---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Sat 08/28/10: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:48 PM - Re: Mod 43 tailwheel extension BiD across cutout? (jpg12305) 2. 03:51 PM - MG Airbrake question (Karl Heindl) 3. 05:50 PM - Re: MG Airbrake question (Bud Yerly) ________________________________ Message 1 _____________________________________ Time: 02:48:41 PM PST US Subject: Europa-List: Re: Mod 43 tailwheel extension BiD across cutout? From: "jpg12305" Doesn't help, but I have exactly the same question at the moment ! The layout sequence is not crystal clear. Any tips/pictures about Mod43 welcome. Jean-Paul France Read this topic online here: http://forums.matronics.com/viewtopic.php?p=310415#310415 ________________________________ Message 2 _____________________________________ Time: 03:51:59 PM PST US From: Karl Heindl Subject: Europa-List: MG Airbrake question Hi motorglider guys. Has anyone made any changes to their airbrakes ? I find they requires a lot of force to hold them in the fully open position. The air pressure on the bottom half far exceeds that on the top.Because of that it is also impossib le to get the maximum deflection of 60 degrees. I mounted an angle indicato r=2C and it shows about 45-50=2C which severely degrades their performance. I don't understand why nothing was ever done about this. They have been pro ducing these wings for about 11 years now.The obvious solution to me is to reduce the area of the bottom half=2C either by putting in holes=2C or trim ming back the trailing edge.These brakes are not really necessary with the engine running=2C but are essential when I get to making dead stick landing s. Karl ________________________________ Message 3 _____________________________________ Time: 05:50:44 PM PST US From: "Bud Yerly" Subject: Re: Europa-List: MG Airbrake question Karl, I normally get 57 degrees and can tweak 60 but usually don't bother for the last 3 degrees. See the notes from my shop instructions attached. I have not minded the pull effort, as they stay at 50% for landing normally. Above 85 knots it is a heck of a pull past 50%. John Bolyard and I have discussed putting holes in his airbrake trailing edge to decrease the deployment effort (as in the Dauntless) or lengthening the leading edge and fitting holes to prevent rapid pressure build up or they will flop wildly open. Unfortunately it will be manual research and trial and error on my part until the factory planes are finished and tested... NASA, or NACA more accurately, and the Air Ministry documents (see one example above in .pdf) are far and few between on air brake analysis as dive or airbrake research was proprietary data of manufacturers who used hydraulics to move their airbrake. Our airbrake is a copy of a Slingsby design which was quite successful, but something went wrong in the translation. Just a note to the others, the MG wings (about 34 sets) were sold only by the original company to the US/North American market ( I think the last set was produced in 2004) but unable to be flown in Europe until recently. Today, Europa is ready to begin new MG wing production certified under JAR-VLA and CS 22 requirements which make them stronger and saleable world wide. It took Dave Stanbridge to make this happen. Now the factory has two MGs being constructed and will be evaluated for these kind of fixes. First a computerized aerodynamic evaluation was made, followed by a detailed structural test, currently the rigging and building is being evaluated, which will be followed by flight test and airbrake fixes will surely follow. Doesn't help your situation now I'm afraid. The airbrakes are not dangerous as is but are very inconvenient to use without pumping up the muscles. You can tell a MG pilot by the size of his right bicep. I know we all are going as fast as time and money permit. Bud ----- Original Message ----- From: Karl Heindl To: europa-list@matronics.com Sent: Saturday, August 28, 2010 6:50 PM Subject: Europa-List: MG Airbrake question Hi motorglider guys. Has anyone made any changes to their airbrakes ? I find they requires a lot of force to hold them in the fully open position. The air pressure on the bottom half far exceeds that on the top. Because of that it is also impossible to get the maximum deflection of 60 degrees. I mounted an angle indicator, and it shows about 45-50, which severely degrades their performance. I don't understand why nothing was ever done about this. They have been producing these wings for about 11 years now. The obvious solution to me is to reduce the area of the bottom half, either by putting in holes, or trimming back the trailing edge. These brakes are not really necessary with the engine running, but are essential when I get to making dead stick landings. 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