Grass Strip Guys: How High?

[SkySteve]

For those of you who fly out of or maintain grass strips, is there a correct grass height? There are some common sense things, of course, like keeping it low enough for prop clearance, but is there a particular length of grass that just "feels right"? If so, what is it? :confused:

[Pilot4Life]

SkySteve,
Because I have that kind of time right now, I just scanned through some advisory circulars (AC 150/5300-13A Airport Construction & AC 150/5370-10 under Turf Establishment) and didn't find any recommended or required lengths. Just in case you thought to look at the FAA side, I'm not finding anything regulatory or recommended. Probably for liability reasons! Happy Hunting!

[kmach]

I remember seeing somewhere? that the grass should be kept axle height or lower.
The taller it is, there is definitely more surface drag.

I cut my grass when it gets around 8" , its cut height is around 2 1/2 "s .

This cut height depends on the type of grass, some do not handle being cut too short.

[avidflyer]

My runway extends out past the yard for 1400', so I mow it when I do the lawn. Some parts grow better than others, so it's often different hights, but lower the better for resistance I would say. I suppose my mower is set about 2 1/2" also. Jim Chuk

[av8rps]

I know this is contraban here on the Kitfox forum, but here is a good picture of me landing my brand X on my runway (that I don't live near so I never cut it). You can't see my large Maule pneumatic tailwheel in the long grass, and my 850 tires are about at the half way point. So it is pretty long for most people. But landing in grass this long presented no problems whatsoever. In fact I think it is softer than a regular runway that is cut to a more normal 3 inch height. The only negative I noticed was getting weeds hung up on my tailwheel to rudder springs. (I have a new tailwheel now that doesn't use rudder springs so even that's not a problem now).

The takeoff was uneventful as well. I used less than 300 ft of the 2450 available without even trying. So if brand X does it, so will our Kitfoxes.

With all that said, I would avoid grass longer than this mostly because I'd be concerned about grass getting wrapped around things and causing some braking effect you might not want.

I used to fly my early Avid Flyer on the tall and narrow motorcyle tires out of any old 3 to 4 ft high hayfield and never had issues except for having to always clean grass wrapped around things. But the tires we all like to use today tend to be short and fat, so I don't think they would work as well in that long of a grass.

[SkySteve]

Perfect. Good real life info from all. I'm more concerned with what works good vrs what some gov'nt agency desires.

[Av8r3400]

My opinion: mow it often enough so that when you do mow it you don't get clumps and piles of grass clippings that tun into obsticals that could damage your plane or cause handling problems.

The over all length of the grass would be to your discretion or preference.

@ Paul: I didn't think you actually flew that plane! I thought it was just another member of your stable. :p

Chapter meeting at JimS's place this Saturday at 10.30 am. Be there or be square.

[SkySteve]

Ab8r3400,
Excellent point re the clumps and clippings.

[Esser]

Why dont people plant clover? It never gets higher than 7" if it even gets that high, is drought resistant, and stays green.

You have to reseed every few years but it beats mower every two weeks. Whats the catch?

[av8rps]

My opinion: mow it (snip, snip)

@ Paul: I didn't think you actually flew that plane! I thought it was just another member of your stable. :p



Ok, teasing me about not flying like I should is fair. My latest project (a 38x42 ft with an empty weight of about 27 tons on a super short gear - but water capable) is still taking a lot of my spare time that would otherwise be available for playing with my stable of airplanes.:(

HOWEVER, I have been able to sneak in a little fun here and there making some improvements to ol' Brand X (new Sensenich 3 blade prop & spinner, extreme extended landing gear, 4 caliper brakes, bigger tires, 12 inch free swivel tailwheel, all new panel, new amphib floats, etc, etc.)

So I'm not quite dead yet ;)

[PapuaPilot]

There are a lot of things to consider for grass runways. The length of the grass is only a part of the concern. You also need to consider how thick it is, how wet it is, what the soil is like underneath (hard, spongy, wet, muddy, etc.) and how is the drainage. Tire size and pressure are also a big factor too.

Axle length or shorter is good. If the soil is very hard and it is thin, tall grass it shouldn't be a problem other than cleaning grass out of you landing gear and green stuff on your prop.

If you lock your brakes in clumped grass I have heard that it can build up in front of the tire and become a chock. This can cause your plane to turn or even flip over a tailwheel plane.

[SkySteve]

My situation is pretty crude. No fancy dancy grass airstrip. Just a pasture/hayfield. It's a combination of pasture grass and alfalfa. It is irrigated but the ground is hard with just enough dirt to keep the underground cobble rocks and large gravel from clunking all night while the alfalfa grows. I will probably only mow a 12 ft wide "strip" through the middle of the field. I've already chopped more alfalfa with my Warp Drive than I should at other places. This will never be a pristine grass strip. We're lucky to get grass to grow here. In fact I don't want it pristine, as I will have horses grazing on it a lot of the time. Think Utah, not Oregon.

[kmach]

Alfalfa or any vine type legume is not desirable for a runway, depending on variety and soil type , they can have a deep strong root and the plant vines like to catch on everything. A taller deep rooted alfalfa plant would definitely alter your course if it hooked on to say a left main gear / axle . :o

I built part of my runway out of a hay field ,approx 80% Brome grass / 20% Alfalfa mix.

I ended up killing the alfalfa on the runway by spot spraying the individual alfalfa plants with roundup (a glyphosate weed killer).

The alfalfa plants grew at a different rate than the grass and always seemed to be 6" or better higher than the grass.

[SkySteve]

Kevin,
Great idea. Mine is about the same mix grass/alfalfa as yours. I use Gly4 instead of Roundup, but same results. 24D works good to kill alfalfa also, without killing the grass. Ah, you gotta love the smell of chemical spray in the morning!

[n85ae]

Fly out of too deep grass/weeds, and you'll end up doing some fabric repair,
this I can say without guessing, or speculating ...

Jeff

[Pilot4Life]

SkySteve,
Rest assured, I agree about the gov bureaucracy...that's why it's a PRIVATE airstrip! Best of luck figuring out what works...safe flying...

[jonstark]

I've got 1000' of OVC mix. That's Orchard, Vineyard and Clover. They spread by rhisome and lay down pretty smooth. They aren't "clump" grasses that come up in tufts which get wider with time but make a really bumpy runway.

I'm pretty partial to landing on a putting green when it's green and lush but 6-8 inches of dry grass is sure fine by me!

jon

[SkySteve]

Jeff,
Understood....in a theoretically way, of course.

[SkySteve]

Chris,
Amen brother!

[SkySteve]

jon,
Yes, dry is gooood!

[High Country]

while clover is awesome for maintenance purposes it can cause its own problems depending on where you live.... ie elk and deer love it and will come from everywhere to enjoy your nice new meadow. not to put it down just something to consider. and yes I have made landings over the top of a herd of deer and had to land long at the end of a short rwy



Why dont people plant clover...

[beeryboats]

I no longer call it yard care, it's combat! 1850' x 100' coarse grass plus the rest of the place. I keep it pretty short just so I can keep up. My KF IV is still in the barn waiting more attention and a new engine. But I've been mowing for 17 years now, but I just bought my KF last fall. I keep it about 2-1/2" with as few clumps as possible. Some take going over a couple times to spread out. You never know, someday, someone may stop by and visit me....... hint, hint.
Google: Newby Landing

Take care,
jay

[sdidier]

I maintain both S73 and my own strip. S73 we keep the grass to 3 inches--a mixture of various grasses.
My own strip is a mixture of blue grass, long stem fescue, perenial rye and clover. I try to keep it mowed to between 3 and 6 inches. And yes the deer love it but they duck for cover with a fly over!

It should be on the next sectional edition for Great Falls as Didier Ranch. any of you Kitfoxers are more than welcome to stop in if you are over the Grangeville, Kamiah area. Call if you can 208 451-0147 or drop a line via this forum.

[SkySteve]

sdidier,
Is there an advantage/disadvantage to having it on the sectional?

[SkyPirate]

I like centipede grass,..it has an awesome root system,..even if the ground gets saturated you can drive a truck on it

[Av8r3400]

sdidier,
Is there an advantage/disadvantage to having it on the sectional?

Explain to me how being noticed further by the federal government is a good thing…

Along the same lines as if I ever owned a firearm I'd buy it at a gun show or from a private individual leaving no paper trail… :rolleyes:

[beeryboats]

I'm on the inset portion of the Indianapolis area on the St Louis sectional. I've had nothing but good things due to the feds knowing about me and being public info. They even advised the state highway department that the newly installed light pole on I-74 was a bad idea. It was right at the end of my runway, but below the glide path. It was gone by the end of the day.

[sdidier]

I was not going to apply for sectional inclusion until I was talking with a local Maule driver who has an extensive background in insurance. His advice, apply, he said there was no downside.
And it will make it easier for you guys to find me>>>;)

[sdidier]

Also look up S73, it is a municipal strip that our Aero Club manages ( CVAC Inc.)
The feds know where we are but we and the city steadfastly refuse to accept any FAA money with the resultant strings attached. And it has not been a problem. We like open access for the local kids and public in general to stop by. We have a very active fight school through owner shares and generally have one or two high school students taking lessons and helping out!

[SkySteve]

So if you apply to the Feds are there any qualifications you must meet? Like distance required from houses, livestock, roads, buildings, etc?

[sdidier]

nope not for a private use strip. You have to provide the lat/long for each end of the runways and the distance to the closest town. and a sketch of the proposed strip. I used google earth did a snapshot and converted it to a pdf. They were happy with that. Been painless so far.

[Flybyjim]

The requirements are based on the state you live in for any registered airstrip, private or public use, the state dept of transportation regulates the airfield not FAA or a flight service center such as NY center, they regulate the airspace starting at just off the surface and up and out. I live in Pa. other states may be different. There are clearance requirements for out buildings, wind socks, approaches and the like.
Jim

[beeryboats]

The former owner did the ground work for the airport, but it must be easy. I'm basically right beside a rural neighborhood of 3/4 acre lots. Knowing the feds there is something in the regs that spells it all out. Without a doubt!!!
Jay

[sdidier]

FLYBYJIM is correct in that the state also regulates airfields.That said, in Idaho unless it is public use ie: commercial there is virtually no requirement. In fact state division of aeronautics will tell you to do the FAA route first.
It does pay to get your neighborson board. In my case the closet one is 1/4 mile from my strip.

[SkySteve]

All good info. I've made my decision. I will not be doing anything that involves any government agency in any way whatsoever. It's my land, my aircraft, my personal business and "they" are not welcome to be part of any of my plans or use. Don't need them, don't want them. However, once I've tested things to my satisfaction, GPS coordinates are always available for any of the Kitfox family that wants to come and play.

[kitfoxnick]

I'm with you Steve. The Feds biggest concern is airports with instrument procedures. Where I live the philosophy of better to ask forgiveness then permission applies. We have a group of lawyers hired by the county council to "defend the rights of the people " called "Peoples Council" scary. If I were to bring this up for a special exemption at a zoning hearing it's not my neighbors who would come against me but the peoples council. So I'll just have my hay field that gets 12 cuttings a year. It's been six years so far.

[SkySteve]

Nick, agreed. That's all I have. A hayfield that part of will be very short. Maybe we can sell tiny winy bales!

[beeryboats]

I'm in agreement if there is an issue with the neighbors. Just do it! I'm sure my late father in law found an airport for sale and jumped on it so as to avoid any paperwork for himself. I do have one neighbor that has a bit of an issue, but I'm not too worried as it is already an approved airport in a rural area. And due to my airstrip and dealings with the town, I have avoided our little slice of heaven being incorporated into the town because of the legal airstrip. The incorporation would have raised everyone's taxes at least 5%, so the grumbling is at a minimum.