When trailers go bad OR How not to tow your Wright Brothers machine

In my last post, I mentioned that I was curently off the airshow circut
for a number of reasons. Greatest of which is the issue with the
homebuilt trailer that formerly hauled my plane and equipment. Well,
for those of you that havn't heard this before, here's the whole story.

The trailer was originally intended to make (and last for) one trip
from Covington, GA to Nag's Head, NC and back. Nothing more. It was
also originally designed to be as small, light, and cheap as possible.
My original tow vehicle was a 4-cyl. Chevy Cavalier, and anything
resembling a "normal" trailer just wouldn't work. So I cobbled together
a bunch of cheap junk.

The rolling chasis started with a 4x8 bolt-together kit from Northern
Tool. The kit was then stretched 13 ft. by replacing the factory tongue
with an 11 ga. 2x3" steel box-tube. Add a pair of 12"x4.8" wheels and
tires.

The deck is 4'x18', pressure-treated 2x4s on 24" ctrs. covered with
3/4" pressure-treated plywood. Everything is screwed and glued and the
corners are steel plate braced.

The box was originally 4'w x 4 1/2' h, 1x2's covered with corrugated
roofing steel. This configuration leaked like the Titanic was nearly
unworkable due to the tight fit of the wings inside. I used the trailer
like this for my first show in Raleigh and my second show in Atlanta.
This configuration also proved nearly uncontrollable behind the little
Cavalier, which had neither the horsepower, nor the brakes or
suspension to handle the load.

Following the second show, I tore off the original box using a
sledgehammer. I then rebuilt the box using 26 ga. steel studs for
framing, and 26 ga. steel "5-V" flat roofing pannels. I also added a
45-degree v-nose. The new demensions were now 4'w. x 6'h. x 18'l. with
an additional 2' in the v-nose. I used the trailer in this
confiruration for the remainder of the 2003 and 2004 seasons, towing it
behind a rented Chevy 3500 Dually. It worked fairly well in this
configuration in the light winds of the southeast, and recorded about
5,000 miles.

I upgraded to a 2002 Dodge Dakota V-8 for the ferry-trip to Colorado.
At about the 2,000 mile mark, I encountered a violent thunderstorm just
outside of Byers, CO. Keep in mind that this territory is open plains
with nothing to break the wind. I intended to turn the rig into the
wind if I encountered a storm, since I knew the trailer was good for at
least 100 MPH in tow. But, two lane roads aren't very accomodating and
I had to turn broadside for 3/4 of a mile to reach the shelter of a
truck stop. Of course, as soon as I turned, a 50+MPH gust hit me and
rolled the trailer. Damage was limited to the coupler, left fender, and
left front corner, and 2 hours later I was rolling again. Thank you,
Byers citizens.

Since then, I've experimented by loading the trailer with sandbags. At
its max gross of 1150 lbs., its still uncontrollable in winds over 20
mph. There's not enough steel in the rolling chasis to change axles or
go to a tandem-axle. Since the trailer is currently configured to haul
my wings standing on their leading edges, ther's no real way to just
cut a little off the top. And since ballast doesn't seem to help much,
I'll have to concentrate on lowering the side profile. This means the
wings will now have to be transported flat, rather than on edge. That
will allow me to reduce the side profile by at least 1/2, if not more.
But it also means the new trailer box will have to be about 6' wide,
and the wings will need to ride in some sort of jig that will allow
them to be packaged and loaded as a single protected unit.

I'm currently working on various methods of accomplishing the new goal
without spending too much cash. I think most of the steel framing and
sheet metal can be used again. But I'll have to work out a new decking
system, etc.

Harry Frey
Wright Brothers Enterprises
Specialist in impractical aircraft and cheap junky trailers

wright1902glider wrote:


Since then, I've experimented by loading the trailer with sandbags. At
its max gross of 1150 lbs., its still uncontrollable in winds over 20
mph. There's not enough steel in the rolling chasis to change axles or
go to a tandem-axle. Since the trailer is currently configured to haul
my wings standing on their leading edges, ther's no real way to just
cut a little off the top. And since ballast doesn't seem to help much,
I'll have to concentrate on lowering the side profile. This means the
wings will now have to be transported flat, rather than on edge. That
will allow me to reduce the side profile by at least 1/2, if not more.
But it also means the new trailer box will have to be about 6' wide,
and the wings will need to ride in some sort of jig that will allow
them to be packaged and loaded as a single protected unit.

Never occured to me that a trailer would
have a max crosswind rating (:

"wright1902glider" wrote

I'm currently working on various methods of accomplishing the new goal
without spending too much cash. I think most of the steel framing and
sheet metal can be used again. But I'll have to work out a new decking
system, etc.

What is the total weight of the loaded trailer, and what is the weight of the
tongue (at the ball) with the load on the trailer? You could have a balance
problem.
--
Jim in NC

What is the total weight of the loaded trailer, and what is the weight
of the
tongue (at the ball) with the load on the trailer? You could have a balance
problem.
--
Jim in NC

No dice Jim. The axle is only 4' forward of the back end. Loaded tongue
weight is at the upper limits, usually 200+, but I've tried several
different balance combinations within the 10-20% of gross range without
any improvement. I don't think an anti-sway hitch would do much good
either, since the trailer has a tendancy to just roll over, rather than
sway wildly.

Good news though. A few months ago, I ferried the boat I inhierited
(sp?) from my Dad. 1500 miles from Louisiana to CO. with no problems.
The boat is 17' long, about 1,000 lbs. gross, and has a side profile
about 3' high. I ran on the same 12x4.8" tires that I pulled off of the
glider trailer, and didn't have any problems with 15-20 MPH crosswinds.
It did tuck in rather nicely behind the Dak, with the top deck at the
same height as the top of the tailgate, so that may help as well.


FYI: I've looked very hard at several sailplane trailers. But all that
I've seen so far will not accomodate the 60" chord wings from the
Wright machine. If anyone knows of a trailer that might, I'm open to
suggestions. Otherwise, I'll keep saving my pennies until I can afford
a 8x44' gooseneck & dually. Then, it would just be a matter of pulling
the front feathers off and stuffing the whole assembled glider into its
rolling hangar.

Harry

There are several good trailer threads on rec.aviation.soaring. It's
been debated endlessly ;-)

There are also manufactured closed trailers for wide chord sailplane
wings. You might check with Blanik America. They have a closed
trailer for the Blanik that has a 66" interior height.
http://www.nwi.net/~blanikam/ba/prod05.htm

Best regards,
Craig

"wright1902glider" wrote

No dice Jim. The axle is only 4' forward of the back end. Loaded tongue
weight is at the upper limits, usually 200+, but I've tried several
different balance combinations within the 10-20% of gross range without
any improvement. I don't think an anti-sway hitch would do much good
either, since the trailer has a tendancy to just roll over, rather than
sway wildly.

So what is the total weight? 200 pounds does not sound like all that much on
the tongue.

Ok, I'm thinking out of the box, here.

Aerodynamics. How about making it more stable to the side wind. First idea, a
skirt around the bottom, lower to the road, so the wind keeps it sucked down to
the road. Plus, if wind can not get under it from the side, then it is also
less likely to be contributing to blowing it over.

Along those same lines, it occurs to me that this light of a trailer must bounce
a good bit. Does it have leaf springs? If so, how about some light shock
absorbers to keep it from bouncing. Every time it gets up in the air, it gives
wind an extra chance at the bottom of it. If the upwind side is bouncing up,
while the downwind side is headed down, that gives it extra exposed bottom
surface area and increased wind pressure on the bottom, plus making the center
of gravity closer to being unstable.

If the only spring is the air in the tires, a different inflation may make it
bounce less. If possible, mount the axles to a swing arm, and use some air
adjustable shocks and use the air pressure as the spring.

Now, really out of the box. Create an adjustable ballast system. Some type of
water containers, one on each side, and as low as possible. Enough water to
fill one container, plus a small amount for plumbing and an inch or so in the
bottom of the empty one. Plumb an electric reversible pump, or two with check
valves. When the wind is not a factor, keep the tanks balanced. When it starts
blowing like snot, fill up the upwind tank. You could run a few wires to the
cab and control it all.

This idea would work, without a doubt. The only question is if you want to go
to the trouble and expense to make it happen.
--
Jim in NC

I have two Hovey Delta Bird biplane ultralights and a non-enclosed trailer
that I picked up at the same time as I bought the first one.

The aircraft rolled up ramps sideways onto the trailer and clamped into
place and then the tail assembly disconnects at the back of the main wings.
The tail assembly then clamps into place reversed to the direction of travel
with the tail end up near the tow ball. The complete aircraft is exposed to
the elements. The ramps are at different elevations such that the rearmost
wheel (starboard landing gear) is about a foot higher than the front wheel
(port landing gear). This means the wings are at an angle that tends to push
the complete aircraft and trailer down while travelling. A decent sloping
roof on your trailer may add considerable downforce to help you handle the
crosswinds.

The single axle has three leaf springs, two as normal and the third upside
down across the axle from side to side. The weight is shared between the
springs. This is similar to the centre spring front end used on an old
Corolla KE10 from the late sixty's. The cross spring is quite effective in
helping to control the trailer. It is bolted to the frame at the centre and
the flat ends ride on a section of channel welded to the axle so there is a
flat surface to wear. The axle is held in place by the side springs which
are mounted with coupling joints like most leaf spring cars. The side
springs have three leaves and the centre spring has four leaves. I suspect
that about half the trailer weight is supported by the centre spring.

This trailer handles quite well and the second aircraft I towed 300 km
through a back road mountain range to get it home in the middle of a storm.
Although I restricted speed to 70 kmh for most of the trip due to potholes,
and 80 kmh for smoother road stretches, I did get up to 110 kmh for a test
stretch in calmer winds.

I will send a couple of pictures to your email address, and also to anyone
else that would like them, just drop a note here....

Hope this helps,
Peter

wright1902glider wrote:

I'm currently working on various methods of accomplishing the new goal
without spending too much cash. I think most of the steel framing and
sheet metal can be used again. But I'll have to work out a new decking
system, etc.

Could you make the box a triangle?

Have the side hinged at the bottom. Fold them down, attach a wing to
each side, fold it closed and pin them together at the top.

The sloped side should be much more wind friendly.

Thanks for all of the unique thinking folks. Lots of good ideas.

Here's a link to my website that has a photo of the "rolling hawg
shed".

hometown.aol.com/wright1902glider/airshow8.html

I've been thinking about this a lot in the past few days, and I keep
coming back to the conclusion that I've got more of a height-to-track
ratio problem or a CG problem than a sway issue. From my rear-view
mirror observations, the trailer doesn't sway so much as it just rocks
up on one wheel. I can push on the side of the trailer near the tail
end and in 3-5 pushes, rock it up and nearly over.

I'd like to stay with a box-trailer with as few openings as possible.
The reason for this is that Wright machines are covered in raw cotton
muslin, and the fabric braces the wings. If they get wet, they're
toast. I think a glider-trailer setup with internal guides and dollies
is the way I want to go.

Jim, I had been thinking about the ballast system. The local glider FBO
in Boulder, who is also an RAH'er suggested something like this. But
the idea for the pump is the missing link. I can see it helping
considerably on the Interstates. Maybe something like a 12v bilge pump
plumbed between two tanks made from large diameter PVC. Sling 'em low
and to the sides like the external fuel tanks on a CH-53 Sea Stallion.
I've also thought about just adding a concrete-filled steel pipe under
the chassis center to act like the keel of a sailboat. All of this will
require testing of course.

Anyone have any thoughts on how much wider I could make the axle? Keep
in mind, the chassis is on 48" spring centers, using 2-leaf
slipper-springs, and currently has a hubface-to-hubface measurement of
60". I've seen heavy air-compressors, like those you see powering
jackhammers, rolling on 3-4' spring centers with about a 6' axle. But
all of the suspension components looked very heavy. My chasis is so
light that I'm concerned about adding too much axle and overloading the
frame attachment points, shackles, etc. with dynamic loads.

I'm also considering much wider tires. I've seen snowmobile and pontoon
boat trailers running 8"x8" tires or larger. I don't want to go too big
though. Again, overloading things with dynamic forces.

Harry

On 3 Nov 2006 09:59:26 -0800, "wright1902glider"
wrote:

Thanks for all of the unique thinking folks. Lots of good ideas.

Here's a link to my website that has a photo of the "rolling hawg
shed".

Harry

Have you considered the toe out or in on the wheels. I believe this
has an affect on the stability although I can't recall which is which.

Ed Sullivan