changing operating limitations

Is it possible to change the operating limitations of your homebuilt
after it has been certified?
Let me take the more extreme case...
I was wondering, if one owned (or bought) an RV3, is it possible to
change the operating limitiations to have a red line of 120 knots, and a
maximum continous RPM that arrives at a speed or 120 knots?
This would potentially make it fit as a sport pilot airplane (when flown
within the operating limitations)


Mike

On a somewhat similar vein. As we know one of the limitations of the LSA is
that it must have a fixed or ground adjustable prop. I called the FSDO and
asked this...

The LSA rules states "(7) A fixed or ground-adjustable propeller if a
powered aircraft other than a powered glider."

Assuming the experimental-homebuilt aircraft fits the LSA rules in all other
ways can it have an adjustable prop that is, in normal operation, in flight
adjustable (variable pitch NOT constant speed) if the in-flight
adjustability is either...

A. Marked "Not for in flight use by sport pilot" or similar words

or

B. Made not inflight adjustable on the ground that cannot be made inflight
adjustable in the air?


Their answer was NO to both A (which didn't surprise me) and B (which is
what I really wanted them to say yes to.)


"Morgans" wrote in message
...

"pittss1c" wrote

if one owned (or bought) an RV3, is it possible to
change the operating limitiations to have a red line of 120 knots, and a
maximum continous RPM that arrives at a speed or 120 knots?
This would potentially make it fit as a sport pilot airplane (when flown
within the operating limitations)

I have heard it discussed that this would not be allowed, from the point
of
just stating a maximum RPM. It has to be a limitation that can not be
overcome by the pilot, without major physical changes to the airframe or
powerplant.

My take is that you could put a fine pitch prop on it, and perhaps a
restrictor plate or throttle linkage that would not allow the engine to
make
full HP, so the maximum throttle setting would not allow you to go faster
than the 120 knots.

I believe (IMHO) that a major change in the prop would allow you to change
the operations limitations, but I'm certainly no expert on all of this.
Someone will give their opinion soon, I'm sure.

Will the RV 3 fit in on weight and stall limitations? You can not change
the weight, I believe.
--
Jim in NC

Morgans wrote:
"pittss1c" wrote
snip
Will the RV 3 fit in on weight and stall limitations? You can not change
the weight, I believe.

stall is 51 MPH, so it just fits the 45 knot rule (VGs might get it lower)

It is about 700-750# empty and 1100 gross as stock.
I was just thinking, the designer sets the operating limitations of a
homebuilt's engine.
therefore one could define an engine based on lycoming parts (up to 100%
lycoming) to have a max continous RPM of...say 2000. (as part of "your"
design to get a higher TBO)

If I was to build up an engine with parts out of my garage, I would set
the operating limitations, and would set the Vne of my own design/airplane.

Mike

"pittss1c" wrote

if one owned (or bought) an RV3, is it possible to
change the operating limitiations to have a red line of 120 knots, and a
maximum continous RPM that arrives at a speed or 120 knots?
This would potentially make it fit as a sport pilot airplane (when flown
within the operating limitations)

I have heard it discussed that this would not be allowed, from the point of
just stating a maximum RPM. It has to be a limitation that can not be
overcome by the pilot, without major physical changes to the airframe or
powerplant.

My take is that you could put a fine pitch prop on it, and perhaps a
restrictor plate or throttle linkage that would not allow the engine to make
full HP, so the maximum throttle setting would not allow you to go faster
than the 120 knots.

I believe (IMHO) that a major change in the prop would allow you to change
the operations limitations, but I'm certainly no expert on all of this.
Someone will give their opinion soon, I'm sure.

Will the RV 3 fit in on weight and stall limitations? You can not change
the weight, I believe.
--
Jim in NC

There are some designs that were made LSA-legal by reproping. The thing
is, they were just a few knots off... the RV3 is like 50Kts over, isn't
it?

Personally, I suspect that such a plane would be a troublemaker. By
putting a grossly wrong prop on it or swapping out the engine you may
create a legally LSA-compliant plane... but people know what an RV3 is.
When you say "LSA-legal" they are going to say "prove it".

Other than that... is the listed stall speed clean? LSA says 45Kt Vs1
(no flaps).

"pittss1c" wrote

to have a max continous RPM of...say 2000. (as part of "your"
design to get a higher TBO)

It will not be allowed. The rule plainly states that it is not to exceed
120 knots at wide open throttle.

You have to make it so that if you push any harder on the throttle, it will
break off! g

Sorry. If it were only so.
--
Jim in NC

"Morgans" wrote in message
...

"pittss1c" wrote

to have a max continous RPM of...say 2000. (as part of "your"
design to get a higher TBO)

It will not be allowed. The rule plainly states that it is not to exceed
120 knots at wide open throttle.

You have to make it so that if you push any harder on the throttle, it
will
break off! g

Sorry. If it were only so.
--
Jim in NC

In the spirit of discussion, how about a throttle stop that prevents more
than a certain amount of throttle movement?

KB

On Mon, 15 Aug 2005 15:19:54 -0500, pittss1c
wrote:

Is it possible to change the operating limitations of your homebuilt
after it has been certified?
Let me take the more extreme case...
I was wondering, if one owned (or bought) an RV3, is it possible to
change the operating limitiations to have a red line of 120 knots, and a
maximum continous RPM that arrives at a speed or 120 knots?

Yes, you can go through the process and change the operating
limitations of a home built.

This would potentially make it fit as a sport pilot airplane (when flown
within the operating limitations)

NO, Any airplane once outside the sport pilot limitations can *never*
be brought in, or back in if it had been there before.

Technically you could initially build the plane with an engine and
propeller combination that would put it in the sport pilot category,
but you can not modify the very same make and model to fit the sport
category if at any time it's operating limitations would have put it
beyond the sport plane limitations.

I don't know how many other ways to phrase it, but once outside the
category, it will remain so forever.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


Mike

"Kyle Boatright" wrote

In the spirit of discussion, how about a throttle stop that prevents more
than a certain amount of throttle movement?

From what I have read, as long as the stop is not defeatable (especially
while in flight) it should pass.

For the real answers to your queries, contact your local FSDO.
--
Jim in NC

In order for an aircraft to qualify as a LSA the aircraft must have met
the limitations of LSA continuously since its original certification.
You can not take a non qualifying aircraft and re-certify it as
qualifying. I am pretty sure that statements to this effect are written
in the LSA regulations.