(It would be great if a mod. would sticky this thread.....)
It's most probably the Garmin panel. It's pretty complete with dual G3X's, GTN750, GMA 240 audio panel, GMC 307 AP controller, a GTR200R comm, GDL 39, remote GTX 330 xpndr, and all the attendant modules that go with supporting these devices. And there are a bunch of them.
Plus I have good solid carpet in the front an rear from Flightline Interiors along with leather seats and armrests.
It all adds up. I will reweigh it after paint and see where we are then.
Any idea what was added for the extra weight from Van's #?
What did Van's -14 end up weighing empty. They don't have an empty weight on the spec page yet.
Yes they do , first link on the opening post.
If my 14 gets close to this, my wife an me can gain a lot of weight and still fly with full tanks and max luggage... not sure if that is a good thing
Just weighed N914VA the other day. 1246 lbs. empty, w/o paint. Empty C.G came out at 81.38".
Will reweigh after paint next month.
As a side note, the empty weight of the proto -14A on the https://www.vansaircraft.com/pdf/RV-14&RV-14A_SampleW&B.pdf worksheet doesn't equal the sum of the three wheel weights. 436 + 364 + 435 = 1235 lb (not 1239 as shown). I'm not trying to nitpick, just wondering if the discrepancy indicates any errors in the original data (which might explain the CG differences as well?).
,
Any chance of getting the actual W&B data from N144VA?
Thanks
Errors in the posted document have been corrected.
These are the official samples based on data from the two prototypes.
Still looking into why Mitch's computed C.G. is actually aft of the taildragger prototypes.
Stoney,
As explained in the response to your PM I sent to you over the weekend, the aft arm position on the sample form got inadvertently labeled tail wheel. The actual position used for weighing was the bolt that attaches the tail spring to the fuselage. A short threaded standoff can be made to thread onto the stub end of the bolt and then the tail supported with a jack stand set up on the scale pad. The tail has to be raised quite high and be carefully adjusted so that the airplane is exactly level. The hydr. jack stand makes this simple.
So, I think if you measure you will find that the distance between the tail spring attach bolt and the tail wheel axle bolt is probably the difference you see.
The sample form will be updated to reflect the difference.
The different CG position for your airplane when compared to N144VA is not really a surprise considering it is only 5 pounds lighter, and it is not painted. A paint job will add more than 5 pounds (8-15+ is common) so that means your airplane is already slightly heavier (at least will be once it is painted) than N144VA. Depending on where that extra weight is located, and then factoring in the shift aft that the C.G will make when it gets painted. As you mentioned, weight on the tail from paint or other objects like an ELT will have a strong influence because of the large moment as a result of the long moment arm.
Based on this information, I think your calculated CG position is probably about what would be expected.
This is a repeat of another post as was requested.
This RV-14A has a new from Van's IO-390 engine and a custom composite two blade CS prop (uses a Hartzell hub). The plane is built to plans, has a full dual EFIS IFR panel, and not yet painted (I suspect the paint will aggravate the nose light issue as the majority of the paint weight will be aft of CG). Seven qts of oil in the sump. The one battery (PC-680) is mounted on the firewall per the plans. As I previously mentioned, I suspect we'll end up putting another PC-680 battery on the firewall to help the CG issue and to address the woefully inadequate battery reserve offered by the single battery.
Here are the numbers. Plug them into the Van's W&B spreadsheet:
Right wheel: 434.5
Left wheel: 425.5
Nose wheel: 352.0
Here is the problem. At full 2050 pound gross (219 pound pilot and passenger, 100 pounds of baggage and full fuel) the CG is at 89.6" (aft limit is 88.24").
Carl
Carl,
You are probably already aware, but the problem is even bigger than you describe.
As fuel is burned off the CG moves even farther aft, so the worst case situation for C.G. position will always be at minimum fuel.
This is a repeat of another post as was requested.
This RV-14A has a new from Van's IO-390 engine and a custom composite two blade CS prop (uses a Hartzell hub). The plane is built to plans, has a full dual EFIS IFR panel, and not yet painted (I suspect the paint will aggravate the nose light issue as the majority of the paint weight will be aft of CG). Seven qts of oil in the sump. The one battery (PC-680) is mounted on the firewall per the plans. As I previously mentioned, I suspect we'll end up putting another PC-680 battery on the firewall to help the CG issue and to address the woefully inadequate battery reserve offered by the single battery.
Here are the numbers. Plug them into the Van's W&B spreadsheet:
Right wheel: 434.5
Left wheel: 425.5
Nose wheel: 352.0
Here is the problem. At full 2050 pound gross (219 pound pilot and passenger, 100 pounds of baggage and full fuel) the CG is at 89.6" (aft limit is 88.24").
Carl
Carl, thanks for posting this information. Thus far I?ve collected empty weight and CG information for three RV-14As that are finished with paint, IO-390s, and Hartzell props. Two of the three have IFR panels but this isn?t a huge factor because panel equipment isn?t far from the CG. All three of them have an empty CG between 80.6 and 80.96. If you run the numbers to fill them up with gas, 100 lbs of baggage, and big people to bring them up to gross weight, and then burn off the fuel down to 8 gallons, you end up (worst case) at 87.47? which is well within the aft limit.
Now suppose I replace the metal Hartzell blades with composite. I?m not sure how much the weight change would be but I can?t imagine it?s more than a 20 lbs reduction (a Whirlwind would be a 16 lb reduction). If I remove 20 lb from the nose (around the 17? station) on the above three example aircraft, the worst case after burning down to min fuel is 88.38??just a hair beyond the 88.24? limit. An unpainted -14A should move the CG measurably further forward. And if you go back to to the full fuel condition that you defined it will move the CG forward another .7 inches. I can?t see how you?re ending up at 89.6? in an unpainted -14A with full fuel?you?d almost have to remove the prop entirely, or install a lead brick in the tail.
As another sanity check, I tried plugging in the weights for your three wheels using the measured arms from the other three -14As. With 219 lb pax & pilot, 100 lb baggage, and full fuel this calculates out to a CG of between 87? and 87.5? (well forward of your 89.6? number). Of course I don?t know the actual arms on the subject -14A?they should be carefully measured with the aircraft in a perfectly level attitude. The nosegear is articulated so the measurement will vary somewhat from one -14A to the next. But I can?t imagine it moving enough to result in such a large discrepancy from the other flying examples.
Adding another PC680 is a big weight penalty so I?d take a very close look at your W&B to make sure you?ve got it right before adding ballast to the FWF area...
Thanks Mark. You got me to redo the W&B spreadsheet. It seems I carried over the baggage arm from the RV-10 - that really screwed up the numbers.
So at 2050 gross and 100 pounds in the baggage compartment, I now have a CG of 87.45" - inside the aft limit.
Your gentle prodding avoided sending the DAR a bad W&B - thanks.
Carl
So at 2050 gross and 100 pounds in the baggage compartment, I now have a CG of 87.45" - inside the aft limit.
Carl
Carl, is that with full fuel?
Edit: You do say "at 2050 gross." What is it at 8 gallons?
I am not an expert in this W & B area. I paid a professional to do my W & B. As stated previously my empty weight is 1288.6lbs and arm 80.9 inches. The aircraft is painted (inside & out) YIO 390 & 74 inch Hartzell and Garmin dual G3X, remote Garmin Transponder, VPX and GTN 650.
On first flight with half tanks we found that we were running out of elevator control on the flair to land. A little more speed (75kts) and a little more power fixed this. I then tried quarter tanks and full tanks in landing configuration, the results remained fairly similar to the first landing. 45lbs of weight (drummed water) was then added to the baggage area. Much better elevator authority on landing.
Another 45 lbs of water was added, now a total of 90 lbs of weight in the baggage area. Two pilots 360lbs and quarter tanks the aircraft handled just superbly with much improved elevator authority on landing. The next flight was with full tanks, 90lbs in the baggage area and 360lbs in the front two seats. Once again landing was conducted with elevator authority. A series of landings from short field, flapless and flapped landings, no issues.
It appears to me that the ballast in the baggage compartment is going to be the norm for everyday flying operations. With further testing I'm positive the baggage capacity will well exceed the 100lbs as stated by Van's. It appears on paper that my wife and I (300lbs) can carry 130lbs of baggage and remain within the envelope. FYI Alan
Doing ANYTHING to PURPOSELY try to make your RV10 or RV14 less nose heavy by building it with different components (propellers, etc..) or component locations (moving batteries, etc..) solely for the idea of making it less nose heavy is a big mistake. The planes get their utility by having the CG towards the front limit, allowing you to load them up and use them as people do. It keeps the RV-14 safer for aerobatics that way also. So don't build an RV-14 with the goal to try to "fix" the noseheavy problem. You would be better off trying to make it MORE noseheavy if anything, as both planes can be loaded out of aft CG if someone tries hard enough...but Van's did good with the CG location as built, so I recommend sticking with it.
Does anyone know if the composite Hartzell prop is light enough to cause a CG problem? It looks really nice on Carl and Rafael's plane and I am inclined to follow their lead, but they haven't done the W&B yet. Sorry, I don't know the weight vs. the aluminum Hartzell.
As a guy who's making his add/delete list for my fuselage order I was thinking about buying the new earth x 680c battery,........but this thread gives me pause. Since the battery box is in the fuselage kit I though now would be the time to replace the std one. Losing 11 lbs is great but at the firewall, that might be a problem. Has anyone else done this on a -14. I guess I could wire two batteries for a aux? Another similar issue is that it appears going for the beringer wheel/brakes package would cause the same issue as the mains on the taildragger are slightly ahead of the c.g. This also saves about 11 lbs. Any input is appreciated
Good info thanks. I will delete the vans battery box and use the convertible one from earth x to give options. Besides moving the elt, another possibility available is buying a lighter weight tailwheel.