Time to Takeoff for float planes

[N.Smith]

Hi All

I've just uploaded an excel spreadsheet produced from an article in SPA's
Water Flying July/Aug 2004 by Paul Armstrong which is based around a formula
from EDO and Leon Kaplan.

Simply enter engine HP, total float buoyancy, wing area, MTOW, and prop type
in the blue area's and it comes up with a time on the water.

I've had to upload it to Elite/float installations as I cannot get it to go
into the software section (Mike...could you sort this for me when you get a
chance please ?)

Comments please only about the accuracy of the equation - NOT about my
skills with Excel :-)

Thanks

Nigel
Elite 745E




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Walter Klatt]

The times seem a little optimistic for mine. If I'm lightly
loaded at 1600 pounds, it says my take-off time should be 4
seconds. I have never seen that, even with a strong wind. Also, I
noticed that the higher the floatation buoyancy, the shorter the
take-off times. At some point the bigger floats would have more
drag, which does not seem to be taken into consideration.

Maybe the formulas are designed around a specific airplane and
float, like a 185 on EDO's?

Walter

-----Original Message-----
From: mike.davis@dcsol.com
[mailto:mike.davis@dcsol.com]On Behalf Of
N.Smith
Sent: Tuesday, August 10, 2004 1:26 AM
To: rebel-builders@dcsol.com
Subject: Time to Takeoff for float planes


Hi All

I've just uploaded an excel spreadsheet produced from
an article in SPA's
Water Flying July/Aug 2004 by Paul Armstrong which is
based around a formula
from EDO and Leon Kaplan.

Simply enter engine HP, total float buoyancy, wing
area, MTOW, and prop type
in the blue area's and it comes up with a time on the water.

I've had to upload it to Elite/float installations as
I cannot get it to go
into the software section (Mike...could you sort this
for me when you get a
chance please ?)

Comments please only about the accuracy of the
equation - NOT about my
skills with Excel :-)

Thanks

Nigel
Elite 745E




-----------------------------------------------------
List archives located at:
https://www.dcsol.com/default.htm
username "rebel" password "builder"
Subscription services located at:
https://www.dcsol.com/public/code/html-subscribe.htm
List administrator: mike.davis@dcsol.com
-----------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Legeorgen]

I saw this article in SPA magazine for float take off times too and plugged
in my own numbers (same as yours Walter) for gross weight and It showed a take
off time of 26 seconds, if I remember right.

I have not seen the formula Nigel posted but I would guess you either
miscalculated or the formula was not copied correctly.

I believe it was intended for a rough estimate as it did not take into
consideration the pitch of the prop if it was a fixed pitch blade. But they did say
it was accurate with most aircraft.

Bruce




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Walter Klatt]

At 1730 gross weight and 3500 (2 X 1750), I get 7.5 seconds,
which is a little fast, even for my little water rocket.

Walter

-----Original Message-----
From: mike.davis@dcsol.com
[mailto:mike.davis@dcsol.com]On Behalf Of
Legeorgen@aol.com
Sent: Tuesday, August 10, 2004 4:25 PM
To: rebel-builders@dcsol.com
Subject: Re: Time to Takeoff for float planes


I saw this article in SPA magazine for float take off
times too and plugged
in my own numbers (same as yours Walter) for gross
weight and It showed a take
off time of 26 seconds, if I remember right.

I have not seen the formula Nigel posted but I would
guess you either
miscalculated or the formula was not copied correctly.

I believe it was intended for a rough estimate as it
did not take into
consideration the pitch of the prop if it was a fixed
pitch blade. But they did say
it was accurate with most aircraft.

Bruce

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------