RV-7A on a Grass Strip?

I have been following the nose gear callapse/strength thread and did not want to hijack....already tried. I am evaluating which RV to build and I will have it based out of a grass strip and did not realize that there may be an issue with this.

I would like to hear from some RV-7A owners that have there plane on a grass strip. I currently fly a 172 out of there and don't have any issues. I hold the elevator full back pressure as much as possible and I figured that would be adeqaute for the 7A. I thought about building a 10, but still trying to decide if I would utilize the back seats enough to justify the expense. The nose gear issue might play a factor. Any thoughts ?

I have a 9A and it lives on a grass strip. I have just started flying after a 5 year build so I do not have a lot of data points to offer you but I do not have any personal concerns about my airplane being used on a grass field. In fact I prefer it over pavement.

We also have a 7A on the same grass strip. He has been on the field for about 3 years now. To be honest he did have a nose gear incident that caused some damage when the gear leg bent over laterally shortly after moving his plane to our field. He has admitted that it was his fault for the nose gear collapse as he attempted to make a 180 turn around at a higher speed than he should have done. This incident is evidence that we cannot be complacent when operating on the ground. He has not had any more issues since.

The truth is that all RV fliers should be treating the nose gear differently than they would a Cessna, Piper, etc. no matter what the surface you are landing on. The gear on those planes are just built to a different level of beefiness than the RV. Pilot technique is going to be important when landing with these nose gear. You have already stated you are adhering to these techniques with your 172 so you are ahead of the game on dealing with it.

I have lived on grass strips for over 12 years, and operating a 6, 7A and 2-10's on them with absolutely no problems, including teaching both of my sons in the RV-7A. Use good pilot technique for soft-fields, which means keeping the weight off of the third wheel, no matter if it is a nose wheel or a tail wheel.

Vic

Flying off of grass is no big deal. Keep the stick aft like with a tail dragger and have at it.

Be careful with comments "stick back like a tail dragger." The right way for a taildragger on grass is stick forward for take-off, in order to get the little wheel out of the draggy grass. Improper technique can drastically affect performance.

Vic

Taken out of context, the thread on nose wheel collapse may seem alarming but the advice in the posts above is IMHO very sound. The VAST majority of landings on grass strips are just fine but there have been a number of nose gear failures and a few flips, usually on non-paved strips. If you want to read around it, there are many posts on this forum but you might also take a look at Peter Pengilly's review here http://www.glosterairparts.co.uk/ (click on RV Information and then RV Nosewheels).

The remaining debate is about why these few failures occur. Some argued that the clearance at the castor pivot was inadequate (and Van's increased the clearance a few years back). Others argue that poor piloting technique is responsible and some believe there is an inherent weakness in the design. Part of the reason for the heat in the debate is that some pilots have landed on rough strips hundreds of times without incident, while at the same time, a few of the accidents involved highly experienced pilots, who believed they were doing nothing wrong or, at least, nothing different to what they've always done in their C172 or whatever.

And, I think that is the key to it. If a C172 were a pickup, an RV-7A would be akin to a racing car. The racing car is lighter, faster and handles better but needs more respect and would be relatively easily damaged on a rough track, because that is not what it is designed for.

My posts on nose gear collapse are motivated by a desire to identify what it is about rough strips that the nose gear doesn't like. Armed with that knowledge, pilots could maybe avoid some of the accidents.

Raiz

I spent a summer instructing in a 6A off 1200' of grass, students weren't able to break the plane even when they tried.

It's a gamble

While there are those that deny it, a nosegear RV (especially a 7) has a definite risk when operated on a non-improved surface. The heavier the nose (200HP, etc) the higher the risk.

Most 6's and 9's fare better (lighter loading on the NG).

At some point, all the factors can just "click" and you may end up upside down going "what the h*ll happened?"

I was not an inexperienced RV pilot when my nosegear failed. Yes it was a "rough" strip. Yes, I had done hundreds of RV landings there before (thousands total).

There's a point in the energy envelope where you CANNOT safely recover. A three inch mound of dirt popped the nose up at the exact speed where I had no elevator to "slow" the resulting drop back into the dirt (the elevator was already fully aft). The nose gear dug in and the rest was just a slow-motion train wreck with me as the helpless passenger.

At last count the total number of nosegear flipped RV's was approaching one percent of all flying RV's, as I recall.

I've flown both, 290 hours as a nosewheel, 460 hours as a taildragger (I have about 2,000 hours total time now).

The taildragger version is no harder to operate than the nosewheel version.
Landing is just as easy (to me anyway). Takeoffs are just as easy. Cruise is no different (just a tad faster). Plus, I like the way it looks.

Taxiing is not difficult. 10 degree S turns give plenty of visibility. Being rather tall, I have pretty good forward visibility anyway.

But, it will take more than a three inch mound of soft dirt to flip me over again.

Yes, there are "flips" of taildragger RV's. But usually not because the gear failed.

And while the "technique" debate rages on, I know that I made a near perfect landing that day. Stick back, held the nose up for a long time, let it down gently, etc. Made absolutely no difference.

YMMV. Mine does.

There are grass strips and there are grass strips... A smooth, well prepared / maintained strip that is not too wet/soft is probably as kind to an -A as a taildragger - and preferable to tarmac in some ways.

A wet / rough / rabbit holed strip is going to increase the chances of the "holes in the cheese" aligning and causing the -A problem to occur. These events are relatively rare, invariably due to a variety of factors, including "luck" (or lack of), so it is hard to state what is "safe" and what is not.

I have seen advocates of the -A attempting to deal with rougher / shorter grass strips. At a certain speed, you do lose elevator authority, and now can get some nasty pitch oscillations and that includes hitting the tail on the ground, and at risk of the noseover now occurring

My 2ps worth. If you have good reason not to want to go with a taildragger (concern over techniques, crosswinds), and it is a nice strip, you will ensure it stays as such, and not fly when it is too soft / wet cannot see the -A being a problem. Of course, a taildragger also has days it is best left in the hanger

Andy

2c's worth Andy - they are Colonials......

Was skydiving with one of your colleagues at Zephyrhills last week - nice chap, James, F/O on 777. Great skydive and two magnificent cabin crew for tandems !!

I never thought I would participate in this street fight, but here goes...

I watched a couple of 9A's taxi and take off from a pretty smooth grass strip a couple days ago (Cavanaugh Bay, ID), and was struck by how toddling they acted on the ground. They bobbed and lurched around much more so than my taildragging 7, and it brought to mind this very issue of nose gear collapse. The accentuated motion is because the 3rd wheel is much closer to the mains than on a taildragger. All the above points about not having absolute pitch control at lower speeds makes it worse in that transitional phase.

I say avoid the issue and build a taildragger. RVs are rather benign TDs, and easier boarding, less under cowl clutter, easier cowl removal, cheaper kits, faster, and no jungle-gym gear structure under foot in the cabin makes the TD version vastly more desirable in my eyes.

John Siebold

I would build the TD if I had known

This is merely my personal view for your consideration.

I always intended to be able to operate on grass. After I was already flying I found out about the -A problem with the 7's, etc.

I have not had an incident but the fear of it is keeping me off of grass strips that I'd otherwise visit.

Fear of a botched landing in a TD motivated me to build the -A.

I'd rather know that the "accident" was my fault than a random event due to the design of the aircraft. For those of you who do SCUBA, it seems to me like the "undeserved hit" of the bends. If you could eliminate that risk, wouldn't you?

I would build a TD if I knew then what I know now. And all the advantages of the TD cited above are true. Of course, there are maintenance issues with the tailwheel - nothing is perfect.

TW Maintenance

hevansrv7a said:

Of course, there are maintenance issues with the tailwheel - nothing is perfect.

Click to expand...

True enough. I just had to pop a whopping $3 (plus postage) to replace my tail wheel bearing. With less than 500 hours!!! (just kidding).

One must keep it clean and lubricated. While I have never had it break loose unexpectedly (stuck pin), I have had the pivot stick to the point the tail wheel would not turn. Since then, I've welded on a boss and a zerc to allow easy greasing and I grease it every 25 hours (or so).

YMMV

Is the RV-10 nosegear more robust? Would it do better on a marginal grass strip than a 7A with same good piloting technique? The strip I fly out of is in good shape, but who's to say a gopher hole would not show up one day. I know they are totally different planes, just asking nosewheel to nosewheel.

imho comparing the -7 to the -10 is apple to oranges in many ways.
don't underestimate the difference in size, money etc... it's a different class for sure.

however the nosegear on the 10 definitely is more beefed up and the lack of incidents would imply that either the 10 gets operated less on grass or it is less susceptible to the same failure mode.

we for ourselves stay off grass...
although i believe 95% of the problem is pilot technique and can be managed relatively easily and consistently (the airplane is very honest and true, predictable) the other 5% of gopher holes, some other resonant excitation or the occasional pilot screw up are just not worth it. for us it's a very small price to pay for the added safety margin.
without wanting to start a never ending debate, i still believe the nosegear is the way to go and we would definitely choose the same again.

but to each his own.

rgds bernie