Temperature measurement with PIC is easy, but there are dozens of temperature sensors and the codes for them are different. What kind of temperature sensor(s) you are using (or going to use)? Give us sensor types or part numbers or - best of all - schematic for your circuit.
Along the same lines, the code for different C compilers would be different. What compiler do you have?
This is a much tougher problem, because the attitude of the aircraft is changing, and the level (assuming for now that it's horizontal) will be changing with respect to the tank onto which the sensor is mounted. The type and purpose of the aircraft plays a big role here, because the dynamics of Boeing 747, Mig-29, Cessna 150 and RC model airplane differ a lot. Please shed some light on this. This is a neat problem to solve.
