VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #1  
Old 11-19-2010, 11:30 AM
donphenry donphenry is offline
 
Join Date: Sep 2010
Location: Rochester, NY
Posts: 16
Default CG with fixed pitch

For some of you seasoned RV 4 flyers. I'm curious about the 4s handling characteristics with a passenger and a fixed pitch prop up front. CG handling, different engines, different fixed pitch props you get the idea. Thanks in advance.
Reply With Quote
  #2  
Old 11-19-2010, 12:38 PM
hempy.4 hempy.4 is offline
 
Join Date: Jan 2007
Location: Marion, Ohio
Posts: 87
Default I have......

been flying my RV4 w/0320 and Catto prop for 200hrs. I find that a passenger calms the beast and I actually think it handles better with someone back there. The reason I purchased my RV4 is because I was given a ride (and Im 195 lbs!) in my RV4 by one he_ _ of a pilot that happens to be a moderator of this site. I can tell you he put me through the FULL range of manuvers that demonstrated the capabilities of the RV4. I will never forget that day! I love my RV4, its the best hobby a guy can have!! PS, I have a 12 lb Landoll harmonic balancer up front to help with rear CG.
__________________
Skipper RV7
Reply With Quote
  #3  
Old 11-19-2010, 04:52 PM
smokyray's Avatar
smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,799
Default Simple math

Don,

1500 hours with a 0-320/FP wood prop. I used a Landoll balancer, Odessey Battery on firewall, forward baggage area where battery was. I set a max weight "aft of the roll bar" of 200lbs, period. The handling with weight aft is no worries, a little sensitive in pitch, no more.

That works out to be a small, cute girl and lots of baggage.

Smokey
HR2

Last edited by smokyray : 11-19-2010 at 04:56 PM.
Reply With Quote
  #4  
Old 11-28-2010, 09:47 PM
Dave Dollarhide Dave Dollarhide is offline
 
Join Date: Nov 2005
Posts: 57
Default CG and performance

Don,

Every airplane will balance out differently, but ideally, you'd want the empty CG to be at the forward limit, as fuel, people and baggage move it aft.

One of my flying buds built a 4 with a Hartzel CS prop and battery in the baggage compartment. He's running an O-360 and has an empty CG that's right on the forward limit.....good stuff!

My RV-4 has an O-360, with Sensenich fixed pitch metal prop and I have a gel cell battery in the foward center console. That should put the CG close to the foward limit, but with a lot of paint and a little extra metal in the rear fuselage, I have an empty CG that's about 4" aft of the fwd limit...not the best.

That said, I can still take a 200# passenger, but the elevator stick force becomes very light. If you fly with a CG aft of the limit, the elevator will have trouble trying to decide if it wants downforce or upforce.

The 4 is the most nimble two seat RV, but when you add a 200# passenger, the takeoff and climb performance really takes a hit. Also, with a rear seat passenger and associated aft CG, the airplane lands differently and even a slight sink rate at touch down when making a wheels landing will create the old tail dragger "jounce." This is even worse in an airplane like mine that already has an aft CG, so smooth is the word. Wheel landings are easiest with a big guy in the back. When solo, three point landings are pretty easy.

That said, I've put 1,000 hrs on the machine, including a lot of aggressive flying like acro/tailchase/dogfighting and back country flying. It's flown great and I've loved every minute, but I still wish I had more of a foward CG.
__________________
Dave Dollarhide
Dreamland Squadron
Haller Airpark, FL 7FL4
RV-4
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 02:54 PM.


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.