VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 09-12-2017, 04:21 PM
Tom Martin Tom Martin is online now
 
Join Date: Jan 2005
Location: Ontario, Canada
Posts: 1,297
Default RV14 V speeds

My final inspection is coming up and I need to get some airspeed numbers to enter into the Garmin system.

Specifically I need the top and bottom of the green and white arcs and the Vne of for the aircraft

Thanks in advance.
__________________
Tom Martin RV1 pilot 4.6hours!
CPL & IFR rated
EVO F1 Rocket 1000 hours,
2010 SARL Rocket 100 race, average speed of 238.6 knots/274.6mph
RV4, RV7, RV10, two HRIIs and five F1 Rockets
RV14 Tail dragger under construction #153

Fairlea Field
St.Thomas, Ontario Canada, CYQS
fairleafield@gmail.com
Reply With Quote
  #2  
Old 09-12-2017, 06:33 PM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 8,812
Thumbs up

Quote:
Originally Posted by Tom Martin View Post
My final inspection is coming up and I need to get some airspeed numbers to enter into the Garmin system.

Specifically I need the top and bottom of the green and white arcs and the Vne of for the aircraft

Thanks in advance.
Perhaps the manufacturer knows...

http://vansaircraft.com/pdf/letters/RV-14_V_speeds.pdf
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Reply With Quote
  #3  
Old 09-12-2017, 06:56 PM
RV8JD's Avatar
RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 480
Default

Quote:
Originally Posted by az_gila View Post
I see Van's still lists Vne in terms of True Airspeed (TAS) even for its latest model. I don't think it is enough for Van's to merely state that Vne is in TAS. Pilot's shouldn't have to think in terms of TAS while flying. I think that Van's should state their Vne (Redline) in terms of IAS (or CAS) as a function of altitude, up to the service ceiling of the airplane. Builders may even want to mark their airspeed indicators accordingly.

I know modern EFIS panels with an OAT sensor input can calculate and display TAS, but Van's (or any designer) should accommodate all levels of instrument sophistication.

I would like to see Van's incorporate that change in its future PAP (production acceptance procedure) for the RV-14/14A that it references in their V-Speeds link quoted above.

See this post for a little more discussion:

http://www.vansairforce.com/communit...5&postcount=69
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 210 Tach Hours
(Pic 1)
RV-8, 1932 Tach Hours
(Pic 1), (Pic 2), (Pic 3) - Sale Pending
Glasflügel H-201B Standard Libelle, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned
Reply With Quote
  #4  
Old 09-12-2017, 07:16 PM
Tom Martin Tom Martin is online now
 
Join Date: Jan 2005
Location: Ontario, Canada
Posts: 1,297
Default

Thanks Gil. I looked at the website and was not able to find it and called the help desk and got some of the numbers but your list is much better.
__________________
Tom Martin RV1 pilot 4.6hours!
CPL & IFR rated
EVO F1 Rocket 1000 hours,
2010 SARL Rocket 100 race, average speed of 238.6 knots/274.6mph
RV4, RV7, RV10, two HRIIs and five F1 Rockets
RV14 Tail dragger under construction #153

Fairlea Field
St.Thomas, Ontario Canada, CYQS
fairleafield@gmail.com
Reply With Quote
  #5  
Old 09-13-2017, 07:37 AM
grubbat's Avatar
grubbat grubbat is offline
 
Join Date: May 2012
Location: Ga
Posts: 497
Default TAS vs IAS

Carl,
Just wondering what altitude /temp I should use as a reference. Is there some sort of standard? I was thinking about 14,500ft as I usually never go higher even with O2 but my service sealing is 18,000+. I agree completely that we should be using IAS/CAS just like all the other certified manufactures do. Years ago, the speed range was the big selling point. Today, the RV reputation can stand on its own and it's time to put TAS to bed.

Quote:
Originally Posted by RV8JD View Post
I see Van's still lists Vne in terms of True Airspeed (TAS) even for its latest model. I don't think it is enough for Van's to merely state that Vne is in TAS. Pilot's shouldn't have to think in terms of TAS while flying. I think that Van's should state their Vne (Redline) in terms of IAS (or CAS) as a function of altitude, up to the service ceiling of the airplane. Builders may even want to mark their airspeed indicators accordingly.

I know modern EFIS panels with an OAT sensor input can calculate and display TAS, but Van's (or any designer) should accommodate all levels of instrument sophistication.

I would like to see Van's incorporate that change in its future PAP (production acceptance procedure) for the RV-14/14A that it references in their V-Speeds link quoted above.

See this post for a little more discussion:

http://www.vansairforce.com/communit...5&postcount=69
__________________
Craig

RV-3 Sold
RV-6a Sold
RV-9 Built & Flying
Twin Comanche Flying
RV-10 Thinking about it...
Reply With Quote
  #6  
Old 09-13-2017, 06:39 PM
RV8JD's Avatar
RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 480
Default

Quote:
Originally Posted by grubbat View Post
Carl,
Just wondering what altitude /temp I should use as a reference. Is there some sort of standard? I was thinking about 14,500ft as I usually never go higher even with O2 but my service sealing is 18,000+. I agree completely that we should be using IAS/CAS just like all the other certified manufactures do. Years ago, the speed range was the big selling point. Today, the RV reputation can stand on its own and it's time to put TAS to bed.
Craig,

Since Van's now says that Vne is stated as True Airspeed (TAS), it is just the conversion of Vne in TAS at each altitude to Calibrated Airspeed (CAS).

I see you have an RV-9, which has a Vne of 210 MPH TAS. So the table below shows Vne's at several altitudes in terms of MPH IAS. (Note that I have not considered any instrument or position error, therefore Indicated Airspeed equals Calibrated Airspeed. And it uses the Standard Atmosphere.)



I hope that answers your question.

(Note to Van's Aircraft: The chart below on your website needs to be updated to reflect your change that Vne is no longer stated as Indicated Airspeed, but as True Airspeed instead.
https://www.vansaircraft.com/pdf/speeds.pdf )
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 210 Tach Hours
(Pic 1)
RV-8, 1932 Tach Hours
(Pic 1), (Pic 2), (Pic 3) - Sale Pending
Glasflügel H-201B Standard Libelle, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 11-08-2017 at 05:43 PM. Reason: Added table for Vne = 230 MPH TAS
Reply With Quote
  #7  
Old 09-13-2017, 06:44 PM
grubbat's Avatar
grubbat grubbat is offline
 
Join Date: May 2012
Location: Ga
Posts: 497
Default Cessna Piper

I used 160 on the EFIS as a starting point. Thanks.
I wonder what PIper or Cessna uses for altitude to determine Vne? I'm assuming they use the service ceiling altitude to determine IAS/CAS for Vne. Any ideas?


Quote:
Originally Posted by RV8JD View Post
Craig,

Since Van's now says that Vne is stated as True Airspeed, it is just the conversion of Vne in TAS at each altitude to Calibrated Airspeed (CAS).

I see you have an RV-9, which has a Vne of 210 MPH TAS. So here are the Vne's at several altitudes in terms of MPH IAS. (Note that I have not considered any instrument or position error, therefore Indicated Airspeed equals Calibrated Airspeed. And it uses the Standard Atmosphere.)



I hope that answers your question.
__________________
Craig

RV-3 Sold
RV-6a Sold
RV-9 Built & Flying
Twin Comanche Flying
RV-10 Thinking about it...
Reply With Quote
  #8  
Old 09-13-2017, 10:03 PM
RV8JD's Avatar
RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 480
Default

Quote:
Originally Posted by grubbat View Post
I wonder what PIper or Cessna uses for altitude to determine Vne? I'm assuming they use the service ceiling altitude to determine IAS/CAS for Vne. Any ideas?
As an example, I looked up the FAA Type Certificate Data Sheet (TCDS) for the Cessna 300/400 series (derived from the Columbia 300/400). For one version it lists a "Maximum Operating Altitude" of 14,000 ft w/o an oxygen system installed, and 18,000 ft with an oxygen system installed.

It states that Vne is 235 KCAS (232 KIAS) and that Vne decreases by 5 KIAS for each 1000 feet above 12,000 feet (pressure altitude).

Interestingly, it also states that Vno (Max Structural Cruising Speed) is 180 KCAS (178 KIAS) and decreases by 4 KIAS for each 1000 feet above 12,000 feet (pressure altitude).
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 210 Tach Hours
(Pic 1)
RV-8, 1932 Tach Hours
(Pic 1), (Pic 2), (Pic 3) - Sale Pending
Glasflügel H-201B Standard Libelle, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 09-13-2017 at 10:14 PM.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 06:44 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.