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General control line discussion => Open Forum => Topic started by: steve pagano on November 28, 2006, 12:08:15 PM

Title: who's plane is this?????????
Post by: steve pagano on November 28, 2006, 12:08:15 PM

Does anybody know whos plane this is.I know its an impact but i would like to ask the builder a question or two about those flaps.

Title: Re: who's plane is this?????????
Post by: Leester on November 28, 2006, 02:06:30 PM

I don't know who's it is but why not just ask away ? Somebody like Sparky or Bill will more than likely be able to answer.

Title: Re: who's plane is this?????????
Post by: Steve Helmick on November 28, 2006, 02:25:18 PM

Howard Rush is the builder and flier of that particular ImpAct.  y1 Steve

Title: Re: who's plane is this?????????
Post by: Randy Powell on November 28, 2006, 02:38:31 PM

And the flaps were an experiment that seemed at least not to hurt anything. I think the point was to reduce stick pressure in corners. I believe Howrd likes them.

Title: Re: who's plane is this?????????
Post by: Steve Helmick on November 28, 2006, 03:30:30 PM

Howard DID have them on the ImpAct when he defeated PW at the Stevenson Memorial Raider Roundup. I believe they have been on the plane all this season. The flap "servo boosters" are easy to make, & linkage is simple. Neat experiment! More power would be another alternative, tho.  ~~>  Steve

Title: Re: who's plane is this?????????
Post by: Howard Rush on November 28, 2006, 05:08:31 PM

Who took the cool picture?  I'd like a copy of the uncompressed version. 

I sent Steve a note, but here's the story on the flaps:
http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=72253&mesg_id=72253&listing_type=search 

Title: Re: who's plane is this?????????
Post by: Trostle on November 28, 2006, 06:52:48 PM

I think it is great that Howard has stepped forward and tried the idea of boost tabs on a serious PA model.   I am looking forward to get a model finished sometime next spring for me to see how much they help. 

There was a model at the 2004 World Championships in Muncie that had the boost tabs on the flaps.  I did not get to see the airplane fly and only had a short conversation with the flier.  I do not even remember which country he was from (Australia??).

I think that there is little weight penalty to incorporate this concept for the flaps and/or elevators.  They cannot hurt and might even help a bit.

There was an article published in Model Airplane News prior to 1994 titled "Labor-Saving Devices for Overworked Servos".  The article has been republished in the MAN publication titled "How To's, Volume 2".  The article discusses aerodynamic balances, paddle balancers, and boost tabs.  It goes into quite a bit of detail about the boost tabs to show how they work, why they work, and how to size them.  Though this was written for RC, the application works for CL.

There are several full size aircraft that use boost tabs to control  the moving surfaces of the aircraft.  Examples are the Douglas DC9.  The B-29 used them to control the ailerons, elevators and rudder, all without hydraulics.  Also, I think the Boeing 727 uses boost tabs.

By the way, there are a lot of good ideas published in those two "How To's" volumes by Model Airplane News.

Title: Re: who's plane is this?????????
Post by: Howard Rush on November 28, 2006, 07:57:41 PM

That was PJ Rowland of Australia at the 2004 Nats.  He thinks, by the way, that the tabs should go halfway between the root and tip.

Balance tabs are a standard aero trick.  I had the B-17 in mind, because it has a high control hinge moment.  We tried them on a conventional stunt plane, and I decided they might be useful for conventional stunters, too.  Coincidentally, PJ used tabs on his Lancaster.