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Technical Support for Navion System


OSBORNE Kit P/N AL-1 (TT2-1) Navion models A, B, D, E, F, and (twin) D16, D16A 

  OSBORNE Flush Aileron Balance Weight kit.  This replaces the factory external weights.

Description Probable Cause Correction
Weight screw will not start  Aileron pre-drilled skin hole not lining up Tap out with 10-32 taping bit
Flush filler does not  harden  Not mixed properly or needed more hardener added  Remove filler and re-apply

OSBORNE Kit P/N 11982 (TT2-1) Navion models A, B, D, E, F, and (twin) D16, D16A

Brief Description: OSBORNE Tip Tank kit consist of fuel lines routed from the Tip Tanks to a “cross feed” valve, then forward to the OSBORNE valve selector valve.  This valve is four position Left hand Tip Tank, Right hand Tip Tank, main tank and off.

Description Probable Cause Correction
Valve is hard to turn Worn out/dry    Grease seat and replace shaft seal
Fuel stain at selector shaft  Worn out/dry Grease seat and replace shaft seal
Handle is loose after installation of new clevis pin Worn out handle and or selector valve shaft Replace handle/valve assembly
Fuel bypassing valve 

Worn out, foreign Debris caught in seat

Replace Valve
Valve handle is attached to selector shaft with a assembly screw on type (handle) Non approved valve  Replace with approved part
Valve turns with no feel or tank position detenting Wrong selector valve body or worn out detent assembly Replace with approved part assembly

OSBORNE Cross Feed Valve P/N 55028  

Kit applications: Navion Kit P/N 11982 (TT2-1)  

This valve is used in level fight when Tip Tank is selected to achieve “cross feed” of both (LH and RH) Tip Tanks usage.  


Probable Cause


One Tip Tank feeds faster

1. Weak cross feed valve  

2.Plugged Tip Tank vent  line

Replace valve Clear slow feeding Tip Tank vent line

No cross feed occurring when cross feed switch is selected “open” 

1. No power to valve 

2. Valve is not engaging

Check power source to valve  

Bad coil replace valve 

Tip Tank fuel is bypassing (siphoning) to opposite Tip Tank; in static condition. “Not in flight”

Seal in valve is worn out

Replace valve  

OSBORNE fuel gauge P/N 55027   

Fuel gauge (single) with selector switch. 


Probable Cause


Reads empty at all times
 with fuel in Tip Tanks

1. Fuel transmitter between Tip Tank and selector switch/gauge is grounded

2. Faulty fuel transmitters

3. No power to gauge

Check fuel transmitter wire
for continuity, check power source

Reads full at all times
 with less than full Tip Tanks

Open fuel transmitter circuit.          

Check fuel transmitter wire
for continuity. Check for loose wire connection

Fuel Transmitter: See P/N 55025