Grass Strip Guys: How High?

[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 .

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!