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7A with Elastomer nose gear - request for as-built information

R

recapen

Well Known Member
Any flying 7A's out there with the new Elastomer nose gear?
What is the clearance from your prop tip to the runway?
What size prop do you have and how many blades?

I am documenting existing application to compare with my 6A that has the new Elastomer nose gear.

Thanks,
 
recapen said:
Any flying 7A's out there with the new Elastomer nose gear?
What is the clearance from your prop tip to the runway?
What size prop do you have and how many blades?

I am documenting existing application to compare with my 6A that has the new Elastomer nose gear.

Thanks,
Click to expand...
I know one flying. Jereme. His build is almost identical to mine. He has a Hartzel Blended Airfoil CS 74" prop. No idea on ground clearance but his build page in here on VAF.
This is his VAF page

RV-7A JCarne

Before commencing on the wheel pants (which will probably be a few months from now) I wanted to get to know the aircraft better before completing them. In the video below you can see as I slow down on the roll out the main gear shimmies a bit. (the rest of the video is just me taxiing) Not my...
vansairforce.net vansairforce.net
 
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I'll try and remember to measure next time I'm out there. It's pretty substantial. Best guess off the top of my head would be about 9-12" but I'll measure.
 
I've got an elastomer nose gear and 2-blade Hartzell 72" propeller, and with the prop oriented vertically, the tip of the prop is 10" off the ground. Tires are inflated to 35PSI. Hope that's helpful.
 
Mine is 8.25", front tire is probably a little low but not by a crazy amount.
 
Thanks for all of the info...
This will help those that are contemplating converting their 6A to the elastomer system.
Van's has a warning sheet about prop clearance - I have 10" clearance with a 72" 3-blade MT.
The 74"prop with 8.25" clearance is probably the minimum allowable clearance - but it does show some variety!
 
It should be the same clearance as the older nose gear.
I have the new nose gear on my RV9A (same fuse as a 7A) and the top longeron is level when sitting on the ground. I think this is the same attitude as the original gear, so the Clarence should be the same. Surely you cant be serious. I am and don't call me Shirley
 
Hey guys- Just as a benchmark here, but; FAR23 minimum allowable prop to ground clearance is 7" for a trike and 9" for a conventional gear. Both measurements assume the "most critical" attitude.

Just something to keep in mind when you get the measuring tape out and try to decide how much is enough.
 
PilotjohnS said:
It should be the same clearance as the older nose gear.
I have the new nose gear on my RV9A (same fuse as a 7A) and the top longeron is level when sitting on the ground. I think this is the same attitude as the original gear, so the Clarence should be the same. Surely you cant be serious. I am and don't call me Shirley
Click to expand...
This is theoretically correct.

When Ralph originally installed the new mount and leg on his RV-6A, he felt sure that the ground attitude changed from what it was with the original mount and leg.
Since we had never actually installed one on an RV-6A at Van's we had no way to confirm what the before and after pitch attitude on the ground was so a custom strut length was provided to Ralph to get it where he wanted it.
This is also the reason for the Disclaimer Document.
https://www.vansaircraft.com/wp-content/uploads/2022/10/RV-6A-EEM-warning.pdf
As has been mentioned in this thread, an RV-9A or RV-7A sits very close to level in a 3 point attitude, in contrast to an RV-6A standard build which sits quite tail low in a 3 point attitude. This should be true whether it has the legacy engine mount and nose gear leg or the new version.

In theory the ground attitude should not have changed just from swapping the engine mount and gear leg of an RV-6A to tthe new style because the RV-6A, RV-7A and RV-9A have always used the same engine mount and gear leg (except for a slight variation on the RV-7A if an O-320 engine was used but that doesn't change the nose gear leg geometry).
 
rvbuilder2002 said:
This is theoretically correct.

When Ralph originally installed the new mount and leg on his RV-6A, he felt sure that the ground attitude changed from what it was with the original mount and leg.
Since we had never actually installed one on an RV-6A at Van's we had no way to confirm what the before and after pitch attitude on the ground was so a custom strut length was provided to Ralph to get it where he wanted it.
This is also the reason for the Disclaimer Document.
https://www.vansaircraft.com/wp-content/uploads/2022/10/RV-6A-EEM-warning.pdf
As has been mentioned in this thread, an RV-9A or RV-7A sits very close to level in a 3 point attitude, in contrast to an RV-6A standard build which sits quite tail low in a 3 point attitude. This should be true whether it has the legacy engine mount and nose gear leg or the new version.

In theory the ground attitude should not have changed just from swapping the engine mount and gear leg of an RV-6A to tthe new style because the RV-6A, RV-7A and RV-9A have always used the same engine mount and gear leg (except for a slight variation on the RV-7A if an O-320 engine was used but that doesn't change the nose gear leg geometry).
Click to expand...
Thanks Scott!
 
My Rv-7a has 11 and 1/4 inches of prop clearance from the tip to the ground. It has a 72 inch Sensenich composite ground adjustable 2 blade prop. BTW the airplane does sit lower in the back than the front. Not as much as an RV-6a but noticeable tail low. My CG is in the aft portion of the range due to light weight prop and VFR dynon avionics. The new elastomer nose gear does add some weight to the front but I guess not that much. That might be the reason the tail sits lower than most RV-7a's.
 
skypilot737 said:
My Rv-7a has 11 and 1/4 inches of prop clearance from the tip to the ground. It has a 72 inch Sensenich composite ground adjustable 2 blade prop. BTW the airplane does sit lower in the back than the front. Not as much as an RV-6a but noticeable tail low. My CG is in the aft portion of the range due to light weight prop and VFR dynon avionics. The new elastomer nose gear does add some weight to the front but I guess not that much. That might be the reason the tail sits lower than most RV-7a's.
Click to expand...
I have a lightweight Catto and the new nose gear on my RV9A (same fuse as a 7A) and mine does not sit low. The fuse longerons are almost perfectly level at rest. I am not sure why yours should be different. My empty CG is 77.36"
 
PilotjohnS said:
I have a lightweight Catto and the new nose gear on my RV9A (same fuse as a 7A) and mine does not sit low. The fuse longerons are almost perfectly level at rest. I am not sure why yours should be different. My empty CG is 77.36"
Click to expand...
Not sure if the 7a and 9a CG numbers are the same but my 7a has and empty CG of 80.49 inches. Allowable CG is 78.7-86.82 inches
 
Thanks for all the additional data points on the new gear.
While the CG info is interesting, my focus here is on the prop clearance!
 
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