Flying Off Grass

Gang --

In real life, most of us fly off grass (and land in grass), not off pristine asphalt circles.

On a recent trip, I had some bad grass landing experiences, although I thought I had great all-purpose big Dave Brown fat wheels, and I thought the grass looked OK. Still had two flips on what I would call good landings -- one with damage to the rudder.

I don't want to carry a lawn mower with me, so what are your tips?

Bleed off all the airspeed you can without stalling, and then drop the model in.

It may not be the way Johnnie Walker did it, but I believe that, if you are practicing for PA, or are flying something that you care about, stalling into the grass pretty much sucks.

There will be significantly less damage to the aeroplane and the gear if a fairly fast approach is made when the motor stops. Apply "up" when "trapping", which, in reality, is what gets accomplished. If you are in a contest, judges think this is "way cool", too!

At the GSCB field we have concrete "launching pads", about 4' wide and 30' long. Then we land on the grass, as the pads seem to snag gear pretty quickly if you kiss the approach end.

See Ya

Larry: Try to land upwind if you can, and try to helicopter the model down with as little airspeed as possible.

You don't need a mower; just bring a golf club thing with the scythe at the end. Cut locally, where you think you will most likely land.

As you are doing, use as large a wheel as is (aesthetically) possible. Spin the wheels on their axles to make certain that they are very free, and recheck the alignment for toe in, toe out, etc.

Good advice above. I've flown off grass quite a bit with fairly large diameter thin racing wheels (sorry, I don't recall the brand.) I can't say if they land better or worse than fat wheels. Moving the landing gear forward helps; also the shorter the landing gear, the better. On my last Twister, I made three holes for the little plastic landing gear clips. Over asphalt, I put the clip bolts through the two back holes. Over grass I would loosen the clips, rotate the landing gear forward, and rotate the clips to use the two front holes. In any case, flying over grass calls for a strong rudder.

Thanks for the above --

No one mentioned any specific sizes. I am using 2 1/2, and have a pair of 2 3/4 I could put on, but hate to do so. Gear alignment has stayed fine, as my crashes have been at the bottoms of outsides.

>I have a pair of
>2 3/4 I could put
>on, but hate to do
>so.

Larry: There's your problem. You stated it yourself. Wheels are too small. There is a significant difference between 2.5 and 2.75" wheels on a marginal grass field. I fly off grass constantly, and will guarantee improvement.

Swallow your pride and your aesthetic sense, and go with the uglier wheels. The 20 Point Wheel Police will not awake you at 3 AM in the morning for your transgression, I can assure you.

Just don't publish the photo in Stunt News. The shame.

I am with Currell. There is nothing wrong with going to 3 inch wheels on grass if that is what it takes. If you get the Dave Brown ones (wide flat tread) they look ugly, but remain light and roll through the grass better. Matt has narrow 2 1/4 inch wheels in wheel pants on the contest gear on his big ship, and has a grass gear without wheel pants and the big wheels for practice. Weight is nearly the same, and the plane flies essentially the same. But if grass is all you have to fly off of, you make do with what you have.

Leonard it is not often I dissagree with you...
In fact this is the first time.( we can still be friends ?? )
When I first came to Australia I had no planes so I threw a plane together with no regard to looks, finish etc.
I used a crappy pair of wheels I got in a kit long before, they were 1/8 inch wide at the centre, going down to points at the outer circumference.( Cheap-and-nasty Keilkraft wheels, however I wanted a plane to fly quickly, I still have it, 20 yrs later......)
They cut through the grass really well and I never had any problems with them at all.
HOWEVER......
Some points to remember, where I fly is fairly dry ( in fact it has been an official drought for 3, I think, years ) and the council mow the grass every week, so it is very short, about an inch or so.
When that plane dies I will use them again.
I am an engineer, I only care how things perform, looks don't mean anything.
Would you like me to re-post some of my "engineer" jokes ???
You are right, perhaps not.........

I don't see any disagreement between you and Len. You have race-style wheels that are sufficiently large for your (CL) landing and takeoff purposes. All's well in the world. So what if they are old? That wasn't the original point.

What's not to like? Currell

>I don't see any disagreement between
>you and Len. You have
>race-style wheels that are sufficiently
>large for your (CL) landing
>and takeoff purposes. All's well
>in the world. So what
>if they are old? That
>wasn't the original point.
>
>What's not to like? Currell
>

I was ( clumsilly ) replying to Len's statement that you need wide tyres ( note the correct spelling..... )
The wheels do look horrible, but so does the whole plane, however it flies well, got me back into flying fast back then and just recently and I enjoy it.
I guess I've just talked myself into saying:-
You are right, What's not to like ?

Dave

I didn't say you needed the wider tires, but in many situations they help. We have a lot of clover where we fly (cut weekly) and when it starts growing out it will grab the tires and want to tip you over. Thin tires just dig in and stop in the stuff. Wider tires tend to roll over the stuff better (but still can get trapped when the clover gets taller and thicker.) If the ground is rough and irregular, the wider tires usually work better. Thick tires tend to find a crack or a pit and fall in.

Now, if the grass is good... Peoria has a flying site that has grass circles. They keep it well manicured and cut short and the "good" gear with wheel pants and all works fine here. So it all depends on what kind of grass surface you have. If you are flying on a putting surface of a golf course, then anything will work.

Gang --

This thread is a good example of how to get the benefit of the knowledge here -- and how not to.

My original post was too vague. The follow-up was a little more precise, and as we speak, my soldering iron is heating up, and I will put on the 2 3/4 wheels. That is the info I needed, and Leonard and Currell jumped in when I asked the question correctly. Learn from my errors.

I have been teaching new fliers how to do maneuvers (loops,eights, wingovers, etc). We are using the Sig Skyray 35s, and are flying over grass. the wheel would catch in the grass on landings even with 3 inch balloon wheels or narrow ones. I removed the wire gear (bolt on type) and they just belly the plane in. There has not been one flip over since we started hand launching for take-offs and belly landing. The only thing that has shown up as a problem is that one fuel tank had an extra long lower vent tube that got bent. I shortened it and that problem was solved. We use Tongue mufflers to keep grass and dirt out of the engine too.
Bigiron

Bigiron --

You are quite correct on all counts. I have just enough pride left that I want to see that gear pointed towards the sky when flying inverted, and using the gear to define the inside and outside portions of the pattern. Hand launching is a low-skill maneuver for both the pilot and launcher, so no problems there. And you can't flip a gearless plane, far as I know. Although we care less and less about the crowd, it is a mind factor. No gear, no problems, just doesn't suit my mentality.

But no, I am not going that way. My goal is to do real grass take-offs and landings. It is a part of the sport that the smart guys can conquer.

I have really skinny (Williams Bros.?) wheels on my Fokker. They have a lot of diameter, though. I get on and off the grass OK with them. Not great, but OK.
The critical variable is diameter, not "tread" width, I think, although width does help some, certainly.

A long time ago and far, far away, we flew off grass. To be more accurate, we hand launched and plopped into the lawn. It was thick and high. So, we obtained, and I forget just who or how, old carpet. We cut these about 3 feet wide and layed out the pieces so we had a long runway in the deeper parts of the lawn. This was at our local high school and the janitor didn't care. Heck, he was related to two of us some how!. Small town of 2,800, everbody is realted to you somehow. Sure hope the gene pool was not to shallow! But the carpet and old linoleum seemed to work. We rolled it up and put it in the back of the station wagon when we were done. Something to try or at least think about.

.
> So, we obtained, and
>I forget just who or
>how, old carpet. We
>cut these about 3 feet
>wide and layed out the
>pieces so we had a
>long runway in the deeper
>parts of the lawn.

I did the same last year. Bought a 10 foot runner remnant for $5 from a carpet store.

But be careful. I was starting my Fokker (Sig) which had minimal prop clearance. Was using a "nylon" (APC) prop. A tip ticked the (relatively hard) carpet, and the blade went flying off. Lucky it didn't hurt anyone.

So, now, if I'm flying off the remnant, I make sure that I have a lot of prop clearance. And I rarely use nylon or non-wood props anyway. Currell

I've had a piece of lightweight carpet suck up into the propeller. A piece of cardboard is better, although getting it to lie down flat on longish grass is a problem. An APC will just slice cardboard and keep on going.

Jim --

Good point. My experience is that cardboard works well for take-offs, is portable, and reusable. Problem is the landings, as I am not good enough to do a carrier landing on the cardboard, and do not have the wherewithall to carry enough cardboard with me for a full circle.

Larry: Yeah. We've walked ourselves into a logic Goat Grope.

The whole reason one would want cardboard or some flat surface in the first place is that the grass is too long, and uneven.

But cardboard doesn't hug this type of surface, remaining uneven, and a semi pain in the butt. Rugs can have the same problem.

The "solution" is a pre-formed something, like a piece of wood that's, say, 2 feet by 6 feet by maybe a quarter inch. Pain to carry around.

I've used cardboard and carpet, but found I like the heavy poly carpet runner the best. It's about 40 inches wide and I cut it to length to about 12 feet.

Just roll it up when finished and it stores easily! I flush it with the hose at home and use some concentrated simple green to clean it. I've been using the poly carpet runner for two flying seasons now without any problems.

Try it, you might like it! Have fun and enjoy...safely!

You're better than me, because I don't recall ever cleaning mine.

Yeah, just roll it up, and throw it in the back of the old Taurus wagon. Currell