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Pitot tube?

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alfolavf(at)online.no
Guest

Posted: Mon Jan 30, 2006 10:09 pm Post subject: Pitot tube?

 	  Quote: 	
		   Hi fellow RV-7 Builders!

 

 I live in Norway and am almost finished with the empennage of my RV-7A.

 I'm just about ready to start with my QB-wings and considering different types of pitot tubes.

 Since it's cold up here, I've to have a heated one.

 

 Is it a type or brand which most Rv-builders use the most?

 

 Best regards Alf Olav Frog

aurbo(at)ak.net
Guest

Posted: Mon Jan 30, 2006 10:37 pm Post subject: Pitot tube?

Alf,



I live in Alaska and it is cold here, -10 today, you do not have to have a 

heated pitot tube. The ones from Van's work just fine.



Mike Ice

Anchorage, Alaska



---

Skykingjfg(at)aol.com
Guest

Posted: Tue Jan 31, 2006 3:54 am Post subject: Pitot tube?

You won't need one unless you plan to fly IFR in the clouds. However, if you decide you want one the cheapest I've found is either Falcon or Dynon. Also Gretz is offering a new model at a reasonable price.

dan(at)rvproject.com
Guest

Posted: Tue Jan 31, 2006 6:14 am Post subject: Pitot tube?

There's no requirement for a heated pitot tube, even for IFR.  It's  simply not required under Part 91.

  

 23.1323 requires a heated pitot tube: "(d) If  certification for instrument flight rules or flight in icing  conditions is requested, each airspeed system must have a heated pitot  tube or an equivalent means of preventing malfunction due to  icing."

  

 However, our airplanes are not required to conform to Part 23.  Plus,  the way the modern operating limitations are structured, we don't have to  request specific "certification" under IFR.  The operating  limitations simply specify that we need to conform to 91.205:

  

  

"(  After  completion of phase I flight testing, unless appropriately equipped for night  and/or instrument flight in accordance with § 91.205, this aircraft is to be  operated under VFR, day only."

  

 That said, you'd be remiss to do any real IFR flying anywhere near the  freezing level without one.  I have warm (hot?) fuzzies as a result of  having one, but I want to clarify that it's not a hard and fast requirement for  amateur built aircraft in the U.S.

  

 )_( Dan

 RV-7 N714D (802 hours)

 http://www.rvproject.com

 [quote]   ---

slipstream13(at)earthlink
Guest

Posted: Tue Jan 31, 2006 9:43 am Post subject: Pitot tube?

Dynon's pitot tube remains unheated.  For several years they worked on a heated version, but apparently they've finally given up on the project -- Last word I heard is that they have no plans to bring a heated tube to market.

  

 Brooks

 N513BW -- Waiting for warmer temps to cut my canopy!

  

 [i]----

frank.hinde(at)hp.com
Guest

Posted: Tue Jan 31, 2006 10:13 am Post subject: Pitot tube?

Bummer!...Oh well at  least there is no point in waiting.

  

 As to the canopy I  PERSONALLY would just cut it....Use a local fan heater to warm the underside for  a few minutes but other than that if you don't want to wait just do it...I have  cut it quite sucessfully in as low as 40F no problem.

  

 Oh by the way, you can  also sand out scratches with wet and dry and polish it back clear with metal  polish pretty easily as well

  

 Frank



   From: owner-rv7-list-server(at)matronics.com  [mailto:owner-rv7-list-server(at)matronics.com] On Behalf Of Brooks  Wolfe

Sent: Tuesday, January 31, 2006 9:41 AM

To:  rv7-list(at)matronics.com

Subject: Re: Pitot  tube?

 

                   Dynon's pitot tube remains unheated.  For several years        they worked on a heated version, but apparently they've finally given up        on the project -- Last word I heard is that they have no plans        to bring a heated tube to market.

        

       Brooks

       N513BW -- Waiting for warmer temps to cut my canopy!

        

       [i]----

dhall(at)donka.net
Guest

Posted: Sun Feb 05, 2006 7:32 pm Post subject: Pitot tube?

While we're on the subject, I just installed my Gretz Aero Pitot Tube.  It's

pretty cool.  It comes with a sensor that only draws power when pitot heat

is really needed.  It has led indicators to let you know when the pitot is

cold or ok, and when it's actually heating.



Here's some pics:

http://donka.net/gallery/view_photo.php?set_albumName=rv7leftwing&id=DSC0542

0



I suppose this pitot tube is on the pricey side, but what the heck.  I will

fly IFR and this will make me feel better.  Around here, I know of other RV

builders that get old Cessna pitots on the cheap, and those melt ice just as

good.



******************************************

 Don Hall                  

 N517DG (registered)

 rv7 wings, fuse on the way!

 http:\\donka.net\rv7project.html

******************************************



--

skikrazi(at)centurytel.ne
Guest

Posted: Mon Feb 06, 2006 6:00 pm Post subject: Pitot tube?

I was thinking about installing a heated pitot tube when building my RV-7A,

but then I got to thinking.  If flying into conditions that would cause me

to need a heated pitot tube, I might also need de-ice boots on prop and

wings......so I said to myself, forget it.

Chuck Imken

200 hours on N735RV



Do not archive.



--

markc(at)conotech.com
Guest

Posted: Tue Feb 07, 2006 10:03 am Post subject: Pitot tube?

Imken wrote:



 	  Quote: 	
		  



I was thinking about installing a heated pitot tube when building my RV-7A,

but then I got to thinking.  If flying into conditions that would cause me

to need a heated pitot tube, I might also need de-ice boots on prop and

wings......so I said to myself, forget it.

Chuck Imken

200 hours on N735RV



  



  



My advice:  if you are expecting to do any flying in instrument 
	


conditions, get a heated pitot tube.  



-Mark Conover



RV9 (emp)



 	  Quote:

skikrazi(at)centurytel.ne
Guest

Posted: Tue Feb 07, 2006 7:53 pm Post subject: Pitot tube?

My advice:  if you are going to fly any RV in instrument conditions without

a heated pitot tube (I do all the time), do get a good weather forecast and

don't fly in anticipated icing conditions.  Having a heated pitot tube

without capability to shed ice from prop and airframe, the heated pitot tube

will merely give you the capability to know how fast you are going to hit

the ground.



Do not archive.



--

markc(at)conotech.com
Guest

Posted: Tue Feb 07, 2006 10:29 pm Post subject: Pitot tube?

(pardon while I briefly veer a bit off topic)



Say, Imken, do you fly in the US Southeast?   I'm curious about 

instrument flying in the various parts of North America.   Do you get 

much ice at lower altitudes?   While I flew VFR in Texas a lot, my 

experience with IMC has so far been restricted to the Pacific Northwest, 

having moved to Seattle ten years ago.   Our wx briefings routinely 

refer to some amount of ice in the forecast; so, we tend to have a keen 

interest in pireps.



(returning to topic)



As to whether to even bother with pitot heat if your airplane can't shed 

ice,  I figure the pitot tube will plug up before flying surfaces are 

affected.  If in IMC, I sure would prefer not to lose the airspeed 

indicator.    Perhaps in these days of GPS, losing the airspeed 

indicator when at altitude is not as dicey as it once was.



Imken wrote:



[quote]



My advice:  if you are going to fly any RV in instrument conditions without

a heated pitot tube (I do all the time), do get a good weather forecast and

don't fly in anticipated icing conditions.  Having a heated pitot tube

without capability to shed ice from prop and airframe, the heated pitot tube

will merely give you the capability to know how fast you are going to hit

the ground.



Do not archive.



--

highflight1(at)gmail.com
Guest

Posted: Wed Feb 08, 2006 3:30 am Post subject: Pitot tube?

Absolutely, Mark, and I was waiting for someone else to point this out. I didn't want to mention it myself because my IFR rating is in the future and I will be flying light IFR in my '7A so perhaps I'm not considered qualified to say this. And before the argument about "light" IFR gets started again, it simply means (to me) a personal requirement for much higher minimums and a mental attitude that more quickly allows a cancellation or diversion from flight plan. 

 But I don't get the fascination with a heated pitot tube in an RV if one is going to have an IFR GPS on board. At altitude, if you lose your pitot intput from ice, your GPS will be plenty accurate to keep you safe. I'd worry more about ice on wings and prop and get myself out of there as quickly as possible. If you're blind and at altitude and neither you nor your FAA weather helpers can find some clear air for you to head for, then as far as I'm concerned, that's a flight you should have made in a fully booted aircraft anyway. 

 For landing, using GPS airspeed and your usual power and flap settings for putting the wheels on the runway will get you down albeit a little fast if you want to be on the safe side. If you get to 100 feet off the ground on approach and can't see the ground during your actual landing, you got a lot more problems than an AWOL pitot tube. 

  

 Vern



 

 On 2/8/06, Mark Conover <markc(at)conotech.com (markc(at)conotech.com)> wrote:  	  Quote: 	
		  --> RV7-List message posted by: Mark Conover <markc(at)conotech.com  (markc(at)conotech.com)>



(pardon while I briefly veer a bit off topic)



Say, Imken, do you fly in the US Southeast?   I'm curious about

instrument flying in the various parts of North America.   Do you get

much ice at lower altitudes?   While I flew VFR in Texas a lot, my 

experience with IMC has so far been restricted to the Pacific Northwest,

having moved to Seattle ten years ago.   Our wx briefings routinely

refer to some amount of ice in the forecast; so, we tend to have a keen 

interest in pireps.



(returning to topic)



As to whether to even bother with pitot heat if your airplane can't shed

ice,  I figure the pitot tube will plug up before flying surfaces are

affected.  If in IMC, I sure would prefer not to lose the airspeed 

indicator.    Perhaps in these days of GPS, losing the airspeed

indicator when at altitude is not as dicey as it once was.

dwight(at)openweave.org
Guest

Posted: Wed Feb 08, 2006 6:00 am Post subject: Pitot tube?

On Wed Feb  8 01:23:34 2006, Mark Conover wrote :

 	  Quote: 	
		  [ ... snip ... ]

As to whether to even bother with pitot heat if your airplane can't shed 

ice,  I figure the pitot tube will plug up before flying surfaces are 

affected.  If in IMC, I sure would prefer not to lose the airspeed 

indicator.    Perhaps in these days of GPS, losing the airspeed 

indicator when at altitude is not as dicey as it once was.


	


Just my $0.02 worth ... I agree that a pitot will ice up before the flying

surfaces do, and I do NOT want to be in IMC with no airspeed. Your thought

about a GPS replacing the pitot/AS is interesting ... but I'm not sure it 

is valid.



If you have ever had to practice using needle/ball/airspeed for recovery

from an unusual attitude you'll remember how critical that AS is to getting

the plane back under control. I am not sure it would be possible with the

-lag- you get from the GPS. I fear that lag might cause repeated overshoot

of the horizon and make the situation unsavable.



Furthermore, the GPS shows groundspeed and NOT airspeed, so it isn't measuring

the right thing anyway. That makes me feel the suggestions that you can use

GPS as an approach speed reference (remember, we are talking about a pitot

failing due to ice in IMC) are questionable to me. It would work if you knew

the winds and made the right adjustment .... but .... if you have a strong

head/tail wind the speeds on the GPS, without adjustment, are NOT going to

be right. If you are flying any non-precision approach I don't see how you

could possibly get (for instance) the missed approach point timed correctly

if time was the only way to identify the miss.



Obviously, if you are stuck with the GPS as the only speed reference then you

do what you can. Do remember what it is actually measuring before using the

numbers blindly though.



I'm putting in a heated pitot even if it costs me. I'm also putting in a

traditional ASI and altimeter, and will be using a TruTrak AP head as a

turn coordinator. This will be to back up a Dynon as I (being a software

engineer myself) don't yet trust the electronic goodies *totally*.



Again, this is just my $0.02 worth. Everyone has to assess their own level

of risk and how much of that risk they are willing to accept. Me ... I'm a

cautious pilot and it shows.



  -- Dwight (do not archive)

dan(at)rvproject.com
Guest

Posted: Wed Feb 08, 2006 7:18 am Post subject: Pitot tube?

At the risk of repeating myself, if you're flying with an EFIS, if the pitot 

ices over it may not just be airspeed that you lose.  You might lose 

reliable attitude indication as well (ouch!).  Find out if your EFIS is 

dependent on airspeed and what it will do if airspeed goes away.  If it will 

do bad things, then I would consider pitot heat even more valuable in that 

case than if you just have steam gauges.



)_( Dan

RV-7 N714D (812 hours)

http://www.rvproject.com



---

markc(at)conotech.com
Guest

Posted: Wed Feb 08, 2006 7:44 am Post subject: Pitot tube?

Dwight Frye wrote:



 	  Quote: 	
		  

Just my $0.02 worth ... I agree that a pitot will ice up before the flying

  



surfaces do, and I do NOT want to be in IMC with no airspeed. Your thought

about a GPS replacing the pitot/AS is interesting ... but I'm not sure it 

is valid.



If you have ever had to practice using needle/ball/airspeed for recovery

from an unusual attitude you'll remember how critical that AS is to getting

the plane back under control. I am not sure it would be possible with the

-lag- you get from the GPS. I fear that lag might cause repeated overshoot

of the horizon and make the situation unsavable.



Furthermore, the GPS shows groundspeed and NOT airspeed, so it isn't measuring

the right thing anyway. That makes me feel the suggestions that you can use

GPS as an approach speed reference (remember, we are talking about a pitot

failing due to ice in IMC) are questionable to me. It would work if you knew

the winds and made the right adjustment .... but .... if you have a strong

head/tail wind the speeds on the GPS, without adjustment, are NOT going to

be right. If you are flying any non-precision approach I don't see how you

could possibly get (for instance) the missed approach point timed correctly

if time was the only way to identify the miss.



Obviously, if you are stuck with the GPS as the only speed reference then you

do what you can. Do remember what it is actually measuring before using the

numbers blindly though.



I'm putting in a heated pitot even if it costs me. I'm also putting in a

traditional ASI and altimeter, and will be using a TruTrak AP head as a

turn coordinator. This will be to back up a Dynon as I (being a software

engineer myself) don't yet trust the electronic goodies *totally*.



Again, this is just my $0.02 worth. Everyone has to assess their own level

of risk and how much of that risk they are willing to accept. Me ... I'm a

cautious pilot and it shows.



  -- Dwight (do not archive)



  




	


Dwight, like you, I'll be installing a heated pitot tube.  The cost is 

certainly worth it to me. 



About ten years ago, I had a GPS failure exactly when I really needed it 

most.  I had stupidly flown into a bad storm -- an experience which 

provoked my getting an instrument rating.  As a new arrival to the 

Seattle area, I did not realize how very quickly autumn storms can move 

into this region.   Unlike the wide open spaces of my native Texas, it's 

easy to get stuck between the nasty storms moving in from Puget Sound 

and the Cascade mountain range.  



Also being a techno geek by trade (and general nature), I like pairing 

the latest gadgets that are now available at a pretty low cost (I can't 

believe how inexpensive is the TruTrak), with traditional steam gauges.



-Mark

skikrazi(at)centurytel.ne
Guest

Posted: Wed Feb 08, 2006 6:08 pm Post subject: Pitot tube?

I agree with Dan that losing reliable attitude indication can be an ouch.

If my 430 and Grand Rapids EFIS ever do go belly up, for backup I use

Control Vision's Anywhere Map, Anywhere Attitude, and Anywhere Weather and

know of one pilot who used it to get out of IMC when he had a complete power

failure.  The Control Vision stuff has about a two-hour separate battery.

Chuck

N735RV



--

brad20j(at)yahoo.com
Guest

Posted: Thu Feb 09, 2006 10:02 am Post subject: Pitot tube?

Remember that your airspeed is one of the most important instruments in unusual attitude recovery.  It's even more critical if you're iced up, since your stall speeds will go up by an undetermined amount, Vy and Vx will change too, as will your power required to stay level/climb/etc., so your normal power/attitude/configuration settings won't be very reliable.  Also, you certainly don't want to mess around too much with flaps if iced up, lest you tempt a tail stall.

   

  Re GPS as a substitute for airspeed, icing is most likely when you have vertical air currents.  Windy, turbulent days, when they're IMC, can have a bunch of fast accumulating ice.  These are the days in which ground speed is at its poorest as a substitute for airspeed.  In a Mooney, on a winter's day with strong mountain waves, I was cruising at an average of 160 KTAS, but having to "climb" and "descend" through the waves to maintain altitude.  The   ground  speed upwind varied from 120 kts to 70 kts.  When I turned around, I saw 235 kts ground speed in the rising air.  While I wouldn't have been up there had it been IMC due to the very high potential for icing that would have been present, there's no way that the GPS ground speed would have helped me get a feel for airspeed.

   

  If I'm going to be flying anywhere near potential icing, an airspeed indicator is not something I'd want to sacrifice.  This is even if you have an obvious out, like clear air below, because ATC in some parts of the country is often fairly inflexible in allowing you to change routes or altitudes, like in the northeast corridor.

   

  I presently fly an icing certified plane.  It's amazing how efficient sharp protrusions are at collecting ice.  The thermometer probe is an excellent ice catcher.  I would imagine that a cold pitot tube would be even better.

     

   >>      But I don't get the fascination with a heated pitot tube in an RV if one is

 	  Quote: 	
		  >      going to have an IFR GPS on board. At altitude, if you lose your pitot

>      intput from ice, your GPS will be plenty accurate to keep you safe. I'd

>      worry more about ice on wings and prop and get myself out of there as

  >>     quickly as possible. If you're blind and at altitude and neither you nor
	


 	  Quote: 	
		  >      your FAA weather helpers can find some clear air for you to head for, then

>      as far as I'm concerned, that's a flight you should have made in a fully

>      booted aircraft anyway.

>      For landing, using GPS airspeed and your usual power and flap settings  for

>      putting the wheels on the runway will get you down albeit a little fast if

>      you want to be on the safe side. If you get to 100 feet off the ground on

>      approach and can't see the ground during your actual landing, you got a lot

>      more problems than an AWOL pitot tube.


	


   



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