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Part# 05-15905-F
MFR Model# S1R-F-3
DescriptionPart No.
Single Lever Quadrant w/Friction05-15905-F


These quality quadrants have been in use for over 35 years in a wide variety of experimental and ultralight aircraft. All quadrants are made with AN standard hardware and aircraft-quality 6061-T6 or 2024-T3 Aluminum. All sizes and models can be utilized for a side mount, center mount, or dual-control hookup. Can be used in Pitts, Cub, Aeronca, Bakeng Deuce, Horizon 2, Dakota Hawk, Quicksilver, Mini Max, Dragonfly, X-Air, etc. If you have an aircraft, we have a quadrant that will fit your needs.

Model #1 -This external reversing quadrant is our most popular for dual-control hookup. It can also be used as a single hookup. Available in S-series only. One, two or three levers. Friction or non-friction.

Four sizes available:
Special series quadrants:
Large Series 4-78" wide x 4" tall. 13 oz.
Standard Series 4" wide x 3-1/2" tall. 11 oz.
3/4 series 3-7/8" wide x 3" tall. 10 oz.
1/2 series 3-7/8" wide x 2-5/8" tall. 8 oz.
RV-series 4" wide x 4" tall. 12 oz.
Panel Mount
4" wide x 3-1/2" tall 12 oz.
Twin Engine
4-7/8" wide x 4" tall 15 oz.
All weights are for two arms and friction. (Except twin engine).
Measurements do not reflect Lever lengths.
California Prop 65 Warning Symbol

WARNING: Cancer and Reproductive Harm -

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I like the unit but the middle knob broke in two . It is a wooden ball ? Split in two . Should be plastic knobs . I need a replacement knob but it does not state the material it is made of ? Would rather have plastic knobs and would be willing to pay more up front .

May 14, 2020

The fiber spacers are unfinished on the edges. They are rough cut and do not conform with the curvature of the aluminum plates. This can be rectified with a bit of work to sand and polish the rough cut and make them conform but that should be done in production. The lack of space between the levers presents a challenge for fitting two clevis adjacent to one another. The Clevis size to use would be useful in the Accessories tab of the product. If such a clevis exists. Without that information one cannot be sure if these may be used without a lot of work.

George G
April 4, 2016


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.