Van's Air Force
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RV-4 on grass
- Thread starter edstepec
- Start date
ccsmith51
Well Known Member
I fly in and out of a 2,600' grass strip on a regular basis. The only issue I have had is grass collecting in the wheel pants and around the tail wheel, both of which are easy to clean.
I occasionally get the firewall oil canning noise if it is really rough, which I am told is not uncommon.
Based on that field are four RV-4's, two RV-6's, an RV-7, and an RV-8 (that I know of, maybe more...). Of the eight mentioned I fly with six of them regularly, and none has mentioned any ill effects from the grass strip. I have flown with four of them twice to ID and MT and landed on shorter, rougher strips, again with no issues.
Hope this helps.
I occasionally get the firewall oil canning noise if it is really rough, which I am told is not uncommon.
Based on that field are four RV-4's, two RV-6's, an RV-7, and an RV-8 (that I know of, maybe more...). Of the eight mentioned I fly with six of them regularly, and none has mentioned any ill effects from the grass strip. I have flown with four of them twice to ID and MT and landed on shorter, rougher strips, again with no issues.
Hope this helps.
Last edited:
Master Designs
Well Known Member
Not an issue unless you have the original (thin) Vans RV-4 motor mount / firewall gussets. Ask me how I know. 
smokyray
Well Known Member
Hooked on Grass....
Ed,
I have fairly extensive experience (25 years) operating off grass with my RV4, HR2 and current RVX with no ill effects. My home strip is a private 2000' very soft turf strip with 50' obstacles at both ends. I also have sojourned to the Idaho back country and Montana numerous times and landed on roads and gravel. My RV4 is still flying with over 2000 hours, and still has no cracks in the engine mount, lower longerons or tail spring attach bulkhead. I did build in the heavy weldments and had short gear. Doesn't matter, my Rocket has Long Titanium Legs and it had no issues nor does my current RVX which I'm using longer RV4 legs mated to an RV6 engine mount.
Here are some tips I have used over the past 25 years.
1. For normal turf the stock early RV4 pants and 500X5 tires work fine, you can reinforce the lower rear of the pant with Kevlar for added strength. Don't remove them as they keep rocks and pebbles off the tail during takeoff. I like the Pressure Recovery pants mounted so that in level flight attitude you have 4" ground clearance at the rear of the tire. Use 30 PSI in the tires for best results. I also replaced the aluminum attach brackets with thin chrome molly steel as fire ant mounds tend to break aluminum...
2. Bigger Tires really help on soft turf and mud. Thanks to Steve Sampson I began using Desser 380X150X5 tires underneath my PR pants and the difference is noticeable, especially when it it gooey in FL (like right now) 30PSI for them too. This thread covers it very well: http://www.vansairforce.com/community/showthread.php?t=27980&highlight=bushwheels+rocket
3. Learn to do bush pilot rolling takeoffs and run-ups as they save prop stains and dings and reduce takeoff roll. For very short strips I use the full flaps at tail rotation technique, get airborne and slowly retract them (need manual flaps) which allows you to takeoff and accelerate in ground effect on very rough or soft surfaces.
4. Landings on very short (less than 1000' long) I use a 3 point full flap 60MPH(55Knots) approach power on tail low and fly to a power on touchdown, full aft stick and light braking.For FP props set your engine idle at 550-600 for best STOL approaches. Longer grass strips and pavement I always wheels land for better forward visibility, braking and style points.
Overall, the RV4 is not a bad STOL sport plane, with techniques and practice you can utilize a great number of unimproved surfaces.
Email me off line for any [email protected]
V/R
Smokey
Ed,
I have fairly extensive experience (25 years) operating off grass with my RV4, HR2 and current RVX with no ill effects. My home strip is a private 2000' very soft turf strip with 50' obstacles at both ends. I also have sojourned to the Idaho back country and Montana numerous times and landed on roads and gravel. My RV4 is still flying with over 2000 hours, and still has no cracks in the engine mount, lower longerons or tail spring attach bulkhead. I did build in the heavy weldments and had short gear. Doesn't matter, my Rocket has Long Titanium Legs and it had no issues nor does my current RVX which I'm using longer RV4 legs mated to an RV6 engine mount.
Here are some tips I have used over the past 25 years.
1. For normal turf the stock early RV4 pants and 500X5 tires work fine, you can reinforce the lower rear of the pant with Kevlar for added strength. Don't remove them as they keep rocks and pebbles off the tail during takeoff. I like the Pressure Recovery pants mounted so that in level flight attitude you have 4" ground clearance at the rear of the tire. Use 30 PSI in the tires for best results. I also replaced the aluminum attach brackets with thin chrome molly steel as fire ant mounds tend to break aluminum...
2. Bigger Tires really help on soft turf and mud. Thanks to Steve Sampson I began using Desser 380X150X5 tires underneath my PR pants and the difference is noticeable, especially when it it gooey in FL (like right now) 30PSI for them too. This thread covers it very well: http://www.vansairforce.com/community/showthread.php?t=27980&highlight=bushwheels+rocket
3. Learn to do bush pilot rolling takeoffs and run-ups as they save prop stains and dings and reduce takeoff roll. For very short strips I use the full flaps at tail rotation technique, get airborne and slowly retract them (need manual flaps) which allows you to takeoff and accelerate in ground effect on very rough or soft surfaces.
4. Landings on very short (less than 1000' long) I use a 3 point full flap 60MPH(55Knots) approach power on tail low and fly to a power on touchdown, full aft stick and light braking.For FP props set your engine idle at 550-600 for best STOL approaches. Longer grass strips and pavement I always wheels land for better forward visibility, braking and style points.
Overall, the RV4 is not a bad STOL sport plane, with techniques and practice you can utilize a great number of unimproved surfaces.
Email me off line for any [email protected]
V/R
Smokey
Last edited:
Master Designs
Well Known Member
Search for "weldments" in the RV-4 section and you will find a wealth of knowledge for your RV-4 shopping. A recent thread can be found here: http://www.vansairforce.com/community/showthread.php?t=96305&highlight=weldments
If the RV-4 you are looking at was built in the late 80's to early 90's, and has the original weldments, they are probably the first style and need to be changed. The original style was cut and folded up from a flat sheet. The revised/newer style is welded together from thicker steel angle.
I probably have photos of both I can post if need be, just let me know.
dukekimbrough
Member
rv 4 on grass
I have experienced significant damage after 30 years of flying my rv 4 on my grass field that is getting rough due to draught conditions here in north texas. if you are hearing oil canning from your firewall, thourghly inspect the F442 brackets for cracks. if they show damage thourghly inspect your mount gear tube welds and mount tubes. I have a very early rv4 and my mount is not repairable because it is cracked and tweeked and will not fit on Russ Mccutchen's jig. he says its trashed and im looking at a new mount which means I will have to change to the long gear legs. Oh well , the joys of aircraft ownership
I have experienced significant damage after 30 years of flying my rv 4 on my grass field that is getting rough due to draught conditions here in north texas. if you are hearing oil canning from your firewall, thourghly inspect the F442 brackets for cracks. if they show damage thourghly inspect your mount gear tube welds and mount tubes. I have a very early rv4 and my mount is not repairable because it is cracked and tweeked and will not fit on Russ Mccutchen's jig. he says its trashed and im looking at a new mount which means I will have to change to the long gear legs. Oh well , the joys of aircraft ownership
Eddie P
Well Known Member
I'm just curious - what does it take to change out the weldments into the new style? And if going through the trouble, then what does it take to get the long gear?
1) Parts list?
2) What sort of work would be required? Would this be a major - major job like it seems to be to me (my perspective is as a non original builder, early 90's vintage RV4 guy)
We've got a good RV but I've often wondered what it would take to get the long gear. We have a big IO-360 up front with a long prop, so the thought of the longer gear seems like it might be an advantage but not totally necessary. But if I ever found an issue with the weldments I'd probably want to make some overall improvements. We fly off of pavement but it might be nice to have a grass/dirt ready airplane too.
1) Parts list?
2) What sort of work would be required? Would this be a major - major job like it seems to be to me (my perspective is as a non original builder, early 90's vintage RV4 guy)
We've got a good RV but I've often wondered what it would take to get the long gear. We have a big IO-360 up front with a long prop, so the thought of the longer gear seems like it might be an advantage but not totally necessary. But if I ever found an issue with the weldments I'd probably want to make some overall improvements. We fly off of pavement but it might be nice to have a grass/dirt ready airplane too.
Steve Barnes
Well Known Member
Long gear conversion
Hi Ed. I have done the conversion and can give you the good and the bad.
Steve (707) 972-3582
Hi Ed. I have done the conversion and can give you the good and the bad.
Steve (707) 972-3582
