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ASIs (was Vixen Information)

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smokey_bear_40220(at)yaho
Guest

Posted: Wed Feb 07, 2007 5:06 pm Post subject: ASIs (was Vixen Information)

Paul,



Any chance that water got in the static line?



Kurt S.



--- Paul Seehafer <av8rps(at)tznet.com> wrote:



 	  Quote: 	
		   Mark,

 

 I've noticed that the airspeed indicator for my

 Model IV is off by sometimes 10 - 15 mph (e.g;

 reading 85-90 when I'm really going 100 mph).  Weird

 thing is that it is not consistent at all......


	




 

8:00? 8:25? 8:40? Find a flick in no time 

with the Yahoo! Search movie showtime shortcut.

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av8rps(at)tznet.com
Guest

Posted: Thu Feb 08, 2007 5:22 am Post subject: ASIs (was Vixen Information)

Kurt,



Yes, very possible.  I guess of all the things I thought of I never thought 

about that one.  I am typically having so much fun flying my Kitfox that I 

ignore the ASI for the most part (chuckle).



Paul

---

barry(at)pgtc.com
Guest

Posted: Thu Feb 08, 2007 6:10 am Post subject: ASIs (was Vixen Information)

My airspeed indicator is just the opposite, it is accurate up to about 90 

mph then starts reading too high, as much as 15 mph at 100 (which has to be 

while decending.)



I operated without a static port, just using the pressure behind the panel, 

until recently when I put a static port in anticipating installation of a 

transponder, but this seemed to have no effect.  I will learn more when the 

system is calibrated and certified.  But there must be  something wrong with 

the airspeed indicator.  Does anyone have any suggestions?



Barry West



---

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Thu Feb 08, 2007 6:12 am Post subject: ASIs (was Vixen Information)

I never got an answer to my personal email to you, so I'll ask again  

here...what are the black objects on the top of your Vixen wing?  

Another lister asked the same question, and I didn't see an answer  

there either.



Lynn

do not archive

On Feb 8, 2007, at 8:17 AM, Paul Seehafer wrote:



[quote] 



 Kurt,



 Yes, very possible.  I guess of all the things I thought of I never  

 thought about that one.  I am typically having so much fun flying  

 my Kitfox that I ignore the ASI for the most part (chuckle).



 Paul

 ---

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Thu Feb 08, 2007 6:35 am Post subject: ASIs (was Vixen Information)

Barry, Mine  reads at  90MPH  TAS   about  105 +

I have no  external static port.

Now If i open the door the ASI drops to about 95 mph

Then if I stick my arm out the door fully exteneded and my  ASI reads about 

90 mph.

I guess you could say that doing this makes the cabin at th proper pressure 

as it would be with a proper external static port.



At lower speeds 75 mph or les it seems fairly accurate to about 45 mph then 

the ASI reads low.



Movies here http://www.cfisher.com



Dave



---

_________________
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http://www.youtube.com/user/kitfoxflyer
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av8rps(at)tznet.com
Guest

Posted: Thu Feb 08, 2007 6:52 am Post subject: ASIs (was Vixen Information)

Sorry Lynn.  I resonded twice last night but the e-mails kept bouncing back. 

I tried again just a few minutes ago to resend.  Let me know if it doesn't 

work.  Btw your e-mails are coming to me just fine.



If you don't get my e-mail I did respond to the lists questions in detail as 

well.  Should show up on the list soon I would think?  (with my internet 

provider one never knows?)



Ok ok, to satisfy your curiousity, those covers are for my dual on board 

radar units....don't all kitfoxes have these?  Alright, just kidding....



Paul Seehafer



Do not archive



---

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Thu Feb 08, 2007 7:31 am Post subject: ASIs (was Vixen Information)

Thanks, Paul, I got all the info now and your emails, and all the  

pictures. Yeah, I have radar units on mine just in case those  

Washington, DC jets get a little too close (kick in the other  

cylinders and leave 'em : )  )



Lynn

do not archive



On Feb 8, 2007, at 9:49 AM, Paul Seehafer wrote:



[quote] 



 Sorry Lynn.  I resonded twice last night but the e-mails kept  

 bouncing back. I tried again just a few minutes ago to resend.  Let  

 me know if it doesn't work.  Btw your e-mails are coming to me just  

 fine.



 If you don't get my e-mail I did respond to the lists questions in  

 detail as well.  Should show up on the list soon I would think?   

 (with my internet provider one never knows?)



 Ok ok, to satisfy your curiousity, those covers are for my dual on  

 board radar units....don't all kitfoxes have these?  Alright, just  

 kidding....



 Paul Seehafer



 Do not archive



 ---

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

smokey_bear_40220(at)yaho
Guest

Posted: Thu Feb 08, 2007 8:37 am Post subject: ASIs (was Vixen Information)

Paul,



Being from Wis myself, I know what you mean with fun

somehow beating out small problems like jittery ASI's.

 I am sure you fly mostly by feel anyway, so it is not

a big problem.  And winter is just when you have fun

without bugs....



I agree with the leaky line idea too.  Be careful

blowing in the pitot.  Very little pressure will bust

the ASI.  I used a looped tube at the pitot instead

for this.  Just add a little water in the lower loop

and raise a few inches to pressure the line.



On mine, I ran the pitot line down the left doorpost

and put a "T" about 6" from the bottom.  The "T" runs

up to the ASI.  I can see thru the line enough to

check for water and drain out the sealed bottom, if

necessary.  It can hold a bit before it ever

interferes.



For the static line, I put a 90 elbow just inside the

plane and ran the line up and over to the other side

in a loop before going forward.  If any water gets in,

it doesn't get past the 90 and drains back out.



All that worked fine until I added my radiator scoop. 

That seems to have changed the airflow over my static

port and changed my accuracy.  



I did make the static port with a center nylon bolt in

it.  This bolt is drilled for airflow and slotted so

that I can screw it in or out to slightly change the

distance from the fabric that I draw static pressure. 

Haven´t tried changing that yet for effect.  Maybe

overkill.  But I liked the building process enough to

enjoy inventing....



Kurt S.  S-5



--- Paul Seehafer <av8rps(at)tznet.com> wrote:

 

 	  Quote: 	
		   Kurt,

 

 Yes, very possible.  I guess of all the things I

 thought of I never thought 

 about that one.  I am typically having so much fun

 flying my Kitfox that I 

 ignore the ASI for the most part (chuckle).

 

 Paul


	




 

Sucker-punch spam with award-winning protection. 

Try the free Yahoo! Mail Beta.

barry(at)pgtc.com
Guest

Posted: Thu Feb 08, 2007 4:09 pm Post subject: ASIs (was Vixen Information)

Thanks Dave, I think we both need an answer.  Anybody have an explanation

to these different problems, Dave's reads too low and mine reads too high?



Barry



Original Message:

-----------------

From: dave dave(at)cfisher.com

Date: Thu, 8 Feb 2007 09:31:45 -0500

To: kitfox-list(at)matronics.com

Subject: Re: Re: ASIs (was Vixen Information)




Barry, Mine  reads at  90MPH  TAS   about  105 +

I have no  external static port.

Now If i open the door the ASI drops to about 95 mph

Then if I stick my arm out the door fully exteneded and my  ASI reads about 

90 mph.

I guess you could say that doing this makes the cabin at th proper pressure 

as it would be with a proper external static port.



At lower speeds 75 mph or les it seems fairly accurate to about 45 mph then 

the ASI reads low.



Movies here http://www.cfisher.com



Dave



---

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Thu Feb 08, 2007 4:32 pm Post subject: ASIs (was Vixen Information)

Barry,   NO  mine reads too  high at cruise.   when I am doing  90 mph  by 

GPS  my  ASI reads 105 or a few more.  Open the  door and pressure changes 

and the ASI drops to about 95 mph.  GPs still the same approx . ( you will 

lose a few mph with door open)



Life sucks when you spend more time in Tractor snowblowing laneway in a week 

then flying.      



Next week I am hoping for a change.



Dave

---

torgemor(at)online.no
Guest

Posted: Thu Feb 08, 2007 4:53 pm Post subject: ASIs (was Vixen Information)

Barry and Dave,

the first step is to check the airspeed indicator, such indicators often  

have a S shape in the graph. I.E. Show too low at low speed near perfect  

in the middle and much to high at max. speed.



Then look at the aircraft side, a crossvented static port (this is a must  

for some "correct" static pressure). Also the pitot line must be without  

leak, etc.



As an example, a frozen pitot head will give increasing speed as you  

climb! Or, vice versa.



Cockpit static source may give some large altimeter error as well.



It is not just enough to check the altimeter against the encoder  

altimeter, you'll also need to check that the altimeter is within the  

required specifications with a ramp tester, and the as a whole system.   

This is really important for those flying in/into controlled airspace,  

lot's of other aircraft with TCAS (traffic collision avoidness system).  

Our altimeter and transponder is important items under such conditions.

Torgeir.



On Fri, 09 Feb 2007 01:08:25 +0100, barry(at)pgtc.com <barry(at)pgtc.com> wrote:



[quote] 

 Thanks Dave, I think we both need an answer.  Anybody have an explanation

 to these different problems, Dave's reads too low and mine reads too  

 high?



 Barry



 Original Message:

 -----------------

 From: dave dave(at)cfisher.com

 Date: Thu, 8 Feb 2007 09:31:45 -0500

 To: kitfox-list(at)matronics.com

 Subject: Re: Re: ASIs (was Vixen Information)

 



 Barry, Mine  reads at  90MPH  TAS   about  105 +

 I have no  external static port.

 Now If i open the door the ASI drops to about 95 mph

 Then if I stick my arm out the door fully exteneded and my  ASI reads  

 about

 90 mph.

 I guess you could say that doing this makes the cabin at th proper  

 pressure

 as it would be with a proper external static port.



 At lower speeds 75 mph or les it seems fairly accurate to about 45 mph  

 then

 the ASI reads low.



 Movies here http://www.cfisher.com



 Dave



 ---

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Fri Feb 09, 2007 7:12 am Post subject: ASIs (was Vixen Information)

Torgeir:



Where I did my training was about two miles directly off the end of RWY 31

at Gander Intl..  All our training planes were more or less fully equipped.

They were the best planes in the world....  They had everything except

pilots!



On day one we were warned never to turn on a transponder.  They were all

mode C without the encoders... They sent the frame sets for the altitude

without altitude info.  Apparently on at least one occasion someone turned

on a transponder and gave a transport cat aircraft some interesting seconds

on take off.  Definitely not a good idea.



BTW all the encoders and encoding altimeters I've seen are connected to

static lines.



I double your call for the cross vented static ports.  And someone else

called for a drip loop on the static lines not altogether a bad idea

especially with the cross port system.



On my first flight last year I was doing a few circuits.  On the water my

ASI was jumping around like a cat on a hot roof.  Once I got airborne it

would settle out but read too high.  When doing my post flight inspection I

found the static port, a plastic fitting, was hanging on, half in half out,

by the static line.  I still have to get another port and install a proper

cross port static set up.



Noel



[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

lcfitt(at)sbcglobal.net
Guest

Posted: Fri Feb 09, 2007 9:53 am Post subject: ASIs (was Vixen Information)

 	  Quote: 	
		  



You can eliminate instrument variables as a reason by using the manometer 
	


and calculator.  If that checks out OK,  the problem would be elsewhere in 

the plumbing and or location of the static port.



Lowell



 	  Quote: 	
		   Thanks Dave, I think we both need an answer.  Anybody have an explanation

 to these different problems, Dave's reads too low and mine reads too high?



 Barry




	




---

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