# Interstate S-1B1 - Type: Aircraft model (FAA registry) - Registry code: 1850302 - Manufacturer (registry): INTERSTATE - Model: S-1B1 - Aircraft type: Fixed wing single engine - Category: Airplane - Engines: 1 · Reciprocating - Seats: 2 - Weight class: Up to 12,499 lb - Cruise speed: 87 mph - Certification: Type certificated - Data sheet: [TCDS A-754](https://openairdocs.org/tcds/A-754) (OpenAirDocs) - Holder: STOL Aviation LLC - Registered aircraft: 23 - Page: https://openairdocs.org/model/interstate-s-1b1 Model codes come from the FAA registry's reference file. ADs are matched to them by model name and maker. ## ADs that may apply (OpenAirDocs) Matched to this model by model name and maker. Each AD's applicability may narrow it by serial number, part number or equipment. None matched. ## Registered aircraft (23) - [N2778Q](https://openairdocs.org/aircraft/N2778Q): [Beresford David M](https://openairdocs.org/faa-owner/BERESFORD%20DAVID%20M), [Huntley, IL](https://openairdocs.org/faa-place/IL/Huntley), S/N 91 - [N30809](https://openairdocs.org/aircraft/N30809): [Brooks Sondra](https://openairdocs.org/faa-owner/BROOKS%20SONDRA), [Callicoon, NY](https://openairdocs.org/faa-place/NY/Callicoon), built 1993, S/N 231 - [N3771Z](https://openairdocs.org/aircraft/N3771Z): [Reed Gretchen M](https://openairdocs.org/faa-owner/REED%20GRETCHEN%20M), [Madison, OH](https://openairdocs.org/faa-place/OH/Madison), built 1943, S/N 196 - [N43LG](https://openairdocs.org/aircraft/N43LG): [Noble Mitchell S](https://openairdocs.org/faa-owner/NOBLE%20MITCHELL%20S), [Carleton, MI](https://openairdocs.org/faa-place/MI/Carleton), S/N 156 - [N46023](https://openairdocs.org/aircraft/N46023): [Lorenz John C](https://openairdocs.org/faa-owner/LORENZ%20JOHN%20C), [Edgewood, NM](https://openairdocs.org/faa-place/NM/Edgewood), built 1943, S/N 155 - [N46243](https://openairdocs.org/aircraft/N46243): [Goracke Terry R](https://openairdocs.org/faa-owner/GORACKE%20TERRY%20R), [Junction City, OR](https://openairdocs.org/faa-place/OR/Junction%20City), S/N 162 - [N46333](https://openairdocs.org/aircraft/N46333): [Wilson Christopher W](https://openairdocs.org/faa-owner/WILSON%20CHRISTOPHER%20W), [Edgewood, NM](https://openairdocs.org/faa-place/NM/Edgewood), built 1943, S/N 93 - [N46336](https://openairdocs.org/aircraft/N46336): [Lewis Samuel K](https://openairdocs.org/faa-owner/LEWIS%20SAMUEL%20K), [Chicago, IL](https://openairdocs.org/faa-place/IL/Chicago), built 1943, S/N 159 - [N46962](https://openairdocs.org/aircraft/N46962): [Soto Del Carpio Nhikitoa](https://openairdocs.org/faa-owner/SOTO%20DEL%20CARPIO%20NHIKITOA), [Fairbanks, AK](https://openairdocs.org/faa-place/AK/Fairbanks), built 1943, S/N 195 - [N47513](https://openairdocs.org/aircraft/N47513): [Sullivan Ronald E](https://openairdocs.org/faa-owner/SULLIVAN%20RONALD%20E), [Sterling, AK](https://openairdocs.org/faa-place/AK/Sterling), S/N 181 - [N47614](https://openairdocs.org/aircraft/N47614): [Trombley Steve DBA](https://openairdocs.org/faa-owner/TROMBLEY%20STEVE%20DBA), [Worland, WY](https://openairdocs.org/faa-place/WY/Worland), built 1943, S/N 44 - [N48027](https://openairdocs.org/aircraft/N48027): [Bodine Douglas](https://openairdocs.org/faa-owner/BODINE%20DOUGLAS), [Anchorage, AK](https://openairdocs.org/faa-place/AK/Anchorage), built 1942, S/N 11 - [N48443](https://openairdocs.org/aircraft/N48443): [Christian James B](https://openairdocs.org/faa-owner/CHRISTIAN%20JAMES%20B), [Peyton, CO](https://openairdocs.org/faa-place/CO/Peyton), built 1943, S/N 122 - [N48616](https://openairdocs.org/aircraft/N48616): [Hall Stanley C](https://openairdocs.org/faa-owner/HALL%20STANLEY%20C), [Sequim, WA](https://openairdocs.org/faa-place/WA/Sequim), built 1943, S/N 78 - [N48652](https://openairdocs.org/aircraft/N48652): [Lorenz John C](https://openairdocs.org/faa-owner/LORENZ%20JOHN%20C), [Edgewood, NM](https://openairdocs.org/faa-place/NM/Edgewood), built 1943, S/N 135 - [N48966](https://openairdocs.org/aircraft/N48966): [Kapellair LLC](https://openairdocs.org/faa-owner/KAPELLAIR%20LLC), [Wickenburg, AZ](https://openairdocs.org/faa-place/AZ/Wickenburg), built 1943, S/N 230 - [N49061](https://openairdocs.org/aircraft/N49061): [Pacific Coast Air Museum](https://openairdocs.org/faa-owner/PACIFIC%20COAST%20AIR%20MUSEUM), [Santa Rosa, CA](https://openairdocs.org/faa-place/CA/Santa%20Rosa), built 1943, S/N 65 - [N49105](https://openairdocs.org/aircraft/N49105): [Carlyle Properties LLC](https://openairdocs.org/faa-owner/CARLYLE%20PROPERTIES%20LLC), [Columbia Falls, MT](https://openairdocs.org/faa-place/MT/Columbia%20Falls), S/N 203 - [N49208](https://openairdocs.org/aircraft/N49208): [Graf Eugene](https://openairdocs.org/faa-owner/GRAF%20EUGENE), [Bozeman, MT](https://openairdocs.org/faa-place/MT/Bozeman), S/N 214 - [N52413](https://openairdocs.org/aircraft/N52413): [Beck Whitney S](https://openairdocs.org/faa-owner/BECK%20WHITNEY%20S), [Wahpeton, ND](https://openairdocs.org/faa-place/ND/Wahpeton), S/N 206 - [N53250](https://openairdocs.org/aircraft/N53250): [Smith Leon Reese](https://openairdocs.org/faa-owner/SMITH%20LEON%20REESE), [Soldotna, AK](https://openairdocs.org/faa-place/AK/Soldotna), built 1943, S/N 240 - [N537KT](https://openairdocs.org/aircraft/N537KT): [Evers Jeffrey D](https://openairdocs.org/faa-owner/EVERS%20JEFFREY%20D), [Deer Park, WA](https://openairdocs.org/faa-place/WA/Deer%20Park), S/N 48 - [N6513C](https://openairdocs.org/aircraft/N6513C): [Zorn Tony P](https://openairdocs.org/faa-owner/ZORN%20TONY%20P), [Lyons, GA](https://openairdocs.org/faa-place/GA/Lyons), S/N 43-2653 ## NTSB investigations (11) 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 ERA13LA366](https://openairdocs.org/ntsb/ERA13LA366), Aug 17, 2013: Interstate S-1B1 (N46336), Lititz, PA, substantial damage. Probable cause: The pilot’s failure to control the airplane’s pitch attitude, which resulted in an aerodynamic stall during the initial takeoff climb. Contributing to the accident was the pilot’s failure to set the… - [NTSB ANC02LA026](https://openairdocs.org/ntsb/ANC02LA026), Mar 29, 2002: Interstate S-1B1 (N48027), Big Lake, AK, substantial damage. Probable cause: The separation of the exhaust system stack from the heat exchanger. A factor associated with the accident was an engine compartment fire. - [NTSB ANC99LA030](https://openairdocs.org/ntsb/ANC99LA030), Mar 4, 1999: Interstate S-1B1 (N48027), Anchorage, AK, substantial damage. Probable cause: Fuel starvation resulting from the pilot not understanding the fuel system procedures, and selecting the improper fuel selector position. - [NTSB FTW94FA102](https://openairdocs.org/ntsb/FTW94FA102), Mar 19, 1994: Interstate S-1B1 (N46951), San Antonio, TX, destroyed, 4 fatal. Probable cause: THE FAILURE OF THE PILOT OF THE OTHER AIRCRAFT TO MAINTAIN ADEQUATE CLEARANCE DURING FORMATION FLIGHT. A FACTOR WAS THE PILOT'S INADEQUATE PREFLIGHT PLANNING AND PREPARATION REGARDING INFLIGHT… - [NTSB ANC87LA007](https://openairdocs.org/ntsb/ANC87LA007), Oct 21, 1986: Interstate S-1B1 (N46243), Eureka Creek, AK, substantial damage, 1 fatal - [NTSB ANC76FAG94](https://openairdocs.org/ntsb/ANC76FAG94), Feb 26, 1976: Interstate S1B1 (N46618), Wasilla, AK, substantial damage - [NTSB MKC75DTG07](https://openairdocs.org/ntsb/MKC75DTG07), Jul 28, 1974: Interstate S-1B1 (N49066), Williston, ND, substantial damage - [NTSB ANC72AA037](https://openairdocs.org/ntsb/ANC72AA037), Mar 11, 1972: Interstate S-1B1 (N46962), Skwentna, AK, destroyed, 1 fatal - [NTSB ANC71DAG62](https://openairdocs.org/ntsb/ANC71DAG62), Nov 26, 1970: Interstate S-1B1 (N46962), Talkeetna, AK, substantial damage - [NTSB OAK71DVD03](https://openairdocs.org/ntsb/OAK71DVD03), Aug 8, 1970: Interstate S-1B1 (N49208), Tracy, CA, substantial damage - [NTSB DEN69A0012](https://openairdocs.org/ntsb/DEN69A0012), Sep 16, 1968: Interstate S-1B1 (N48100), Bitter Creek, WY, destroyed, 1 fatal ## FAA accident and incident reports (12) 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 20130817016929A](https://openairdocs.org/incident/20130817016929A), Aug 17, 2013: Interstate S-1B1 (N46336), Lititz, PA, Substantial damage. Pilot departed on runway 13, the fifth of a six aircraft group taking off in intervals of approximately 75 to 100 foot spacing between aircraft. After a normal… - [Accident 20020330009689A](https://openairdocs.org/incident/20020330009689A), Mar 30, 2002: Arctic S1B1 (N48027), Goose Bay, AK, No damage. (-23) Shortly after takeoff the aircraft lost power. The pilot landed the aircraft on a snow machine trail and flipped over after landing. Landing of the… - [Incident 19990831028749I](https://openairdocs.org/incident/19990831028749I), Aug 31, 1999: Arctic S1B1 (N46618), South Naknek, AK, Substantial damage. (-23) Reports indicate pilot made a hard landing 165 feet inside landing threshold on runway 12 resulting in total landing gear failure. Attempts to interview… - [Accident 19990304013749A](https://openairdocs.org/incident/19990304013749A), Mar 4, 1999: Arctic S1B1 (N48027), Anchorage, AK, Substantial damage. (.19) On March 4, 1999, at 1453 Alaska standard time, an interstate S-1B1 Arctic tern, tail wheel equipped airplane, N48027, was substantially damaged during a… - [Incident 19980822030309I](https://openairdocs.org/incident/19980822030309I), Aug 22, 1998: Arctic S1B1 (N46336), Frederick, MD, Substantial damage. On local passenger ride sudden engine vibration and stoppage experienced at 2000 MSL, 3 miles south of Frederick, Maryland. Successful power off forced landing… - [Incident 19950610020529I](https://openairdocs.org/incident/19950610020529I), Jun 10, 1995: Arctic S1B1 (N49105), Cabin Creek, ID, Minor damage. Practicing landings high field elevation short strip. Stalled on flare. Collapsed landing gear. Blamed windshift. - [Incident 19940618015479I](https://openairdocs.org/incident/19940618015479I), Jun 18, 1994: Arctic S1B1 (N49105), Twin Falls, ID, Minor damage. Right main landing gear failed on landing rollout. - [Accident 19940319005852A](https://openairdocs.org/incident/19940319005852A), Mar 19, 1994: Arctic S1B1 (N46951), San Antonio, TX, Destroyed, 2 fatal. 3 Aircraft on photo formation. Interstate L6 and L2 a tcraft n 596BH. Collided. Piper L3 not involved. - [Incident 19890927063679I](https://openairdocs.org/incident/19890927063679I), Sep 27, 1989: Arctic S1B1 (N46962), AK, Minor damage. Aircraft slightly damaged on landing on a gravel bar. Repairs made on site. Type of damage not stated. - [Accident 19861021049509A](https://openairdocs.org/incident/19861021049509A), Oct 21, 1986: Arctic S1B1 (N46243), Eureka Creek, AK, Substantial damage. Aircraft struck obstacle during go around. Pilot was inexperienced. Winds were reported strong and gusting. - [Accident 19760216003719A](https://openairdocs.org/incident/19760216003719A), Feb 16, 1976: Arctic S1B1 (N46618), Wasilla, AK, Substantial damage. L gr failed. Rust found along break. - [Accident 19740728026309A](https://openairdocs.org/incident/19740728026309A), Jul 28, 1974: Arctic S1B1 (N49066), Williston, ND, Substantial damage. Bounced ldg,r wing raised,acft dscndd on l gr. ## STCs that may be installed (OpenAirDocs) (50) Approved for this 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 SA04837NY](https://openairdocs.org/stc/SA04837NY): Installation of AeroLED's Holdings, LLC., position lights, navigation lights, strobe lights and beacon lights. AeroLED's Holdings, LLC - [STC SA04652CH](https://openairdocs.org/stc/SA04652CH): To allow use of 100R grade aviation fuel meeting Swift Fuel, LLC specification. Swift Fuels LLC - [STC SA7965SW](https://openairdocs.org/stc/SA7965SW): Application of fabric and polyurethane finishing system. Shady Aviation LLC - [STC SA01240SE](https://openairdocs.org/stc/SA01240SE): Installation of secondary voltage indication system. Visual Instruments LLC - [STC SA04568CH](https://openairdocs.org/stc/SA04568CH): Installation of the uAvionix tailBeaconX, a tail mounted position light with integrated Automatic Dependent Surveillance - Broadcast (ADS-B) Out and 1090MHz Mode-S transponder functionality. uAvionix Corporation - [STC SA01967WI](https://openairdocs.org/stc/SA01967WI): Use of GAMI G100UL High Octane Unleaded Avgas. General Aviation Modifications Inc - [STC SA04776NY](https://openairdocs.org/stc/SA04776NY): The HIPEC Covering and Finishing System must be performed and maintained. HIPEC Aircraft Coatings Inc - [STC SA02553AK](https://openairdocs.org/stc/SA02553AK): Fabrication and installation of a Tail Wheel Anti-Shimmy Dampener. Keller Engineering Group LLC - [STC SA00410BO](https://openairdocs.org/stc/SA00410BO): Installation of an AV-30-C Multi-Mode Indicator. uAvionix Corporation - [STC SA00344BO PAGE 2](https://openairdocs.org/stc/SA00344BO%20PAGE%202): Installation of Parmetheus Plus LED PAR36 and PAR46 taxi and landing lights. Whelen Aerospace Technologies - [STC SA02212AK](https://openairdocs.org/stc/SA02212AK): Replacement of existing landing and/or taxi light reflector and bulbs with high intensity discharge (HID) lighting systems. Seaplanes North LLC - [STC SA02428SE](https://openairdocs.org/stc/SA02428SE): Installation of an Air Stream Switch for an electric time recording device on non-pressurized aircraft. Henry F Rogers/David E Polley - [STC SA00780SE](https://openairdocs.org/stc/SA00780SE): Installation of the True Lock Safety Retention Axle Lock Nut System. True Lock LLC - [STC SA00478CH](https://openairdocs.org/stc/SA00478CH): Installation of Cooper Superflite 102 Fabric. Aviation Products Systems Inc - [STC SA4305WE](https://openairdocs.org/stc/SA4305WE): Installation of GAR-AERO wheel adapters and tundra type tires on the main landing gear. Seaplanes North LLC - [STC SA02283SE PAGE 1](https://openairdocs.org/stc/SA02283SE%20PAGE%201): Installation of Electronics International Inc. Glass Panel Engine Monitor (with In Flight Data) CGR-30P. Electronics International Inc - [STC SA02402SE PAGE 1](https://openairdocs.org/stc/SA02402SE%20PAGE%201): Installation of Electronics International Inc. Glass Panel Engine Monitor (with In-Flight Data) CGR-30C. Electronics International Inc - [STC SA02428AK](https://openairdocs.org/stc/SA02428AK): Installation of a hydraulically actuated ski drag assembly. Northern Airframes LLC - [STC SA00432SE](https://openairdocs.org/stc/SA00432SE): Installation of EGT 701 series fuel flow instrument. J P Instruments - [STC SA00861SE](https://openairdocs.org/stc/SA00861SE): Installation of J.P. Instruments (JPI) fuel flow indicating system. J P Instruments - [STC SA2693NM](https://openairdocs.org/stc/SA2693NM): Installation of Electronics International digital volt/amp gauges and accessories. Electronics International Inc - [STC SA01988SE](https://openairdocs.org/stc/SA01988SE): Installation of Electronics International Inc. Glass Panel Engine Monitor (with In-Flight Data) MVP-50P. Electronics International Inc - [STC SA622AL](https://openairdocs.org/stc/SA622AL): Modification of powerplant installation, fuselage (other than weld assembly), wing flaps, and tail wheel installation to conform to the designs of the corresponding installations, assemblies, and components of the Model S-1B2 airplane. STOL Aviation LLC c/o Tom Csatari - [STC SA4005NM](https://openairdocs.org/stc/SA4005NM): Precise Flight Inc. Pulselite Control System. Precise Flight Inc - [STC SA320AL](https://openairdocs.org/stc/SA320AL): ONE ONLY STC, S/N 195 AND S/N 231: Installation of Lycoming O-320-A2B engine, McCauley 1A175/GM82 propeller, Cleveland 20-6, 6.00 - 6 main wheel and brake assemblies with 8.50 - 6, 6-ply tires, leaf tail spring with Scott Model 3200 tail wheel assembly, squared wing tips, and miscellaneous other design changes to airplanes S/N 195 and S/N 231. STOL Aviation LLC c/o Tom Csatari - [STC SA415AL](https://openairdocs.org/stc/SA415AL): Application of Dacron fabric as exterior covering material. STOL Aviation LLC c/o Tom Csatari - [STC SA468AL](https://openairdocs.org/stc/SA468AL): Installation of United Airmotive Inc. model 25-A skis. STOL Aviation LLC c/o Tom Csatari - [STC SA574AL](https://openairdocs.org/stc/SA574AL): Installation of Cleveland 40-28, 6.00 - 6 main wheel assemblies and Cleveland 30-18 brake assemblies. STOL Aviation LLC c/o Tom Csatari - [STC SA2683NM](https://openairdocs.org/stc/SA2683NM): Installation of Precise Flight, Inc. stand-by vacuum system (SVS). Precise Flight Inc - [STC SA01944CH](https://openairdocs.org/stc/SA01944CH): Modify airplane to fly on unleaded automotive gasoline, 87 minimum antiknock index, per ASTM Specification D-439 or D-4818 of any volatility class, A through E, or 82UL AVGAS per ASTM D-6227. Experimental Aircraft Association Inc - [STC SA946GL](https://openairdocs.org/stc/SA946GL): Superseded by STC SA01944CH. Modify for unleaded automotive gasoline, 87 minimum antiknock index. EAA Aviation Foundation - [STC SA8075SW](https://openairdocs.org/stc/SA8075SW): Installation of fiberglass covering. (M-62 SERIES PT-19) (G-73 SCHWEIZER). Razorback Fabrics Inc - [STC SA1008WE](https://openairdocs.org/stc/SA1008WE): Installation of Poly-Fiber covering material. Poly-Fiber Inc - [STC SA489EA](https://openairdocs.org/stc/SA489EA): Installation of ARP Inc. carburetor ice detection system. Aircraft & Rotorcraft Products (ARP) Inc - [STC SA1051GL](https://openairdocs.org/stc/SA1051GL): Install Cooper Superflite. Cooper Aviation Supply Company, Inc - [STC SA2687NM](https://openairdocs.org/stc/SA2687NM): Installation of Truboplus/ Electronics Int'l gauges and switches. Aero Manufacturing Inc - [STC SA00715SE](https://openairdocs.org/stc/SA00715SE): Installation of a vortex generators on the wing leading edge and the horizontal stabilizer. Dolan Terrance A - [STC SA4724NM](https://openairdocs.org/stc/SA4724NM): Installation of Cleveland brakes. Machen 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 SA2350NM PAGE 1](https://openairdocs.org/stc/SA2350NM%20PAGE%201): Installation of Electronics International Inc digital carburetor/outside air temperature gauges. Electronics International - [STC SA4624NM](https://openairdocs.org/stc/SA4624NM): Installation of F. Atlee Dodge springs 2097 and 2127 to replace bungee cords on ski equipped airplanes. F Atlee Dodge Aircraft Service - [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 SA2190NM PAGE 1](https://openairdocs.org/stc/SA2190NM%20PAGE%201): Installation of electronics International Digital Volt/Amp Gauges and Accessories. Electronics International - [STC SA1351WE](https://openairdocs.org/stc/SA1351WE): Replace existing fabric on wings, fuselage, empennage, and/or control surfaces, with Ceconite101 material. (262A Series -12). Ceconite Inc - [STC SA308EA](https://openairdocs.org/stc/SA308EA): Installation of carburetor ice detection system 105AP in single and twin engine aircraft and single engine helicopters powered by Continental, Franklin, and Lycoming type engines equipped with Marvel-Schebler MA-2, MA-3, MA-4, MA-4-5, MA-6 and HA-6 series carburetors. (Normal,Utility and Acrobatic Category airplanes and helicopters equipped with engines and carburetors as described.). Alfred R Puccinelli - [STC SA4-1514](https://openairdocs.org/stc/SA4-1514): Ceconite 101 covering of entire airplane. Cooper Engineering Corporation. Lists S-1B Series - [STC SA4-289](https://openairdocs.org/stc/SA4-289): BN-1 propeller spinner. Raymond M Stits. Lists S-1B Series - [STC SA001410BO](https://openairdocs.org/stc/SA001410BO) (historical): Installation of an AV-30-C Multi-Mode Indicator. uAvionix Corporation - [STC SA2350NM](https://openairdocs.org/stc/SA2350NM) (historical): Installation of Electronics International Inc digital carburetor/outside air temperature gauges listed on the attached continuation sheet and the associated accessories. Electronics International ## The same model under other registry codes Amateur-built copies and renamed makers get their own codes. - [Interstate/Smith L6 S1B1](https://openairdocs.org/model/interstate-smith-l6-s1b1): 1 registered aircraft, registry code 1850307 - [Interstate/Gallette J B INTRSTE S1B-1 (L-6)](https://openairdocs.org/model/interstate-gallette-j-b-intrste-s1b-1-l-6): 1 registered aircraft, registry code 1850315 - [Callair S-1B1](https://openairdocs.org/model/callair-s-1b1): 0 registered aircraft, registry code 1850308 - [Interstate/Gallette J B S1B-1 (L-6)](https://openairdocs.org/model/interstate-gallette-j-b-s1b-1-l-6): 0 registered aircraft, registry code 1850309 - [Harlow S1B1](https://openairdocs.org/model/harlow-s1b1): 0 registered aircraft, registry code 4160156 --- 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.