# N255PH: Bell 47J-2A

- Status: Valid registration
- Airframe: [Bell 47J-2A](https://openairdocs.org/model/bell-47j-2a) (registry code 1181106, 2 seats)
- Engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534)
- Data sheets: [TCDS 2H1](https://openairdocs.org/tcds/2H1) (Scott's-Bell 47 Inc), [TCDS E-304](https://openairdocs.org/tcds/E-304) (Lycoming Engines) (OpenAirDocs)
- Serial number: 3307
- Type: Rotorcraft
- Engine type: Reciprocating
- Airworthiness: Multiple
- Airworthiness date: June 12, 1997
- Certificate issued: July 25, 2023
- Expires: July 31, 2030
- Mode S code: A26B5E
- Registered owner: [Egenolf Evan Patrick](https://openairdocs.org/faa-owner/EGENOLF%20EVAN%20PATRICK)
- Location: [Laramie, WY](https://openairdocs.org/faa-place/WY/Laramie)
- Owner type: Individual
- Owner's area on the map: 41.1749° N, 105.4379° W: Placed by OpenAirDocs at the center of ZIP code 82073, within about 2 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=255PH
- Page: https://openairdocs.org/aircraft/N255PH

From the FAA registry file of October 24, 2026. ADs below are matched by the registry's airframe and engine model codes. They may apply; each AD's applicability can narrow it by serial number, part number or installed equipment. This is not a compliance determination. The registry lists only the engine series, so ADs for every Lycoming VO-540 model are included.

## ADs that may apply (OpenAirDocs): 52 in force

### Matched by airframe (Bell 47J-2A)

- [AD 2023-11-07](https://openairdocs.org/ad/2023-11-07): Ground Proximity System · Airbus Helicopters 47, 206, 210 and 237 more. Effective Jun 22, 2023
- [AD 2009-12-01](https://openairdocs.org/ad/2009-12-01): Main rotor blade box beam clip (clip) · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jun 29, 2009
- [AD 2001-17-17](https://openairdocs.org/ad/2001-17-17): Main Rotor Blade Grip Threads · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective Oct 3, 2001
- [AD 98-07-09](https://openairdocs.org/ad/98-07-09): Stabilizer Bar Damper Link Assembly · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective May 6, 1998
- [AD 96-06-12](https://openairdocs.org/ad/96-06-12): Inspect Tail Rotor Blade & Abrasion Strip · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective May 29, 1996
- [AD 91-20-10](https://openairdocs.org/ad/91-20-10): Main Rotor Grip · Scotts-Bell 47 47G-2, 47G-2A, 47G-2A-1 and 11 more. Effective Nov 14, 1991
- [AD 85-08-03](https://openairdocs.org/ad/85-08-03): Tail Rotor Blade Assemblies · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Apr 29, 1985
- [AD 85-02-06](https://openairdocs.org/ad/85-02-06): AN/NAS Standard Bolts · Scotts-Bell 47 47G-2A, 47G-2A-1, 47G-3 and 12 more. Effective Feb 6, 1985
- [AD 81-17-01](https://openairdocs.org/ad/81-17-01): Starting Vibrator Assemblies · Bendix Starting Vibrator Assemblies, B-2, B-2A and 49 more. Effective Aug 13, 1981
- [AD 80-10-04 R1](https://openairdocs.org/ad/80-10-04-R1): Tail Rotor Blades · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Feb 28, 1981
- [AD 81-04-03](https://openairdocs.org/ad/81-04-03): Tail Rotor Drive Assembly · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Feb 2, 1981
- [AD 80-21-09 R1](https://openairdocs.org/ad/80-21-09-R1): Tail Rotor Pitch Link · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Nov 24, 1980
- [AD 78-03-01](https://openairdocs.org/ad/78-03-01): Hopper Support Bracket (STC SH357SW) · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Mar 6, 1978
- [AD 77-21-01](https://openairdocs.org/ad/77-21-01): Tail Rotor Gear Boxes · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Nov 14, 1977
- [AD 70-10-08](https://openairdocs.org/ad/70-10-08): Tail Rotor Grips · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jul 20, 1976
- [AD 74-08-02](https://openairdocs.org/ad/74-08-02): Mast Control Stabilizer Bar Assembly · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jun 14, 1974
- [AD 74-07-01](https://openairdocs.org/ad/74-07-01): Main Rotor Control Tube Assembly · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective May 30, 1974
- [AD 73-19-04](https://openairdocs.org/ad/73-19-04): Main Rotor Blade Grip · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Oct 10, 1973
- [AD 72-02-05](https://openairdocs.org/ad/72-02-05): Control Rod Assembly · Scotts-Bell 47 47G, 47G-2, 47G-2A and 11 more. Effective Feb 22, 1972
- [AD 70-08-02](https://openairdocs.org/ad/70-08-02): Tail Rotor Drive Shaft · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jan 1, 1971
- [AD 65-04-01](https://openairdocs.org/ad/65-04-01): Freewheeling Clutch · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Feb 17, 1965
- [AD 62-27-02](https://openairdocs.org/ad/62-27-02): Wood Tail Rotor Blades · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jan 29, 1963
- [AD 62-23-02](https://openairdocs.org/ad/62-23-02): Main Rotor Mast Thrust Bearing · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Oct 29, 1962
- [AD 61-22-01](https://openairdocs.org/ad/61-22-01): Pitch Link Rod End Bearing · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Nov 7, 1961
- [AD 59-05-01](https://openairdocs.org/ad/59-05-01): Tail Rotor Blade Inspection · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 58-26-02](https://openairdocs.org/ad/58-26-02): M-S MA4-5AA Carburetor · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 57-08-01](https://openairdocs.org/ad/57-08-01): Tail Rotor Drive Shafts · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 57-07-02](https://openairdocs.org/ad/57-07-02): Rotor Hub Equalizer Link · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 56-25-02](https://openairdocs.org/ad/56-25-02): Tail Rotor Pitch Bearings · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 56-15-02](https://openairdocs.org/ad/56-15-02): Swashplate Control Ring · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 56-05-01](https://openairdocs.org/ad/56-05-01): Tail Rotor Drive Shafts · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 55-16-01](https://openairdocs.org/ad/55-16-01): Tail Rotor Hub Fillet · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 52-28-03](https://openairdocs.org/ad/52-28-03): Tail Rotor Gearbox Shaft · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 52-21-01](https://openairdocs.org/ad/52-21-01): Lord Mount Guards · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 52-05-03](https://openairdocs.org/ad/52-05-03): Engine Mount Safety Strap · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 52-01-06](https://openairdocs.org/ad/52-01-06): Tail Boom Spoiler · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 51-27-01](https://openairdocs.org/ad/51-27-01): Engine Mount Replacement · Scotts-Bell 47 47, 47B, 47B3 and 21 more
- [AD 48-13-02](https://openairdocs.org/ad/48-13-02): Fuel Pump Rocker Pin · Scotts-Bell 47 47, 47B, 47B3 and 21 more

### Matched by engine (Lycoming VO-540 series)

- [AD 2026-04-11](https://openairdocs.org/ad/2026-04-11): Engine (Reciprocating) · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 605 more. Effective Apr 8, 2026
- [AD 2022-16-03](https://openairdocs.org/ad/2022-16-03): Engine (RECIPROCATING) · Continental Aerospace Technologies GTSIO-520-C, GTSIO-520-D, GTSIO-520-F and 236 more. Effective Aug 15, 2022
- [AD 2012-03-07](https://openairdocs.org/ad/2012-03-07): Carburetor · Lycoming Engines GO-435, GO-435-C2 (O-435-17), GO-435-C2A and 389 more. Effective Mar 27, 2012
- [AD 2004-10-14](https://openairdocs.org/ad/2004-10-14): Crankshaft gear · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 642 more. Effective Jun 25, 2004
- [AD 97-15-11](https://openairdocs.org/ad/97-15-11): Cylinder kits · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 538 more. Effective Aug 12, 1997
- [AD 92-12-05](https://openairdocs.org/ad/92-12-05): Piston Pins · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 532 more. Effective Jul 10, 1992
- [AD 89-04-02](https://openairdocs.org/ad/89-04-02): Carburetors · Continental Motors O-470-11, O-470-11-CI, O-470-11B and 175 more. Effective Mar 8, 1989
- [AD 80-04-04 R1](https://openairdocs.org/ad/80-04-04-R1): Crankshaft Flange Bolts · Lycoming Engines IVO-540-A1A, TIVO-540-A2A, TVO-435-A1A and 38 more. Effective Aug 18, 1980
- [AD 73-23-01](https://openairdocs.org/ad/73-23-01): Piston Pin Assembly · Lycoming Engines AIO-360-A1A, AIO-360-A1B, AIO-360-A2A and 215 more. Effective Jan 13, 1977
- [AD 73-05-01](https://openairdocs.org/ad/73-05-01): Connecting Rod Bearing Assemblies · Lycoming Engines IVO-540-A1A, TIVO-540-A2A, TVO-540-A1A and 21 more. Effective Jul 9, 1974
- [AD 69-24-03](https://openairdocs.org/ad/69-24-03): Carburetors · Continental Motors A-65-1, A-65-12, A-65-12F and 321 more. Effective Nov 29, 1969
- [AD 66-06-03](https://openairdocs.org/ad/66-06-03): Connecting Rod Assemblies · Lycoming Engines GO-435-C2 (O-435-17), GO-435-C2A, GO-435-C2A2 and 317 more. Effective Jan 16, 1969
- [AD 68-08-08](https://openairdocs.org/ad/68-08-08): Hydraulic Valve · Lycoming Engines IGSO-480-A1A6, IGSO-480-A1B6, IGSO-480-A1C6 and 44 more. Effective May 19, 1968
- [AD 62-03-02](https://openairdocs.org/ad/62-03-02): Hydraulic Valve Tappet Body and Plunger Assembly · Lycoming Engines VO-540-A1A, VO-540-B1A, VO-540-B1B and 6 more. Effective Feb 27, 1962

### Historical (superseded or no longer in force)

- [AD 2021-23-13](https://openairdocs.org/ad/2021-23-13) (historical): Ground Proximity System · Airbus Helicopters K-225, K-190A, K-240 and 237 more. Effective Dec 9, 2021
- [AD 2000-18-51](https://openairdocs.org/ad/2000-18-51) (historical): Main Rotor Blade Grip · Bell Helicopter Textron 47B, 47B3, 47D and 19 more. Effective Nov 30, 2000
- [AD 86-06-08 R1](https://openairdocs.org/ad/86-06-08-R1) (historical): Main Rotor Blade Grips · Bell Helicopter Textron 47B, 47B3, 47D and 25 more. Effective Jul 10, 1987
- [AD 2024-21-02](https://openairdocs.org/ad/2024-21-02) (historical): Engine (Reciprocating) · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 548 more. Effective Dec 5, 2024

## Information bulletins (advisory) (2 in force)

- [SAIB NE-19-08](https://openairdocs.org/saib/NE-19-08): Reciprocating Engine Cylinder Section - Lycoming Engines Parallel Valve Cylinders. Issued May 2, 2019
- [SAIB NE-14-13](https://openairdocs.org/saib/NE-14-13): Reciprocating Engine - Cylinder Mounting Studs. Issued Mar 24, 2014

## NTSB investigations (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 NYC86LA227](https://openairdocs.org/ntsb/NYC86LA227), Aug 22, 1986: Bell 47J-2A (N255PH), Newburyport, MA, substantial damage

## FAA accident and incident reports (1)

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 19860822044989A](https://openairdocs.org/incident/19860822044989A), Aug 22, 1986: Bell 47J2A (N255PH), Newburyport, MA, Substantial damage. Engine quit as pilot practiced autorotation. Main rotor severed tail no hard landing. Fuel selector on empty tank.

## Service difficulty reports

None filed for this aircraft. Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model.

## STCs that may be installed (OpenAirDocs) (120, first 50)

Approved for this aircraft's airframe or engine model, in force first, then newest. The registry doesn't record which STCs an aircraft has; its records do.

### Approved for the airframe (Bell 47J-2A)

- [STC SA800EA](https://openairdocs.org/stc/SA800EA): Installation of Whelen Anti-Collision, Position, or Anti-Collision/Position Light System, and applicable associated power supplies. Whelen Aerospace Technologies
- [STC SH3319NM](https://openairdocs.org/stc/SH3319NM): Installation of Precise Flight Pulselite Control Unit in the Landing /Taxi Recognition Visual Control Light system,. Precise Flight Inc
- [STC SH1152NW](https://openairdocs.org/stc/SH1152NW): Installation of the Automatic Flagman Model 135 Control Stick Grip. Air Products & Parts LLC
- [STC SR09066RC](https://openairdocs.org/stc/SR09066RC): Fabricate the HAC-47-3 Tail Rotor Blade. Scott's-Bell 47 Inc
- [STC SR02704SE](https://openairdocs.org/stc/SR02704SE): Installation and maintenance of the Sunspot 36 and 46 series lights. AeroLED's Holdings LLC
- [STC SA02268CH](https://openairdocs.org/stc/SA02268CH): Installation of Airwolf Filter Corp. Air Oil Separator. Airwolf Filter Corporation
- [STC SA615EA](https://openairdocs.org/stc/SA615EA): Installation of a Whelen Anti-Collision Strobe Light System as replacement for originally installed anti-collision lights. Whelen Aerospace Technologies
- [STC SR00359BO](https://openairdocs.org/stc/SR00359BO): Installation of Parmetheus Plus LED PAR36 and PAR46 taxi and landing lights. Whelen Aerospace Technologies
- [STC SR00408NY](https://openairdocs.org/stc/SR00408NY): Installation of Airwolf remote mounted engine oil filter model AFC-600. Airwolf Filter Corporation
- [STC SR02487AK](https://openairdocs.org/stc/SR02487AK): Installation of L-3 Communications Avionics Systems ESI-500 Standby Instrument System. ADS-B Technologies, LLC
- [STC SR02470AK](https://openairdocs.org/stc/SR02470AK): Installation of the L-3 Communications NGT -1000/2000/2500 ADS-B System. ADS-B Technologies, LLC
- [STC SR02471AK](https://openairdocs.org/stc/SR02471AK): Installation of the L-3 Communications NGT -9000/9000R ADS-B System. ADS-B Technologies, LLC
- [STC SR02394AK](https://openairdocs.org/stc/SR02394AK): Replacement of existing landing and/or hover light bulbs with Light Emitting Diode (LED) lighting system. Seaplanes North LLC
- [STC SR09321RC](https://openairdocs.org/stc/SR09321RC): Installation of Improved Main Rotor Grips and Matching Adapter Nut. Scott's Bell 47 Inc
- [STC SH194WE](https://openairdocs.org/stc/SH194WE): Installation of a Jasco Alternator Part No. 7555-1 24-volt system. Hartzell Engine Technologies, LLC
- [STC SR09346RC](https://openairdocs.org/stc/SR09346RC): Installation of main rotor blade grip with modified root radius and matching adapter in accordance with Helicopter Tech, Inc., Drawing List R47-120-252-1000, Revision IR, dated May 15, 2002, or later Federal Aviation Administration (FAA) approved revision. Helicopter Tech Inc
- [STC SA00068SE](https://openairdocs.org/stc/SA00068SE): Installation of fuel flow/pressure instruments. (W/TSIO-360-MB1). Electronics International Inc
- [STC SA2693NM](https://openairdocs.org/stc/SA2693NM): Installation of Electronics International digital volt/amp gauges and accessories. Electronics International Inc
- [STC SA02033AT](https://openairdocs.org/stc/SA02033AT): Modification to install an air-oil separator to prevent oil from being aspirated from the engine breather line. M-20 Oil Separators LLC
- [STC SA00680SE](https://openairdocs.org/stc/SA00680SE): Installation of Electronics International model UBG-16 or UBG-16T bar graph engine analyzer. Electronics International
- [STC SR01745LA](https://openairdocs.org/stc/SR01745LA): One-time STC to install a hand control device for the anti-torque pedal control on Bell 47J-2A, serial number 3305. Chap J
- [STC SA01258SE](https://openairdocs.org/stc/SA01258SE): Installation of the Automatic Flagman Dispenser Models in accordance with Automatic Flagman Master Drawing Lists specified in attached AML, or later FAA approved revision.This STC supercedes several existing STC s as listed in the notes on the attached AML. R-S Sales Inc
- [STC SA489EA](https://openairdocs.org/stc/SA489EA): Installation of ARP Inc. carburetor ice detection system. Aircraft & Rotorcraft Products (ARP) Inc
- [STC SA02520AT](https://openairdocs.org/stc/SA02520AT): Installation of M-20 Oil Separator, model 600-WP. M-20 Oil Separators LLC
- [STC SH102WE](https://openairdocs.org/stc/SH102WE): Installation of automatic flagman model 5. R-S Sales Inc
- [STC SA2687NM](https://openairdocs.org/stc/SA2687NM): Installation of Truboplus/ Electronics Int'l gauges and switches. Aero Manufacturing Inc
- [STC SH12CE](https://openairdocs.org/stc/SH12CE): Replace existing engine induction air filter with AC Spark Plug Filter. Brackett Aero Filters Inc
- [STC SA1626NM PAGE 1](https://openairdocs.org/stc/SA1626NM%20PAGE%201): Installation of Electronics Int'l Digital EGT/CHT Instruments and accessories. (201 Series). Electronics International
- [STC SH8442SW](https://openairdocs.org/stc/SH8442SW): Installation of a float assembly. Aero Products, Inc
- [STC SA2844CE](https://openairdocs.org/stc/SA2844CE): Installation of a plastic cap enclosure over the anti-collision strobe light system. Air Transport Inc
- [STC SA2350NM PAGE 1](https://openairdocs.org/stc/SA2350NM%20PAGE%201): Installation of Electronics International Inc digital carburetor/outside air temperature gauges. Electronics International
- [STC SA4302NM](https://openairdocs.org/stc/SA4302NM): Installation of Electronics Int'l digital automatic engine analyzer. Electronics International
- [STC SA3862NM PAGE 1](https://openairdocs.org/stc/SA3862NM%20PAGE%201): Installation of Electronics International Primary TIT/EGT/CHT instruments, remote switches and associated accessories. Electronics International
- [STC SA4173NM](https://openairdocs.org/stc/SA4173NM): Installation of Simplex Model 7600 modular electrical system. (47G-5 WITH 12 VOLT SYSTEM). Simplex Manufacturing Company
- [STC SH4173NM](https://openairdocs.org/stc/SH4173NM): Installation of Simplex Model 7600 modular electrical system. (US ARMY OH-13E M74A). Simplex Manufacturing Company
- [STC SA2190NM PAGE 1](https://openairdocs.org/stc/SA2190NM%20PAGE%201): Installation of electronics International Digital Volt/Amp Gauges and Accessories. Electronics International
- [STC SH505GL](https://openairdocs.org/stc/SH505GL): Installation of modified tail rotor gearbox using original installation hardware and components. Helicopters, Inc
- [STC SH25SW](https://openairdocs.org/stc/SH25SW): Transceivers KY90, KY90E, KY90H, KY95, KY95E, and KY95H. Honeywell International Inc. Lists 47 Series
- [STC SH199WE](https://openairdocs.org/stc/SH199WE): Installation of stirrup assemblies to directional control pedals for operation by handicapped pilot. Dallwig Barry C
- [STC SA584WE](https://openairdocs.org/stc/SA584WE): Installation of oil filter assemblies. Nelson Filter
- [STC SA105NW](https://openairdocs.org/stc/SA105NW): Mounting and wiring for occasional installation and use of Barnes Engineering Company airborne fire spotter system. State of Washington
- [STC SH252SW](https://openairdocs.org/stc/SH252SW): Bendix 100-ampere generator30E16-11C. Ward Intl Aircraft Service. Lists 47 Series
- [STC SH5-25](https://openairdocs.org/stc/SH5-25): Installation of tundra snow shoes. ERA Helicopters, Inc. Lists 47 Series
- [STC SH4-1512](https://openairdocs.org/stc/SH4-1512): Installation of adapter assembly for bomb shackel, or cargo hook. USDA Forest Service. Lists 47 Series
- [STC SH48WE](https://openairdocs.org/stc/SH48WE): Installation of turbosupercharged Lycoming TVO-435-B1A engine. Jobmaster Co Inc
- [STC SH479SW](https://openairdocs.org/stc/SH479SW): 6V350A engine. Franklin Engine Co Inc. Lists 47 Series
- [STC SH4-1315](https://openairdocs.org/stc/SH4-1315): Seeding accessory. Rollinger Bernard J. Lists 47 Series
- [STC SA5-24](https://openairdocs.org/stc/SA5-24): Additional seat belt fittings to provide individual belts. ERA Helicopters Inc. Lists 47 Series
- [STC SA5-34](https://openairdocs.org/stc/SA5-34): Northern radio 414. ERA Helicopters Inc. Lists 47 Series
- [STC SA5-35](https://openairdocs.org/stc/SA5-35): Northern radio 414. ERA Helicopters Inc. Lists 47 Series

All 120: https://openairdocs.org/aircraft/N255PH/stcs.md

## Related

- Other Bell 47J-2A aircraft: https://openairdocs.org/model/bell-47j-2a/aircraft.md
- The Lycoming VO-540 series engine: https://openairdocs.org/engine/lycoming-vo-540-series.md

---
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.