Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Antennas
Goto page Previous  1, 2
 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
gmcjetpilot(at)yahoo.com
Guest





PostPosted: Sun May 21, 2006 7:28 pm    Post subject: Antennas Reply with quote

Quote:
From: Gilles Thesee <Gilles.Thesee(at)ac-grenoble.fr>
Aren't we talking about experimental aircraft ?
By the way, why should aluminum RVs be able to
hide antennas and not composite airplanes ?
Wingtips, fin cap, etc...
>Regards, Gilles Thesee Grenoble, France

Quote:
http://contrails.free.fr

s'il vous plat

Yes Sir, there is no reason, but they work terribly,
that is a fact. The word, WORKS, to might mean
you can talk to the tower 5 miles in front of you,
but ATC 100-140 miles away no. I am totally put
off by wing tip antennas and like ideas (in metal
planes) because there is such a huge compromise
in radio performance. To me communications and
navigation is too important to safety to compromise
on so much for such a small gain in drag reduction.




> From: Gilles Thesee <Gilles.Thesee(at)ac-grenoble.fr>
Quote:
Your HP values are way off, and I'll prove my point with
analytical values and flight test data, beg your attention.

>Thank you for your message.

Quote:
I was quoting your numbers :
***************************************
"There is a recent article in Plane & Pilot which
features the Socata Trinidad. Interesting enough,
the engineers at Socata actually quantified the
cruise speed impact of each antenna:"
ADF - .75 knots
G/S - .32 knots
VOR - .59 knots
ELT - .16 knots
***************************************
The total speed reduction is indeed in the vicinity of
1.82 knot. We ought to include one COM antenna.

Fair enough but experimental's usually do not have
ADF's. Most split the VOR for the G/S so the speed
would be 0.75kts + COM, or about 1 kt (1.15 mph).
The values are MAX drag, but still it matches my
number with in 3% to 18%. Again the point is that
most people assume too much drag from the antennas
alone, so consider external antennas for max radio
performance for a little drag (metal planes. There is
lots of drag to get rid if, like cooling drag.



>Oh, you really should check
Quote:
http://contrails.free.fr/index_en.php

NICE!



>Just like weight reduction, small gains add to small
Quote:
gains, and in the end it makes quite a difference.

NO argument from me. Every little bit helps, however
the BIG PICTURE is on metal planes we just have
lousy, awful, terrible, severely restricted and limited
radio performance when we use wing top, empennage
cowl and cockpit antennas. They WORK but again
I want more than a 5 mile conversation with tower.


In the US we have large expanse of land and REMOTE
radio outlets. To get ATC for radar, Flight Watch for
weather or Flight Service to open / close flight plans,
a clear powerful radio is so so important. Also we
have many class B and C air spaces that require a
good radio.

This is what my hidden antenna friends heard all the time:

AIRCRAFT CALLING WASHINGTON CENTER YOU ARE
WEAK AND SCRATCHY, WHAT IS YOUR REQUEST?

SAY AGAIN?

It's not worth 1 mph, when you are going 195 mph.



Quote:
They are designed by, ahem, aircraft engineers. Many of
them have the same "pas une affaire" background. The
industry doesn't believe in the existence of drag. Especially
in the land of cheap gas and big engines.


What land and engineers are we talking about, monsieur.
American engineers? pardonnez-moi


Land of cheap gas and big engines? America?

No offense taken, but give some examples to back up
your comment, aircraft engineers just know how to put a
big engines in from the "land of cheap gas and big engines".

I think a debate of airframes and engines are better for
another time or off this aeroelectric list.

I would say a long EZ, even with 160HP is way more efficient
than a MCR 4S or even a RV-9A with 115HP, and it has nothing
to do with engine size. I also say a RV-9A is more efficient than
your MCR 4S. Looking at the RV-9A with 115HP it has 10kt
faster speed (150kts). Not sure what engine you have 80 or
115 hp.

Anyway we can talk off line about efficency and
engine size. They are two different things.


>I just have to watch similar airplanes with their antennas
Quote:
sticking out, and receding in my slipstream Wink

Ha ha ha ha good for you. Want to race my big engined
RV-7 with O360 190HP?

It would be a good experiment to take your buddies plane's
antennas off and do a before and after. You will than see what
it they really cost in speed.

As far as big engine's, I can dial my RV-7 back and fly
140 kts and burn about the same fuel as you do. However
I have the option to fly as fast as 192 kts. How do I say in
French, as I pass you?

au revoir, mangez ma poussire, voyez-vous plus


Cheers nice talking to you,

George



__________________________________________________


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group