sales LLC](https://openairdocs.org/faa-owner/AIRCRAFT%20SALES%20LLC), [Caledonia, MI](https://openairdocs.org/faa-place/MI/Caledonia), built 1967, S/N SA51
- [N182B](https://openairdocs.org/aircraft/N182B): [Lay Lawrence W](https://openairdocs.org/faa-owner/LAY%20LAWRENCE%20W), [Douglass, KS](https://openairdocs.org/faa-place/KS/Douglass), built 1948, S/N 36
- [N184B](https://openairdocs.org/aircraft/N184B): [Taz Air Service Inc](https://openairdocs.org/faa-owner/TAZ%20AIR%20SERVICE%20INC), [Middletown, DE](https://openairdocs.org/faa-place/DE/Middletown), built 1959, S/N 45
- [N225B](https://openairdocs.org/aircraft/N225B): [Hammock Flying Service Inc](https://openairdocs.org/faa-owner/HAMMOCK%20FLYING%20SERVICE%20INC), [Smithville, AR](https://openairdocs.org/faa-place/AR/Smithville), built 1949, S/N 149
- [N225RE](https://openairdocs.org/aircraft/N225RE): [Moonshadow Aviation Inc](https://openairdocs.org/faa-owner/MOONSHADOW%20AVIATION%20INC), [Wilmington, DE](https://openairdocs.org/faa-place/DE/Wilmington), S/N DLW3
- [N234SM](https://openairdocs.org/aircraft/N234SM): [Robertson Kenneth W](https://openairdocs.org/faa-owner/ROBERTSON%20KENNETH%20W), [Sussex, NJ](https://openairdocs.org/faa-place/NJ/Sussex), built 1955, S/N 55-4101
- [N237DJ](https://openairdocs.org/aircraft/N237DJ): [James David R](https://openairdocs.org/faa-owner/JAMES%20DAVID%20R), [Wayne, MI](https://openairdocs.org/faa-place/MI/Wayne), S/N 237
- [N2480B](https://openairdocs.org/aircraft/N2480B): [Willert Fred J](https://openairdocs.org/faa-owner/WILLERT%20FRED%20J), [San Diego, CA](https://openairdocs.org/faa-place/CA/San%20Diego), built 1955, S/N 1360
- [N263SS](https://openairdocs.org/aircraft/N263SS): [Madden Russell E](https://openairdocs.org/faa-owner/MADDEN%20RUSSELL%20E), [Graford, TX](https://openairdocs.org/faa-place/TX/Graford), S/N 265
- [N2821B](https://openairdocs.org/aircraft/N2821B): [Lumley William B](https://openairdocs.org/faa-owner/LUMLEY%20WILLIAM%20B), [Delray Beach, FL](https://openairdocs.org/faa-place/FL/Delray%20Beach), built 1956, S/N 1530
- [N2831B](https://openairdocs.org/aircraft/N2831B): [Taz Air Service Inc](https://openairdocs.org/faa-owner/TAZ%20AIR%20SERVICE%20INC), [Middletown, DE](https://openairdocs.org/faa-place/DE/Middletown), built 1957, S/N 1361
- [N2891B](https://openairdocs.org/aircraft/N2891B): [Costa James J](https://openairdocs.org/faa-owner/COSTA%20JAMES%20J), [Goff, KS](https://openairdocs.org/faa-place/KS/Goff), built 1957, S/N 1535
- [N307AJ](https://openairdocs.org/aircraft/N307AJ): [Swashbuckle Air LLC](https://openairdocs.org/faa-owner/SWASHBUCKLE%20AIR%20LLC), [Anchorage, AK](https://openairdocs.org/faa-place/AK/Anchorage), built 1952, S/N 426
- [N3103G](https://openairdocs.org/aircraft/N3103G): [Lancaster Helicopters Inc](https://openairdocs.org/faa-owner/LANCASTER%20HELICOPTERS%20INC), [Landisville, PA](https://openairdocs.org/faa-place/PA/Landisville), built 1959, S/N 185
- [N310A](https://openairdocs.org/aircraft/N310A): [Anverse Inc](https://openairdocs.org/faa-owner/ANVERSE%20INC), [Cartersville, GA](https://openairdocs.org/faa-place/GA/Cartersville), built 1947, S/N 82
- [N3116G](https://openairdocs.org/aircraft/N3116G): [Alvis Michael E](https://openairdocs.org/faa-owner/ALVIS%20MICHAEL%20E), [Parkton, NC](https://openairdocs.org/faa-place/NC/Parkton), S/N 284
- [N3657F](https://openairdocs.org/aircraft/N3657F): [Douglas Helicopter Inc](https://openairdocs.org/faa-owner/DOUGLAS%20HELICOPTER%20INC), [Douglas, GA](https://openairdocs.org/faa-place/GA/Douglas), built 1959, S/N 900
- [N38767](https://openairdocs.org/aircraft/N38767): [Pockrus Pat B](https://openairdocs.org/faa-owner/POCKRUS%20PAT%20B), [Mineral Wells, TX](https://openairdocs.org/faa-place/TX/Mineral%20Wells), S/N 1037
- [N39WL](https://openairdocs.org/aircraft/N39WL): [Minnesota Military And Veterans Museum](https://openairdocs.org/faa-owner/MINNESOTA%20MILITARY%20AND%20VETERANS%20MUSEUM), [Little Falls, MN](https://openairdocs.org/faa-place/MN/Little%20Falls), S/N 514
- [N4250A](https://openairdocs.org/aircraft/N4250A): [Ixl Inc](https://openairdocs.org/faa-owner/IXL%20INC), [Sulphur, LA](https://openairdocs.org/faa-place/LA/Sulphur), S/N 421
- [N4254A](https://openairdocs.org/aircraft/N4254A): [James David R](https://openairdocs.org/faa-owner/JAMES%20DAVID%20R), [Wayne, MI](https://openairdocs.org/faa-place/MI/Wayne), built 1950, S/N 229
- [N427HS](https://openairdocs.org/aircraft/N427HS): [Taz Air Service Inc](https://openairdocs.org/faa-owner/TAZ%20AIR%20SERVICE%20INC), [Middletown, DE](https://openairdocs.org/faa-place/DE/Middletown), built 1959, S/N 427
- [N4419E](https://openairdocs.org/aircraft/N4419E): [Ratledge Thomas D](https://openairdocs.org/faa-owner/RATLEDGE%20THOMAS%20D), [Bethel, AK](https://openairdocs.org/faa-place/AK/Bethel), S/N K651
- [N47242](https://openairdocs.org/aircraft/N47242): [Pockrus Pat B](https://openairdocs.org/faa-owner/POCKRUS%20PAT%20B), [Mineral Wells, TX](https://openairdocs.org/faa-place/TX/Mineral%20Wells), built 1952, S/N 491
- [N472DM](https://openairdocs.org/aircraft/N472DM): [Mcdowell David M](https://openairdocs.org/faa-owner/MCDOWELL%20DAVID%20M), [El Cajon, CA](https://openairdocs.org/faa-place/CA/El%20Cajon), built 1963, S/N WH5007
- [N4733C](https://openairdocs.org/aircraft/N4733C): [Taz Air Service Inc](https://openairdocs.org/faa-owner/TAZ%20AIR%20SERVICE%20INC), [Middletown, DE](https://openairdocs.org/faa-place/DE/Middletown), S/N 260
- [N4786C](https://openairdocs.org/aircraft/N4786C): [Kincanon Richard F](https://openairdocs.org/faa-owner/KINCANON%20RICHARD%20F), [Elk River, MN](https://openairdocs.org/faa-place/MN/Elk%20River), built 1942, S/N 654
- [N47TK](https://openairdocs.org/aircraft/N47TK): [Millenium Helicopters I Inc](https://openairdocs.org/faa-owner/MILLENIUM%20HELICOPTERS%20I%20INC), [Middletown, DE](https://openairdocs.org/faa-place/DE/Middletown), built 1952, S/N 52-7904
- [N47WF](https://openairdocs.org/aircraft/N47WF): [Cantarini Cody M](https://openairdocs.org/faa-owner/CANTARINI%20CODY%20M), [Fallbrook, CA](https://openairdocs.org/faa-place/CA/Fallbrook), built 1966, S/N T-610
- [N47ZA](https://openairdocs.org/aircraft/N47ZA): [Ganuza Diego](https://openairdocs.org/faa-owner/GANUZA%20DIEGO), [North Miami Beach, FL](https://openairdocs.org/faa-place/FL/North%20Miami%20Beach), built 1956, S/N 1533
- [N4924C](https://openairdocs.org/aircraft/N4924C): [Britton John E](https://openairdocs.org/faa-owner/BRITTON%20JOHN%20E), [Emmett, ID](https://openairdocs.org/faa-place/ID/Emmett), built 1960, S/N 2
- [N5104V](https://openairdocs.org/aircraft/N5104V): [Outka Wade R](https://openairdocs.org/faa-owner/OUTKA%20WADE%20R), [Aberdeen, SD](https://openairdocs.org/faa-place/SD/Aberdeen), built 1963, S/N JR-1
- [N5306V](https://openairdocs.org/aircraft/N5306V): [Donnelly Matthew J](https://openairdocs.org/faa-owner/DONNELLY%20MATTHEW%20J), [Romulus, NY](https://openairdocs.org/faa-place/NY/Romulus), S/N 632
- [N5311V](https://openairdocs.org/aircraft/N5311V): [Botello Michael C](https://openairdocs.org/faa-owner/BOTELLO%20MICHAEL%20C), [Rancho Mirage, CA](https://openairdocs.org/faa-place/CA/Rancho%20Mirage), built 1955, S/N 703
- [N5317V](https://openairdocs.org/aircraft/N5317V): [International Air Services Inc Trustee](https://openairdocs.org/faa-owner/INTERNATIONAL%20AIR%20SERVICES%20INC%20TRUSTEE), [Carson City, NV](https://openairdocs.org/faa-place/NV/Carson%20City), built 1956, S/N 768
- [N5320V](https://openairdocs.org/aircraft/N5320V): [Albertson James M](https://openairdocs.org/faa-owner/ALBERTSON%20JAMES%20M), [Slocomb, AL](https://openairdocs.org/faa-place/AL/Slocomb), built 1956, S/N 786
- [N5326V](https://openairdocs.org/aircraft/N5326V): [Jstream Lc](https://openairdocs.org/faa-owner/JSTREAM%20LC), [Sheridan, WY](https://openairdocs.org/faa-place/WY/Sheridan), built 1956, S/N 865
- [N538AC](https://openairdocs.org/aircraft/N538AC): [Hardy John S](https://openairdocs.org/faa-owner/HARDY%20JOHN%20S), [Fort Worth, TX](https://openairdocs.org/faa-place/TX/Fort%20Worth), built 1953, S/N 538
- [N59BT](https://openairdocs.org/aircraft/N59BT): [Bisek Michael David](https://openairdocs.org/faa-owner/BISEK%20MICHAEL%20DAVID), [Bulverde, TX](https://openairdocs.org/faa-place/TX/Bulverde), built 1963, S/N CC1-463

All 84: https://openairdocs.org/engine/franklin-6v4-series/aircraft.md

## NTSB investigations (285, newest 50)

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 WPR26LA247](https://openairdocs.org/ntsb/WPR26LA247), Jul 3, 2026: Bell 47G (N7985A), Springtown, TX, substantial damage, investigation ongoing
- [NTSB WPR21LA077](https://openairdocs.org/ntsb/WPR21LA077), Jan 1, 2021: Bell 47D (N74823), Marana, AZ, substantial damage. Probable cause: The pilot's failure to maintain helicopter control, which resulted in a hard landing.
- [NTSB CEN17LA264](https://openairdocs.org/ntsb/CEN17LA264), Jul 6, 2017: Bell 47D1 (N153B), Big Lake, MN, substantial damage. Probable cause: The failure of the metal core assembly within a wooden main rotor blade due to undetected corrosion and fatigue, which caused the wooden blade to separate from the rotor mast.
- [NTSB CEN17LA113](https://openairdocs.org/ntsb/CEN17LA113), Feb 9, 2017: Bell-Transworld Helicopters 47D1 (N2875F), Archer City, TX, substantial damage. Probable cause: The total loss of engine power due to fuel starvation, which resulted from the pilot’s inadvertent positioning of the mixture control to the “fuel cutoff” position.
- [NTSB GAA15CA221](https://openairdocs.org/ntsb/GAA15CA221), Aug 11, 2015: Bell 47D1 (N74823), Clanton, AL, substantial damage. Probable cause: The student pilot's abrupt cyclic and collective inputs during the approach to land which resulted in abnormal runway contact and a subsequent tail boom strike by the main rotor blades.
- [NTSB WPR14LA180](https://openairdocs.org/ntsb/WPR14LA180), May 3, 2014: Bell 47G (N7895B), El Monte, CA, substantial damage. Probable cause: A partial loss of engine power during climbout due to a malfunctioning magneto and spark plugs.
- [NTSB ERA14LA099](https://openairdocs.org/ntsb/ERA14LA099), Jan 21, 2014: Bell 47D1 (N93067), Pell City, AL, substantial damage. Probable cause: The pilot’s use of an improper clutch engagement procedure, which resulted in clutch glazing, slippage, and, ultimately, the in-flight disengagement of the clutch and a loss of rotor rpm.…
- [NTSB ERA13LA390](https://openairdocs.org/ntsb/ERA13LA390), Aug 31, 2013: Continental Copters 47G (N6356X), Sandy Hook, KY, substantial damage. Probable cause: The in-flight disengagement of the tail rotor extension shaft from the tail rotor gearbox, resulting in a loss of tail rotor control.
- [NTSB ERA13LA308](https://openairdocs.org/ntsb/ERA13LA308), Jun 29, 2013: Hiller UH-12A (N6331D), Florence, AL, substantial damage. Probable cause: The student pilot’s failure to maintain control of the helicopter while landing, which resulted in a tail rotor ground strike and collision with terrain.
- [NTSB CEN13LA396](https://openairdocs.org/ntsb/CEN13LA396), Jun 28, 2013: Bell 47D1 (N78900), Lake Ozark, MO, substantial damage. Probable cause: The improper rebuild and maintenance of the helicopter and inadequate subsequent inspections, which resulted in undetected fuel contamination and a subsequent total loss of engine power during cruise…
- [NTSB WPR12LA244](https://openairdocs.org/ntsb/WPR12LA244), Jun 4, 2012: Hiller UH-12B (N93467), Pasco, WA, substantial damage. Probable cause: The pilot's failure to maintain the helicopter's rotor rpm while maneuvering at a low altitude over a fruit orchard.
- [NTSB WPR12LA029](https://openairdocs.org/ntsb/WPR12LA029), Nov 8, 2011: Bell 47D1 (N4251A), San Diego, CA, substantial damage. Probable cause: The flight instructor's inadequate supervision of the student pilot during a simulated autorotation and the pilots’ failure to use carburetor heat while operating at reduced engine power while in…
- [NTSB WPR11LA469](https://openairdocs.org/ntsb/WPR11LA469), Sep 27, 2011: Bell 47D1 (N9158R), Ahwahnee, CA, substantial damage. Probable cause: The pilot’s failure to maintain adequate main rotor rpm during the landing approach, which resulted in a loss of control.
- [NTSB ERA10CA262](https://openairdocs.org/ntsb/ERA10CA262), May 9, 2010: Hiller UH12 (N116S), Sarasota, FL, substantial damage. Probable cause: The pilot's delayed remedial action to maintain main rotor rpm, which resulted in a loss of lift and hard landing.
- [NTSB ERA10CA001](https://openairdocs.org/ntsb/ERA10CA001), Oct 2, 2009: Bell 47D1 (N74004), Dorrance, PA, substantial damage. Probable cause: A total loss of engine power due to fuel exhaustion for undetermined reasons.
- [NTSB DFW07WA062](https://openairdocs.org/ntsb/DFW07WA062), Jan 25, 2007: Hiller UH-12B (N727JR), Panama City, Panama, substantial damage
- [NTSB LAX06LA030](https://openairdocs.org/ntsb/LAX06LA030), Nov 10, 2005: Bell 47D1 (N16356), Rancho Murieta, CA, substantial damage. Probable cause: a separation of the tail rotor assembly due to the reverse bending fatigue fracture of a tail rotor pitch change link bolt, resulting in a loss of control of the helicopter, and a hard landing during…
- [NTSB LAX05LA112](https://openairdocs.org/ntsb/LAX05LA112), Mar 12, 2005: Hiller UH-12B (N5311V), Thermal, CA, substantial damage. Probable cause: the pilot's inadequate in-flight planning and failure to refuel the helicopter, which resulted in fuel exhaustion.
- [NTSB LAX05LA022](https://openairdocs.org/ntsb/LAX05LA022), Oct 31, 2004: Bell 47D1 (N903B), San Martin, CA, substantial damage. Probable cause: A loss of power for undetermined reasons.
- [NTSB ANC04LA027](https://openairdocs.org/ntsb/ANC04LA027), Feb 22, 2004: Hiller UH-12B (N5304V), Bradenton, FL, substantial damage. Probable cause: The pilot's inadequate in-flight planning/decision which resulted in fuel exhaustion. Also causal was the pilot's failure to maintain adequate rotor speed, resulting in a hard landing.
- [NTSB NYC03LA069](https://openairdocs.org/ntsb/NYC03LA069), Mar 23, 2003: Bell 47D (N74120), Princetown, NY, substantial damage. Probable cause: The student's failure to maintain control while executing a takeoff to a hover, and the flight instructor's delayed remedial action. A factor in the accident was the muddy ground.
- [NTSB FTW02LA044](https://openairdocs.org/ntsb/FTW02LA044), Dec 1, 2001: Bell 47G (N5226), Ardmore, OK, substantial damage. Probable cause: the flight instructor's selection of an unsuitable area for practicing a full touchdown autorotation, which resulted in a nose over. A contributing factor was the soft ground.
- [NTSB ATL01LA108](https://openairdocs.org/ntsb/ATL01LA108), Sep 7, 2001: Bell 47G (N6327D), Berry, AL, substantial damage. Probable cause: The failure of the main rotor system stabilizer damper control horn assembly, resulting in an uncontrolled descent and subsequent collision with a tree and terrain.
- [NTSB CHI01FA231](https://openairdocs.org/ntsb/CHI01FA231), Jul 22, 2001: World Helicopters 47D1 (N17301), Ballard, MO, destroyed, 2 fatal. Probable cause: The pilot's improper preflight planning which resulted in fuel exhaustion, and the pilot's subsequent improper autorotation.
- [NTSB LAX00LA288](https://openairdocs.org/ntsb/LAX00LA288), Aug 5, 2000: Bell 47D (N39KH), Stockton, CA, substantial damage. Probable cause: The pilot's inadequate planning by which he miscalculated fuel consumption which resulted in fuel exhaustion.
- [NTSB MIA00LA111](https://openairdocs.org/ntsb/MIA00LA111), Mar 17, 2000: Hiller UH-12B (N5304V), Sanford, FL, substantial damage. Probable cause: The pilot's improper collective and cyclic control usage during an emergency descent, following the onset of a 1 to 1 vibration for undetermined reasons, resulting in the helicopter landing hard and…
- [NTSB NYC00LA044](https://openairdocs.org/ntsb/NYC00LA044), Nov 27, 1999: Bell 47G (N940B), Coudersport, PA, substantial damage. Probable cause: The pilot's improper preflight planning and decision to attempt a takeoff with the passenger from the confined area.
- [NTSB ATL99LA108](https://openairdocs.org/ntsb/ATL99LA108), Jul 16, 1999: Hiller UH12-C (N5317V), Venice, FL, substantial damage. Probable cause: Loss of engine power due to fuel starvation as a result of the passenger inadvertently shutting off the fuel supply.
- [NTSB CHI99LA012](https://openairdocs.org/ntsb/CHI99LA012), Oct 24, 1998: Hiller UH-12C (N9739C), Clinton, IA, substantial damage. Probable cause: the failure of the 90 degree gearbox for reasons undetermined. Factors were the failure of the gearbox, and it not being possible for the pilot to maintain control of the aircraft.
- [NTSB MIA98LA254](https://openairdocs.org/ntsb/MIA98LA254), Sep 29, 1998: Bell 47-D1 (N755E), Oxford, MS, substantial damage. Probable cause: The pilot's failure to maintain directional control due to vibration from the main rotor blade for undetermined reasons. A related finding was the improper repair of a crack in the laminant of the…
- [NTSB MIA98LA170](https://openairdocs.org/ntsb/MIA98LA170), May 28, 1998: Bell 47G (N182JR), Bunnell, FL, substantial damage. Probable cause: The pilot-in-command(CFI) failure to maintain control of the aircraft.
- [NTSB FTW98LA144](https://openairdocs.org/ntsb/FTW98LA144), Mar 11, 1998: Bell 47D1 (N13012), Jeanerette, LA, substantial damage. Probable cause: The in-flight disconnect of the rotating scissors due to the separation of its hinge bolt.
- [NTSB MIA98LA051](https://openairdocs.org/ntsb/MIA98LA051), Jan 3, 1998: Bell 47D1 (N59326), Bunnell, FL, substantial damage. Probable cause: the student pilot's improper planning/decision, which resulted in fuel exhaustion, loss of engine power, and a forced landing.
- [NTSB MIA97FA248](https://openairdocs.org/ntsb/MIA97FA248), Sep 19, 1997: Bell 47G (N70747), Saluda, SC, destroyed, 2 fatal. Probable cause: in-flight collision with a tree, for undetermined reason(s).
- [NTSB ATL97LA121](https://openairdocs.org/ntsb/ATL97LA121), Aug 11, 1997: Bell 47-D1 (N908B), Holcomb, MS, substantial damage. Probable cause: The failure of the pilot to adequately see and avoid all obstructions while doing aerial application work.
- [NTSB FTW96LA192](https://openairdocs.org/ntsb/FTW96LA192), Apr 26, 1996: Bell 47D1 (N5226), Ardmore, OK, substantial damage. Probable cause: the student's inadvertent dynamic rollover, and inadequate supervision by the flight instructor.
- [NTSB ATL96LA023](https://openairdocs.org/ntsb/ATL96LA023), Dec 18, 1995: Hiller 12C (N234SM), N. Myrtle Beach, SC, substantial damage. Probable cause: The pilot's improper operation of the flight controls during a practice autorotation, and the certified flight instructor's inadequate supervision of the operation
- [NTSB LAX96FA045](https://openairdocs.org/ntsb/LAX96FA045), Nov 12, 1995: Bell 47D1 (N78900), Shafter, CA, destroyed, 2 fatal. Probable cause: the pilot misjudged the altitude and ground clearance while performing an unwarranted low altitude flight maneuver.
- [NTSB LAX95LA326](https://openairdocs.org/ntsb/LAX95LA326), Sep 6, 1995: Hiller UH-12C (N1348Z), Porterville, CA, substantial damage. Probable cause: the flight instructor's inadequate supervision of the flight; the dual student's improper use of the flight controls; and improper remedial action.
- [NTSB LAX95LA238](https://openairdocs.org/ntsb/LAX95LA238), Jul 3, 1995: Hiller UH-12C (N1348Z), Rio Vista, CA, substantial damage. Probable cause: The result of a chafing failure of the left anti-torque control cable while the aircraft was in flight. An inadequate preflight inspection by the pilot-in-command, and an inadequate 100-hour…
- [NTSB ATL94LA172](https://openairdocs.org/ntsb/ATL94LA172), Sep 13, 1994: Bell 47D1 Wasp (N908B), Hazel Green, AL, substantial damage. Probable cause: UNDETERMINED.
- [NTSB FTW94LA221](https://openairdocs.org/ntsb/FTW94LA221), Jul 3, 1994: Bell OH-13E (N39WL), Mountain View, AR, substantial damage. Probable cause: THE FUEL EXHAUSTION AS RESULT OF A STRUCK FUEL DRAIN VALVE. FACTORS WERE THE HIGH DENSITY ALTITUDE, AND THE UNSUITABLE TERRAIN AT THE PILOT'S DISPOSAL FOR THE FORCED LANDING.
- [NTSB FTW94LA193](https://openairdocs.org/ntsb/FTW94LA193), Jun 4, 1994: Bell 47H-1 (N2831B), Tulsa, OK, substantial damage. Probable cause: THE PILOT'S FAILURE TO MAINTAIN ROTOR RPM, HIS DELAYED LANDING FLARE, AND THE IMPROPER TOUCHDOWN.
- [NTSB FTW94LA166](https://openairdocs.org/ntsb/FTW94LA166), May 18, 1994: Bell 47G (N933B), Sulphur, OK, substantial damage. Probable cause: THE LOSS OF ENGINE POWER DUE TO THE FAILURE OF AN ENGINE ACCESSORY OIL PUMP GEAR. A FACTOR WAS THE LACK OF SUITABLE TERRAIN FOR THE AUTOROTATION.
- [NTSB MIA94FA125](https://openairdocs.org/ntsb/MIA94FA125), Apr 22, 1994: Bell 47D1 (N9660), Marathon, FL, destroyed, 2 fatal. Probable cause: SEPARATION OF THE TAIL ROTOR GEARBOX AND TAIL ROTOR BLADES FOR AN UNDETERMINED REASON. FACTORS RELATED TO THE ACCIDENT WERE: FAILURE OF MAINTENANCE PERSONNEL TO FOLLOW THE PROPER MAINTENANCE…
- [NTSB MIA93LA144](https://openairdocs.org/ntsb/MIA93LA144), Jun 19, 1993: Bell 47G (N3628G), Panama City, FL, substantial damage. Probable cause: IMPROPER PLANNING/DECISION BY THE PILOT-IN-COMMAND AND HIS FAILURE TO MAINTAIN ROTOR RPM, WHICH RESULTED IN FAILURE OF THE HELICOPTER TO ATTAIN EFFECTIVE TRANSLATIONAL LIFT. FACTORS RELATED TO THE…
- [NTSB MIA93LA032](https://openairdocs.org/ntsb/MIA93LA032), Dec 21, 1992: Hiller UH-12C (N38767), New Smyrna Bch, FL, substantial damage. Probable cause: THE PILOT-IN-COMMAND'S IMPROPER APPLICATION OF CYCLIC AND COLLECTIVE PITCH CONTROL DURING AN AUTOROTATIVE LANDING.
- [NTSB SEA92LA141](https://openairdocs.org/ntsb/SEA92LA141), Jun 29, 1992: Bell-World 47D1 (N17301), Wenatchee, WA, destroyed. Probable cause: CARBURETOR ICE AND THE PILOT IN COMMAND'S NOT BEING ABLE TO MAINTAIN CLEARANCE. FACTORS CONTRIBUTING TO THE ACCIDENT WERE: CARBURETOR ICING CONDITIONS AND TREE(S).
- [NTSB MIA92LA102](https://openairdocs.org/ntsb/MIA92LA102), Apr 2, 1992: Bell 47-D-1 (N322A), Fayette, MS, substantial damage. Probable cause: THE PILOT IN COMMANDS FAILURE TO INSURE THE PROPER FUEL QUANTITY FOR THE FLIGHT WAS PLACED ON THE AIRCRAFT AND HIS FAILURE TO MONITOR FUEL QUANTITY DURING FLIGHT RESULTING IN FUEL EXHAUSTION.
- [NTSB MIA92LA069](https://openairdocs.org/ntsb/MIA92LA069), Jan 27, 1992: Bell 47D1 (N93067), Cross City, FL, substantial damage. Probable cause: PARTIAL LOSS OF ENGINE POWER DUE TO UNDETERMINED REASONS AND UNSUITABLE TERRAIN ENCOUNTERED DURING THE AUTOROTATIVE LANDING.

All 285: https://openairdocs.org/engine/franklin-6v4-series/ntsb.md

## FAA accident and incident reports (198, newest 50)

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft 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.

- [Accident 20210101001599A](https://openairdocs.org/incident/20210101001599A), Jan 1, 2021: Bell 47D1 (N74823), Marana, AZ, Substantial damage. While hover taxiing back to ramp on taxiway, a CE-182 entered the same taxiway approaching the helicopter. PIC stated that no radio contact could be made with…
- [Accident 20170706010589A](https://openairdocs.org/incident/20170706010589A), Jul 6, 2017: Bell 47D1 (N153B), Big Lake, MN, Substantial damage. The pilot was performing agriculture spray operations and had just completed a refill operation of pestidices. After increasing engine RPM to 3,100 RPM and…
- [Incident 20170310002009I](https://openairdocs.org/incident/20170310002009I), Mar 10, 2017: Bell 47G (N6359X), Minor damage. During hover at approximately 3 ft., aircraft began to yaw. Pilot applied left pedal and aircraft settled hard onto the left skid. The left skid, forward and…
- [Accident 20170209001379A](https://openairdocs.org/incident/20170209001379A), Feb 9, 2017: Bell-Transworld Helicopters 47D1 (N2875F), Archer City, TX, Destroyed. On February 9, 2017, at approximately 1400, a Bell 47D1 helicopter registration number N2875F, registered to [privacy data omitted], impacted terrain southeast…
- [Accident 20150811016529A](https://openairdocs.org/incident/20150811016529A), Aug 11, 2015: Bell 47D1 (N74823), Clanton, AL, Substantial damage. 08/11/2015 1500 Local time winds were observed as 340 at 10 KTS. Student pilot was manipulating the controls of N74823 a Bell 47D1 on final terminating with a…
- [Accident 20140503013909A](https://openairdocs.org/incident/20140503013909A), May 3, 2014: Bell 47G (N7895B), Whittier, CA, Substantial damage. On may 3, 2014, civil aircraft N7598B, a Bell 47G helicopter, departed san gabriel valley airport (EMT) at 1618UTC for a flight to compton woodley airport…
- [Accident 20140121001109A](https://openairdocs.org/incident/20140121001109A), Jan 21, 2014: Bell 47D1 (N93067), Pell City, AL, Substantial damage. Helicopter was descending, according to the pilot's statement, and at approximately 25' to 35' AGL he heard a loud snap/pop along with an immediate…
- [Accident 20130831018569A](https://openairdocs.org/incident/20130831018569A), Aug 31, 2013: Continental Copters Inc 47G (N6356X), Sandy Hook, KY, Substantial damage. A bell 47G helicopter was operating near Sandy Hook KY. During the landing phase of the pilot lost use of tail rotor, pilot began auto rotation procedures.…
- [Accident 20130629011939A](https://openairdocs.org/incident/20130629011939A), Jun 29, 2013: Hiller UH-12A (N6331D), Florence, AL, Substantial damage. Pilot was operating helicopter to load it on a tow trailer. Witness stated the helicopter was about to touchdown on the trailer surface, it began a slow drift…
- [Accident 20130628013159A](https://openairdocs.org/incident/20130628013159A), Jun 28, 2013: Bell 47D1 (N78900), Lake Ozark, MO, Substantial damage. Pilot stated that during cruise flight at 1500 MSL the engine sputtered. In response he rolled the throttle on and the engine came back on, then seconds later…
- [Accident 20120604011459A](https://openairdocs.org/incident/20120604011459A), Jun 4, 2012: Hiller UH-12B (N93467), Pasco, WA, Substantial damage. Pilot was maneuvering while drying cherries at low altitude, experienced a low RPM condition and put aircraft down into field impacting cherry trees.
- [Accident 20111108026759A](https://openairdocs.org/incident/20111108026759A), Nov 8, 2011: Bell 47D1 (N4251A), San Diego, CA, Substantial damage. The owner of the aircraft was receiving rotorcraft flight instruction when the aircraft impacted the ground during an autorotation landing. The student stated…
- [Accident 20110927022599A](https://openairdocs.org/incident/20110927022599A), Sep 27, 2011: Bell 47D1 (N9158R), Ahwahnee, CA, Substantial damage. On September 27, 2011, N9158R a Bell 47 helicopter, with the owner and a certificated mechanic on board conducting a maintenance flight were involved in an…
- [Accident 20100509033889A](https://openairdocs.org/incident/20100509033889A), May 9, 2010: Hiller UH-12A (N116S), Sarasota, FL, Substantial damage. On may 09, 2010, at 1900 eastern time, a Hiller UH-12A, aircraft, registration N116S, experienced the loss operational control during cruise flight near…
- [Incident 20091219052779I](https://openairdocs.org/incident/20091219052779I), Dec 19, 2009: Bell 47D1 (N8975), Oakdale, CA, Minor damage. A Bell 47 helicopter was involved with a hard landing during a FAA flight test with a designated pilot examiner on board. During the execution of a steep…
- [Accident 20091002049919A](https://openairdocs.org/incident/20091002049919A), Oct 2, 2009: Bell 47D1 (N74004), Hazleton, PA, Minor damage. Pilot was flying approximately 1500 ft AGL when the engine quit. He autorotated into an old portion of a quarry, landing on some piles of stone and dirt. The…
- [Accident 20051110028389A](https://openairdocs.org/incident/20051110028389A), Nov 10, 2005: Bell 47D1 (N16356), Rancho Murieta, CA, Destroyed. (-23) While on a training flight the student pilot experienced a vibration in the anti-torque pedals. This changed to an oscillation (helicopter moving from…
- [Incident 20051104028539I](https://openairdocs.org/incident/20051104028539I), Nov 4, 2005: Bell 47D1 (N16356), Rancho Murieta, CA. (-23) On 11/04/2005 the pilot [privacy data omitted] made an emergency landing at the Rancho Murieta Airport due to a broken tail rotor control cable. The…
- [Incident 20050413006029I](https://openairdocs.org/incident/20050413006029I), Apr 13, 2005: Bell 47D1 (N4229A), New Cumberland, PA. (-23) On April 13, 2005, the pilot [privacy data omitted] operated Bell helicopter N4229A from capital city airport until the engine failed due to fuel…
- [Accident 20050312010179A](https://openairdocs.org/incident/20050312010179A), Mar 12, 2005: Hiller UH12B (N5311V), Thermal, CA, Substantial damage. (-23) The pilot, flying his Hiller UH-12B helicopter, was performing touch and go takeoffs and landings at jacqueline cochran regional airport in Thermal,…
- [Accident 20041031028379A](https://openairdocs.org/incident/20041031028379A), Oct 31, 2004: Bell 47D1 (N903B), San Martin, CA, Substantial damage. (-23) At approximately 0915 hours on October 31, 2004, CFI randy sharp and owner/student pilot robert seuss departed rhv (san jose) for 3O7 (hollister) with…
- [Accident 20040222031169A](https://openairdocs.org/incident/20040222031169A), Feb 22, 2004: Hiller UH12B (N5304V), Bradenton, FL, Substantial damage. (-23) On February 22, 2004, at 1140 EDT, a Hiller UH-12B, registered to danny bals, engine quit due to fuel depletion and auto rotated into panther park,…
- [Accident 20011201034399A](https://openairdocs.org/incident/20011201034399A), Dec 1, 2001: Bell 47G (N5226), Ardmore, OK, Substantial damage. (.19) On December 1, 2001, at 1030 central standard time, a Bell 47D1 helicopter, N5226, was substantially damaged during a practice autorotational landing at…
- [Accident 20010907026269A](https://openairdocs.org/incident/20010907026269A), Sep 7, 2001: Bell 47G (N6327D), Berry, AL, No damage. (-23) The pilot was flying over hostile terrain conducting police surveillance on a suspected drug smuggling operation, accompanied by the local sheriff.…
- [Accident 20010722038489A](https://openairdocs.org/incident/20010722038489A), Jul 22, 2001: Bell 47D1 (N17301), Ballard, MO, No damage, 2 fatal. (-23) The student pilot/helicopter owner and a passenger were ferrying the aircraft from the owner's farm in tonganoxie, Kansas, to rolla, Missouri, where it…
- [Accident 20000804009349A](https://openairdocs.org/incident/20000804009349A), Aug 4, 2000: N39KH, Stockton, CA, No damage. (-23) On Thursday August 3, 2000 pilot fueled aircraft to the maximum capacity of 29 gallons of fuel. At approximately 0600 hours the pilot flew from lodi…
- [Accident 20000317013279A](https://openairdocs.org/incident/20000317013279A), Mar 17, 2000: Hiller UH12B (N5304V), Orlando, FL, No damage. (-23)Pilot said extreme vibration caused him to lose control of his helicopter, resulting in hard landing. The heli hit t/r first then slid approx 100 ft. then…
- [Accident 19991127047829A](https://openairdocs.org/incident/19991127047829A), Nov 27, 1999: Bell 47G (N940B), Coudersport, PA, Substantial damage. (-23) Pilot attempted take-off from confined area surrounded by trees with full throttle and began to lose engine RPM. He lowered the collective to maintain…
- [Accident 19990716009169A](https://openairdocs.org/incident/19990716009169A), Jul 16, 1999: Hiller UH12C (N5317V), Venice, FL, Substantial damage. Power failure in flight. Aircraft soft landed in gulf of Mexico.(.19) on July 16, 1999, at 0812 eastern daylight time, a Hiller UH12-C, N5317V, ditched into…
- [Incident 19990312016329I](https://openairdocs.org/incident/19990312016329I), Mar 12, 1999: Bell 47H1 (N2831B), Ontario, CA. (-5) The pilot of a Bell helicopter BHT-47 reported to the Ontario tower that he had a loss of engine power. The pilot made a precautionary landing in a dirt…
- [Accident 19981024040399A](https://openairdocs.org/incident/19981024040399A), Oct 24, 1998: Hiller UH12C (N9739C), Clinton, IA, Substantial damage. (-23) While in cruise flight, the pilot was unable to maintain altitude and heading. An emergency landing was initiated which resulted in loss of control…
- [Accident 19980929033749A](https://openairdocs.org/incident/19980929033749A), Sep 29, 1998: Bell 47D1 (N755E), Oxford, MS, Substantial damage. (.19)On September 29, 1998, about 0700 central daylight time, a Bell H-13D, N755E, registered to precision air services, inc, collided with trees during a…
- [Accident 19980528011249A](https://openairdocs.org/incident/19980528011249A), May 28, 1998: Bell 47G (N182JR), Bunnell, FL, Substantial damage. On may 28, 1998, about 1630 eastern daylight time, a Bell 47G helicopter, N182JR registered to s & j investments, operated by wing and rotor international as a…
- [Accident 19980311003149A](https://openairdocs.org/incident/19980311003149A), Mar 11, 1998: Bell 47D1 (N13012), Jeanerette, LA, Substantial damage. Heli was practicing approaches when it started to vibrate vertically and laterally, landed hard. Jeanerette, LA (-23) on March 12, 1998, it was reported that…
- [Accident 19980103000069A](https://openairdocs.org/incident/19980103000069A), Jan 3, 1998: Bell 47D1 (N59326), Bunnell, FL, Substantial damage. Engine stopped 300FT AGL. Dropped to ground. Fuel exhaustion. (-23) helicopter sustained substantial damage, after student pilot on unsupervised solo made…
- [Accident 19970919027619A](https://openairdocs.org/incident/19970919027619A), Sep 19, 1997: Bell 47G (N70747), Saluda, SC, Destroyed, 2 fatal. Helicopter crash wooded area near 6J4 homebase. Burned. Possible rotor decay on autorataion. Needles were split. (-23) 1) aircraft and engine log books…
- [Accident 19970811021649A](https://openairdocs.org/incident/19970811021649A), Aug 11, 1997: Bell 47D1 (N908B), Holcomb, MS, Substantial damage. Helicopter was involved in aerial application, hit a telephone line and landed in a field.(.4) the pilot stated the cotton field he was going to spray with…
- [Accident 19960426008929A](https://openairdocs.org/incident/19960426008929A), Apr 26, 1996: Bell 47D1 (N5226), Ardmore, OK, Substantial damage. Familiarzation flight student landed short in tall grass. Tried takeoff with skid in soft earth. Rolled on side. (-23) during a familiarization flight in the…
- [Accident 19951218041489A](https://openairdocs.org/incident/19951218041489A), Dec 18, 1995: Hiller OH23G (N234SM), North Myrtle Be, SC, Substantial damage. Practice autorotations. Flared nose high. Tail rotor struck the ground. Two pilots on board.
- [Accident 19951112036359A](https://openairdocs.org/incident/19951112036359A), Nov 12, 1995: Bell 47D1 (N78900), Shafter, CA, Destroyed, 2 fatal. Departed to spray water over trees to rinse system. Crashed and burned. Had unauthorized passenger on board.
- [Accident 19950906027929A](https://openairdocs.org/incident/19950906027929A), Sep 6, 1995: Hiller UH12C (N1348Z), Porterville, CA, Substantial damage. Drifted backwards after liftoff. Lifted collective. Rotor RPM lost. CFI attempted recovery too late. Hard impact.
- [Accident 19950703016069A](https://openairdocs.org/incident/19950703016069A), Jul 3, 1995: Hiller UH12C (N1348Z), Rio Vista, CA, Substantial damage. Low rotor RPM demo. Aircraft began uncommanded turn. Landed hard, bounced. Left antitorque cable broke due wear.
- [Accident 19940913026889A](https://openairdocs.org/incident/19940913026889A), Sep 13, 1994: Bell 47D1 (N908B), Hazel Green, AL, Substantial damage. Aborted takeoff for unknown condition. Tried slide landing in tall grass skid caught cotton. Broke. Rolled over.
- [Accident 19940703017549A](https://openairdocs.org/incident/19940703017549A), Jul 3, 1994: Bell OH13EISENBG (N39WL), Mountain View, AR, Substantial damage. Lost power en route. Auto rotated into rock pit. Rotor decay caused hard landing, chopped boom. Fuel drain open.
- [Accident 19940604014999A](https://openairdocs.org/incident/19940604014999A), Jun 4, 1994: Bell 47H1 (N2831B), Tulsa, OK, Substantial damage. During practice autorotations to a field allowed rotor RPM decay. Landed hard. Main rotors flexed. Chopped tailboom
- [Accident 19940518011819A](https://openairdocs.org/incident/19940518011819A), May 18, 1994: Bell 47G (N933B), Sulphur, OK, Substantial damage. Engine failed on spray run pullup. Unable full autoratation. Hard impact. Cut tailboom. Oil pump drive gear failed.
- [Accident 19940422012699A](https://openairdocs.org/incident/19940422012699A), Apr 22, 1994: Bell 47D1 (N9660), Marathon, FL, Destroyed, 4 fatal. Loud bang. Parts came off tail. Yawed right. Impact on island. Bounced into water. Overtime tail rotor blades failed
- [Incident 19940419013749I](https://openairdocs.org/incident/19940419013749I), Apr 19, 1994: Bell 47G (N182JR), Ozark, MO, Minor damage. Student allowed forward speed o get too slow. Yawed left and began to sink. Made a hard landing.
- [Accident 19930619019439A](https://openairdocs.org/incident/19930619019439A), Jun 19, 1993: Bell 47G (N3628G), Panama City, FL, Substantial damage. Departed downwind. Unable clear obstacles. Loss rotor RPM. Collided with bush and rocks. Unverified downdraft.
- [Accident 19921221052829A](https://openairdocs.org/incident/19921221052829A), Dec 21, 1992: Hiller UH12C (N38767), New Smyrna Beac, FL, Substantial damage. Tail rotor struck ground during a demo autorotation with power recovery. Tail rotor separated.

All 198: https://openairdocs.org/engine/franklin-6v4-series/incidents.md

## STCs that may be installed (OpenAirDocs) (6)

Approved for this engine model: the STC's model list names it on its data sheet, or a series that includes it. In force first, then newest. The registry doesn't record which STCs an aircraft has.

- [STC SE04651CH](https://openairdocs.org/stc/SE04651CH): To allow use of l00R grade aviation fuel meeting Swift Fuel, LLC specification SPEC-l00R-22. Swift Fuels LLC. Lists 6V4-200-C32
- [STC SE2932SW](https://openairdocs.org/stc/SE2932SW): Install carburetor air temperature indicator. Approved for Aircooled Motors (Franklin Engine Co.) equipped with float carburetors. Model eligibility included here may not be inclusive. Alcor LLC. Lists 6V4-178-B3
- [STC SE1311SO](https://openairdocs.org/stc/SE1311SO): Installation of Shivers carburetor temperature gauge with a Richter Aero Equipment B-5 carburetor temperature probe. LegacySTC.com. Lists 6V4-178-B3
- [STC SE03309CH](https://openairdocs.org/stc/SE03309CH): Installation of Engine Preheat Kit, p/n TSP6CYL-2927-115 for 115 volt application. Hartzell Propeller Inc. Lists 6V4-178-B3
- [STC SE01966WI](https://openairdocs.org/stc/SE01966WI): Use of GAMI G100UL High Octane Unleaded Avgas in spark ignition piston aircraft engines. General Aviation Modifications Inc. Lists 6V4-178-B3
- [STC SE1-201](https://openairdocs.org/stc/SE1-201): Installation of the Richter Aero Equipment Type B-4 or B-5 Temperature Probe. (O-360 SERIES (excl. A1C, C2B, C2D)). MidContinent Instru Co Inc. Lists 6V4-178-B3

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