[NSRCA-discussion] F17 barrel roll

Wed Aug 26 13:21:43 AKDT 2015

After so many years of people having lively discussions of snap rolls that look like 
barrel rolls, now we can look forward to discussions about barrel rolls that look like snap rolls.
That's just funny. I'm waiting...
Emory

Sent from my iPad

> On Aug 26, 2015, at 4:11 PM, Doug Cronkhite via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> wrote:
> 
> People can't even accurately describe this maneuver.. How the hell is anyone going to judge it?
> 
> 
> 
>> On Aug 26, 2015, at 12:49 PM, Herb Kurlan via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> wrote:
>> 
>> Not according to the diagram and description from Michael Ramel. The barrel roll is entered and exited at 45 degrees but the roll travels along a horizontal sphere with 4 geometric positions defining the maneuver.
>> 
>> 
>> 
>> -------- Original message --------
>> From: cahochhalter via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> 
>> Date: 08/26/2015 12:16 PM (GMT-08:00) 
>> To: "Dr. Michael Harrison, DDS" <drmikedds at sbcglobal.net>, General pattern discussion <nsrca-discussion at lists.nsrca.org> 
>> Subject: Re: [NSRCA-discussion] F17 barrel roll 
>> 
>> Correct as I read since the plane is climbing nose high throughout the roll.
>>  
>> You agree?
>> 
>> 
>> 
>> Sent from my Verizon Wireless 4G LTE smartphone
>> 
>> 
>> -------- Original message --------
>> From: "Dr. Michael Harrison, DDS via NSRCA-discussion" <nsrca-discussion at lists.nsrca.org> 
>> Date: 08/26/2015 2:06 PM (GMT-06:00) 
>> To: 'Don Ramsey' <donramsey at gmail.com>, 'General pattern discussion' <nsrca-discussion at lists.nsrca.org> 
>> Subject: Re: [NSRCA-discussion] F17 barrel roll 
>> 
>> If you go by the absolute description in the rule book there is no call for horizontal in the barrel roll.
>> 
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>> From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Don Ramsey via NSRCA-discussion
>> Sent: Wednesday, August 26, 2015 5:15 AM
>> To: 'General pattern discussion'
>> Subject: Re: [NSRCA-discussion] F17 barrel roll
>> 
>>  
>> 
>> Clarification for F-17.07 "Barrel Roll" by Michael Ramel: 
>> 
>> "At first, please recall the manoeuvre description as in the Sporting Code: 
>> 
>> F-17.07 Barrel-Roll 
>> 
>> From upright, pull through a 1/8 loop into a 45° upline, perform a barrel-roll with 45° spiral pitch, perform a 45° upline, push through a 1/8 loop, exit upright. 
>> 
>> You first pull into a 45° upline, then at mid level you start to perform a full roll with the flight path going around a horizontal cylinder in a spiral (as the thread of a screw in a 45° pitch). 
>> 
>> Assumed you fly from right to left performing the barrel roll into right direction: 
>> 
>> From low level, the aircraft pulls upright in a 45° upline first, then will be in a knife-edge (right wing down) position after the first 1/4 of the roll heading away from you in a 45° angle seen from above, then it is inverted on a 45° downline after the second 1/4 of the roll, then in a knife-edge position (right wing up) after the third 1/4 of the roll heading towards you in a 45° angle seen from above, finally it is upright again in a 45° upline after the fourth 1/4 of the roll as to finish the manoeuvre on high level. 
>> 
>> You have seen this barrel roll many times in show flight performances when ie. one aircraft is flying on a level line, while another aircraft spirals around it in one or more barrel rolls. However, for F3A this manoeuvre is precisely described and brakes down to the various geometric reference points."
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>> From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Derek Koopowitz via NSRCA-discussion
>> Sent: Sunday, August 23, 2015 11:26 AM
>> To: Ed Alt; NSRCA List
>> Subject: Re: [NSRCA-discussion] F17 barrel roll
>> 
>>  
>> 
>> Perhaps a barrel roll isn’t the best name for this maneuver – I would call it a slow wave roll instead.  There are very clear areas of judging criteria to look for in this maneuver…. First the pull to a 45 up line, the knife edge view of the plane at the top radius of the 45 up line, the inverted downline, the knife edge on the bottom radius and the completion (upright) view of the plane on the 45 up line before a push to level flight.  Since this roll would have to be flown slowly, the difficulty is pretty high.  Obviously ensuring that all the radii are the same as well.
>> 
>>  
>> 
>> From: NSRCA-discussion on behalf of NSRCA List
>> Reply-To: Ed Alt, NSRCA List
>> Date: Sunday, August 23, 2015 at 5:35 AM
>> To: NSRCA List
>> Subject: Re: [NSRCA-discussion] F17 barrel roll
>> 
>>  
>> 
>> I'm not sure , but after 100 years or so, it seems that the barrel roll may have a new definition.  This appears to require that the model skid around the entire rotation, which is not really how a barrel roll is typically done as far as I know.  I believe that you would normally do one mainly with simultaneous pitch and roll inputs, and maybe touches of rudder to keep that coordinated, in much the same  way as  a coordinated turn would be done in a full scale aircraft to keep the turn & bank indicator's ball centered. As a result, it would present itself as if the aircraft were traveling along the inside of a cylinder with both of it's main gear wheels always in contact with its inner surface, hence the name barrel roll.  Executed this way, you could do that Bob Hoover demonstration of keeping a glass of some liquid perfectly still, resting on top of the instrument panel.
>> 
>>  
>> 
>> This definition seems to be more of a variation on an integrated roll, and as a result you would expect to see the tail pointed at perhaps a 45 deg yaw angle at one point (when roll angle = 90 deg), and the nose yawed at you 45 deg at another (when roll angle = 180 deg).  And I think that as a result it would also mean that the wing tip in the direction of the roll would always be in contact with the inner surface of the imaginary cylinder, instead of both wheels.  Am I visualizing that correctly?  It seems like it would be tricky to judge accurately.
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>> Ed
>> 
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>> 
>> Date: Sat, 22 Aug 2015 23:10:49 -0700
>> To: underdw at gmail.com; nsrca-discussion at lists.nsrca.org
>> Subject: Re: [NSRCA-discussion] F17 barrel roll
>> From: nsrca-discussion at lists.nsrca.org
>> 
>> Hopefully this helps…
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>> From: NSRCA-discussion on behalf of NSRCA List
>> Reply-To: Daniel Underkofler, NSRCA List
>> Date: Saturday, August 22, 2015 at 6:21 PM
>> To: NSRCA List
>> Subject: [NSRCA-discussion] F17 barrel roll
>> 
>>  
>> 
>> In F17 there is a cryptic aresti symbol that is described in the figure description as a barrel roll.  Will somebody please describe this in more detail and what control inputs will obtain the required result?
>> 
>>  
>> 
>> Thanks, Dan
>> 
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