Matronics Email Lists :: View topic - Classic stall characteristics (High Top Mod)

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Classic stall characteristics (High Top Mod)

Matronics Email Lists Forum Index -> Europa-List

View previous topic :: View next topic

Author Message

g-iani(at)ntlworld.com
Guest

Posted: Sun Sep 07, 2008 2:32 am Post subject: Classic stall characteristics (High Top Mod)

Frans



Both the original High Top (with the high cowl) and the new version (lowered

cowl, bigger screen) the difference in max speed and cruise speed (for a

fixed power setting) is too small to measure given the other variables such

as weight and very small build differences.



The only thing I have noticed since we completed testing is that the new

(64b) setup seems to be very slightly less stable in pitch.  Having modified

the aircraft we cannot go back to the original to get a real comparison.

The new deeper screen seems to generate a little more lift from the

fuselage.  Flying "hands off" in gusty conditions, and directly into wind,

the nose will hunt up and down very slightly with a period of about 10

seconds.  This is so slight that the original High Top may have been the

same but we did not notice until we started to look carefully for

differences.  If you have your hand on the stick you damp this out.  Most of

this testing was done with the TruTrak autopilot on to maintain the heading

and this could be the cause. 



Has any other high top owner noticed anything similar?

Ian Rickard G-IANI XS Trigear, 200 hours

Europa Club Mods Rep (Trigear)

e-mail mods(at)europaclub.org.uk   

   or direct g-iani(at)ntlworld.com

- The Matronics Europa-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?Europa-List

frans(at)paardnatuurlijk.
Guest

Posted: Sun Sep 07, 2008 8:32 am Post subject: Classic stall characteristics (High Top Mod)

Hi Ian,



 	  Quote: 	
		   The only thing I have noticed since we completed testing is that the new

 (64b) setup seems to be very slightly less stable in pitch.  Having modified

 the aircraft we cannot go back to the original to get a real comparison.


	


You might be interested to know that we have incorporated a modified

mod64b, that is, we have lowered the forward section only by 3,5 cm

(about halfway), and made it parallel with the lower fuselage. With some

juggling we were able to use the original windscreen for this. (Actually

we bought the deeper windscreen as well, but this one was not going to

fit with our modified mod, so we extended the rear window flange

slightly so we could use the original windscreen, which was a bit

oversized anyway). We thought this to be a good alternative because:

1) We didn't like the look of mod 64b too much (don't feel offended,

this is just a matter of personal taste), and now it looks much more

like a regular Europa XS. The windscreen remains flatter, and does not

extend below the side windows.

2) We already built a customised instrument panel, which partly utilized

the taller panel space available.

3) We wanted to have a better view outside, but we didn't desire to see

the entire cowling. 



We are not flying yet, but you may be sure we will give a detailed

report. Not that this will say anything, as we have incorporated a few

more mods.



If we find some time we will post a few pictures. Too busy building

until now to worry about pictures. 



-- 

Frans

- The Matronics Europa-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?Europa-List

frans(at)paardnatuurlijk.
Guest

Posted: Sun Sep 07, 2008 12:13 pm Post subject: Classic stall characteristics (High Top Mod)

A picture about my hi-top mod64B mod:

[img:9080fbc341]http://www.privatepilots.nl/europa/modfranshi.jpg[/img:9080fbc341]

Visit -  www.EuropaOwners.org

- The Matronics Europa-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?Europa-List

g-iani(at)ntlworld.com
Guest

Posted: Mon Sep 08, 2008 12:49 am Post subject: Classic stall characteristics (High Top Mod)

Frans



Pictures as soon as possible please.



I never feel offended that others decide to do things in a new and different

way.  This is what the Club and development is all about.  What we want to

do is to take the best ideas and make them available to others.  Yours may

be better looking, structurally stronger, easier to fly, cheaper to produce

etc or it may be the opposite so let us all know what you are doing.

Perhaps we could do an article for the Europa Flyer at some stage.  It would

also be useful to know what regulations apply to what you are doing.  In the

UK we would need to convince the LAA that it was sound engineering.



Ian Rickard G-IANI XS Trigear, 200 hours

Europa Club Mods Rep (Trigear)

e-mail mods(at)europaclub.org.uk   

   or direct g-iani(at)ntlworld.com

- The Matronics Europa-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?Europa-List

frans(at)paardnatuurlijk.
Guest

Posted: Mon Sep 08, 2008 3:19 am Post subject: Classic stall characteristics (High Top Mod)

Hi Ian,



 	  Quote: 	
		   Pictures as soon as possible please.


	


I posted already a picture. It shows where I cut the upper fuselage. It

also shows that I had to fiddle a little bit with the window flange to

make the window fit again. The rear flange got a bit narrow, so I

extended it with 5 layers of bid, then temporary put the window in with

plastic tape over the edges to fil the gap with expancel. For the lower

flange I extended the 3mm foam from the insert and shaped it into the

window's curve. The cut itself is fixed a la the mod 64B manual. On the

outside there are a few extra layers of bid. It is probably stronger

than it used to be. Once this was ready, fitting and bonding the window

was no different than normally.



The idea was that the hi-top extended the head room with 5 cm, but the

firewall with 7 cm. Compared to the normal XS this would cut 2 cm of the

lower part of the vision to the outside. I wanted to take that back,

plus a little bit more, without changing the look of the normal XS, and

retaining the panel space that became available by the still taller

firewall.



 	  Quote: 	
		   It would

 also be useful to know what regulations apply to what you are doing.  In the

 UK we would need to convince the LAA that it was sound engineering.


	


In the Netherlands we have no regulations.  Well, we need a compass,

an ASI, and Altitude gauge. There is no inspection. Once the airplane is

ready I only need a statement from a certified mechanic (not an

inspector!) that he has no objections and that's it! He will walk

around, kick the tires, confirm that it pretty much looks like an

airplane, and sign it off. I don't have to tell anything about mod's etc.

Once I have gone through that, I'm finished with it for the rest of my

life. The builder is considered to be the manufacturer, and once a year

I have to sign a document that I maintained my airplane conform the

rules of the manufacturer (yep, that's me too), in order to get a new

airworthiness certificate. If I want to cut off the last foot of my

wings, to see how it flies without it, I'm free to do so.

It is no coincidence that some mod's (nose wheel springs, tail wheel

mod, etc.) originate from the Netherlands. This is probably the most

liberal country for experimentals worldwide.



Frans

- The Matronics Europa-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?Europa-List

david.stanbridge(at)swift
Guest

Posted: Mon Sep 08, 2008 11:32 am Post subject: Classic stall characteristics (High Top Mod)

One contributing factor to the reduced stability will be that the higher fuselage perimeters resulting from the modification has shifted the aerodynamic centre of the wing / fuselage combination forward. This then reduces the longitudinal static margin (distance between CG and AC) and as a result the aircraft will be less stable in pitch.   

   

      Frans  

        

      Both the original High Top (with the high cowl) and the new version (lowered  

      cowl, bigger screen) the difference in max speed and cruise speed (for a  

      fixed power setting) is too small to measure given the other variables such  

      as weight and very small build differences.  

        

      The only thing I have noticed since we completed testing is that the new  

      (64b) setup seems to be very slightly less stable in pitch.  Having modified  

      the aircraft we cannot go back to the original to get a real comparison.  

      The new deeper screen seems to generate a little more lift from the  

      fuselage.  Flying "hands off" in gusty conditions, and directly into wind,  

      the nose will hunt up and down very slightly with a period of about 10  

      seconds.  This is so slight that the original High Top may have been the  

      same but we did not notice until we started to look carefully for  

      differences.  If you have your hand on the stick you damp this out.  Most of  

      this testing was done with the TruTrak autopilot on to maintain the heading  

      and this could be the cause.   

        

      Has any other high top owner noticed anything similar?  

   

   

David Stanbridge  

   

   

       [quote][b]

- The Matronics Europa-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?Europa-List

Display posts from previous:

	Matronics Email Lists Forum Index -> Europa-List	All times are GMT - 8 Hours
Page 1 of 1

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