aerobatic kit planes

Dudley Henriques wrote in
:

The guy who owned the one we leased back got a double hit in one day.
He landed on the grass on a field down near the Susquehanna River, tried
to wheel it on and had it nailed until he went over the mound in the
middle of the runway that he didn't know about. The main gear legs
compressed and he caught the prop tips bending the hell out of it.
The next day he called and said he had received the AD on the wing.
He was ONE unhappy camper!!



Well, all you had to do was cut some holes and inspect them, though I think
that was settled on eventually after some consultation with the FAA. I
think when it first came out is was replace or nothing.
To be fair, a lot of spars were found to be damaged. We plan to have a
policy of inspecting the spars on ours if the airplane is groundlooped,
even if it doesn't look lke any contact was made with the tips, or if 4.5G
is exceeded, or if the paint is inexplicably marked due hangar rash. It'll
cost us nothing! Our spars are brand new and are significantly beefier than
the originals. The original ribs had slots in them that allow an extra
1/16th of an inch in thickness and another 1/8th inch in depth, which makes
the spar about 15% stronger. There's a guy out in Washington state who does
this mod and he makes a couple of other small detail mods as well, like
wingtip mounting and feathered doubler plates to avoid stress risers.
Probably even better are getting the metal spars, but our's was done when
we got it, so ...

Bertie

wrote in news:a4e90596-4834-48d2-9236-
:


I've done a little welding but nothing my LIFE depended on!


You learn,. And you learn how to read the weld so if it looks good, it is
good.
I had the same concern when I started learning to do aircraft welding. I
talked to the guy who dsigned my airplane, Dudley Kelly. He told me to get
some lessons and then weld it up and not worry. In his words "If you get
25% of each joint right it will still exceed design specs"
You should see the welds on old pipers! They're crap!
And Bellanca were using MIG to weld their fuselages for a long time and to
my knowledge, none of them has come apart because of that..
After I learned to do only a passable job ( i'm better at it now) I found
that I could take a piece I'd made, put it in a vice and beat the hell out
of it and the weld and the area around it would be the last thing to fail.
Ask in RAH, though. Plenty of guys building/have built the kinds of
airplanes you might be interested in.

Bertie

Bertie the Bunyip wrote:
Dudley Henriques wrote in
:
The guy who owned the one we leased back got a double hit in one day.
He landed on the grass on a field down near the Susquehanna River, tried
to wheel it on and had it nailed until he went over the mound in the
middle of the runway that he didn't know about. The main gear legs
compressed and he caught the prop tips bending the hell out of it.
The next day he called and said he had received the AD on the wing.
He was ONE unhappy camper!!



Well, all you had to do was cut some holes and inspect them, though I think
that was settled on eventually after some consultation with the FAA. I
think when it first came out is was replace or nothing.
To be fair, a lot of spars were found to be damaged. We plan to have a
policy of inspecting the spars on ours if the airplane is groundlooped,
even if it doesn't look lke any contact was made with the tips, or if 4.5G
is exceeded, or if the paint is inexplicably marked due hangar rash. It'll
cost us nothing! Our spars are brand new and are significantly beefier than
the originals. The original ribs had slots in them that allow an extra
1/16th of an inch in thickness and another 1/8th inch in depth, which makes
the spar about 15% stronger. There's a guy out in Washington state who does
this mod and he makes a couple of other small detail mods as well, like
wingtip mounting and feathered doubler plates to avoid stress risers.
Probably even better are getting the metal spars, but our's was done when
we got it, so ...

Bertie
Sounds like a plan.

--
Dudley Henriques

On Dec 17, 8:51 pm, Bertie the Bunyip wrote:
I had the same concern when I started learning to do aircraft welding. I
talked to the guy who dsigned my airplane, Dudley Kelly. He told me to get
some lessons and then weld it up and not worry. In his words "If you get
25% of each joint right it will still exceed design specs"
You should see the welds on old pipers! They're crap!

You talkin bout a Kelly D biplane?

On Dec 18, 5:37 am, "Viperdoc" wrote:

The only fatal accident associated with a spar occurred around here, and it
was the lift strut attach fitting, not the spar itself. I used to have some
nails back out, and the epoxy/rib nail solution worked pretty well. The
check for compression fractures on the top of the spar could be done with
mirrors, without cutting holes in the top of the wing.. Also, it was not
uncommon to break nose ribs over time.

I used to fly the 8GCBC for a living and IIRC there were 4 inflight
failures resulting in fatalities. I think these were traced back to
inproper repairs after the planes had been groundlooped or blown over.
We had a fleet of 8 of these and found cracks in the spars in all but
one. Me thinks the metal spars, at least in the Scout, was a good
ider.


Also, cross wind landings are easier in the Extra due to its higher landing
speed and lower cross sectional area. The Super D is a great plane and a lot
of fun.
And the Super D is easier to issure
F Baum

"Bertie the Bunyip" wrote in message
.. .
wrote in news:a4e90596-4834-48d2-9236-
:


I've done a little welding but nothing my LIFE depended on!


You learn,. And you learn how to read the weld so if it looks good, it is
good.

Very bad information. How a weld "looks" has very if anything to do with
it's effectiveness.


I had the same concern when I started learning to do aircraft welding. I
talked to the guy who dsigned my airplane, Dudley Kelly. He told me to get
some lessons and then weld it up and not worry. In his words "If you get
25% of each joint right it will still exceed design specs"

This is going to be entirely load or design dependant. Yes, two sleeved
tubes, laterally loaded can easily survive with just a couple of tack welds,
but if the joint is in tension 25% is seldom even close.

You should see the welds on old pipers! They're crap!
And Bellanca were using MIG to weld their fuselages for a long time and to
my knowledge, none of them has come apart because of that..
After I learned to do only a passable job ( i'm better at it now) I found
that I could take a piece I'd made, put it in a vice and beat the hell out
of it and the weld and the area around it would be the last thing to fail.
Ask in RAH, though. Plenty of guys building/have built the kinds of
airplanes you might be interested in.


Yes, a lot of good welds look terrible, and yes it is very dependant on the
design and load of the joint. But either statement taken in general context
is very incorrect.

Viperdoc wrote:
The metal spar may be over rated. I think a lot of the doom and gloom about
the wood was perpetuated by ACA, who was in the business of selling metal
spars. Over time, wood may actually resist fatigue fractures better than
aluminum. The FAA testing was done with a static load, not cyclic.

The only fatal accident associated with a spar occurred around here, and it
was the lift strut attach fitting, not the spar itself. I used to have some
nails back out, and the epoxy/rib nail solution worked pretty well. The
check for compression fractures on the top of the spar could be done with
mirrors, without cutting holes in the top of the wing.. Also, it was not
uncommon to break nose ribs over time.

Interesting.

Flying the Super D does require smooth control inputs- it was in some ways a
lot harder to fly than the Extra. Energy management was more critical, but
things happened a lot more slowly and required more inputs. In the monoplane
there is a temptation to slam the stick from side to side and corner to
corner since the airplane can take a lot more than most pilots, especially
me. It's a whole different style of flying.

Also, cross wind landings are easier in the Extra due to its higher landing
speed and lower cross sectional area. The Super D is a great plane and a lot
of fun.




Got a ton of time teaching in the Decathlon. :-))

I would agree on the energy management as related to the Extra on the
performance basis. The Ps bleed on the Decathlon vs the Extra and the
control pressure relationships are a huge change.

The tendency to throw the stick around in the higher performance acro
planes is the first thing a good acro instructor takes out of the flying
equation. Taking a student out of the Decathlon into an S2 Pitts or an
Eagle and demonstrating a 4 point roll then letting them try one usually
does the trick. Slamming in the aileron and stopping it with using even
the control pressure used in the Decathlon usually ends up in a knife
edge PIO with the student over controlling to each side out of sync
trying to stabilize the ailerons. One time doing this usually does the
trick and the student learns right then and there that flying something
like a Pitts or an Extra is done with the fingertips and a smooth hand.


--
Dudley Henriques

Dudley Henriques wrote:
Viperdoc wrote:
The metal spar may be over rated. I think a lot of the doom and gloom
about the wood was perpetuated by ACA, who was in the business of
selling metal spars. Over time, wood may actually resist fatigue
fractures better than aluminum. The FAA testing was done with a static
load, not cyclic.

The only fatal accident associated with a spar occurred around here,
and it was the lift strut attach fitting, not the spar itself. I used
to have some nails back out, and the epoxy/rib nail solution worked
pretty well. The check for compression fractures on the top of the
spar could be done with mirrors, without cutting holes in the top of
the wing.. Also, it was not uncommon to break nose ribs over time.

Interesting.

Flying the Super D does require smooth control inputs- it was in some
ways a lot harder to fly than the Extra. Energy management was more
critical, but things happened a lot more slowly and required more
inputs. In the monoplane there is a temptation to slam the stick from
side to side and corner to corner since the airplane can take a lot
more than most pilots, especially me. It's a whole different style of
flying.

Also, cross wind landings are easier in the Extra due to its higher
landing speed and lower cross sectional area. The Super D is a great
plane and a lot of fun.




Got a ton of time teaching in the Decathlon. :-))

I would agree on the energy management as related to the Extra on the
performance basis. The Ps bleed on the Decathlon vs the Extra and the
control pressure relationships are a huge change.

The tendency to throw the stick around in the higher performance acro
planes is the first thing a good acro instructor takes out of the flying
equation. Taking a student out of the Decathlon into an S2 Pitts or an
Eagle and demonstrating a 4 point roll then letting them try one usually
does the trick. Slamming in the aileron and stopping it with using even
the control pressure used in the Decathlon usually ends up in a knife
edge PIO with the student over controlling to each side out of sync
trying to stabilize the ailerons. One time doing this usually does the
trick and the student learns right then and there that flying something
like a Pitts or an Extra is done with the fingertips and a smooth hand.


On that roll it should read "stabilize the ELEVATORS not the ailero
Senior moment there :-))

--
Dudley Henriques

"Viperdoc" wrote in
:

The metal spar may be over rated. I think a lot of the doom and gloom
about the wood was perpetuated by ACA, who was in the business of
selling metal spars. Over time, wood may actually resist fatigue
fractures better than aluminum. The FAA testing was done with a static
load, not cyclic.


That's right, it does. I'm happier with the wood spars from a safety
point of view, if not from an economic point of view.

The only fatal accident associated with a spar occurred around here,
and it was the lift strut attach fitting, not the spar itself. I used
to have some nails back out, and the epoxy/rib nail solution worked
pretty well. The check for compression fractures on the top of the
spar could be done with mirrors, without cutting holes in the top of
the wing.. Also, it was not uncommon to break nose ribs over time.


I think there was one Citabria that lost a wing, but it was due to
concealed damage from a previous incident as well as a suspected
exceedence of limitations.


Flying the Super D does require smooth control inputs- it was in some
ways a lot harder to fly than the Extra. Energy management was more
critical, but things happened a lot more slowly and required more
inputs. In the monoplane there is a temptation to slam the stick from
side to side and corner to corner since the airplane can take a lot
more than most pilots, especially me. It's a whole different style of
flying.


Well, goes to my argument that while the new giant model airplanes are
terrific, they probably don't make such good trainers.

Also, cross wind landings are easier in the Extra due to its higher
landing speed and lower cross sectional area. The Super D is a great
plane and a lot of fun.



Yep!

Bertie

"F. Baum" wrote in
:

On Dec 17, 8:51 pm, Bertie the Bunyip wrote:
I had the same concern when I started learning to do aircraft
welding. I talked to the guy who dsigned my airplane, Dudley Kelly.
He told me to get some lessons and then weld it up and not worry. In
his words "If you get 25% of each joint right it will still exceed
design specs" You should see the welds on old pipers! They're crap!

You talkin bout a Kelly D biplane?


No, the Hatz.


Bertie