VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #41  
Old 07-22-2012, 11:37 AM
mike in phx mike in phx is offline
 
Join Date: Apr 2007
Location: phx
Posts: 61
Default Didnt answer !!!

You did not answer why all the "reference"
What is your obsession with my airplane and vne ????

This is for everybody DONT EXEDE VNE
You only have one chance to get there !!!!

Yes we are getting closer all the time
My personal vne is reached and i have .020 skins on my tail instead of .016
Instead of l shape stiffners they are z shape
One piece wing skins and speedbrakes
These top speeds are only performed in calm wheater
And please there are for sure some one out there like chiefpilot here
Thats going to pick it all apart.
If you dont feel comfortble dont go there
Im for sure not going to slap my stick at these speeds.
Use your head and common sense we are not supermen if we where we didnt need doug reeves and his vaf ( no offense doug )
__________________
Mike Poulsen
Phoenix
RV 6 TURBO
N 694 MP
Reply With Quote
  #42  
Old 07-23-2012, 12:04 PM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
Default

Quote:
Originally Posted by mike in phx View Post
You did not answer why all the "reference"
What is your obsession with my airplane and vne ????
Check your PMs.
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
Reply With Quote
  #43  
Old 08-18-2014, 09:36 PM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,692
Default

Quote:
Originally Posted by Jetj01 View Post
In short, if you cruise your RV type aircraft at cross country altitiudes- 10,500 Westbound and 9,500 Eastbound is gnereally where I am, and fly 'full throttle' at those altitudes, generally around 20 in MP, if you lower the nose, you WILL exceed VNE TAS, unless you significantly decrease power setting. It is just a fact.
I ran into this last week and was looking for a place to post it. Found this thread via search. I was at 11.5K and decided to descend at about 700 fpm to get under an approaching cloud deck. The IAS inched up as the nose went down but what I did not expect was the redline (autocalculated for TAS by the GRT display) dropping far enough to nearly engulf the entire yellow part of the ASI tape. Redline was hovering at just over 170Kts indicated and I was already doing it. . Pulled some power back.

Thanks to GRT and other EFIS makers for displaying this data. Without it I would have gone way over TAS redline.
__________________
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 850 hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.
Yeah. The boss got a Silhouette Cameo 4 Xmas 2019.
Reply With Quote
  #44  
Old 08-19-2014, 06:50 PM
donaziza's Avatar
donaziza donaziza is offline
 
Join Date: Jun 2007
Location: Atlanta
Posts: 745
Default

I'm very embarrassed to admit this, but years ago when I first got my RV 8, and was just learning how to fly it, I didn't realize just how slippery it was. I was in a descent, checked my airspeed and was shocked to see the airspeed needle up against the peg. The peg was at 240 KTS, so I have no idea how fast I was really going. I chopped the power and gradually-y-y-y-y pulled the nose up. The airplane turned out to be fine. I only admit this and print it, so that some other soul doesn't make the same mistake I made. It's very very easy to go over VNE in a descent in an RV 8 if you don't pay close attention.

( OK everyone out there, make fun of me, I'm ready)
Reply With Quote
  #45  
Old 08-29-2014, 04:59 AM
rmartingt's Avatar
rmartingt rmartingt is offline
 
Join Date: Nov 2006
Location: Savannah, GA
Posts: 1,029
Default

Quote:
Originally Posted by donaziza View Post
I'm very embarrassed to admit this, but years ago when I first got my RV 8, and was just learning how to fly it, I didn't realize just how slippery it was. I was in a descent, checked my airspeed and was shocked to see the airspeed needle up against the peg. The peg was at 240 KTS, so I have no idea how fast I was really going. I chopped the power and gradually-y-y-y-y pulled the nose up. The airplane turned out to be fine. I only admit this and print it, so that some other soul doesn't make the same mistake I made. It's very very easy to go over VNE in a descent in an RV 8 if you don't pay close attention.

( OK everyone out there, make fun of me, I'm ready)
Not going to make fun of you because I did almost the same thing in a -6
We were up high (10,000ft or so) and it was a typical hazy summer afternoon around Atlanta--hazy enough that the horizon wasn't distinct and you couldn't really see the ground over the nose, or really at all unless you looked mostly downwards. I'm sure you're familiar with those. Anyway, both of us got distracted for a minute looking at the GPS or something, and eventually noticed that the wind noise was getting really loud. Turns out we were about 30mph past redline and accelerating, in a diving turn. Same recovery--cut power, wings level, graduall pull-up. Several lessons were learned.
__________________
RV-7ER - finishing kit and systems installation
There are two kinds of fool in the world. The first says "this is old, and therefore good"; the second says "this is new, and therefore better".
Reply With Quote
  #46  
Old 08-29-2014, 02:56 PM
Jerry Cochran's Avatar
Jerry Cochran Jerry Cochran is offline
 
Join Date: Jan 2005
Location: Sherwood, Oregon
Posts: 981
Default Lower the nose?

I was taught to pull the power back for descent rather than "lowering the nose". Trim it for the speed you want and no worries about VNE.

Didn't read the entire thread so maybe someone pointed this out.

Would some who use either method please weigh in?

Jerry
Reply With Quote
  #47  
Old 08-29-2014, 04:02 PM
Marc Bourget Marc Bourget is offline
 
Join Date: Apr 2009
Location: Stockton, California
Posts: 296
Default

I've read most of the posts of this thread and have been impressed. I guess it may come with ##s, but you got some smart, experienced people on this board.

One thing I didn't see is a few minor points in Vd testing.

First, Vne is a load choice made by the designer. You run the tests to Vd to verify Vne.

Second, and first significant point, is that only one "mode" is tested at a time. Flutter being an aeroelastic phenomena, causes trouble when things start vibrating in sync (laypersons term) Testing one impulse (stick left; stick back, kick right rudder pedal, ect, one at a time) may catch someone by surprise some day when they're making a descending left turn and have to reverse to the right, all of a sudden.

Third, on test procedure. nose up trim is good, but a better technique, explained to me by John Thorp is to dive to speed "x", put the bird in a shallow climb and when it slows to "X-5mph" then do your impulse. This way, the bird is already slowing down, rather than waiting the approx 1.5 seconds (3/4 for perception and 3/4 sec for reaction) needed to release the control, then the wait for the trim to take effect. If you start low enough (and you should start below Va) you have always flown the bird at the next test speed - until you're "done" that is.

Caca can happen really quick and you want to give yourself all the chances available to stay out of the deep stuff :^)

Onward and upward.

mjb
Reply With Quote
  #48  
Old 08-29-2014, 05:39 PM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,692
Default

Quote:
Originally Posted by Jerry Cochran View Post
I was taught to pull the power back for descent rather than "lowering the nose". Trim it for the speed you want and no worries about VNE.
The woes of flying with a fixed pitched prop.
__________________
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 850 hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.
Yeah. The boss got a Silhouette Cameo 4 Xmas 2019.
Reply With Quote
  #49  
Old 08-30-2014, 11:09 AM
David Z David Z is offline
 
Join Date: Aug 2010
Location: Thunder Bay Ontario
Posts: 335
Default

Quote:
Originally Posted by Jerry Cochran View Post
I was taught to pull the power back for descent rather than "lowering the nose". Trim it for the speed you want and no worries about VNE.

Didn't read the entire thread so maybe someone pointed this out.

Would some who use either method please weigh in?

Jerry
In the plane I fly during my day job, we just push the nose down to get the required descent rate. The airspeed jumps initially because of the descent, then will slowly climb more as the engines start to make more power during the descent. Once we get close to the barber pole, then we start to bring the power back to maintain the airspeed and descent rate. In that airplane, the power typically stays at cruise until about 15,000 before power reductions are required.
All we are doing is using power to control airspeed and descent rate make the airplane do what we want.

Unfortunately RVs typically do not have a barber pole easily displaying the IAS limit at altitude, but it would be easy to placard the IAS-TAS limits beside the airspeed indicator.
I imagine you could use the same descent style in an RV. Lower the nose until the aircraft reaches the TAS Vne-5, then reducing power as required to maintain the vertical speed.
__________________
RV-8
Empennage Passed Pre-close Inspection
Wings mostly done
Fuselage is "in the mail"
83126
Dash 8 day job is financing the RV-8
Donation till September 2021
Reply With Quote
  #50  
Old 08-30-2014, 11:56 AM
SHIPCHIEF SHIPCHIEF is offline
 
Join Date: Mar 2008
Location: Seattle
Posts: 1,412
Default

"The woes of flying with a fixed pitched prop."
Bill;
I fly a fixed pitch prop and a manifold pressure gauge. Initially I was skeptical, but it turns out that Propeller RPM remains nearly unchanged at high speed decent with an inch or three reduction in manifold pressure.
Yet the power delivered and the thrust reduce as desired.
For determining power, I fly RPM in the pattern, and combination RPM/Manifold pressure in transitional flight, but at cruise, I mostly watch the Manifold pressure.
__________________
Scott Emery
http://gallery.eaa326.org/v/members/semery/
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)
2019
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 06:17 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.