Sender: <marv@lancaironline.net>
To: lml@lancaironline.net
Date: Sun, 14 May 2006 18:23:11 -0400
Message-ID: <redirect-1113247@logan.com>
Received-SPF: none
 receiver=logan.com; client-ip=205.152.59.67; envelope-from=aadamson@highrf.com
From: "Alan K. Adamson" <aadamson@highrf.com>
Subject: RE: [LML] Re: Ok, *Lancair* racers
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Thread-Index: AcZ2CL9sZh9mEO4wQaaAet6IlTtthgBikC1A
In-Reply-To: <list-1111047@logan.com>

Ok, I've been doing a little more armchair thinking about this.  Most on
supposition as I don't have a Legacy flying yet.

But, assume for a minute that a Legacy can run at reduced power (I've not
tired it, but heard it can be done) and be made to burn about 9gph LOP at
about 210kts TAS.  The average ground speed of the Glasair that just set the
record was 258mph or about 224kts.   He used 76 gal on a 9.5hr flight that
is 8gph.  He was going from West to east and he did it up high where there
are good winds.

So, theoretically, if you could find 20kt tailwinds, with 210kts TAS, you'd
have a ground speed of 230kts.  Now if you could come up with the right
combination of power/fuel burn and speed (TAS + strong tailwinds), you
should be able to beat this record.

Weight is still an issue tho, but maybe not.  It does appear you'd need
extra fuel (unless you can go faster on less burn than my theory above).  

So, let's continue the theory.  Let's say that the Legacy is empty at
1500lbs and you have to fit under 2204, so you have 704 useful.  Pilot at
170 (not me, but someone I'm sure).  That leaves 534 for fuel.  At 6 lb/gal,
that's 89 gals of fuel.  There's 65 in the airplane (stock), so 24gal extra
or 144lbs of extra fuel.

Mind you all of this is back of the napkin and with no margins.

Unless I'm missing something totally (and perhaps I am and I know my bladder
wouldn't make it :) ).... This seem entirely doable.

Does anyone know, in order to meet the FAI weight limit, does the airplane
have to be "placarded" for the weight, or does it just simply have to *not
exceed* that class of weight on takeoff.

With as many "cross country" racers as there are on this list ( at least
based upon the heckling  :) ).  This seems right up their alley.  I'm happy
to "crew" for someone :)...

Hmmm, sponsorships.... Hmmm....Maybe Paul could come up with a Killer FP
prop that could help :)...

I know, I'm as bad as Richard Titsworth.... I should be building on my
Legacy, but just had a twisted thought after I learned there are some
"stretching fuel economy vs. speed" due to current gas prices.  It got me
thinking.

Alan - too much spare time - admitted!

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Jack
Cowell
Sent: Friday, May 12, 2006 5:12 PM
To: Lancair Mailing List
Subject: [LML] Re: Ok, *Lancair* racers

Don't know much about lower power settings as I very seldom fly in the
flight levels at less than 29 inches. TAS at FL240 using these temps and
power settings is 265-270 kts.

colyncase on earthlink wrote:
> /Jack said,
> /
> /Your fuel burn will be dependent on the air density at your selected 
> altitude, and the RPM and MAP #s you choose. On a  65 degree F. day at 
> sea level with 2500 RPM and about 29 inches MAP I burn about 16-16.5 
> gph at 60 LOP at FL230-240.  I've never seen 15 gph at power and air 
> density #s like the ones I referenced above./
> 
> sounds right.   what do you get at lower power settings (which I think 
> means leanER of peak)?
> ...and what was your corrected TAS at the above?
>  

--
For archives and unsub http://mail.lancaironline.net/lists/lml/