Worried about a leading edge crack in the fiberglass wing laminate ofmy PW-5

Two things caught my attention from the OP.

First, if using a rigger in a crosswind, do everything in your power to have the cradle set and LOCKED at the far upwind side of the axle before rotating the wing to the leading edge down position. Why? Give you the longest arm for overturning moment. Longer axle might help, but not if you are in the middle of it or at the downwind end of it!

Second, you have a glider and no way to haul the trailer around yourself? You said you would have to rent or borrow a vehicle to move the trailer. This seems a bit off to me. But, a car is not required to roll a trailer a wing panel length and turn it 90 degrees so it is pointed into the wind. Then move it back into the tiedown spot after you have rigged or de-rigged. Yes, more work, but minimal risk for damage that way.

Just my observations. Hope you get your wing repaired quickly!

Steve Leonard

First, if using a rigger in a crosswind, do everything in your power to have the cradle set and LOCKED at the far upwind side of the axle before rotating the wing to the leading edge down position. Why? Give you the longest arm for overturning moment. Longer axle might help, but not if you are in the middle of it or at the downwind end of it!

I disagree, at least on a MM Wing Rigger. Imagine there is no wind at all. If you lock it on the open side of the wing rigger cradle, then entire weight of the wing now rests just above the wheel and becomes very unstable. (Got that t-shirt.) Now imagine the crosswind again. Yes, you are right, as long as you don't turn the wing so that it is now parallel to the wind, which is going to happen when you put it in the trailer (also parallel to the wind) per discussion above. I agree that it's all about longer moment, but there are different ways to skin that cat. One of them would simply be a longer axle. This WOULD help for sure, even if you lock the in the middle. By locking it in the middle, you mitigate the risk of crosswind toppling it PLUS the risk of toppling it by simply having the wing weight directly over a wheel when you turn it upwind.

I'm curious what Mark of MM recommends on this, i.e. setting the Wing Rigger directly over a wheel.


Second, you have a glider and no way to haul the trailer around yourself? You said you would have to rent or borrow a vehicle to move the trailer. This seems a bit off to me. But, a car is not required to roll a trailer a wing panel length and turn it 90 degrees so it is pointed into the wind. Then move it back into the tiedown spot after you have rigged or de-rigged.. Yes, more work, but minimal risk for damage that way.

Yes, I do. The glider lives in its trailer at the airport. I only have a Honda Civic, so it may seem a bit "off", but it's true. I'm not just making an excuse here. I normally borrow my brother's truck to move it.

Further, all of the gliders are stored in one spot on the airport and they are all lined up quite close to each other so it is impossible to turn mine 90 degrees without first towing it away from the other trailers.

Thus far the best overall solution (in my particular situation) seems to be to get a (a) longer wheel base and (b) keep the cradle locked in the center (so that the wing weight is over the center of the wheel base) and (c) keep the wing horizontal as much as possible. (Here, I'm assuming there is no one around to hold the opposite end of the wing in case it decides to topple.)

I will also try to talk the airport manager into letting me move my glider to a different spot where I can turn the trailer 90 degrees as you say.

Honda Civic?!?!

I crewed (late '70's?) for a person from near Boston with an original "super Beetle" (oxymoron.......) with a ASW-15 and a large plywood trailer.
Empty trailer on flat ground, I was looking to draft motorhomes to maintain 55-60MPH on a highway........
Loaded trailer......sigh......Frikkin forget uphill........

Your Civic can do well pulling a trailer, just moving it around an airport, sheesh, no issue.

Yes, a helper is great, but not always available.

On 2/13/2018 4:49 AM, wrote:
Snip...
...The glider lives in its trailer at the airport. I only have a
Honda Civic, so it may seem a bit "off", but it's true. I'm not just making
an excuse here. I normally borrow my brother's truck to move it.

It took a while, but eventually sufficient rust fell off my memory cell, thus
regenerating a coupla possibly-actionable anecdotes...

- some years ago a soon-to-be friend arrived at my home field (KBDU) towing an
original PIK-20A in an original PIK factory trailer behind a 2nd-generation
Civic. They'd moved from Louisiana with the rig. Not the cutesy 1st-gen
liquid-cooled-engine Civic, but its slightly supersized successor (that soon
allowed Honda to show its after-sale customer support by warranty-replacing
beaucoup rusted-through front fenders). It was years before he replaced that
particular tow-vehicle. Anemic in the mountains, but he never killed it
mechanically by using it in that manner. Memory sez he had some sort of
generic tow hitch installed on the vehicle.

- even more years ago (1973!) I bought a generic tow hitch (from Sears!) to
install on my 1972 Maverick. It didn't fit properly, but I was lucky enough to
have Wil Schuemann as an officemate, who welded-it-to-necessary-length, plus
welding on 2 triangulation braces. Trouble-free towed gliders with that
car/hitch until I sold it in 2009!

- ~2000-ish I installed a generic hitch on my eventual-wife's 1987 4-banger
Mustang which she used for several years to tow a 1-26, including to/from Air
Sailing (NV) and Dalhart (TX) from eastern CO. Health forced her to sell the
1-26 ~6 years ago; the 'Stang's original engine/tranny/running gear are
presently returning from the moon with ~275k miles on 'em.

Bob W.

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LOL. Where there's a will there's a way!

I'll try that with my Honda Civic coz I LOVE my glider. The Honda Civic -- ehhh...not so much. :-)

Seriously, thanks for all the advice, people.

Oh Eric. Pardon my ignorance, but what's a LAME?

On Sunday, February 11, 2018 at 9:20:59 AM UTC-8, wrote:
Hi all.

I own a PW-5. I have a MM Fabrication Wing Rigger I use when put the glider together and take it apart.

Yesterday, a gust of wind caught the wing when it was vertical on the wing rigger, and even though I was holding the wing steady near the spar, the wind force was strong enough to topple the wing rigger and slam the leading edge on the ground (grass). Personally I think these wing riggers need longer wheel bases to provide more moment against moderately strong wind, but that is another story.

An initial inspection for damage showed a 3 inch crack in the fiberglass in the leading edge where it struck the ground. The crack is deep enough to show the square pattern of the underlying fiberglass cloth layer, so it's not just a surface crack. (A PW-5 doesn't have a gel coat anyway. It has a coat of paint over the fiberglass laminate.)

I'm now worried about structural integrity of the wing, of course. Should I be? What should be your next steps? or what would you do next if you were I?

Respectfully,
Charles "Ben" Ethridge

ANY damage to the wing forward of the mainspar MUST be inspected before further flight, repaired as necessary, and a logbook entry made.

ANY damage to the wing forward of the mainspar MUST be inspected before further flight, repaired as necessary, and a logbook entry made.

I'm trying to imagine how one would inspect this to make sure there is no internal structural damage. X-ray?

At 11:51 13 February 2018, wrote:
ANY damage to the wing forward of the mainspar MUST be inspected before
further flight, repaired as necessary, and a logbook entry made.

I'm trying to imagine how one would inspect this to make sure there is no
internal structural damage. X-ray?


That part of the wing does not have internal structure to speak of. Damage
to D-nose sandwich structure is easily detectable by an experienced LAME.

"I'm curious what Mark of MM recommends on this, i.e. setting the Wing Rigger directly over a wheel."

Charles- There is no problem with positioning the chassis and wing cradle all the way to one side or the other to counter a crosswind. The PW-5 has a lightweight wing, and when rotated to the vertical position, it becomes a pretty big sail. Moving the vertical column to the UPWIND side and locking the axle (!) can help by giving more lateral support. Remember that you are not actually "setting the WingRigger directly over a wheel." The axle support tube is ten inches long, so the vertical column is offset. (Not so much on the side the saddle is rotated to.) The most important step is securing the lateral movement with the axle lock knob (and checking it before moving!)

However, if you want a longer axle, contact me and we can discuss options.