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Loop problem

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Charles Heathco

Joined: 10 Jan 2006
Posts: 201

Posted: Mon Aug 31, 2009 4:19 am Post subject: Loop problem

Late yesterday I finally got up courage to try a  loop in my 6a, stalledout just as was starting back down. Recovered strait down,  no problem. I wasn expecting that as I had succesfully looped cherokee 140's  several time back in 68. I entered from a shallow dive at about 170 mph. Only  thing I can think of was I didnt make it tight enuff. I remmbered B F Billy  demoing one with me in a 6a, and was very quick and high G. Is that the  key? Charlie H 

   [quote][b]

panamared505(at)brier.net
Guest

Posted: Mon Aug 31, 2009 5:56 am Post subject: Loop problem

Loop  entry is not so much about speed as it is about Gs, I pull 3.5 to 4Gs at entry,  going over the top I transition to 0Gs, float over the top to get a round loop  and then at the 270 degree of loop back to 3.5-4Gs for pull out.  140 KTS is a good entry speed for my  RV6, but I have done them as slow as 125 KTS.<?xml:namespace prefix = o ns =  "urn:schemas-microsoft-com:office:office" /> 

Doing  acro in an RV, a necessary instrument is the G meter.  It is real easy to exceed the 6 G limit  on the downside of many maneuvers, control the speed with the G, control the G  with speed.  Avoid VNE at 6+Gs, no  good way out. 

 

Bob

 [quote]    

   Late yesterday I finally got up courage to try a    loop in my 6a, stalledout just as was starting back down. Recovered strait    down, no problem. I wasn expecting that as I had succesfully looped cherokee    140's several time back in 68. I entered from a shallow dive at about 170 mph.    Only thing I can think of was I didnt make it tight enuff. I remmbered B F    Billy demoing one with me in a 6a, and was very quick and high G. Is that    the key? Charlie H 

[b]

pitts_pilot(at)bellsouth.
Guest

Posted: Mon Aug 31, 2009 6:42 am Post subject: Loop problem

I have no experience in looping a 6A, so I may be blowing smoke here. 

There's a band of airspeed/G's that will get you a good loop.  The entry 

speed needs to be high enough to have the kinetic energy to get you over 

the top with a little extra airspeed than you just had, but pulling more 

Gs also scrubs off that kinetic energy.  There's a fine balance there 

that you may get from another aerobatically inclined pilot, or just keep 

at it on your own.  My only suggestion when you're breaking new ground 

in the flight envelope is to do it high .... very high ...... and, of 

course, wear a 'chute.  Better to carry one and not need it than need it 

and not have it.

Linn



charlie heathco wrote:

 	  Quote: 	
		   Late yesterday I finally got up courage to try a loop in my 6a, 

 stalledout just as was starting back down. Recovered strait down, no 

 problem. I wasn expecting that as I had succesfully looped cherokee 

 140's several time back in 68. I entered from a shallow dive at about 

 170 mph. Only thing I can think of was I didnt make it tight enuff. I 

 remmbered B F Billy demoing one with me in a 6a, and was very quick and 

 high G. Is that the key? Charlie H

wdleonard(at)gmail.com
Guest

Posted: Mon Aug 31, 2009 7:56 am Post subject: Loop problem

I agree with Bob except that it it pretty easy to keep it to 3 to 3.5 G's.  Going to zero G's over the top is a nice touch, but not really necessary as no one is usually watching anyway.  But you do need to ease the pull over the top as your airspeed will be very low.  Either way, remember to NOT be at low G's as you come down the back side or speed and G's will build up quickly as you go through the bottom. (i.e. keep the pull going as you come down the back side). 

 

I use an entry of anything more than 140 KTS with full power, straight into a 3 G pull easing to less than 1 G over the top, then throttle to idle and build back to 3 G's out the bottom.  Dont forget to add rudder on the way up.

 

If you are going to do them with a passenger get good at the low G technique first, because you will most likely be over the aerobatic weight limit.



There is no substitute for instruction, but it is really fun to perfect these on you own.

 

Dave Leonard



On Mon, Aug 31, 2009 at 7:03 AM, Panama Red <panamared505(at)brier.net (panamared505(at)brier.net)> wrote:

 	  Quote: 	
		           

Loop  entry is not so much about speed as it is about Gs, I pull 3.5 to 4Gs at entry,  going over the top I transition to 0Gs, float over the top to get a round loop  and then at the 270 degree of loop back to 3.5-4Gs for pull out.  140 KTS is a good entry speed for my  RV6, but I have done them as slow as 125 KTS. 

Doing  acro in an RV, a necessary instrument is the G meter.  It is real easy to exceed the 6 G limit  on the downside of many maneuvers, control the speed with the G, control the G  with speed.  Avoid VNE at 6+Gs, no  good way out. 

 

Bob



  	  Quote: 	
		      

   Late yesterday I finally got up courage to try a    loop in my 6a, stalledout just as was starting back down. Recovered strait    down, no problem. I wasn expecting that as I had succesfully looped cherokee    140's several time back in 68. I entered from a shallow dive at about 170 mph.    Only thing I can think of was I didnt make it tight enuff. I remmbered B F    Billy demoing one with me in a 6a, and was very quick and high G. Is that    the key? Charlie H 





t="_blank">http://www.matronics.com/Navigator?RV-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


	


-- 

David Leonard



Turbo Rotary RV-6 N4VY

http://N4VY.RotaryRoster.net

http://RotaryRoster.net

   [quote][b]

johnd(at)wlcwyo.com
Guest

Posted: Mon Aug 31, 2009 8:30 am Post subject: Loop problem

Get a G meter before trying any Acro.  

3.5 to 4 G’s on entry is good with an entry speed of 160 or 170mph.  

I float over the top with 0G’s and pull 3 to 3.5 G’s coming out on the bottom end.  

Usually the problem is that your worried about pulling to many G’s on entry. This is why you need a G meter. And your again worried about the g’s on the pull out.  

         

  

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of charlie heathco

 Sent: Monday, August 31, 2009 6:19 AM

 To: rv-list

 Subject: Loop problem  

  

     

Late yesterday I finally got up courage to try a loop in my 6a, stalledout just as was starting back down. Recovered strait down, no problem. I wasn expecting that as I had succesfully looped cherokee 140's several time back in 68. I entered from a shallow dive at about 170 mph. Only thing I can think of was I didnt make it tight enuff. I remmbered B F Billy demoing one with me in a 6a, and was very quick and high G. Is that the key? Charlie H   

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      [quote][b]

sbuc(at)hiwaay.net
Guest

Posted: Mon Aug 31, 2009 9:26 am Post subject: Loop problem

Linn Walters wrote:

 	  Quote: 	
		   

<snip>
	


   My only suggestion when you're breaking new ground

 	  Quote: 	
		   in the flight envelope is to do it high .... very high ...... and, of 

 course, wear a 'chute.  Better to carry one and not need it than need it 

 and not have it.

 Linn


	




Very unlikely you would ever be able to get out of the RV-6A........ 



Sam Buchanan

rv8a2001(at)yahoo.com
Guest

Posted: Mon Aug 31, 2009 11:19 am Post subject: Loop problem

From what I have read tells me you are not familiar with performing aerobatics and I dont mean that as a put down. Get some basic training it will be the best money spent.



Scott

 RV-8a



--- On Mon, 8/31/09, Linn Walters <pitts_pilot(at)bellsouth.net> wrote:



  	  Quote: 	
		  

From: Linn Walters <pitts_pilot(at)bellsouth.net>

Subject: Re: Loop problem

To: rv-list(at)matronics.com

Date: Monday, August 31, 2009, 7:37 AM



 --> RV-List message posted by: Linn Walters <pitts_pilot(at)bellsouth.net (pitts_pilot(at)bellsouth.net)>



I have no experience in looping a 6A, so I may be blowing smoke here. There's a band of airspeed/G's that will get you a good loop.  The entry speed needs to be high enough to have the kinetic energy to get you over the top with a little extra airspeed than you just had, but pulling more Gs also scrubs off that kinetic energy.  There's a fine balance there that you may get from another aerobatically inclined pilot, or just keep at it on your own.  My only suggestion when you're breaking new ground in the flight envelope is to do it high .... very high ...... and, of course, wear a 'chute.  Better to carry one and not need it than need it and not have it.

Linn



charlie heathco  wrote:

 	  Quote: 	
		   Late yesterday I finally got up courage to try a loop in my 6a, stalledout just as was starting back down. Recovered strait down, no problem. I wasn expecting that as I had succesfully looped cherokee 140's several time back in 68. I entered from a shallow dive at about 170 mph. Only thing I can think of was I didnt make it tight enuff. I remmbered B F Billy demoing one with me in a 6a, and was very quick and high G. Is that the kbsp;  --> http://foru             - List Contribution We                     &nbs;--> 


	


	


         [quote][b]

sbuc(at)hiwaay.net
Guest

Posted: Mon Aug 31, 2009 12:55 pm Post subject: Loop problem

<am sending this post to the list since Linn's private address bounced>

Linn Walters wrote:

 > Sam Buchanan wrote:

 >> 

 >>

 >> Linn Walters wrote:

 >>> 

 >> <snip>

 >>   My only suggestion when you're breaking new ground

 >>> in the flight envelope is to do it high .... very high ...... and, 

of course, wear a 'chute.  Better to carry one and not need it than need 

it and not have it.

 >>> Linn

 >>

 >>

 >> Very unlikely you would ever be able to get out of the RV-6A........ 

 > Why is that?  Inquiring minds want to know!

 > Linn

Linn,

There are two canopy designs on the side-by-side RVs:

tip up; Originally designed with a quick release mechanism that *may* 

have worked properly when the canopies were built without hydraulic 

assist (guess in an emergency you wouldn't worry about whether or not it 

would take off your head or the vertical stab as it departed the 

plane....). But since mid-90's, the hydraulic struts have been shipped 

with finish kits and would almost certainly prevent the canopy from 

detaching as designed.

slider; can be opened in flight, however.......

The airloads on both designs make it nearly impossible to get either 

canopy open more than a few inches in flight. The tip up can be pushed 

up with difficulty maybe 6-12", the slider can be pushed back less than 

12". In either case a pilot would find it practically impossible to exit 

the aircraft. If a builder was serious about aerobatics quick-release 

pins might be incorporated into the slider installation. Some have done 

this with the RV-8.

As far as I know, there are *no* documented cases of someone bailing out 

of a side-by-side RV with either canopy. Matter of fact, there are no 

documented cases of anyone even attempting to jettison the tip up canopy.

A parachute in a RV-6/6A might make you feel safer until you actually 

needed to use it.  

Sam Buchanan

panamared505(at)brier.net
Guest

Posted: Mon Aug 31, 2009 12:56 pm Post subject: Loop problem

 	  Quote: 	
		   Very unlikely you would ever be able to get out of the RV-6A........ 



 Sam Buchanan


	


I have often thought this about  my RV6.  Opening the canopy in normal 

flight beyond about 2 inches is next to impossible.  I mentioned this to a 

retired USAF F-4 Driver and his response was "It depends upon how motivated 

you are!"



But the caution about having plenty of altitude is good.  It will give you 

more time to try and regain control even if you don't think you can bail 

out.  The IAC requires parachutes in competiton, so I use one regardless of 

what I think its usefullness might be.  And who knows, if I loose control in 

an inverted flat spin and can't regain control, maybe I will be able to open 

the canopy.



Bob

RV6 "Wicked Witch of the West"

bmeyette

Joined: 14 Mar 2007
Posts: 72
Location: Cornish, NH

Posted: Mon Aug 31, 2009 4:17 pm Post subject: Loop problem

For that reason and because my tipup quick release bar was in the way of my

avionics, I used AN bolts instead of the sliding pins to hold my canopy

hinges.

Brian

--

_________________
Brian Meyette, Cornish, NH

RV-7A QB tipup, supercharged Subaru STi engine, MT CS prop, all glass day/night/IFR panel, being built with solar and wind power

N432MM

http://brian76.mystarband.net/RV-7Ahome.htm

Charles Heathco

Joined: 10 Jan 2006
Posts: 201

Posted: Tue Sep 01, 2009 3:43 am Post subject: Loop problem

Yes Sam I agree, Parachute would note be of any use. When I first got my 6a 

I forgot to t latch the canopy a few times and had to pull full flaps and 

slw to near stall to be able to move the canopy enuf to latch. I had always 

thought that it could not be opened if ypou had to try to et out in flight.

---

camdaddy

Joined: 19 Sep 2009
Posts: 3

Posted: Sat Sep 19, 2009 4:41 am Post subject: Re: Loop problem

Hey, Charlie.  I wonder how your loops have been progressing? 



When I got my first acro training in an Extra 300L, the military instructors drilled into me to get a feel in my butt for 3 and 4 Gs.  In a couple days I knew what they meant and could sense when I was loading the plane to those levels.



In my RV that feeling was a little different and I had to re-learn what 3Gs and 4Gs felt like.  Now, that along with a sense for the elapsed time I'm taking to get to the top lets me know how the loop will look.



I also placed a piece of pinstripe tape on the inside of my canopy at eye level on my left to act as my horizon marker.  It's not as good as a wingtip sighting device, but it's a good low-tech solution that's better than nothing.  Once I lose sight of the horizon up front, I turn my head left to watch my wing.  The tape will tell me when I'm nearing the top and it's time to look "up"  and unload the plane.



One other thing I did that helped me... I did a bunch of Split- Ss.  I would slow the plane to just above stall speed, roll it over, and pull a Split-S.  This gave me a good feel for how my loops would finish.



-Cam

Charles Heathco

Joined: 10 Jan 2006
Posts: 201

Posted: Sat Sep 19, 2009 5:47 pm Post subject: Loop problem

Thanks for the pointers Cam. It has been raining here most every day past 2 

wks, havent been up. Im suprised to hear that the plane will roll going that 

slow, would seem like could easily slip into a spin. Charlie

---

camdaddy

Joined: 19 Sep 2009
Posts: 3

Posted: Sat Sep 19, 2009 6:47 pm Post subject: Re: Loop problem

It will roll over just fine.  It's slow... kinda wallows over, but not bad.  Don't let it get too slow and it CAN'T spin b/c for a spin to happen it needs yaw to couple with the stall.  Keep the bubble centered and the plane unloaded (stick-wise, I mean, not cargo-wise)... you'll be fine.



In fact, I have to really work to get my -4 to spin.  It will do it, but I have to hold pro-spin inputs for awhile.  Once it spins and I am done, I give the PARE recovery inputs and it pops right out without hesitation.  Even with a back seat passenger.  The side-by-side RVs I've flown seem to want to spin easier than the -4s I've flown.  But I wouldn't be concerned about them being "stubborn" in the spin.  



But do only what you're comfortable with and listen to that all-important "little voice".  ...and keep me posted.

Charles Heathco

Joined: 10 Jan 2006
Posts: 201

Posted: Sat Sep 19, 2009 7:48 pm Post subject: Loop problem

Ok, I am itchi8ng to get up, maybe a window some time tomorrow

---

dale1rv6(at)comcast.net
Guest

Posted: Sun Sep 20, 2009 2:12 am Post subject: Loop problem

I would suggest at least a starting altitude of 4,000 AGL for your

introductory split S. 5,000 ft would be even safer.

Dale

RV6a 1230 hrs GRT S200 0-360 Hartzell



--

jvanlaak(at)aol.com
Guest

Posted: Sun Sep 20, 2009 4:53 am Post subject: Loop problem

Two suggestions:

    

   First, you may find that making a level, coordinated roll just above stall is actually quite difficult.  Instead, consider starting at a more "normal" speed like 80 and lifting the nose 20 degrees before rolling you end up with the same condition - inverted at about 60 - with more control authority and less adverse yaw.  The nose wants to fall quickly at low speeds even when "unloaded" especially as you go through knife edge.  Raising the nose give you the room for that to occur before seeing the horizon inverted to confirm you in fact got through 180 degrees of roll.  Otherwise you could find the windshield full of ground and no idea how far you rolled and what direction is the shortest one to right side up.

    

   Second, pay attention to CG.  One of the most common mistakes in aviation is to neglect the effect of cg on stalling and spinning characteristics.  When you read somebody telling how hard a Cessna 172 is to stall you see that they only attempt the maneuver with the back seat empty (I think by POH restriction).  But if they happened to inadvertently stall with the seats and baggage area full they would find an entirely different result.  In the case of RVs, the empty CGs vary wildly depending on engine and especially prop (a CSP versus wood prop is huge) and of course the tandems can change greatly with who is sitting where.

    

   Explore spinning and other new maneuvers with a forward CG and lots of altitude.

    

   Jim

 

 

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