# N777TC: 2018 Cook Timothy HUMMER 260L - Status: Valid registration - Airframe: [Cook Timothy HUMMER 260L](https://openairdocs.org/model/cook-timothy-hummer-260l) (registry code 05637XV, 4 seats) - Engine: [Lycoming VO-435-A1F](https://openairdocs.org/engine/lycoming-vo-435-a1f) (registry code 42200) - Data sheets: [TCDS E-279](https://openairdocs.org/tcds/E-279) (Lycoming Engines) (OpenAirDocs) - Serial number: 0834 - Year built: 2018 - Type: Rotorcraft - Engine type: Reciprocating - Kit: Vertical Aviation Technologies HUMMINGBIRD 260L - Airworthiness: Experimental, amateur built - Airworthiness date: September 13, 2018 - Certificate issued: August 23, 2018 - Expires: August 31, 2028 - Mode S code: AA84B4 - Registered owner: [Cook Timothy](https://openairdocs.org/faa-owner/COOK%20TIMOTHY) - Location: [Byrdstown, TN](https://openairdocs.org/faa-place/TN/Byrdstown) - Owner type: Individual - Owner's area on the map: 36.5622° N, 85.1490° W: Placed by OpenAirDocs at the center of ZIP code 38549, within about 5 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based - FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=777TC - Page: https://openairdocs.org/aircraft/N777TC 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. ## ADs that may apply (OpenAirDocs): 8 in force ### Matched by airframe (Cook Timothy HUMMER 260L) None in force. ### Matched by engine (Lycoming VO-435-A1F) - [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 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 90-04-06 R1](https://openairdocs.org/ad/90-04-06-R1): Propeller Governor External Oil Line · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 427 more. Effective May 28, 1991 - [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 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 ### Historical (superseded or no longer in force) - [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 ERA21LA335](https://openairdocs.org/ntsb/ERA21LA335), Aug 18, 2021: Hummer 260L (N777TC), Livingston, TN, substantial damage. Probable cause: A total loss of engine power for reasons that could not be determined. Contributing to the accident was the pilot’s operation of the helicopter in a flight regime that would not allow for a… ## 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 20210818014409A](https://openairdocs.org/incident/20210818014409A), Aug 18, 2021: Cook Timothy HUMMER 260L (N777TC), Livingston, TN, Substantial damage. Aircraft departed 8A3 to the north. The aircraft accelerated through etl and began its departure climb. At approximately 100 ft AGL the engine quit. Pilot… ## 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) (22) 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 engine (Lycoming VO-435-A1F) - [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 VO-435 Series - [STC SE01954SE](https://openairdocs.org/stc/SE01954SE): Installation of engine crankcase seal. Ly-Con Rebuilding Company - [STC SE8628SW](https://openairdocs.org/stc/SE8628SW): Installation of oil nozzles for lubrication of cam and filters. Cygnet Aerospace Corp - [STC SE4408SW](https://openairdocs.org/stc/SE4408SW): Miscellaneous engine cylinder replacement parts. Continental Motors, Inc. Lists VO-435 Series - [STC SE7504SW](https://openairdocs.org/stc/SE7504SW): Installation of any or all parts listed on Airmotive Engineering Drawing List No. 852-1, Rev. 1, dated 10/4/88, or later FAA approved revision. Continental Motors, Inc. Lists VO-435 Series - [STC SE7665SW](https://openairdocs.org/stc/SE7665SW): Installation of parts listed on Airmotive List No. 8810-3, Rev 6. Continental Motors, Inc. Lists VO-435 Series - [STC SE8776SW](https://openairdocs.org/stc/SE8776SW): Installation of coated cylinders and piston rings. Continental Motors, Inc. Lists VO-435 Series - [STC SE2902NM](https://openairdocs.org/stc/SE2902NM): Lycoming valve cover gasket. Real Gaskets Tennessee - [STC SE144GL](https://openairdocs.org/stc/SE144GL): Modify engine to increase compression ratio to 8.7:1. Scott's Bell 47 Inc - [STC SE2500SW](https://openairdocs.org/stc/SE2500SW): Modification to higher compression ratio. Scott's Bell 47 Inc - [STC SE2733SW](https://openairdocs.org/stc/SE2733SW): Modification to higher compression ratio. Scott's Bell 47 Inc - [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 VO-435 Series - [STC SE09492SC](https://openairdocs.org/stc/SE09492SC): Installation and usage of Exxon 20W50 multigrade aircraft engine oil conforming to Exxon Oil formulation WS-3013. Exxon Company USA. Lists VO-435 Series - [STC SE00350SE](https://openairdocs.org/stc/SE00350SE): Installation of sump mounted chip detector. Aviation Development Corporation - [STC SE8023SW](https://openairdocs.org/stc/SE8023SW): Installation and usage of AEROSHELL. Shell Development Co. Lists VO-435 Series - [STC SE5879SW](https://openairdocs.org/stc/SE5879SW): Use of Phillips X/C II 20W-50 and25W-60 oil (OSS 55875) in all Avco reciprocating aircraft engines from 65 to 450 BHP. Phillips Petroleum Co. Lists VO-435 Series - [STC SE5924SW](https://openairdocs.org/stc/SE5924SW): Installation of stainless steel replacement exhaust studs on AVCO engines. Perrigo & Steele Aircraft Engr Company. Lists VO-435 Series - [STC SE80NE](https://openairdocs.org/stc/SE80NE): Installation and usage of Bel-Ray synthetic aviation oil, Bel-Ray Aero 1, (nonsupercharged), horizontally opposed direct drive, aircraft engines of 350 hp. or less. Bel-Ray Company, Inc. Lists VO-435 Series - [STC SE128NE](https://openairdocs.org/stc/SE128NE): Use of AMS/OIL 15W 50 synthetic piston aircraft oil in Avco engines. AMS/OIL. Lists VO-435 Series - [STC SE959EA](https://openairdocs.org/stc/SE959EA): Modification to higher compression ration. Agrotors, Inc - [STC SE2-856](https://openairdocs.org/stc/SE2-856): American Bosch Induction vibrator VJR24B56X. Bell Helicopter Textron. Lists VO-435 Series - [STC SE44WE](https://openairdocs.org/stc/SE44WE): Use of Kling Aviation Oil, Specifications KL-100, KL-200 and KL-300 in Continental and Lycoming engines. Kling Oil Company. Lists VO-435 Series ## Earlier aircraft with N777TC The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N777TC before. - [Cancelled 2006-04-17](https://openairdocs.org/deregistered/N777TC-2006-04-17): Piper PA-23-250, S/N 27-2632, built 1964. Registration revoked. Owner: [Mccament George R Jr](https://openairdocs.org/faa-owner/MCCAMENT%20GEORGE%20R%20JR), [Miami, FL](https://openairdocs.org/faa-place/FL/Miami) ## Related - Other Cook Timothy HUMMER 260L aircraft: https://openairdocs.org/model/cook-timothy-hummer-260l/aircraft.md - The Lycoming VO-435-A1F engine: https://openairdocs.org/engine/lycoming-vo-435-a1f.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.