zero fuel w & b

john smith wrote:
d&tm wrote:

Are there any single engine airplanes out there that really can go
outside
the envelope by burning fuel? ( I am only interested in the normal
ategory - not utility). Perhaps the training is just to prepare you
for

Piper PA32's will can also develope this situation.


I'd previously posted links for some weight and balance info for a few
aircraft I've flown over the years. One of them happens to be a PA32.
This link http://www.4-fs.com/new/flying/N3000AWB.xls is to the W&B
spreadsheet for the Piper Lance (PA32-RT300T) which we've been flying
the last few years. I had included variables for fuel at departure and
'low fuel' for landing for just this reason. You can plug in the
following plausible values for a real flight and end up with the CG in
range (though precariously aft) at the start of the flight and have the
CG aft of the limits with 15 gallons remaining at the end of a flight:

Pilot+no front passenger: 180 lb
Center Passengers: 0
Rear Passengers: 360 lb
Fuel: 94 gal
Front Baggage: 0
Rear Baggage: 90

The CG only moves 0.22 inches to the rear after burning 79 gallons of
fuel, but it does take you 0.20 inches past the aft CG limit during the
flight.

Flying this plane with club seating does allow for some interesting
weight shifting when passengers (wife and kids typically) swap seats in
flight. You definitely do feel the change, and as such I always keep in
mind which passengers sit in which seats. Imagine the above loading
with the rear passengers (2x180lb) in the center row of seats and the
rear seats empty. Once airborne they decide they don't like to fly
'backwards' in the club seating and 'help themselves' to the the empty
rear seats. Suddenly we go from a very comfortable CG to a precariously
aft CG. Not a situation one generally needs to worry about in 2 and 4
seat airplanes.

That is part of why I find these spreadsheets so helpful in quickly
looking at a bunch of 'what if' scenarios before we depart.

Steve