REFLECTOR: Weight and Balance Levelling

Tue Nov 11 09:08:46 CST 2008

Where can I find the Velocity flight manual that has the weight and 
balance procedure?

Terry Miles wrote:
> Dear all,
> Here below was a piece I posted when I did my wgt and balance.  I hope it
> helps.  I am happy to talk further on this if somebody needs further ideas.
> I used Ronnie Brown's program.  
> Terry
>
>
>
> Dear All,
> I did my wgt and balance this week.  Here is the news and comments.  
>
> First the news:  She came in at 1892.5 pounds and 136.7 aft of datum. I am
> very happy with that.  Here are some particulars:
> 	300 HP Lycoming which is another 60 pounds more than the 260 HP
> version.  
> 	Two full sized batteries in the nose, 
> 	All the seats, seat cushions, hooker seat belts, and the false fire
> wall in place.  No carpet or headliner or trim. 
> 	A couple of headsets, and my backup handheld GPS and VHF/VOR ICOM
> and a small fire extinguisher.  
> 	A final exterior paint job and some Zolatone on the gear legs, wheel
> wells and ceiling beams    
>
> I used locally borrowed certified scales.
>
> Minor irregularity:  I thought the "Owners Flight Manual and Wgt & Bal" book
> was nicely done and provided me with some approximate figures.  That gave me
> a reasonableness crosscheck as I started to get my own numbers.  I take
> exception to one number in the Velo book on page 33 where it shows the sump
> tank at 145 inches.  It is over 150 inches.  The reading comes from the fact
> that the gas won't all drain into the sump so using gear wgt numbers on the
> scales may not be the most accurate approach for this particular
> measurement.  Especially in the RG where the sump is only half the size of
> the FG.  Be aware that with any two known numbers you can calculate the
> third.  I backed in my wheel numbers (moment)and used the known fuel weight
> and the known arm.  
>
> "Been There" Advice:  
> 	I made the mistake of pouring all the first 20 gal into one tank
> thinking that it would level across wings in no time flat.  Wrong.  What I
> did was introduce a heavy wing and small bank angle.  It would be better to
> put the fuel in equally to each tank then wait a couple of minutes.  Pick a
> slow time for the fuel truck man!  Then rocks the wings slightly.   Be sure
> you are chocked.    
> 	I didn't measure the distances from datum to various key points
> prior to putting the aircraft on the scales.  Points like wheel axel points,
> aprox wgt centers for front seat, rear seat, spots you have earmarked for
> Jepp bags, door cubbyholes, you name it.  (Like what's the exact measurement
> of the aft lower corner of the entry door?)  It is much harder to do this
> with the aircraft on scales.   All these can be done easier with a plumb bob
> and marking spots on the hangar floor then record them all on a sheet of
> paper before you begin.  All this for a reasonableness crosscheck as you do
> the measurements.  You will need to know all the other distances the day you
> load the airplane for a trip to grandma's.  Good idea to get them now.
> 	Leveling:  My airplane as it sat empty on the hangar floor was nose
> high.  I should have thought to shim the main wheels with a pc of plywood as
> I mounted the airplane on the scales.  I didn't.  
> 	You can let air into or out of the tires within a range to get the
> pitch and bank level numbers you need.  A friend on hand suggested that and
> it worked great, with this exception.  If you have the nose tire down to
> complete deflation as you add wgt the side walls will compress on you some.
> The wgt change on the nose from empty to full is about 50 pounds.  
> 	I did my fuel probe calibration at the same time to include marking
> my cabin sight gauges and a dip stick.  That's a lot going on at once.  Make
> yourself a checklist.  Or be ready with siphon pumps and barrel for
> oversights!  
> 	Check BOTH tanks as you add fuel with the dowl stick from the
> hardware store.  I had a wing to wing wgt imbalance as the night went along
> that didn't affect the CG, but was a puzzle to me until I realized I had a
> small wing droop (gear flex?)  that didn't show up much on my centerline
> mounted digital level in the aft cabin.    For the XL: for me:   the dip
> stick for me came out at 1 inch equals 5 gallons or close enough from empty
> to full.
>
> Terry
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Douglas Holub
> Sent: Monday, November 10, 2008 11:39 AM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Weight and Balance Levelling
>
> Hi Brian,
>
> I'm planning on doing mine this week, too. I think I'll write down what I'm 
> planning to do just FYI, and also to help organize myself.
>
> My fuselage came with a fore-aft level line. When the work on the kit began,
>
> little plastic bubble levels were epoxied to the fuselage to make it easy to
>
> level the fuselage fore and aft. When it came time to prime the airplane, 
> before I removed those little plastic levels I leveled the plane and drilled
>
> two small 1/16" holes which were level and about 2 feet apart located below 
> the strake on the right side of the fuselage. Now when I want to level the 
> airplane, I stick two 1/6" drill bits in those holes and lay a carpenter's 
> level on them. (I got the idea from someone on the Reflector, but I forget 
> who.)
>
> I've already leveled the plane and used a tape measure and a plumb bob to 
> find the arm of the nose wheel axle and the main gear axles. Mine is 34.5 
> inches and 133.5 inches with the nose of the fuselage being zero.
>
> The W&B procedure in my Velocity Owner's Flight Manual says to weigh the 
> airplane empty with no fuel in the sump. Makes sense to me. I'm mildly 
> curious to know how the CG would be affected if I ever ran the sump dry. 
> I've got a 6.5 gallon sump, so it probably makes more of a difference in my 
> case than in yours. I've got an old Jaguar with two selectable 12 gallon 
> fuel tanks. We ran the car on one tank until it was dry. We'll drain the 
> fuel currently in the Velocity into the Jaguar and a gas can and weigh the 
> plane when it's empty, then use a siphon hose and the gas can to put 6.5 
> gallons of fuel back into the airplane and record those weights, then fill 
> the tanks up and record the weights again. I may also record the weights 
> when the tanks are half full, because I think the fuel tank moment might 
> change a little as the tanks are filling.
>
> The rest is easy.  While the plane is on the scales with no fuel on board, 
> I'll weigh my son and then sit him in the pilot's seat and record the 
> weights, sit him in the co-pilot's seat (it is staggered about 2" back from 
> the pilot's seat) and record the weights, then put him in the back seat and 
> record the weights.
>
> Doug Holub
> Standard FG w/ electric nose lift
>
>
> ----- Original Message ----- 
> From: "Brian Michalk" <michalk at awpi.com>
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Sent: Monday, November 10, 2008 9:44 AM
> Subject: REFLECTOR: Weight and Balance Levelling
>
>
>   
>> I'm planning on doing my weight and balance this weekend.
>>
>> I have not brushed up on exactly what needs to be done for the process,
>> so I am starting here.
>>
>> 1)  I'm assuming I need to level the plane fore/aft.  What points do I
>> use for levelling?  left/right is easy.
>>
>>
>> 2) I plan on measuring with full sump as baseline.  Add fuel in
>> increments.  Also do a W&B with pilots.  Of course all interior and
>> accessories are installed.  The plane is close to a "flying condition".
>>
>> 3) A buddy is bringing over his Cessna 210, and we're going to use that
>> for the fuel, and then return it after we are finished.  I have not yet
>> done fuel flow testing, and did not want to mess with a full load of
>> fuel in the plane.
>>
>> Any comments on procedure?
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>
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