# N305AT: Air Tractor AT-504

- Status: Valid registration
- Airframe: [Air Tractor AT-504](https://openairdocs.org/model/air-tractor-at-504) (registry code 0390310, 2 seats)
- Engine: [Pratt & Whitney Canada PT6A-34AG](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-34ag) (registry code 52251)
- Data sheets: [TCDS A17SW](https://openairdocs.org/tcds/A17SW) (Air Tractor Inc.), [TCDS E4EA](https://openairdocs.org/tcds/E4EA) (Pratt & Whitney Canada Corp.) (OpenAirDocs)
- Serial number: 504-4005
- Type: Fixed wing single engine
- Engine type: Turbo-prop
- Airworthiness: Restricted, agriculture and pest control
- Airworthiness date: September 18, 2024
- Certificate issued: March 30, 2026
- Expires: March 31, 2033
- Mode S code: A331F7
- Registered owner: [Aircraft Trustee Services Inc Trustee](https://openairdocs.org/faa-owner/AIRCRAFT%20TRUSTEE%20SERVICES%20INC%20TRUSTEE)
- Location: [Dover, DE](https://openairdocs.org/faa-place/DE/Dover)
- Owner type: Corporation
- Owner's area on the map: 39.1815° N, 75.4736° W: Placed by OpenAirDocs at the center of ZIP code 19901, 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=305AT
- Page: https://openairdocs.org/aircraft/N305AT

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): 9 in force

### Matched by airframe (Air Tractor AT-504)

- [AD 2021-05-14](https://openairdocs.org/ad/2021-05-14): TE flap control system · Air Tractor AT-250, AT-300, AT-301 and 19 more. Effective Apr 29, 2021

### Matched by engine (Pratt & Whitney Canada PT6A-34AG)

- [AD 2022-08-13](https://openairdocs.org/ad/2022-08-13): Turbine Section · Pratt & Whitney Canada PT6A-34, PT6A-34B, PT6A-34AG and 2 more. Effective May 27, 2022
- [AD 2014-11-05](https://openairdocs.org/ad/2014-11-05): Reinforcement liner to the power turbine (PT) containment   
  ring and, for certain PT containment rings, adding scallops · Pratt & Whitney Canada PT6A-11, PT6A-110, PT6A-112 and 18 more. Effective Aug 5, 2014
- [AD 2011-25-12](https://openairdocs.org/ad/2011-25-12): Sun gear · Pratt & Whitney Canada PT6A-15AG, PT6A-27, PT6A-28 and 4 more. Effective Dec 28, 2011
- [AD 2011-20-51](https://openairdocs.org/ad/2011-20-51): Gears · Pratt & Whitney Canada PT6A-15AG, PT6A-27, PT6A-28 and 4 more. Effective Nov 1, 2011
- [AD 2002-23-13](https://openairdocs.org/ad/2002-23-13): Turbine Exhaust Ducts · Pratt & Whitney Canada PT6A-11, PT6A-110, PT6A-112 and 20 more. Effective Dec 31, 2002
- [AD 97-04-12](https://openairdocs.org/ad/97-04-12): Compressor Bleed-off Valve · Pratt & Whitney Canada PT6A-11, PT6A-110, PT6A-112 and 52 more. Effective Mar 14, 1997
- [AD 90-12-05](https://openairdocs.org/ad/90-12-05): Engine Overhaul · Pratt & Whitney Canada PT6A-15AG, PT6A-27, PT6A-28 and 3 more. Effective May 30, 1990
- [AD 80-08-12](https://openairdocs.org/ad/80-08-12): Fuel Pump Drive Coupling Splines · Pratt & Whitney Canada PT6A-11, PT6A-112, PT6A-135 and 24 more. Effective Apr 18, 1980

## Information bulletins (advisory) (5 in force)

- [SAIB CE-18-06](https://openairdocs.org/saib/CE-18-06): Flight Controls, Rudder Control System. Issued Dec 1, 2017
- [SAIB CE-16-27](https://openairdocs.org/saib/CE-16-27): Flight Controls, Trailing Edge (TE) Flap Control System. Issued Oct 31, 2016
- [SAIB CE-11-41](https://openairdocs.org/saib/CE-11-41): Fuselage, Wing Attach Fittings. Issued Jun 29, 2011
- [SAIB CE-11-30](https://openairdocs.org/saib/CE-11-30): Aircraft Structures. Issued May 9, 2011
- [SAIB NE-12-04](https://openairdocs.org/saib/NE-12-04): Turbine/ Turboprop Engine: Reduction Gearbox. Issued Nov 1, 2011

## NTSB investigations

None matched to N305AT.

## FAA accident and incident reports

None matched to N305AT.

## 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.

## Service difficulty reports on N305AT not matched to an aircraft (3)

They name N305AT, but no registry record covers the date, the aircraft registered then was built later, or the report describes another aircraft.

- [SDR GNB2005F00006](https://openairdocs.org/sdr/GNB2005F00006), May 25, 2005: CONTROL CABLE. WORN. CABLE BLENDED AT PULLEY. PROBABLE CAUSE, SOFTER NEW STYLE STAINLESS STEEL CABLE MATERIAL. SERVICE LIFE IS ONLY FRACTIONS OF OLD STYLE STEEL CABLES. (K)
- [SDR 20010205CW005](https://openairdocs.org/sdr/20010205CW005), Feb 5, 2001: VALVE SPRING. BROKEN. DURNING DETAILED INSPECTION OF LEFT ENGINE, COMPRESSION CHECK OF NR4 CYLINDER REVEALED LOW COMPRESSION. APPROX 80/20, UPON FURTHER INSPECTION THE OUTER SPRING O
- [SDR 96ZZZX3917](https://openairdocs.org/sdr/96ZZZX3917), Jul 18, 1996: FITTING. CRACKED. WHILE C/W CESSNA SB MEB 95-10, FOUND RT ELEVATOR FITTING CRACKED AT AREA WHERE THE TAPER PIN COMES THROUGH. SUBMITTER SUGGESTS THAT THESE FITTINGS ARE INSPECTED

## STCs that may be installed (OpenAirDocs) (42)

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 (Air Tractor AT-504)

- [STC SA04484CH](https://openairdocs.org/stc/SA04484CH): Installation of a Reabe Aircraft Improvement Power Gate Control System. Reabe Design LLC
- [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 SA02019SE-D](https://openairdocs.org/stc/SA02019SE-D): Installation of Garmin Model GTN 625/635/650; 725/750 Navigation System. Garmin International Inc
- [STC SA12204WI](https://openairdocs.org/stc/SA12204WI): Wing Spar Cap manufacturing process change. Air Tractor Inc
- [STC SA03040CH](https://openairdocs.org/stc/SA03040CH): Installation of a digital payload hopper quantity and spray boom pressure indicating system. Reabe Design LLC
- [STC SA04046CH PAGE 1](https://openairdocs.org/stc/SA04046CH%20PAGE%201): Installation of L-3 GENESIS (TM) Electronic Standby Instrument System (ESI-500/MAG-500). Acron Aviation Inc
- [STC SA04676CH](https://openairdocs.org/stc/SA04676CH): Installation of a True Quantity Gauge System. Reabe Design LLC
- [STC SA02266SE](https://openairdocs.org/stc/SA02266SE): Installation of a Lever Throttle Quadrant. Kawak Aviation Technologies Inc
- [STC SA02444AK](https://openairdocs.org/stc/SA02444AK): Approval of the L-3 Communications NGT 9000/9000R ADS-B system installed. ADS-B Technologies LLC
- [STC SA01714WI](https://openairdocs.org/stc/SA01714WI): Installation of a Garmin transponders: (a) GTX 330/330D/33/33D with ADS-B Out functionality; (b) GTX 335/335R/345/345R with ADS-B Out and In functionality; or (c) GTX 335R/345R with ADS-B Out functionality in select airplanes installed with G950/G1000 systems. Garmin International Inc
- [STC SA02135SE](https://openairdocs.org/stc/SA02135SE): Installation of Electronics International Inc. Glass Panel Engine Monitor (with In-Flight Data). Electronics International Inc
- [STC SA04165NY](https://openairdocs.org/stc/SA04165NY): Installation of Latitude Technologies Skynode S200 Satcom system must be performed. Latitude Technologies Corporation
- [STC SA01323CH](https://openairdocs.org/stc/SA01323CH): Installation of a ground single point fueling system. Turbine Conversions Ltd
- [STC SA04145NY](https://openairdocs.org/stc/SA04145NY): Installation of the Flight Data Acquisition Storage and Transmission System (Fast). Amtech Aeronautical Limited
- [STC SA01745WI](https://openairdocs.org/stc/SA01745WI): Installation of a Cable Cutter System on the Main Landing Gear. Hershey Flying Service Inc
- [STC SA01845WI](https://openairdocs.org/stc/SA01845WI): Installation of a Center Windshield. Hershey Flying Services
- [STC SA09873AC](https://openairdocs.org/stc/SA09873AC): Installation of Night Vision Goggle (NVG) compatible lighting system in Air Tractor, Inc. REB Technologies Inc
- [STC SA00382BO](https://openairdocs.org/stc/SA00382BO): Installation of Globalstar Antenna and Cradle provisions to support a Globalstar GPS-1700 in non-composite airplanes. Avidyne Corporation
- [STC SA02276AK](https://openairdocs.org/stc/SA02276AK): Installation of AMSAFE Aviation Inflatable Restraints. AMSAFE Inc
- [STC SA02119SE PAGE 1](https://openairdocs.org/stc/SA02119SE%20PAGE%201): Installation of Garmin GDL 88 ADS-B UAT Transceiver System. Garmin International Inc
- [STC SA03439CH](https://openairdocs.org/stc/SA03439CH): Installation of a Hartzell Propeller model .HC-B4TN-3C/T10702NS (4 Blade). Aero Innovations LLC
- [STC SA02442AK PAGE 1](https://openairdocs.org/stc/SA02442AK%20PAGE%201): Approval of the L-3 Communications NGT 2000/2500 ADS-B system. ADS-B Technologies, LLC
- [STC ST03554CH](https://openairdocs.org/stc/ST03554CH): Installation of Rotary Gatekeeper and provisions equipment. Turbine Conversions Ltd
- [STC SA00403SE](https://openairdocs.org/stc/SA00403SE): Installation of Vortex Generators on the wings. Micro AeroDynamics Inc
- [STC SA02985CH](https://openairdocs.org/stc/SA02985CH): Installation of a Cool Start System in accordance with Installation Instructions , Revision A, dated April 14, 2011, or later FAA Approved revision. Turbine Conversions Ltd
- [STC SA00068SE](https://openairdocs.org/stc/SA00068SE): Installation of fuel flow/pressure instruments. (W/TSIO-360-MB1). Electronics International Inc
- [STC SA02110CH](https://openairdocs.org/stc/SA02110CH): Installation of a Time Trac Data Recorder. P2 Incorporated
- [STC SA2693NM](https://openairdocs.org/stc/SA2693NM): Installation of Electronics International digital volt/amp gauges and accessories. Electronics International Inc
- [STC SA04677CH](https://openairdocs.org/stc/SA04677CH): Installation of a Powered Hopper Lid and Auger System. Reabe Design LLC

### Approved for the engine (Pratt & Whitney Canada PT6A-34AG)

- [STC SE00002EN](https://openairdocs.org/stc/SE00002EN): Instructions for Continued Airworthiness for the PT6A-34, -34AG, -34B, -36, -114, -114A, -116, -135, and -135A engine models that define specific maintenance tasks and their associated maintenance schedules, and that are used as a supplement to the applicable Pratt & Whitney Canada manuals. MORE Company Inc
- [STC SE00014EN](https://openairdocs.org/stc/SE00014EN): Installation of the Pratt & Whitney Engine Services, Inc. CrossCheck Engine Monitor Kit P/N HUMS-K-071-1, Rev. A on the specified PT6A engine models and kit P/N HUMS-K-071-2 on the specified A250 engine models. Pratt & Whitney Engine Services Inc
- [STC SE00020EN](https://openairdocs.org/stc/SE00020EN): Installation of the Pratt & Whitney Engine Services, Inc. TrendCheck/ TrendCheck Plus Engine Monitor Kit P/N TREND-K-010-1. Pratt & Whitney Engine Services Inc
- [STC SE2960SO](https://openairdocs.org/stc/SE2960SO): Installation of an oil filler cap safety adapter. Jet Avion Corporation
- [STC SE615GL](https://openairdocs.org/stc/SE615GL): Incorporation of a fuel flow transducer. Shadin Avionics
- [STC SE01805NY](https://openairdocs.org/stc/SE01805NY): Installation of Fuel Nozzle Adapters using studs and nuts. Atlantic Turbines International Inc
- [STC SE09286SC](https://openairdocs.org/stc/SE09286SC): Installation of an alternate gas generator case. Airforce Turbine Service
- [STC SE09257SC](https://openairdocs.org/stc/SE09257SC): Convert P&W Engine Models PT6A-15AG, -27, and -28, into PT6A-34 configuration. Covington Aircraft Engines, Inc
- [STC SE659NE](https://openairdocs.org/stc/SE659NE): Installation of oil tank filler neck check valve, P/N TSA-76A. Aviation Components Support
- [STC SE539NE](https://openairdocs.org/stc/SE539NE): Modification of compressor turbine sealing segments to incorporate honeycomb material on the inside diameter thereby providing an abradable surface for turbine blade contact. Airwork Corporation
- [STC SE5601SW](https://openairdocs.org/stc/SE5601SW): Replacement splined end and oil mist lubrication on accessory drive gearshaft. Aviall of Texas, Inc
- [STC SE1165EA](https://openairdocs.org/stc/SE1165EA): Assembly and installation of AW10262 wet spline starter gear seal. Airwork Corporation
- [STC SE4607SW](https://openairdocs.org/stc/SE4607SW): Revise the starter-generator drive spline to provide lubrication with engine oil. Aviall of Texas, Inc

## Earlier aircraft with N305AT

The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N305AT before.

- [Cancelled 2016-11-30](https://openairdocs.org/deregistered/N305AT-2016-11-30): DJI PHANTOM 3 PROFESSION, S/N P76DCL2. Assigned (non-type certificated), pending cancellation

## Related

- Other Air Tractor AT-504 aircraft: https://openairdocs.org/model/air-tractor-at-504/aircraft.md
- The Pratt & Whitney Canada PT6A-34AG engine: https://openairdocs.org/engine/pratt-whitney-canada-pt6a-34ag.md

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