---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Thu 06/29/17: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:40 AM - Re: Re: Stall Warner - switch problems (Ian Cook) 2. 04:23 AM - Re: Cheap chinese landing light (carlp101) 3. 05:11 AM - Re: Landing Light Positioning (John Wighton) 4. 05:21 AM - Re: Re: Cheap chinese landing light (William Daniell) 5. 05:58 AM - Re: Landing Light Positioning (carlp101) 6. 06:58 AM - Re: Mode S Hexidecimal code (carlp101) 7. 12:48 PM - Re: Stall Warner - switch problems (Kelvin Weston) ________________________________ Message 1 _____________________________________ Time: 02:40:27 AM PST US From: Ian Cook Subject: RE: Europa-List: Re: Stall Warner - switch problems Bud, Not very often I disagree with you, but the stall warning switch does not work as you describe. Under normal flight the switch senses +VE pressu re (connecting an ASI up to the stall system) both the A/C normal ASI and s tall warning see almost the same pressure and read the same value. As the angle of attack increases the air separation transition point (-VE pressure moves down the leading edge) and it is this suction that operates the swit ch as the stall is approached. With the trial ASI still connected, at this point it reads zero or below with the ASI pointer on the stop. Next test fl ight will be conducted with a +VE and -VE 5" water gauge connected to the s tall system to measure the actual +VE and -VE pressures. This work is being done as part of the Permit work for the UK MG test flight programme as the LAA are insisting on a stall warning system on the motor glider. On trying to use the standard EUROPA XS system we are having trouble getting the swi tch to work consistently. Note: the wing LE profile of the MG is different to the XS and the stall speed is much lower at 42 KIAS at max 1370 lbs lowe r with the airbrake just cracked open. On my machine, the stall is very ben ign with very little airframe buffet. Regards Ian Cook G-CBHI MG From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-serv er@matronics.com] On Behalf Of Bud Yerly Sent: 29 June 2017 03:23 Subject: RE: Europa-List: Re: Stall Warner - switch problems Kelvin, The switch is a pressure switch. With the relative wind nearly straight on the air into the tube is under suction. The switch is assembled to the ho se to the leading edge using its pressure side. The switch is normally ope n so with suction on the tube, the light is off at low angles. At about 14 degrees angle of attack the switch is now under pressure from t he ram air. The switch is normally open and at about 3 inches of water ish , the switch will close and allow current to flow to the light/horn. Once you land, and the speed diminishes, the pressure drops and the switch opens and the horn goes off. Not rocket science. See photo below: Regards, Bud Yerly[cid:image001.png@01D2F0C2.29A422B0] Sent from Mail for Window s 10 From: Kelvin Weston Sent: Tuesday, June 20, 2017 5:03 PM Subject: Europa-List: Re: Stall Warner - switch problems o:kelv@kdweston.biz>> Hi Bud and all Now I am really confused. I have fitted the Europa stall warning mod and sw itch but not yet used in anger. How is this switch designed to work? Is it normally closed and held open by pressure above a certain speed. Or is it normally open and is closed by low pressure (vacuum), like a conve ntional Cessna stall warner, caused by the angle of the wing. The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option. The switch has a hose connection to both sides of what I assume is a diaphr agm, so it is easy to connect incorrectly. If it is normally closed then does that result in the buzzer operating cont inually on the ground until above the stall speed? I think that would eventually get to be a bit of a pain, especially during long holds on the ground. -------- Regards Kelv Weston Kit 497 kelv@kdweston.biz Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470288#470288 st Email Forum - pa-List">http://www.matronics.com/Navigator?Europa-List p; - MATRONICS WEB FORUMS - ums.matronics.com p; - NEW MATRONICS LIST WIKI - matronics.com p; - List Contribution Web Site - p; -Matt Dralle, List Admin. http://www.matronics.com/contribution ________________________________ Message 2 _____________________________________ Time: 04:23:54 AM PST US Subject: Europa-List: Re: Cheap chinese landing light From: "carlp101" I use 3480 lumen LED light from Jaycar. See https://www.jaycar.co.uk/3486-lumen-ip68-solid-led-spot-light/p/SL3919. It's as quite as a mouse and cheap too. Regards Carl Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470574#470574 ________________________________ Message 3 _____________________________________ Time: 05:11:30 AM PST US Subject: Europa-List: Re: Landing Light Positioning From: "John Wighton" The installation looks interesting but raises a few questions about efficiency of cooling air flow. Is there a moulded cover on the inside? Does it reduce the cruise speed (a Go-Pro sized camera on mine reduces the cruise by a noticeable amount). Did the LAA approve the Mod without any supporting stress calcs? My scheme does not involve making a sizable hole in the cowling - just a 1/2 dia hole for the cables, sealed with silicon. The light and moulded support sit around 2.5in max off the OML. -------- John Wighton Europa XS trigear G-IPOD Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470578#470578 ________________________________ Message 4 _____________________________________ Time: 05:21:17 AM PST US From: William Daniell Subject: Re: Europa-List: Re: Cheap chinese landing light Thanks Will On Jun 29, 2017 07:26, "carlp101" wrote: > > I use 3480 lumen LED light from Jaycar. See https://www.jaycar.co.uk/3486- > lumen-ip68-solid-led-spot-light/p/SL3919. It's as quite as a mouse and > cheap too. > > Regards > Carl > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=470574#470574 > > ________________________________ Message 5 _____________________________________ Time: 05:58:07 AM PST US Subject: Europa-List: Re: Landing Light Positioning From: "carlp101" Hi John, Good questions. The body of the light is designed as a heat sink and as such has channels through it for the air to pass through. These are aligned with the flow of air into the cowl, providing minimal reduction in flow. I can't say I have noticed a reduction in the cruise speed. I'm burning about 15 liters per hour at 110 kts. The LAA didn't require any stress calculations as this is not a load bearing part of the cowl, and the metal bracket helps reinforce the area in any case. The mod number is 14394. Regards Carl Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470583#470583 ________________________________ Message 6 _____________________________________ Time: 06:58:37 AM PST US Subject: Europa-List: Re: Mode S Hexidecimal code From: "carlp101" Hi William, If you know your octal or binary code from your FAA registration you can covert it to hexadecimal here: http://www.kloth.net/radio/icao24lookup.php Regards Carl Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470588#470588 ________________________________ Message 7 _____________________________________ Time: 12:48:11 PM PST US Subject: Europa-List: Re: Stall Warner - switch problems From: "Kelvin Weston" Hi Bud I think I might have to go with Ian on this one. The Europa Mod 61 leaflet does state: Inside the fuselage an adjustable vacuum switch, triggered by reduced pressure in the line It also describes connecting the hose to the same side of the switch as the terminals. Looking at the tech details on the switch, this is side A and should have vacuum applied to operate the switch. -------- Regards Kelv Weston Kit 497 kelv@kdweston.biz Read this topic online here: http://forums.matronics.com/viewtopic.php?p=470595#470595 Attachments: http://forums.matronics.com//files/l317443_01_140.gif ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.