What would you do (FARs)

[Airway]

Me and a private student finished pre-flight and we got into the airplane to get it started and for a lesson, and on start, the fuel quantity indicator for the right tank failed. We had just had the tanks topped off, so we were definitely full and fine for our flight, but I refused to take the plane, which pissed off our mechanic. We just took another 172 (easy enough).

The FARs state that a fuel quantity indicator indicating the amount of fuel in "each tank" is required, however, if you want to be technical, it doesn't say "an operating fuel gauge indicator" (I don't buy that stuff). I refused to take the plane not because I couldn't safely fly (I knew we had full tanks, and we would go up for what, 1.4 hours), but I did it to set an example for my student, and stay within the law.

But, I'm asking basically out of curiosity, what would you do? I took crap from the mechanic and I basically just sat there and nodded my head while he proceeded to be a jackass about it.

As far as I know, for VFR day, a fuel quantity indicator is required (unless I'm missing something).

Airway.

 

[JetBlast2000]

As the instructor, IMHO it’s a no-go item. You want to set a good example for your student. If you were to say “well, we got 4 hours of full, lets go,” your student is more likely to pass on bad habits and possible apply them elsewhere. Is it legal to take the plane, no. You could get away with it sure; I think you made the right call. Besides if you were to “feel pressure” from a mechanic every time you sq’d an airplane you’d be a basket case.

 

[erj-145mech]

Airway, your mechanic is just being very lazy. Rule number one, don't bust your ass. Rule number two, don't let anyone bust your ass for you.

You need to speak to someone in charge, that mech is out of line to suggest that you should fly with that inop instrument. Reference 14CFR 23.1305(b), 23.1337(b), and 91.205(b), unless you have a MEL system for the airplane. I had a C-310R on a certificate that could be dispatched with an inoperative fuel quantity indicator providing that the tanks were verified full, and the flight terminated prior to the time, minus one hour, that the engine would have comsumed the fuel at the maximum consumption rate. This was with the FAA's blessing, and could only occur in VFR conditons.

 

[Khirsah]

With tongue planted firmly in cheek, the argument could be made that if the fuel gauge failed to a zero or empty indication and you drained the tank, you'd be legal according to 23.1337(b) which states that the "fuel quantity indicator must be calibrated to read "zero" during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply determined under 23.959(a)" and 91.205(b) which is your minimum VFR day equipment requirement.

Of course, I wouldn't have gone.

 

[CAVOK69]

i think you did the right thing, but probably I would go if I didnt have another plane. I have rarely flown a cessna where the fuel gage was worth a crap anyway.

 

[Gutenberg]

That's happened to me a lot. Here's what I do: get out of the plane, shake the wingtip. Then move inboard and pound your fist on the fuel tank. Watch the needle go back to where it should be about 90 percent of the time. We have a pile of bad sending units from the new breed of skyhawks in a box, some are unfixable in this way, some are. It is definately a flaw in the design, and a huge hassle.

 

[midlifeflyer]

With tongue planted firmly in cheek, the argument could be made that if the fuel gauge failed to a zero or empty indication and you drained the tank, you'd be legal according to 23.1337(b)

Tongue in cheek or not, the "they only have to be accurate when the tanks are empty" myth is unfortunately believed by a =lot= of people.

 

[Geronimo4497]

Ah, the good ol' kick it till it works method! You did the right thing, BTW. Setting a bad example for a student is not a very good idea.

 

[Pilot124]

It's as simple as an MEL. Set an example by showing your student where to find it in the MEL book and how to do it. I wouldn't have half the time I have now if every time something small went wrong I just grounded the plane.

 

[Khirsah]

Tongue in cheek or not, the "they only have to be accurate when the tanks are empty" myth is unfortunately believed by a =lot= of people.

Which is, strangely enough, why I said "drain the tanks" and threw the 91.205(b) reference in there.

(9) Fuel gauge indicating the quantity of fuel in each tank.

If the tank is empty and the gauge reads zero, the gauge is indicating the quantity in the tank.