VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #11  
Old 06-25-2019, 02:03 PM
StickNRudder StickNRudder is offline
 
Join Date: Apr 2015
Location: Tustin, CA
Posts: 47
Default

Last night I was doing my BFR, my instructor was surprised at the glide ratio. On approach into KSNA, she ask if we could glide to the airport. I was 2.4 nm from the threshold at 1160 feet agl with a 7 knot headwind (just looked at the datalog). We made it with 10 feet to spare. That is a 11.9:1 glide ratio.

What a great plane! An RV-7 with a three-blade Catto fixed pitch prop. Best glide at mid weight is 80 KIAS.
__________________
Rick Woods
N5427W == Jack, Hank, Barbara, and Rick Woods.
RV-7
Flying, but not done, never done.
Reply With Quote
  #12  
Old 06-25-2019, 04:48 PM
scottmillhouse's Avatar
scottmillhouse scottmillhouse is offline
 
Join Date: Apr 2007
Location: Madison, AL
Posts: 314
Default

From my experience that glide ratio may be a little optimistic since the engine is running and probably putting out some thrust. When you shut down the engine and stop the prop it may not be as good. I did an engine and prop stopped on my 12 at best glide speed of 60 knots and got 10.3:1, less than the generally recognized ratio of 13:1. The 12 wing airfoil should be more efficient in glide than the 7.

Since I just finished a 7A I am interested in any real numbers. Reviews of others POH charts shows glide ranges of about 1 nm per 1000' for a ratio of 6.4-7.2:1 depending upon the prop position.
__________________
Scott- 2019 dues paid
New RV-7A N579RV, 24 hours still in phase I
Built RV-12, 328 hours-sold, purchased RV-12 sold, Built RV-9A, 536 hours-sold, Not completed RV-7 sold, Built Kitfox sold
Reply With Quote
  #13  
Old 06-25-2019, 05:13 PM
StickNRudder StickNRudder is offline
 
Join Date: Apr 2015
Location: Tustin, CA
Posts: 47
Default

Quote:
Originally Posted by scottmillhouse View Post
From my experience that glide ratio may be a little optimistic since the engine is running and probably putting out some thrust.
I just looked at the datalog. The engine was turning between 950 to 1050 rpm which is higher than my idle speed (about 700) so I assume the engine was being backdriven. So I would expect my drag to be higher than a stopped prop, but lower than a windmilling prop.
__________________
Rick Woods
N5427W == Jack, Hank, Barbara, and Rick Woods.
RV-7
Flying, but not done, never done.
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 11:34 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.