RV-10 Elevator with Full Flaps

Posting this question for a friend:

On the plane's first test flight with a pilot and a flight engineer, during landing with full flaps, the stick was pulled back against stop to fly the final approach. There was no more stick travel for landing flare but it did grease the touch down.

Is this common on RV-10?

If not, where do you recommend looking for possible causes?

Thanks in advance,

David

Data

Approach speed?

CG?

Elevator UP limit?

Did you check your C of G prior to flight? The -10 is nose heavy and in mine, I must cary 50 lbs (Water bag) in the bagage compartment when only the front seats are occupied to remain within the envelope. Hope this help

Michel

definitely check the W&B envelope in the flying configuration. I need 10#'s of ballast solo to stay in envelope, but use 50#'s. I have never been close to full elev travel on final approach. I can easily trim to hands off while on a 70 kt final, though I tend not to trim that much to avoid issues on a go around.

I don't see how you could have full up ele on final in a proerly rigged RV-10. As you slow down, you need more to flare. Definately need to look at rigging.

Larry

Never seen that kind of up elevator

I agree with folks above, only 300 h in my 10, but never been close to full up elevator on final (with two in the front, nothing in the back). Might check the attack angle of the stabilizer, make sure you got the spacers set right. Also, in full cruise speed you should have essentially no trim tab deflection to speak of...check that too down the road. Might give you more info to use. Personally, I land at half flaps most of the time, I find the flare just a bit easier, airspeed at touch down almost the same, and nose wheel is well in the air. But never a bad thing to use full flaps! Congrats on the build and the first flight!!

Mike Wright
2020 dues paid
RV7 built/flown/sold
RV10 built and flying
RV7 started in 2020

To answer the question, no - this is way wrong. The RV-10 has massive nose up trim range, even when solo with nothing in the back. There is always enough trim to take the pressure off the stick.

Perhaps if you post the W&B we can better address your issue. Also state if you mounted the battery(s) aft per the plans.

I assume you verified that the trim tab travels are in spec.

Carl

Check the rigging of your elevator trim tabs too.

Carl Froehlich said:

I assume you verified that the trim tab travels are in spec.
Carl

Click to expand...

If elevators were at the stops, trim tabs won't make a difference. ... But with the same idea, if one of the front seats is all the way forward, is the stick hitting the seat? Or in the tunnel where the linkage is connected to the cross-bar is there interference? There is a rod-end bearing in there that extends way out and is safety wired. If this is not far enough out, it will feel like you are hitting the stops, but will actually be jamming up in here.

Was the stick hitting the stop, the seat, or the pilot's belly?

Snowflake said:

Was the stick hitting the stop, the seat, or the pilot's belly?

Click to expand...

The other thing is, relative to the other RV's the pitch forces on the -10 are pretty heavy in the flare when flown solo or with two up front.

You may think you've exercised all of the pitch throw, but...

Something is wrong there. Heavier engine/prop, misrigged elevators, wrong horizontal stabilizer spacers. Maybe post some weight and balance numbers and we'll know if it's a CG or a rigging issue.
You may run out of trim, but not elevator. That's scary!

Lenny

RobinHou said:

Posting this question for a friend:

On the plane's first test flight with a pilot and a flight engineer, during landing with full flaps, the stick was pulled back against stop to fly the final approach. There was no more stick travel for landing flare but it did grease the touch down.

Click to expand...

I can't help but wonder if there is some details that were lost when the situation was described by your friend (there is a lot happening during a first flight...... relying on memory for details can often be wrong).

I find it doubtful that the stick was full back during the approach and then the airplane made a greaser landing with no more elevator deflection available for a round out and flair.

If what you say is true, the landing would have looked like a typical Naval aircraft carrier arrival, unless a bunch of power was added at just the right time to turn the decent profile into level flight just above the runway.

But to answer your question (if it really happened as described), no, it is not normal.

What is normal (assuming that the elevator travel limit is within spec, that a stick isn't hitting on something to limit travel such as a seat cushion, and that the C.G. is aft of the fwd limit) is that an RV-10 with no payload in the rear seats or baggage compartment can be elevator limited during the flare for landing with full flaps, such that the nose wheel will might only be an inch or two off the runway, but it will never require full up elevator to trim the airplane to a normal approach speed.

This is not really any different than any other smaller aircraft with a lot of load carrying capability (C-182 for example). If an aircraft has a good usable C.G. range for payload flexibility, it is going to feel a bit elevator limited at the fwd C.G. limit when full flaps are used. One way to reduce the influence is to land with only half flaps when you know that you are near the fwd C.G. limit.

trim tab vs elevator forces....

Lots of good thoughts and comments. I disabled one of my trim tabs (both electric) and land typically with ~50% of the up trim (on one trim tab!) with extremely light forces on the stick in flare, and I am a very nose up and stay up as long as possible pilot. As I mentioned before, I do land with 50% flaps unless really needed. I am wow, compared to a Cessna 210 or alike that I have hours in, the RVs (all of them!) are so light on the stick and so responsive, kudos to VANS to design such great planes. For sure all the angle checks, elevator travel, etc on the ground are a must, but if they check, then while you are flying at cruise, check the elevator position and trim tab, they should be very very close to neutral, if not, then the stabilizer incidence may be off, it is not rigging. That does not change much at all with all the loading scenarios when in cruise. RV10s fly, and I think as designed, with the surfaces in the least drag position, or at very close to it, regardless of CG loading. I have my RV 10 loaded with four and some baggage etc... or just two up front, the elevator in cruise looks the same, and I check these things.

Cheers, Mike

When our plane is at the forward limit of CG, the elevator is quite far back. I've never hit the stops on round out, but I have right at / after touchdown on a full stall landing with a forward to the limit CG. Used all the elevator I had left to keep the nose up with reducing elevator authority due to the decreasing airspeed.

We also throw some ballast in the back. I need about 10# to stay in CG. I keep about 40# in the baggage compartment against the bulkhead.

It's W&B

If your friend does the W&B on how they flew the aircraft he/she will notice they are at the forward limit. When I did my test flight with Vans in their factory 10, the demo pilot, Ken, pointed this out to me. This was with him and I in the front, and a small box of lead ballast weight he added to the rear of the cargo area. I'm 200 lbs and Ken was probably 170. I'm building a 10 and am planning on adding O2 and a BRS so that will take away that effect, but will also limit my AFT CG W&B. I don't ever plan on having 400 lbs in the back and luggage so I will have to diligently map out my W&B envelope.