Re: [RCSE] Still using aileron differential?
It means aileron goes only up and zero down from that point anything down would me more then stall => disaster Zbigniew Michalczyk The Soaring Little Fleet of Poland www.LittleSoaringFleet.com http://mysite.verizon.net/vze2qbfc/ - Original Message - From: "Robert Samuels" <[EMAIL PROTECTED]> To: Sent: Sunday, June 12, 2005 10:03 PM Subject: Re: [RCSE] Still using aileron differential? Mark Drela wrote " I use about 12 deg of full-span camber on launch, and trim close to stall. I don't want any downward TE deflection in this condition." I don't understand not wanting "any downward TE deflection in this condition" Isn't camber a downward deflection?Maybe I'm not understanding something. Robert Samuels.St. Louis _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] Still using aileron differential?
Mark Drela wrote " I use about 12 deg of full-span camber on launch, and trim close to stall. I don't want any downward TE deflection in this condition." I don't understand not wanting "any downward TE deflection in this condition" Isn't camber a downward deflection?Maybe I'm not understanding something. Robert Samuels.St. Louis _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] Still using aileron differential?
> 1) still use aileron differential in 2 and 3 meter planes and > 2) still couple the ailerons to the flaps (so they act as flaperons) Here's what I use on my Supra: 1) During normal flying: * 10% differential, which is almost nothing in practice * 20% Ail->Rud * 40% Ail->Rud when airbraking The Ail->Rud mix is to make the aileron stick nearly a pure roll control, and it's in no way a replacement for independent ruddering. I still use the rudder stick a lot during circling maneuvers. During launch: * 100% differential * 100% Ail->Rud I use about 12 deg of full-span camber on launch, and trim close to stall. I don't want any downward TE deflection in this condition. 2) Yes, I make the flaps respond to the aileron stick, about 60% as much as the ailerons do. This is a compromise between: - least drag in roll maneuvers (wants flaps moving 33% as much as ailerons) - maximum tip stall resistance (wants flaps moving 100% as much as ailerons) RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] Still using aileron differential?
I to saw Phil's post about Dr. Drela's message. Because of my respect for Dr. Drela's academic achievements (Masters in Aeronautical Engineering and Professor at MIT) and his real world experience I immediately tried his suggestion on my XP4 DLG. I reduced the differential from 55% to 0 and increased the rudder to aileron coupling from 60% to 90% (yes I realize Mark Drela flies without rudder coupling but my left thumb isn't as good as his). The improvement was immediate. The plane track better and I was able to fly in much tighter turns without falling off. I did feel that the nose wasn't coming into the turn quite enough so I went to 100% rudder coupling with ailerons and again a noticible improvement. But it still wasn't quite as coordinated a turn as I wanted. So I added back 20% differential and for my real world test it was perfect. So after what I felt was a successful test with noticible improvement on my DLG I decided to try reducing differential on my 128" Escape Lt. The improvement from reducing differential and increasing rudder on my Escape were just as obvious. End results were I went from 65% differential to 35% and from 30% rudder coupling to 70%. As with the hand launch the improvement was immediate. So for me I would have to say Dr. Drela is right about the use of aileron differential. Because though I don't fly with rudder and ailerons uncoupled, as Mark Drela does, reducing differential with increasing rudder coupling (to compensate for the weak left thumb) defiantly made an improvement in the handling of my XP4 DLG and my 128" Escape Lt. Just what I think Maurice - Original Message - From: "Robert Samuels" <[EMAIL PROTECTED]> To: Sent: Sunday, June 12, 2005 2:56 PM Subject: [RCSE] Still using aileron differential? I recently followed a link provided by Phil Barnes to a message posted by Dr. Drela. The message was that Dr. Drela did not use aileron (flaperon) differential in DLG planes. The rational was that the differential caused some unwanted pitch changes. My questions concern the application of Dr. Drela's theory to the larger planes. I wonder whether you all (experts): 1) still use aileron differential in 2 and 3 meter planes and 2) still couple the ailerons to the flaps (so they act as flaperons) Robert SamuelsSt. Louis _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
