Top ten glider trailer features?

Mount the stuff that you use every time you rig/de-rig at the rear of the trailer. Saves several trips back and forth to the front of the trailer. I have cleaning supplies, tape, ballast funnels, and the one man rigging dolly mounted in the rear. For me, it is much easier to get the rigging dolly out of the back of the trailer than trying to wrestle it out through the front hatch.

P9

On Tuesday, November 26, 2013 7:51:59 PM UTC-8, shkdriver wrote:
I wished we had trailer-wide drawers in front and in back of the axle. One could stow a lot of rigging stuff there.

Heinz

My ten....

Newer cobra trailers have trays attached to the wing dollies that bring the
cleaning materials in them down the back when rigged. Nice touch.

I wouldn't be without my hydraulic jack. Much much easier.

I store my probes inside the clamshell at the back, safe from damage.

Easily swappable number plate. Install mountings at the standard cobra
pitch so crew can easily attach their number plate.

Very strong hinges, fittings, and locks.

Solar panels or wind turbine that can drive a fan or dehumidifier as well
as charge batteries. I wish I could power a small heater to keep the
temperature above freezing.

Screw jacks are a pain. If you do not want to prop with the door (the rear
of my trailer sits on tyres) then fit drop down stands and wind the front
up on the dolly jack to drive them into the ground.

Single axle better than dual but fit Tyrons to ensure tyres cannot come off
when flat.

Double skin or insulation to ward off condensation.

Maintenance free exterior - hate washing and polishing.

Build "canopy holder" brackets inside the top of the rear clamshell. Older sailplanes had detachable canopies. If I recall correctly, your SHK canopy, like our Open Cirrus, detaches completely / is not hinged. Placing it on the ground is a recipe for disaster. Our rule was the canopy was either securely on the sailplane cockpit or up in the trailer brackets after the fuselage was rolled out.

As was suggested for clearance, use larger rims than typical for rear clearance into dips, swales, bar-ditches. Especially important for off-road retrieves.

Some trailer history as I recall it: Back in the sixties when the first glass sailplanes were imported from Germany, the enclosed factory trailers were generally an afterthought. Many pilots built trailers from scratch. Cobra type trailers today are a vast improvement - just pick your options and write a check (I have two plus a Swan copy.) At the national contest at Marfa in 1967 Dad (Fritz Compton) and I took many photos of the innovative devices in the all-wooden trailers that the legendary Ben Greene built for his SHK, SH-1 and others. Those trailers were works of art. (Do any survive to this day?)

In 1968 Dad welded up his trailer before the 17.7 meter Open Cirrus arrived at the dock, based on the dimensions of the sailplane. Some adjustment was built-in for the dollies and it worked very well. The ratchet tooth bar tilting system in front allowed precise tilting in 2 seconds. Time and motion efficiency was a priority. The wingstand (none available commercially) was a cut down step ladder which I still use. Dad and I could assemble the big Cirrus in ten minutes / de-rig in five especially when a t-storm was approaching! I still have that trailer and the Open Cirrus is assembled in my hangar at Marfa, Texas. One of prettiest sailplane profiles in the air. Dad lets me fly it occasionally . . .

On Tuesday, November 26, 2013 7:51:59 PM UTC-8, shkdriver wrote:
Hello,

I am in the early stages of building a Luebke patterned clamshell trailer for my Schempp-Hirth SHK. The trailer is an aluminum sheathed steel frame 'interpretation' of the cobra and comet style trailers. I have been paying attention to every glider trailer I've been around for the last few years, with the intention of incorporating the best features. Some of these features are;



Tracks and captured wing root dollies with adjustable tension hold down

brackets for the spar root (seen in a cobra containing a ventus)



Captured aluminum ramp with fold over center track, with either hydraulic

or double screw jack height adjustment (cobra again).



Pivoting lower carriage wheels on belly support dolly (cobra).



Drop down tailgate which provides a braced repeatable height of tail end

of trailer for rigging and derigging.



Front access hatch, ventilators, spare tire access when loaded.

Good lights with some lights down the length of the trailer.



Storage space for all the ground handling gear.



So, what am I missing or forgetting? Does anyone have any comments on favorite features or also, features which should be avoided at all costs? I want to eliminate those unforeseeable miserable items which pinch fingers, rash gliders, and detract from the chore of rigging and trailering a glider. I would also like to have a system which uses the least amount of loose gear lying about.



Thanks,

Scott W.

N-1521

Make the forward storage compartment big enough to store your one- man-rigger mostly assembled (3 wheels on the lift post). Lift the 3-wheels out, slide the saddle on and she's ready to go. I set my fuselage height a tad low, slide both wings in, shove my 12" broom handle into the far spar holes, then pump the hydraulic jack with my foot as I watch the near spar holes come into alignment. When the two spar holes come together, I shove in the first spar pin, then remove the broom handle and make any indicated height adjustment with foot jack as I watch the other holes.
I would make the final axle placement with everything in place, adjusting axle location to give about 100 pounds of tongue weight. Electric brakes are probably the best.
JJ

Scott,
Provide method of securing empty fuselage and wing dollies so they won't roll around in an empty trailer during a retrieve.

Someone else mentioned spare tire, but make it easy to get the spare tire out and the flat tire back into the trailer. My spare is located under the trailer behind the axle. It's "okay" to remove, but a real tough chore to remount. The 15" steel rim and tire are HEAVY. I've thought about making the "hoist" type of arrangement that some pickup trucks have for their spares.

Don't skimp on the size of the front cargo door. The newer Cobras have large doors. Older trailers have smaller doors. Go big!

Ray

And when you go big on the front door, put a two latches, towards each bottom corner, not just one in the center of the door. I have a wide Cobra trailer (use to hold an ASH-25) that now has THREE latches for the front door! Think it can be easily done with 2, each about a quarter or so of the way in from the edge along the bottom.

Steve

I would never tow a trailer with the spare wheel stowed under
the trailer by the axle again -or if I had to I would take a set of
axle stands. I had that arrangement on a trailer that had a flat
tyre when I was towing it solo. It sank down so that there was
insufficient vertical room to access and drop the spare wheel
down. I had to jack the trailer up and go under it to undo the
rusted securing nut by the side of the road with the trailer
above me swaying about as trucks etc went by. It was not
particularly enjoyable.

John Galloway


At 17:30 27 November 2013, rlovinggood wrote:
Scott,
Provide method of securing empty fuselage and wing dollies
so they won't
ro=
ll around in an empty trailer during a retrieve.

Someone else mentioned spare tire, but make it easy to get
the spare tire
o=
ut and the flat tire back into the trailer. My spare is located
under the
=
trailer behind the axle. It's "okay" to remove, but a real tough
chore to
=
remount. The 15" steel rim and tire are HEAVY. I've thought
about making
=
the "hoist" type of arrangement that some pickup trucks have
for their
spar=
es.

Don't skimp on the size of the front cargo door. The newer
Cobras have
lar=
ge doors. Older trailers have smaller doors. Go big!

Ray

On Wednesday, November 27, 2013 12:35:59 PM UTC-7, John Galloway wrote:
I would never tow a trailer with the spare wheel stowed under

the trailer by the axle again -or if I had to I would take a set of

axle stands. I had that arrangement on a trailer that had a flat

tyre when I was towing it solo. It sank down so that there was

insufficient vertical room to access and drop the spare wheel

down. I had to jack the trailer up and go under it to undo the

rusted securing nut by the side of the road with the trailer

above me swaying about as trucks etc went by. It was not

particularly enjoyable.



John Galloway





At 17:30 27 November 2013, rlovinggood wrote:

Scott,

Provide method of securing empty fuselage and wing dollies

so they won't

ro=

ll around in an empty trailer during a retrieve.



Someone else mentioned spare tire, but make it easy to get

the spare tire

o=

ut and the flat tire back into the trailer. My spare is located

under the

=

trailer behind the axle. It's "okay" to remove, but a real tough

chore to

=

remount. The 15" steel rim and tire are HEAVY. I've thought

about making

=

the "hoist" type of arrangement that some pickup trucks have

for their

spar=

es.



Don't skimp on the size of the front cargo door. The newer

Cobras have

lar=

ge doors. Older trailers have smaller doors. Go big!



Ray




Yes, what John and Ray said to watch out for is important. With the tire under the trailer and behind the axe it's really a pain getting it back up. I use my small jack and after lifting the tire up, side the jack under it, then jack it up to hold it in position while securing it again. If you can make room inside the trailer for the tire, might be the best way to carry that spare.
My ASW 27 trailer held the spare in front of the nose cone hold and came that way from Cobra.

Screw-down stabilizer jacks like the ones used on Cobra trailers now are great. When I bought my Avionic in '04 they only had one at the back. If there had been an option to get one on each corner I would have taken it. As it is I crank down the rear one and set the front of the trailer on a pair of jackstands when it's parked in its usual location at my airfield. Nice and stable even when the trailer is closed. I prefer that to putting strain on the tailgate.

As Bert Compton mentioned a place to put the canopy would be GREAT! I have an ASW-15 and the canopy is kind of awkward to deal with when rigging.

The over-center mechanism for raising and lowering the fuselage dolly ramp is good if you can assemble the glider easily without the ability to make fine changes in the height of the fuselage. In my case the only thing I would need to raise and lower the fuselage for would be to raise and lower the gear so the over center lever approach would work fine.

A third rail and ramp for the tailwheel would be nice, especially if the glider has a heavy tail. The 15 isn't heavy but being able to get the fuselage in and out without lifting the tail would have been worth the extra cost.

Contrary to what Bill White says my preference would be for a number plate holder which makes it difficult to remove the plate because where I live the trailer has its own VIN, title, insurance and number plate. I assume he lives somewhere where the trailer plate must be the same as the vehicle towing it.

Electrical connections for the lights should be whatever is most common with your fellow pilots. Either that, or make sure you keep an adapter or two on hand in case you need a retrieve!

For a similar reason, despite the advantages of electric brakes I would still go with a mechanical surge brake. It might not work as well, but at least it will work with any vehicle they're hooked up to.

A bit more ground clearance than is common with newer trailers would be good too as long as you don't get too carried away. The one thing my old trailer had over the Avionic that replaced it was the ease with which it could get in and out of driveways without bottoming out. Some sort of skid plates at the rear should be installed anyways, just in case.

The slide out under floor storage drawers seen on newer trailers are a fantastic idea.

Don't make it "just wide enough" for the glider to fit. Give yourself a few extra inches space. It makes getting things in and out MUCH easier. My old trailer was a non-clamshell type but because the builder resisted the temptation to make it small it was actually very useable. You could actually make your way from one end of the trailer to the other inside the trailer when the glider was in it. Too bad the wood it was made from had rotted so much.

I have yet to make up my mind when it comes to how the fuselage is held in the dolly. A single strap attaches easily but it only works to prevent the fuselage moving rearward in the dolly. Two metal arms swinging up from the dolly and attaching to points on the fuselage (e.g. with bushings in the ends of the arms slipping over the pins sticking out of the fuselage and held there with a spring clip) seems more secure but you would have to get the fuselage in exactly the right place on the dolly before they would line up.

Looking back at trailer history it still amazes me how long it took for some people to figure out the "fuselage in nose first, wings in root first, right wing on the right, left wing on the left and tailplane in a bracket above" arrangement.