RV-9A cg

Ed_Wischmeyer · #1 03-07-2017, 09:55 AM

Just put together a spreadsheet for my -9A, with the cg expressed in % MAC. I suspect I've got an error somewhere, because as long as the weights are within bounds (75 lb baggage), the spreadsheet says that I can't load the plane out of the "utility category" envelope.

Do I need to keep looking for an error in the spreadsheet, or is the cg envelope really that usable?

Ed

alpinelakespilot2000 · #2 03-07-2017, 10:06 AM

That sounds about right, at least for my -9. I used a 4# crush plate which allows me to carry 100# in baggage area and still be within c.g. in almost any realistic configuration, but I suspect if I would have been willing to give up that extra 25# of baggage I could have done it without the crush plate.

bruceh · #3 03-07-2017, 12:37 PM

I gave myself an extra 50 pounds of gross weight and I can't realistically get it out of balance unless the pilot weighs nothing, with minimum fuel and full baggage (100 pounds).

YellowJacket RV9 · #4 03-07-2017, 12:58 PM

I can't find any realistic way to get out of CG either, as long as I am in the plane - I can take up to 100lbs baggage. I have an O-320 at metal Sensi FP prop.

Chris

krw5927 · #5 03-07-2017, 01:05 PM

This is what I found as well. It's not necessarily a mistake in your numbers. For my plane, as long as there's a pilot (even a young kid) and enough gas to get off the ground, I can load out the remainder of the gross weight any way I want and not worry about CG being out of the envelope. Yours may vary of course, but what you're finding isn't uncommon.

Ed_Wischmeyer · #6 03-07-2017, 07:45 PM

Thanks, all!

Ed

AF_Alan · #7 03-08-2017, 05:13 PM

Similar results on my 9A, FP, IO-320.

I used a spreadsheet to calculate W&B for numerous scenarios prior to DAR visit:
- Couldn't exceed aft C.G even with bingo fuel and aircraft at 1,750 gross with pilots and baggage (I placarded for 100# limit).
- Light pilot solo and low fuel would be enough to exceed forward C.G limit.
- Flown solo and full fuel needs a few pounds in baggage area to prevent exceeding the nose wheel limit.

Love my RV!

Ed_Wischmeyer · #8 03-09-2017, 07:12 PM

What's the nosewheel limit? I missed that along the way.

Thanks!

Ed

Robert M · #9 03-13-2017, 05:41 AM

While we are on the subject of W & B, I was curious, has anyone ever PUT 100 lbs. of weight in the back of an RV-9 or -9A?

And as always, thanks for the replies.

airguy · #10 03-13-2017, 07:20 AM

Quote:

Originally Posted by Robert M

While we are on the subject of W & B, I was curious, has anyone ever PUT 100 lbs. of weight in the back of an RV-9 or -9A?

And as always, thanks for the replies.

I was quite close to it going to Oshkosh last year.