Hey Guys,
I've had a project working for over a year and it just was completed last
week. I now have a straight left wing. Sorry for the long narrative,
but it's the only way I know how to tell this story.
Brief history for those not familiar. I was an early ES buildshop
customer and the left wing jig at Lancair was out of alignment when I closed my
wings. It was discovered during flight testing a year and half
later. My left wing had about 0.5 degrees washout instead of the 2.0
degrees in a properly shaped wing. 8 to 12 other wings were closed
before the problem was discovered. The jigs were promptly replaced.
Tim developed a fix using eccentrics to slightly modify the incidence of the
wings to eliminate the right rolling tendency. Several people are flying
with eccentrics. I did for over a year with good results.
But I was never completely satisfied. I began asking questions about
the wing. The opinions ranged from "no big deal" to "death trap".
The truth was likely somewhere in between. As I researched washout it
became apparent to me that there's more to this than just flying straight.
I could go on for another thirty paragraphs describing the research. Tim
ultimately asked an aerodynamicist what he thought. I think it was Greg
Cole, the designer of the Legacy and the Columbia. The aerodynamicist said
that any less washout and I would absolutely need to fix it, if I had half the
problem I'd be crazy to fix it. He said the wing was "borderline".
Needless to say, I wanted a wing that met the factory specifications.
I didn't think Lancair was going to give me a new wing, even though some
opinions thought they should. I credit Drew Dickinson (same wing problem)
for coming up with the idea of re-closing the wing. If the jigs lock in
the wing geometry, re-closing should give me a wing with 2 degrees of
washout.
Tim thought Drew and I were nuts! Who would go to that kind of
trouble with a straight flying airplane? Tim said that wing skins have
been pulled before for various reasons, leaky fuel bays, poor bonding,
etc. So it could be done, but would it work? I was confident it
would. Drew was enjoying his airplane and wasn't sure this would be worth
it. I was in the paint shop! But we both committed to a trip to
Redmond to tear our wings apart. I told my painter to hold off on the
wings and just paint the fuselage.
Initially, when Tim checked the misaligned jigs, he found that the outboard
two cradles were the only ones that were off. So Drew and I began thinking
about a partial re-closing. If we only separate the lower wing skin from
the tip to the inboard edge of the aileron, the wing should lay down in the jig
and correct the geometry. We wouldn't have to get into the fuel tank or
the flap pocket. Tim thought we might only have to separate from the
leading edge back to the spar in the outer section, but said you'll only know
once you start tearing into the wing. Tim cautioned that we might end
up pulling the entire wing skin.
Drew and I scheduled the trip. He was able to get there on time, but
I was stuck in Colorado for three days due to weather. He was
done with the re-closing before I got there. We talked on the phone a
couple times a day. He ended up separating the lower wing skin back
to the inboard edge of the aileron. When I got there, he was finishing up
his body work. We reassembled his plane and he took it up for a flight
test. He still had some right rolling tendency, but most of the original
wing washout was back in the wing. I was waiting for his results before
making a final decision on how much I was going to tear apart my own wing.
Drew was on a much tighter timeline and had to get back home. I had more
time, so I had more choices. There was definitely an advantage to going
second. I learned a lot from Drew's experiences. I decided to "go
for it" and removed the entire wing skin.
A couple notes about wing skin removal. It's violent, loud popping
sounds, crunching, etc. Some damage to the inner wing skin is
inevitable. The damage is easily repaired with additional layups. It
takes about 6 hours to remove the wing skin. You start by sanding off all
the micro over the layups, and using a heat gun to peel off the layups.
Then the wedges come out and you start hammering the wedges in along the ribs
and spar.
We sanded and prepped the wing and re-closed. I left the shot bags on
for an extra day. When the weight came off the wing was flat down in the
jigs. But how would it fly? Three days of layups,
pressure testing the fuel tank, and many hours of body work.
Reinstalling the flap brackets, fuel probe, fuel fittings, flight controls,
etc. Deja vu all over again! We sloshed the tank
and reinstalled the wing on the plane, but with zero eccentrics
this time. The weather moved in and the flight test was delayed.
A few days later, I packed up my stuff in the plane, jumped in, told
the Lancair people that I'd either be back in 10 minutes or I'm heading home to
Colorado. I set the aileron trim to neutral, took off. I was 1,500 feet
AGL before I realized it was flying perfectly straight! So a 4 hour
plus test flight and I'm back home in Colorado with a new wing. The rudder
trim is neutral, the control surfaces are in trim. I flew down final at 75
KIAS with confidence. I'm very happy with the outcome.
Since I only tore off the bottom wing skin, my upper wing root fairing
still lines up perfectly. The bottom side is off slightly. It will
stay that way since my fuselage is already painted. I have several days of
body work left to get it ready for the painter again.
Tim was supportive, even though he still thinks I'm crazy. To quote Joe
Bartels, "Thank you for being a loyal customer
and it is our privilege to make adjustments where appropriate."
Is this for everybody? Definitely not. But I personally think
it was worth the effort and expense. Lancair paid for our hotel and loaned
us a vehicle during our stay. And supplied all the buildshop supplies and
plenty of extra hands to speed the process along. The mechanics loaned us
tools. The crating department helped out with the forklift for removing
and reinstalling the wing. Tim even took us out for an awesome BBQ
dinner. It's great to have a solid company stand behind its product.
Thanks Lancair!
I have photos.
Mike Easley
Colorado Springs