Fuel quantity indicating

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
43a72v
Posts: 11
Joined: Sat May 18, 2002 1:44 am

Fuel quantity indicating

Post by 43a72v »

One other question (for tonight)...Just after topping off both tanks, I'll go fly. Upon levelling off, I glance at the left fuel gauge and it shows about 3/4 full! This is consistent and I fuel the airplane myself, so I know I'm getting as much fuel in as possible. Sitting on the ground, the gauge shows full, as does the right side. Any thoughts? Also, is there any available option of going to an electric type system? Cessna apparently does not have anything for the 170s, was wondering if anyone else does. Thanks!
Josh
User avatar
mit
Posts: 1049
Joined: Wed May 01, 2002 1:54 am

Re: Fuel quantity indicating

Post by mit »

43a72v wrote:One other question (for tonight)...Just after topping off both tanks, I'll go fly. Upon levelling off, I glance at the left fuel gauge and it shows about 3/4 full! This is consistent and I fuel the airplane myself, so I know I'm getting as much fuel in as possible. Sitting on the ground, the gauge shows full, as does the right side. Any thoughts? Also, is there any available option of going to an electric type system? Cessna apparently does not have anything for the 170s, was wondering if anyone else does. Thanks!
the best fuel gauge that you have is your watch, backed up by the gauges.
Tim
Dave Clark
Posts: 894
Joined: Mon Apr 22, 2002 6:25 pm

Post by Dave Clark »

By all means use the watch. But to answer your question the cork float could be getting heavy with fuel penetration.
Dave
N92CP ("Clark's Plane")
1953 C-180
c170ragwing
Posts: 3
Joined: Mon Apr 22, 2002 11:16 pm

Fuel Gages!

Post by c170ragwing »

I recently had both gages out on the bench and the accuracy is plus or minus 25%.......one thing I did do was calibrate the "empty" to read "empty" when it was actually empty. Full is with your eyes looking down in the tank but there is one thing sometimes overlooked on the ragwings.....it takes a few minutes for the fuel to bleed over to the second tank attached to it via front and rear inter-tank hoses. Who can read those gages anyway? They bounce all over the place.
User avatar
GAHorn
Posts: 20968
Joined: Fri Apr 12, 2002 8:45 pm

Re: Fuel quantity indicating

Post by GAHorn »

43a72v wrote:One other question (for tonight)...Just after topping off both tanks, I'll go fly. Upon levelling off, I glance at the left fuel gauge and it shows about 3/4 full! This is consistent and I fuel the airplane myself, so I know I'm getting as much fuel in as possible. Sitting on the ground, the gauge shows full, as does the right side. Any thoughts? Also, is there any available option of going to an electric type system? Cessna apparently does not have anything for the 170s, was wondering if anyone else does. Thanks!
You might try levelling your airplane on the ground with full fuel to confirm your guage calibration. In any case, you should consider that any aircraft fuel quantity indication system has limitations. These mechanical guages are about as fool-proof as any system designed as long as they are maintained and properly calibrated. (The FAA only stipulates that the fuel indicating system read "Empty" when the tank is empty. I guess by that standard, as long as the guage is stuck on empty then all is well. :? )Electric indicating systems are far more troublesome and unreliable than these good-ol' direct-reading mechanical guages. (Virtually all the problems with these guages can be traced to old-age and lack of proper maintenance.)
The last thing in the world I'd personally wish for would be electric fuel guages and their problems of inaccuracy, complexity, loss of electrical power or ground and calibration errors, not to mention sending unit scarcity and lack of replacement parts for the guages. And where would you mount the things, anyway?
Post Reply