Originally Posted by
Genghis the Engineer
I just looked up the Post Flight Report for a C172P I did an air test on last month.
I put down that with just me (180lb) and full fuel, I was at 1864lb, which was 81% MTOW - MTOW 2300lb I believe.
So, add in another 3 medium sized adults I'd have to lose 17 gallons of fuel to be on MTOW, which would give me 26 gallons of fuel. Allow 9 gallons an hour, and assume landing with an hour's fuel, that gives me about 1:50 airborne time.
Okay, my 10 miles comment was a bit pessimistic. You'd manage around 200 miles.
G
At the risk of being pedantic the C172P has a MGTOW of 2400 lbs, not 2300 lbs like the earlier marks. The extra 100 pounds will return 16.5 USG of the 17 gals you said you needed to offload. However that is the weight the aircraft must be at at the moment of takeoff.
The POH specifies that 1.1 gallons will be used for start/taxi and runup so you can add the last .5 gal to full (standard) tanks and have 3.5 pounds to spare for inflight snacks during your 3+45 flight
