Republic Seabee Airframe Modifications

Republic Seabee Airframe Modifications

Several modifications have been developed by Seabee owners and engineers to improve the aerodynamic performance of the Seabee. Such modifications include extended wings, droop wing tips, wing tip end plates ('splates'), inboard 'splates'. Other modifications, such as extended spray rails and longitudinal steps, have been designed to improve the water performance and reduce water spray into the propeller.

Below is a summary of all Seabee modifications and STCs known to this author. If you have any corrections, comments and additions - please e-mail Steinar Saevdal.

DISCLAIMER - These web pages do not represent or promote any of the Seabee modifications or businesses listed below. The purpose of this list is to give basic information on some of the Seabee modifications and conversions that have been installed. Some of the modifications listed might no longer be available.

	Brake Conversions Cleveland (Dual Puck) Brake Conversion - [FAA STC # SA815NW]. Developed by Simuflight for seaplane use. The original Seabee wheels and tires are used. New master cylinders, adaptors and hardware are installed. Contact: Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

Larger Image	Cabin Heaters Southwind 940 CABIN Heater Installation - [FAA STC # SA915NW]. The Simuflight designed installation provides for a more comfortable air distribution than the original heater installation. The installation is fully approved and comes complete. It is available for either 12 or 24 volt electrical systems. FAA approved installation for the Southwind 940 heater, with defrost vents. The Southwind 940 heater uses fuel from the main feul tank and has the following specifications. Fuel consumption: Low Heat: 0.12 gph High Heat: 0.37 gph Heat output: Low Heat: 15,000 btu/hr High Heat: 27,500 btu/hr These are approx. numbers, and this heater has a number of models and there is a slight variance in the performance of each model. The numbers indicated here are for the latest model available. Installation time for this kit is between 30 and 40 hours depending on how you want your panel arranged. General condition and status of the aircraft can impact this installation estimate as well. Contact Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

	Extended Spray Rails Tapered Wide Spray Rails - [FAA STC # SA-392-NW] were originally designed by STC Bee Inc. (Jack Daubenspeck) to protect the propeller from water spray during water operations. The 'Tapered Wide Spray Rails' extend 13½" from fuselage at step and will give a super flat water spray pattern. Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558 USA Tel: 360-458-7715 Miller Extended Spray Rails - [FAA STC # SA3-30, issued 1956-04-19] were designed by Miller Flying Service in the mid 1950ies to reduce water spray. The Miller Spray Rails, made from .125" -75ST sheets, were riveted onto the the original 44" long spray rails and along the chines. Each Miller Spray Rail had a weight of 10 lbs and extended 9 - 10" out from fuselage, with a total length of 112" from the step and forward. Contact: ~~Russel A. Miller~~ Miller Flying Service North Benton, Ohio USA

	Electric Trim Electric elevator and rudder trim - replacement [STC Pending]. This is a complete replacement for the existing trim system. It consists of two electrically actuated server motors for the elevator and one servo for the rudder. The entire kit weights approx one pound and allows for the complete removal of the existing trim system and all components. Controls can be panel mounted and/or yoke mounted with panel mounted trim position indicators. Contact: Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

	Engine Controls Overhead Engine Controls - Overhead engine and propeller controls installed on Seabee N3500G by Randy Komko, Transition AirCraft Inc. (Photo on the left). Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558, USA Tel: 360-458-7715 www.seabee-transition.com Panel Mounted Control Verniers - Simuflight offered a complete set of panel mounted Control Verniers (throttle, mixture and governor) made to the exact length necessary for Simuflight's Lycoming engine conversions. All controls used threaded rod ends. All necessary brackets to mount on the engine and all hardware need were included in the kit.

	Flush Fuel Fill Flush Fuel Fill - [FAA STC # SA-391-NW, issued 1976-12-28]. The original Seabee fuel filler cap was installed on a tube extruding into the air on the left side of cabin just behind and above main landing gear. There are reports of cases were a loose filler cap have fallen off and into the propeller in flight. The Flush Fill modification, originally designed by Jack Daubenspeck, will improve the appearance and prevent a loose filler cap from flying into the propeller. Flush fuel fill modifications of different designs have been observed on other Seabees. Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558 USA Tel: 360-458-7715 www.seabee-transition.com

	Instrument Panel IFR Instrument Panel - A number of different IFR instrument panel modifications have been installed on Seabees, most of them 'one-of-kind'. It is known that STC Bee Inc. (Jack Daubenspeck) offered an IFR instrument Panel Kit Model 1-TP-1 under STC # SA-374-NW, issued 1976-11-01, during the 1970ies. STC Bee, Inc. ceased operations with the death of Mr. Daubenspeck. The IFR panel on the photo (left) was made for N3500G by Transition Aircraft, Inc. Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558 USA Tel: 360-458-7715 www.seabee-transition.com Shock Mounted Instrument Panel - Simuflight offered this modification with space for standard grouped flight instruments and radios, plus extra space for options. Contact: Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

	Longitudinal Steps Longitudinal Steps - [FAA STC # SA-575-NW, issued 1978-03-16]. This modification was developed by STC Bee (Jack Daubenspeck) for the installation of two longitudinal stiffeners on outside hull bottom - one on each side of keel. According to the designer, the modification would stiffen the hull bottom and make the Seabee hull plane at a lower angle on water, resulting in less air drag. Much less up elevator would be required to trim the aircraft on plane against power moment and step drag moment that both force the nose down. Due to the longitudinal step stiffeners long fore-aft area, the water pressure counteracting the power and step drag moments would be increased.

	Main Step "Cross Vent" Main Step Cross Vent - [FAA STC # SA-393-NW, issued 1976-12-28]. The Main Step "Cross-Vent" modification was designed by STC Bee Inc. (Jack Daubenspeck) to shorten smooth-water ('glassy' water) take off distance. A plate with several holes was mounted on keel gusset. STC Bee, Inc. ceased operations with the death of Mr. Daubenspeck. Contact: ~~STC Bee, Inc.~~ 10900 Rainier Avenue S. Seattle, WA 98178 USA

	Pitot/Static System Heated Pitot/Static System - [FAA STC # SA1153NW]. Simuflight offered a 'current design' heated pitot/static system that was very light in weight. The mounting position had been checked with a FAA 'airspeed test boom'. All switches and parts were included in the kit. Contact: Scott A. Henderson: Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

	Reverse Valve Reverse Valve Installation - [FAA STC # SE914NW]. This is a more compact and practical Reverse Valve installation than the one supplied by Hartzell Propeller Co. The roughly made Hartzell valve mounts between the Nose Case Governor Adaptor (Lycoming Part No: 69290) and the Governor. It contains a Spool Valve to switch oil direction and act as a 'followup' for the Beta system. Also provided is a Governor Drive Shaft Extension, made necessary by the additional depth of their Reverse Valve. The Simuflight Reverse Valve installation is a combination of the two above mentioned parts (Hartzell Reverse Valve and Lyc. Part No: 69290) manufactured to very exact standards and tolerance. No additional Drive Shaft Extensions are required. All extra reverse linkage needed to complete the installation is included. Contact: Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482

	Retractable Wing Floats Retractable Wing Floats - It is reported that Mr. Henri Briaco 2004 installed retractable floats on his Seabee C-FJIT s/n 148. Henri's lives in Quebec Canada, his phone number is 450 667 4060. Photo courtesy of Alban Marcoux. Brian Robinson reported in March 2004 that he was developing a retractable wing float system for the Seabee. The design is complete, and the Robinson's are now sourcing someone to manufacture them.

	Skis Non certified wheel-skis from Datum Air www.datumair.com The main skis move fore and aft with the use of an electric motor. The main wheels climb on the skis and you land in the snow. The tail ski is a fix penetration ski with the wheel showing under the ski. The landing gear handle is lock in the down position. You don’t want to put the main gears up!! Contact: Datum Inc. Jean-Marc Augé 9805 Route des Ormes Bécancour, Quebec G9H 3R4 Canada Tel: 819-297-2426 Fax: 819-297-2425 E-mail: datumair@datumair.com Website: www.datumair.com

	Step Vents Step Vents - [FAA STC No: SA-577-NW]. The Step Vents modification was designed by STC Bee (Jack Daubenspeck) to reduce step drag on both water and in the air. According to designer, these vents would show more relative effect, the heavier the Seabee was loaded. Two 3" diameter step vents (outlets) were installed in aft hull bottom just behind the main hull step. The step vents were vented through two tubes (6" wide, 1.25" deep and 77.625" long) mounted inside hull, having their inlet vents at each side of the aft cabin fuselage above the step. STC Bee, Inc. ceased operations with the death of Mr. Daubenspeck. Contact: ~~STC Bee, Inc.~~ 10900 Rainier Avenue S. Seattle, WA 98178 USA

	Water Rudder 'Non-original' water rudder installations have replaced the original water rudder on some Seabees. In most cases this probably have been done when original spare water rudders have not been available. Fiskflyg Water Rudder The water rudder illustrated on the left is installed on Seabee SE-AXY (s/n 830) in Sweden. The installation was probably made be the former owner Fiskflyg AB, which operated the Seabee as a pure flying boat (wheels removed).

	Windows Extra Door Windows - At least one of Commodore Air Services' Seabees (N6275K s/n 485), operating out of Sausalito, California, had extra windows installed in the lower side panels of the aft cabin and in the side doors. The purpose was prabably to improve the cabin viewing visability for sightseeing passangers. Reshaped Aft Cabin Side Windows - [FAA STC # SA-395-NW, issued 1976-12-28]. Originally developed by STC Bee Inc. (Jack Daubenspeck), the modification will reduce the "1939 Ford look" of the original aft side windows and improve cabin visability. This modification is available for both rubber and flush mounting. Transition AirCraft is still offering similar modifications to the side windows. Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558 USA Tel: 360-458-7715 www.seabee-transition.com

- Increase rate of climb 150 ft/min - Get on the step in 8 secs - Take off distance - land 600 ft - Lift off water 27 secs - Lower stall speed 8 mph - Land at 50 mph - reduce landing roll - Make power off landings with ease - Not adversely affect cruise speed - Fly at a reduced angle of attack - Eliminate propeller erosion - Give you confidence in the Seabee	Wing Extensions The Miller Wing Extensions - [FAA STC # SA3-30, issued 1956-04-19] were originally developed and marketed by Russell A. Miller; Miller Flying Service, North Benton, Ohio, in the mid 1950ies. Miller was a Seabee distributor and operator, and always thought of the Seabee as 'a well made, safe and sound airplane'. The Miller Wing Extension would add 24" to each wing. Each wing extension would have a weight of 17 lbs. The combined Miller Wing/Spray Rail modification was issued FAA STC No: SA3-30 on 19 April 1956, and promised the several performance improvements. Most Seabees flying today will have the Miller Wing Extensions installed. In the promotional literature for the Miller modifications, Miller wrote this well written praise of the Seabee. Contact: ~~Russel A. Miller~~ Miller Flying Service North Benton, Ohio USA 'RICE' Wing Extension - [FAA STC # SA1-18] is described in FAA records as: Increasing the the wing span 16 inches and incorporating wing tip spill plates. Contact: Ned C. Rice 470 Silver Lane East Hartford, CT 06108 USA KENMORE Wing Extension - [FAA STC # SA17CE, issued 2000-10-27] is described in FAA records as: 'Extension of each wing tip 24 inches on outboard end'. Contact: Kenmore Air Harbor, Inc. P O Box 82064 Kenmore, WA 98028-0064 USA

	Wing Floats Fibreglas Wing Floats - The fibreglass wing float illustrated above has been developed by Transition AirCraft Inc. (Randy Komko) to replace the original aluminum wing floats. Contact: Transition AirCraft, Inc. P.O. Box 285 McKenna, WA 98558 USA Tel: 360-458-7715 www.seabee-transition.com

	Wing Fuel Tanks Wing Fuel Tanks - Second generation Seabee Guru, Henry Ruzakowski, has developed some leading edge wing fuel tanks that will hold a least 15 useable gallons per side. They are made of carbon fiber and Kevlar and will gravity feed to the main tank with the operation of one lever. They will be done on a field approval only, so you'll have to take your airplane to him in Florida... Henry Ruzakowski 10941 Deneau Road Boynton Beach, FL 33437 USA Tel: 561-436-0821

	Wing Tips At least three different Seabee wing tip modifications are known to exist; all with the purpose of improving the Seabee's performance by reducing induced drag due to wing tip vortex. (1) DROOP TIPS Daubenspeck 'Model 2 DT' fibreglass droop wing tips were approved under FAA STC # SA-394-NW, issued 1976-12-28. Daubenspeck 'Model D-1' fibreglass droop wing tips were approved under FAA STC # SA2386WE, issued 1971-07-28. STC Bee, Inc. ceased operations with the death of Mr. Daubenspeck. Droop tips are currently available at Simuflight; Contact: Scott A. Henderson Simuflight Inc. 3763 Image Drive Anchorage, Alaska 99504 USA Tel: 907.337.2860 Fax: 907.333.4482 (2) 'SPLATES' Spill Plates are flat plates replacing original wing tips of the Seabee. The are larger than the wing airfoil section, and thus are sometimes referred to as 'wing tip fences'. Most Seabees operated by the Einarson Brothers in Minnesota had 'splates' installed. (3) ENDPLATES Larger versions of the wing tip endplates (similar to the Splates), of various shapes, have been spotted on some Seabees.

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Updated: 2018-01-19		© 2006-2018 Steinar Saevdal