What do all you guys think of converting my RV4 to tricycle gear?
I have been told to wheel land it at 80 MPH.
That is a field length penalty and a much worse crash if you screw
up.
As I understand it they are dangerous in cross wind landings. I have
a friend with one that refuses to fly under sever cross wind
conditions.
Paul Lamar
It's not the beginning of April already is it ?
John
No john I am serious. I have already spent $1000 with
some jerk up in Oregon trying to teach me to wheel land at 80 MPH.
Actually most of the time was spent doing 360's just under the overcast
and just above the trees like I needed to do that :)
When a tail wheel airplane first touches a paved runway with
any cross wind component at all the side force is ahead of the
CG and by any definition that is severe instability.
Tails wheels were designed back in the days when dirt air fields
were 2 miles square and you could always land into the wind.
Also the coefficient of friction of rubber tires on dirt or grass is much
less than on pavement.
I don't want to be put in position of either running out of gas
or landing in a cross wind with a tail wheel.
Paul Lamar
I learned to fly on a C120 and loved it. That one you could wheel land
or 3 point land. The 3 pointer landing actually happened in a fairly
short distance as we were taught to try and touch the tailwheel down 1
second before the mains so you didn't touch mains first and set up a
bounce. Worked like a charm and its the same technique as landing the
tricycle just that you hold it off a bit higher and a bit longer.
Touchdown speed was lower than a wheeler landing due to the high angle
of attack at touchdown. Are you not supposed to 3 point land a RV4? All
serious short field planes with tail dragged config seem to be able to
land in a reasonably short distance so I guess they 3 point land it,
Alex
Touching down on a locked tail wheel should work great. Maybe I should
focus on finding or making a locking tail wheel.
Paul Lamar
Dear Mr. Lamar:
I would check with the Kit manufacturer and ask IF they have any
information regarding landing a Tricycle Gear RV4 in crosswinds. As they
offer a Tricycle Gear option, they should have a chart or information
about how it handles in crosswind landings, etc. that should be in the
aircraft manual.
I would also ask the Kit manufacturer IF they could send you the name
and addresses of several of their customers that have and fly a Tri Gear
RV-4s. I would contact those individuals. I am sure Tri Gear RV-4 owners
and operators could give you a lot of information based on experience
how the Tri Gear RV-4 handles in cross winds.
I would also check on installing Vortrice Generators on your airplanes
wings and tail to improve handling of your ariplane at low speeds.
All My Best
Brannen Sanders
http://www.vansairforce.com/community/showthread.php?t=29562
<http://www.vansairforce.com/community/showthread.php?t=29562>
"The 8 has a larger rudder and longer fuselage and stiffer gear, is
heavier with different crosswind manners. To answer your question, in my
RV4 I used 20 knots max direct cross using a wheels landing, wing low on
touchdown technique. Any more and it's gets squirrley when you lower the
tail as the fuselage blanks alot of the rudder.The Rocket with an RV4
rudder is even more pronounced.
Most production taildraggers use 17 knots direct crosswind as a limit.
I asked a FSDO guy once about that and he said that years ago all of the
manufacturers got together and agreed on a number, the insurance
companies liked it and there it was, 17 knots. Your mileage may vary..."
"Rob Ray
1500 Hours RV4
HR2"
So apparently the rudder is blanked and that is why they insist
on wheel landings.
Back to nose gear :)
Paul Lamar
If I remember correctly wheel landings were done only a few MPH faster
than full stall landings. Used to get good control with rudder and
aileron, perhaps one brake in a cross wind. People that do it, do it all
of the time. Just to keep a keen edge on that tool. If you cannot stay
on the centerline during approach with bank and rudder, you need to use
a different runway, or airport.
You are not landing at 80 MPH. You are flying across an airport with
the wheels on the ground. That would be a low pass. Just get in some
slow time in a Champ or Cub and an old instructor. You just cannot beat
conventional gear for getting in and out of short fields.
I got stuck out in a cross wind and low on fuel over a paved airport
that had gas. I could not stay over the runway in my BC12D, so I landed
on the turn around circle at the end right into the stiff wind. A couple
of boys came out and clipped a rope into the tie down ring on the right
wing and walked me to the fuel pumps.
Lynn E. Hanover
The airplane is finished and flying.
Since the tail is blanked at 3 point landing angles of attack perhaps
vortex generators on the canopy and fuselage sides would help.
A larger rudder with more area at the bottom would also help. The
rudder is
structurally weak anyway and prone to flutter at speeds over 200 MPH.
We considered
making a new balanced one out of carbon fiber to stop that. The stock RV4
rudder is not balanced. The balanced part at the top would help.
Van should be doing this.
A tall wheel faring that looks like a rudder would also help.
Paul Lamar
Paul,
80 mph seems pretty fast for an RV4. Are the flaps down?
Helio aircraft were available in both tailwheel and trigear
configurations. Most operators prefer the nose wheel. It is easier to
control and actually takes off a little quicker because of the level
attitude during the take off run. However, very rough runways work
better with a tailwheel, as the main gear are quite a bit stronger. The
nose wheel is prone to collapse on a rough surface.
The Helio had the most pronounced crosswind challenges I have ever
met.When approaching at 45 mph, a 15 knot crosswind required a 30 degree
crab angle. With the mains well forward, to prevent nose over in very
soft terrain, quite a lot of weight on the tailwheel, and the slow
speeds, the plane could be very difficult to reign in, once the nose
began to wander. The factory solution, early on was to castor the main
gear. This worked quite well, but could feel a bit goofy as you land,
still crabbed 20 degrees into the wind. Very difficult to taxi until
the wheels were locked again in place. A guaranteed crash if one main
gear castored and the other stayed locked--a lot of pilots had the
heebie jeebies over it. When production resumed in the eighties, the
factory solution evolved to a locking tailwheel. Very simple pin,
extended through a hole in the tailwheel steering shaft. Like this, a
three point landing is almost a non event. Wheel landings in a Helio
are a dicey affair, mostly done when the pilot is showing off, just to
prove he can do it. Nothing wrong with three point, 100% of the time.
A hangar partner of mine recently porpoised his RV6A (trigear) on a
grass runway in Idaho. The nosewheel folded back up into the cowling
and drove his propeller into the dirt. He is now rebuilding the plane
with a tailwheel.
My Pitts Model 12 must be landed three point every time, due to the size
of the prop. I have landed in some very powerful crosswinds without
much issue. Since you are concerned about it, figure out a tailwheel
lock for the RV4. Set it up to engage whenever the stick is held all
the way aft (like a P51) and make three point landings.
I would not recommend a nosewheel for the RV4. Get some better
training. Yes, tailwheel configurations are old, but they have remained
in play this long because they actually work pretty well. If you are
worried about an engine out landing into a field, the tailwheel would be
a better choice.
Lewis Bjork
Yea you drive it on.
That jerk up in Oregon never told me about the tail blanking. If he had
I might have tried
harder. He was a friend of Van's and Van does not like people talking
about his airplane's design
short comings. If it were me I would come up with a retrofit fix and
sell it. Maybe the lawyers are
controlling the situation and to come up with and sell a fix is an
admission of a design flaw.
Beech stone walled the V tail doctor killer for years until some body
lived through
a tail coming off and proved it. Beech would just say; "don't exceed the
VNE".
The truth of the matter was it was all too easy to exceed the VNE in
IMC in a V-tail.
Put the nose down a bit and bingo you are past VNE.
You can put the nose straight down on a C182 and it won't go past VNE :)
Clean airplanes designers have to design the tail with higher VNE margins.
I have landed down in Baja many times in the C182 with a 30 kt cross wind.
Slip and crab :)
Paul Lamar
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