List of known 337 forms for the Republic Seabee
Below is a list of known "337" forms for the Republic Seabee. STC's are also added where available. Keep in mind that STC's are the property of the STC holder and their permission is required to install the modification. Some of the following 337's include STC numbers that can be referenced for installation and/or purchase.  Contact the STC holder for more details. Addresses and contact information for the STC holder(s) can be found on the FAA (Federal Aviation Administration) web site.

If you have any additional 337 forms that are not listed here
send them to me ( and I will list them here for all Seabee owners to take advantage of.  An older (but still acceptable) list of STC's is available here.

The FAA, in their infinate wisdom, copies ALL papers submitted to them by aircraft owners to be included in their aircraft records (i.e.: 337 forms); blank or not. The blank pages of the 337's submitted to the FAA have been omitted below to save space and your paper.
One important safety note: Jim Poel made a modification to add shoulder harnesses to the Seabee (Listed below). As you all know, Republic was not required to have shoulder harnesses back in 1947 so consequently Jim has taken it upon himself to modify the Seabee for them. We strongly recommend that you consider such a modification to your Seabee. They could easily save your life.

(Ed note: I have seen them personally and am very impressed with the simplicity and structural integrity of these shoulder harnesses. Steve M.) 

If you need a blank 337 form, you can download it here! (Microsoft Word format or Adobe® PDF)

If you need Adobe Acrobat reader (PDF), get it here!
Acrobat Reader

If you need a Microsoft Word viewer (DOC), get it here! Microsoft Word Reader

List of known 337 forms for the Republic Seabee
Cleveland Brakes Droop Tips Facet Fuel Pump
Loran 'C' Installation Radio Change Radio Change #2
Radio Change #3 Repaint-Wing Extensions Rudder Tail Repair
Steerable Tail Wheel and Ballast Tire Size Change United Air Oil Cooler
Wing Extensions and Spray Rails
N398CM (N6196K)
Ground Adjustable Rudder Trim Air Conditioning System Installation Air Wolf Oil Filter
Door Hinge Replacement Door Replacement Flush Fuel Filler Cap
Fuel Cell Replacement Instrument Panel Replacement Landing Light Installation
Landing Light Installation Lift Strut Fittings Longitudinal Step Vents
Lycoming GSO-480-A1A6 (STC) Manifold Heater Piper Pitot Tube
Piper Seat Installation Propeller Governor Adapter Rear Seat Modification
Rudder Spar Repair Skytronics Alternator Southwind Heater Installation
Spray Rail Repair Spray Rail Replacement Trim Tab Box Replacement
Two Axis Autopilot Whelen Strobe Installation Whelen Strobe Installation
Wing and Flap Extension Installation Landing Light
N565CB (N6669K)
Aux Hydraulic Pump Bildge Pump Installation Bow Door Repair
Cleveland Brakes Hull Bottom Repair Hull repair
Droop TIp Installation Skytronics/Jasco Alternator Installation Wing Root Fences
Landing Light Installation Overhead Engine Controls Rib and Spar Repair
Rudder Repair Wide Spray Rails Wing Tip End Rib Repair
N713ET (N6499K)
Alcor Alternator Battery Master and Start System CHT and EGT System
Cleveland Brakes Engine Analyzer Fuel Flow and Fuel Pressure
Manifold Pressure Oil Pressure and Temperature Tachometer
Electricc Hydraulic Pump Electrical Modifications Electrical-Engine Instrumentation
ELT Model 2000 ELT Relocation Engine Aux Instrument Panel
Flashing Beacon Flying Boat Front Seat Replacement
Fuel Injection System Hartzell Propeller Heater
Ignition Switch Ignition Switch Diode Instrument Panel
Instruments Jasco Alternator Landing Light
Lycoming Engine and Propeller Miscelleneous Additions Oil Cooler
Remove Wing Extentions Rudder Modification Scott tailwheel
Vertical Seat Adjustment Steerable Tailwheel Vacuum System
Wing Extensions
N5166B (N6102K)
180 degree Door Quick Release ACK ELT Installation ACS Ignition Switch Installation
Anchor Light Replacement AOA Installation Bildge Pump Installation
Bow Door Handle Installation Ceiling Panel Installation Cleveland Brakes
Cockpit Lighting Installation EI Fuel Flow-Pressure Installation Equipment Cooling Fan
Extended Baggage Compartment Fabric Interior Installation Fire Extinguisher Installation
Flush Fuel Cap Installation Fuel Boost Pump Override Installation Fuel Cell Installation
Gear Position Advisory System GEM Engine Analyzer Installation Instrument Panel Installation
Intercom Installation Kenair Fire Warning System Kenair Sinking Alarm System
Kenair Water in Fuel Detector King KMA-24 Audio Panel Installation King KX-125 Tranceiver
King GPS Installation King Transponder Installation Lower Wing Strut Fittings
Lycoming IGSO-480 Installation (STC) Main Wheel Bearing Seals Mitchell Oil Pressure Gauge
Mitchell Oil Temperature Gauge Oil Filter Chip Detector Optima Battery Installation
Piper Seat Installation Propeller Governor Installation Pulselight Installation
Schurter PTT Switch Seat Belts and Shoulder Harness Landing Light (STC)
Skysports Fuel Quantity Gauge South Wind Heater Installation Tail Wheel Locking Installation
Trim Relocation Under Seat Storage Boxes Uniden Depth Sounder Installation
Whelen Strobes Wing Extensions
Battery Box Fuel Pump Rotating Beacon
EI Engine Analyzer
(STC SA4302 NM)
ELT Install Facet Fuel Pump
Grimes Landing Light Hat Section Doubler Miller WIng Extensions and Spray Rails
(STC SA-3-30)
Propeller Install Radio Install Radio Install #2
Radio Remove and Install
12 to 24 volt conversion, Inst. Panel, Cessna Front Seats,
Pioto Heat
Aero-Tech Fuel Cell Alernator, Regulator, Tail Wheel
Bilge Pump Prop Governor-Engine-Cleveland Brakes-ELT
Airwolf Oil Filter (Franklin)
Cleveland Brakes D'Shannon Oil Separator
Fuel Cell Installation Interav Alternator (Franklin) JP 800 EGT Instrument
Nicholas Flynn Spray Rails Shoulder Harness Skytec Starter (Franklin)
Spill Plates Wide Spray Rails Wing Root Fences
Electronic Ignition Electroair Electronic Ignition Electric Fuel Pump
Hand Hole (Access plate) Bilge Pumps EI Voltmeter
Fuel Filter and Check valve Gear Advisory System Ground Power Plug
Oil Filter Pulselight Restraint System
Westberg Fuel Measuring System Westberg Fuel Pressure System
Ammeter-EGT-CHT Electric Rudder and Aileron Trim Engine Change STC
Left Wing Repair Numerous STC's Numerous STC's Part 2
Oberg Series 600 Oil Filter Seat Modification TIO540A2C Engine Change
Trailing Edge Fairings
Franklin Overhaul-Airframe Rebuild Hull Repair Left Wing Repair
Lower Rudder Hinge Propeller Change
Airwolf Oil Filter Electric Hydraulic Pump Stewart Warner 940-F Heater
Lycoming Engine Oil Cooler Spray Rails
Tail Wheel Tire - GPAS
Fuel Pump (Franklin) Electric Fuel Pump (Franklin) Fuel Pump Schematic Illustration (Franklin)
Brackett Filter (Franklin)
Electroair Ignition System
N9042N (N6092K)
Spray Rails (Henry Ruzakowski)
Gear Positon Advisory System
(Lake and Air STC SA39CH)
Oil FIlter - Air Wolf (STC SA00024NY)
Lycoming GO-480 Engine
(STC SA 615 NW)
Insight Graphic Engine Monitor
(STC SA02930NY)
Cleveland Brakes (STC SA 815 NW)
Auxiliary Hydraulic Pump
(STC SA 1158 NW)
Longitudinal Step Kit
(STC SA 575 NW)
Tapered Wide Spray Rails (old Style)
(STC SA 392 NW)
Brackett Air Filter (STC SA 71 GL) Wing Extensions
(STC SA 2635 NM)
Martech ELT
Aux Fuel Pump Bulkhead Repair Cleveland Brakes
Hartzell Propeller Change HC-12X20-3E Hartzell Propeller Change HC-D3X20 Airnav 20 Loran
Landing Lights and Strobes Wide Spray Rails Instrument Relocation
Oil Cooler Change/Alcor Alternaeland Brakestor Prop Shaft Repair Wing Extensions/Flush Fuel Door/VG's/
Cessna Seats/Wing Fences
Wing Float Strut Replacement - -
Electric Fuel Pump    (Rev. 2 here) Angle of Attack (Incl. N87504) Electric Fuel Pump (Incl. N6240K)
King KRA 10/10A Radar Altimeter Wide Spray Rails Flush Fuel Cap
Landing Lights Aft Bulkhead Modification Pilot/Co-pilot Seats
Instrument Panel Cleveland Brakes Cabin Door Hinges
Radar Altimeter Cooling Fan Modifiaction
Fuel Pump-Electric
Electroair Ignition System Pre Oiler Air Wolf Oil Filter STC
Cleveland Brakes-Early Electric Hydraulic Pump
Angle of Attack (AOA)-Proprietary Software System, Inc.

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Updated August 20, 2021 (Added AOA 337, Added N87567, Added N6240K Electric Fuel Pump)