hello

I would like to know, experiences of pilots who fly in grass ( REGULAR, LIKE FOOTBALL FIELD ), which the result of the impact in the landing gear and structure of plane. I have a Boomerang ELAN with a JETCAT P-70.

thank's
Jose

I have been mostly flying off of Grass for 10 years now. We have a 600' strip with pretty smooth grass. I have used Robart gear that has held up well. We make our own upper struts, we keeps the cost down when I have to replace them after a not so smooth landing. [X(]
I think the Boomerang should handle the grass well. Good Luck

[img][/img]

nice field and nice landing with the red plane ( dead stick!! ), thank's for your help

jose

Our field is a very rough grass field with neat things like animal holes dug all over the place to drop a wheel into.
I have not yet seen an Elan at our field but the intro and XL Boomers get a lot of flights in.
The only times that the gear have problems is if you land right on a hole fairly hard. As long as you land gently, even the holes are not a big problem. With stock wire gear you have to bend them back after a few landings.
From what I have seen at our field, most scale ships do not handle the grass well without structural problems.

Hi Jose:

All depends on how smooth your grass is......we roll our field each spring with up to 6000 lb roller and cut it to 5/8-3/4 inches during flying season with a golf course-type reel mower, not a rotary mower which tends to scalp and leave tracks......

Currently clubmembers fly all types of scale and sport planes including big BVM F-86, JHH F-86, SuperBandit, UltraBandit, Kingcat, Bobcat ARF, Boomer Intro, Boomer XL, Deviator, Twin EDF Phantom, EDF A-10, Eurosport, HotSpot, Kangaroo, Skymaster F-22, Skymaster F-18, Avonds F-15 and F-16......one of our members will have a SM F-4 ready for this spring.....no problems with the landing gear except when we prang one....I went the whole 2007 season without busting a flex plate on my BVM F-86(80inch)......use mainly Robart 630 and 635, BVM, and Skymaster gear.........BVM usually needs no beefup, but we often add some Carbon fiber plate, 1.5 or 3.0mm to the mounting plates in some of the other kits just for added protection.....

Your Elan/P-70 should be fine, but I would add some C/F or hardwood to the mounts....they come a bit soft from the factory.......

Our field is 850 ft long by 200 ft wide with long, clear approaches both ends......

T.....

A larger diameter than normal nose wheel will help some too. Won't tend to tuck under or skid as bad and make it easier to steer.

flying off 75x1350 grass mowed about 1-1.5 inches.Roll complete runway every year.Roll center of runway 3-5 times a year.Center stays very smooth with no bounce at all.Boomerang Intro with T500 loaded with 70 ounces K1 and 32 ounces smoke small tires it will struggle a bit 300ft.With no smoke oil 100-150 ft. Eurosport With Rhino bigger tires more power up with ease.The bigger planes with larger tires would preform better on a marginal grass runway.

After struggling with bent struts for a while on our rough grass strip I changed to 1/4 inch piano wire legs with a loop on my 21 pound jet. Problem solved so far. - John.

Thank's all guys, for your help, I go to try in our grass field.

regards

jose

Hi Jose

Take a look on this link... there is a lot of info regarding flying Boomer of grass
http://www.rcuniverse.com/forum/m_23...anchor/tm.htm#

Here is a link to my first and second flight
first flight : http://www.enrarot.net/videos/senja/svein03.wmv
second flight http://www.coaslip.com/rc/Video/SMFK...ng%20Intro.wmv


Brgds
Svein-Roe

thank's Roe,
fantastic your flight!!, I had a B.Boomerang like yours ( yellow ), at this moment we have a Elan, and our first flight was last saturday, but the left axle is broke in landing, ( the axle from robart is very weak ), Achilles my partner manufactured in steel ( alen screws ).
The grass of your field is regular like a football field ?

regards
Jose

I have found that any type of trailing link strut is superior to a straight strut on grass! once I switched to these, all broken pins, and bending problems went away regardless of the condition of the field!

I find that grass tends to limit terminal velocity of takeoff roll out in MPH, I see this real time using EagleTree telemetry. it appears to me to relate to wheel size and length of grass. Any wheel under 2.75" is very hard in grass and critical to length of grass, angle of attack, no matter what the model.

Heres some examples for me: The BVM Kincat Ive not yet been to a grass feild it wont take off from (BEST in class) I can take off of rotary mowed dry grass with a BVM Bobcat XL with 2.75 main wheels and set @ high positive angle of attack This same feild in the morning hours with dew creates enough drag to limit takeoff speed I cannot lift off, I need to bring out the KingCat before noon at times. I have a Cermark Viper Jet with 2.5" of wheels that wont take off grass mowed with the rotary mower, my home feild has 600' concrete, so I takeoff concrete with the ViperJet and land in grass with no grass issues and wheels/struts. I firmly believe if I got to 3" wheels in this model it would do fine as its only about 7MPH short of normal takeoff speeds from concrete versus grass.........

large wheels is more easy to take-off, but the small planes is very dificult to use large wheels.
JOSE

If larger diameter isn't possible then the next best is find the fattest wheels and tires that will fit.
The idea is get the model to ride on top off the grass and not sink into it.

The other trick is to let the plane rotate early so that the wing will take some of the weight off of the wheels.
Once the plane lifts off the ground, level out at a few inches off the ground to finish accelerating to flying speed. Once the wheels break ground it does not take long to get to flying speed, just a few feet.
The plane can lift off in ground effect while it is still below stall speed, so if you try to climb to soon it will stall unless you have the power for vertical acceleration.
I had to use this technique to get out of deep snow with my jet.

This is the same as the soft field takeoff that is taught in learning to fly full size.