weight and balance

[Lan Vinh Do]

Hi
I am about to make a trip with 4 adult and luggage baggage.
I have a mt prop and a 02 tank in the tail so my cg is probably more aft that others and as i burn fuel, my cg go farther back.

When i calculate my w&b i am ok on take off but if i land with only 10 gal, i will be 0.2 inch pass the aft limit.
My queation is : is the 114.58arm for pilot and copilot is calculated with the pilot seat completely at the rear position. I am only 5feet 7 and i always put my seat the more foward i can. So of i put the pilot front seat at 112.58, i am ok.

if not, anything bad to land with a cg 0.2 inch aft of the rear limit?

[AltonD]

I cannot answer your question. I am an RV7A Driver.
I can ask another one: Have you ever tried landing with a CG too far aft? I have in a spam can. I will never do it again. Be careful out there.

[RV10Rob]

Originally Posted by Lan Vinh Do

if not, anything bad to land with a cg 0.2 inch aft of the rear limit?

I strongly recommend you don't fly with the CG outside the range you tested during Phase 1. The time to try it is not with 3 other people aboard.

-Rob

[BobTurner]

"is the 114.58arm for pilot and copilot is calculated with the pilot seat completely at the rear position"

I thought it was an average (middle of the adjustment range) number.
Obviously there are some variations here. If you have the seatback more reclined your cg moves back. If you wear heavy shoes, it moves forwards.
I attempted to put in numbers based on the seat back being as upright as it goes, since that's how I fly. I use 113.3" for me, which is one notch back from full forward.

Yes, with aft loadings the CG moves further aft as you burn gas.

Of course you should put in the proper number for the front seat passenger, too, depending on if he/she is full forward, full aft, or in-between.

Flying with the cg too far aft will display the following characteristics:
1. Aircraft will be very light in pitch, and if cg is really too far aft, pitch will become divergent (small bump raising the nose, nose will continue to rise). It may become uncontrollable by a human pilot.
2. Stalls may become unrecoverable.

If necessary try to relocate some luggage between the two front seats. The other alternative is to make intermediate fuel stops to keep the tanks more full. 10 gal on landing is my personal minimum, regardless of what the FARs say.

[Lan Vinh Do]

Hi
Thank you for the answer. I don't want to scare anybody. My normal trip will put me at 30 gal in the tank so well in the cg limit. I was considering worst case senario. IFR, miss approach, going to alternate etc. If it's low ifr, i will not make the trip as my wife don't like these condition and passergers only flew once before. At 113.3 for pilot and copilot it would be ok even with only 10 gal.
Any other answer will be welcome.

[Lan Vinh Do]

I will have a good trip. I decided that the wifes can only bring bikini and lace dress. They will never say no if it's for safety.

[Wayne Gillispie]

Because I have aux bat beside main battery, I limit baggage to 99 lbs in the rear. Anything else goes in passenger floorboard areas. In cruise if passengers need more leg room they can move it behind them until descent. Being near aft cg limit makes us more efficient in cruise. Don't forget to move it back before landing. The wife keeps purse up front against spar. Whatever you do don't push the limits with friends, use dogfood or similiar as I did.

I heard from a friend...it can make landing very interesting with aft cg. He told me he did not wish to make that mistake twice. I forgot his name.

[Wayne Gillispie]

We definitely want a detailed trip report with lots of pictures.

[johngoodman]

Remove the O2 tank.

[TSwezey]

I never had a rear CG issue.
Come in hot. And gentle stick movements.