Question WRT Fuelling + C of G (NOOB!!)

[GeneralT001]

I was looking at the Long Ez POH and looking at the C of G with no one on board and a full fuel load. Clearly it is well out of Aft C of G. So to put full fuel on it I guess you must start with the nose fully down and then as the tanks fill up get in the aircraft, raise the nose and finish fuelling? - so someone or some "dummy" weight must be in the cockpit IOT take on a full fuel load?

[Marc Zeitlin]

On 11/27/2024 at 3:42 PM, GeneralT001 said:

I was looking at the Long Ez POH and looking at the C of G with no one on board and a full fuel load. Clearly it is well out of Aft C of G. So to put full fuel on it I guess you must start with the nose fully down and then as the tanks fill up get in the aircraft, raise the nose and finish fuelling? - so someone or some "dummy" weight must be in the cockpit IOT take on a full fuel load?

Not as simple as you posit. Firstly, even with an O-320 engine burning (not economically) 8 gph, the 52 gallons in the tanks (if built per plans) give a 6 hour endurance plus 1/2 hour VFR reserves. In 22 years of flying my COZY MKIV, I've done two legs of 6 hours or more - most folks very rarely fly more than 4 hour legs. So the first point is that even with an O-320 and crappy leaning techniques and efficiency planning, you're extremely unlikely to ever WANT the tanks to be filled. And with an O-235 Long-EZ that worst case will burn 6 gph, well, you've got 8 hours of endurance with reserves. I can count the # of folks who are willing to sit in a LE for 8 hours on the fingers of one hand.

But let's say you do want really long legs and full tanks. If you have electric nose gear, you can extend the nose gear about 2/3 - the plane will not tip aft and you can fill the tanks to about 95% full. Since the main gear axles are at 110" and the fuel is at 104.5", once you've got 300 lb. of gas on board, you can probably extend the gear the rest of the way (and that's assuming that there's zero weight in the back seat, which is all ahead of the axles so only makes it less likely to be able to tip back) and put in the last few gallons of gas, if you want. If you have a rear seater or 50 lb. of luggage, then that essentially guarantees no tip- back. And the gear doesn't have to be fully extended to fill the tanks - it can be extended 90% of the way with no loss of fill capacity.

If you have manual gear, then yes - the nose would be on the ground, you'd put in 90% of the tank capacity, then lift the nose, extend the gear, put your back seater in (or the luggage, which would have already been in) and finish filling.

Each plane is a bit different, with a different empty CG, but this is the essential process, depending upon airplane configuration.

Most likely, you'll NEVER fill the tanks, so can just fuel up to whatever level you actually do need for the leg you're going to fly with the nose on the ground or 1/2 way up (if electric nose lift) and be on your way.