I must apolgise for not seeing this sooner. The AoA sensor that John described is a great idea, but it won't work (or is not accurate) in the location he described it to be.
The AoA sensor must be out of the propwash flow! "Duh!" Such a tube could be easily mounted beneath the wing in a horizontal fashion, with one hole on the bottom and one on the side or front. Someone has already posted a sketch of this layout in the past, and it's the way the production models work. Do a google search for 'reserve lift indicators' and you will come to a site right away that has an image of their commercial sensor. Thanks for the info on the mini magnahelic Eduardo. PJ mailto:pjohn...@voyageur.ca ----- Original Message ----- From: "Eduardo M. Iglesias" <emigles...@cpenet.com.ar> To: "KRnet" <kr...@mylist.net> Sent: Wednesday, March 10, 2004 6:26 AM Subject: Re: KR>Angle of Attack Indicator-Gauge Option > It´s the Dwyer Minihelic II, serie 5000 from Dwyer Instruments Inc. > e-mail i...@dwyer.inst.com http//www.dwyer-inst.com > If you want I have a draw of the sensor. It has two holes guided forward and > they has 90° between it, so that the differential pressure measured among > them is shown in the instrument. > Eduardo > > ----- Original Message ----- > From: "Peter Johnson" <pjohn...@voyageur.ca> > To: "KRnet" <kr...@mylist.net> > Sent: Tuesday, March 09, 2004 9:58 PM > Subject: Re: KR>Angle of Attack Indicator-Gauge Option > > > > Just because this is something I'm familiar with I thought I'd add some > > input to John's description of his friends homemade AoA's. > > > > The use of a low speed ASI in the cockpit as a gauge is a good one. > Another > > option that could be used is a mini magnahelic gauge. These gauges are > very > > common in industry and are used for heating and ventilating pressure > > readouts, induced air pressure measurement, etc. > > > > The gauges come in a variety of 'high-low' capacitys and ranges. Go to > your > > yellow pages and look under 'Industrial Supply' or 'Heating and > Ventilating > > Design'. If the firms you call don't sell them directly, they can tell > you > > who does. > > > > I would also like to say that of all the different homemade AoA's that > I've > > looked at and designed myself, I like this one the best, especially for > it's > > 'tuning' capability. Thanks for posting John. > > > > Hope this is of help to someone. > > > > Peter Johnson > > KR-2Sexy with a Corvair > > Kenora, Ontario > > Canada > > > > mailto:pjohn...@voyageur.ca > > > > > > ----- Original Message ----- > > From: "Martindale Family" <johnj...@chc.net.au> > > To: "KRnet" <kr...@mylist.net> > > Sent: Tuesday, March 09, 2004 2:09 PM > > Subject: Re: KR>Angle of attack indicator > > > > > > > Folks > > > > > > A friend of mine designed his own AoA indicator. Simply a 1/2" tube, > > sealed > > > at the end with row of small holes drilled into it. The tube is mounted > > out > > > of the fuselage wall on the extended chord line 8"or so ahead of the > > leading > > > edge root and is parallel to it. He has the holes pointed down at right > > > angles to the chord so that at zero AoA there is minimal pressure in the > > > tube. As the wing/fuselage is rotated to provide an AoA so too does the > > > tube, the holes present to the air flow and the pressure increases. A > > > reading is obtained on some sort of sensitive pressure gauge (maybe just > a > > > low speed ASI) that has it's face recalibrated in arbitary units (he > just > > > uses numbers 1 to 5 and has the dial named " partner's pressure level"). > > > The tube can be rotated to provide calibration (or desired absolute > needle > > > movement) and the readings noted as he approaches the stall. He flies > this > > > gauge on approach, more so than the ASI. > > > > > > John > > > > > > > > _______________________________________ > > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > > please see other KRnet info at http://www.krnet.org/info.html > > --- > > [This E-mail scanned for viruses by Declude Virus] > > > > > > > > > --- > [This E-mail scanned for viruses by Declude Virus] > > > _______________________________________ > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
