---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Thu 04/22/21: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:08 AM - Re: Rotax 912ULS Low Fuel Pressure (Ian Cook) 2. 01:25 AM - Re: Rotax 912ULS Low Fuel Pressure (Steve Ivell) 3. 01:40 AM - Re: Rotax 912ULS Low Fuel Pressure (Pete Jeffers) 4. 03:46 AM - DOTH UK Abergavenny today (graeme bird) 5. 05:01 AM - Re: DOTH UK Abergavenny today (D McFadyean) 6. 09:35 AM - Re: Rotax 912ULS Low Fuel Pressure (Dave Disney) 7. 01:37 PM - Cruise speed data for Monowheel with 912ULS (n7188u) 8. 08:19 PM - Re: Rotax 912ULS Low Fuel Pressure (Griffo) 9. 08:47 PM - Re: Cruise speed data for Monowheel with 912ULS (Griffo) ________________________________ Message 1 _____________________________________ Time: 12:08:30 AM PST US From: Ian Cook Subject: RE: Europa-List: Rotax 912ULS Low Fuel Pressure Check your fuel filters for contamination. Ian -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Pete Sent: 21 April 2021 23:58 Subject: Re: Europa-List: Rotax 912ULS Low Fuel Pressure What I notice is that when the electric pump is shut off, the pressure does drop to near zero, but recovers within about 5 seconds back to the normal 5-7psi. >From my research, this type of intermittent drop is acceptable when the series boost pump is turned off. Cheers, Pete > On Apr 21, 2021, at 6:55 PM, arwel pritchard wrote: > > > > Good Evening > > I noticed something strange this evening asI was climbing out at full power, when I got to about 1000ft, I switched the electric fuel pump off and the fuel pressure dropped quite alarmingly from about 0.32bar to below 0.2bar. When I noticed it, I immediately switched the electric pump back on to restore the pressure. I then leveled off, reduced power and flew a tight circuit back to land. > > After landing, I monitored the pressure at various power levels (with mechanical pump only) and saw the pressure was at around 0.3bar continuously. > > I have seen it posted on various forums that its 'one of those things' and its nothing to worry about, but I do!! > > I should also mention that Im seeing the pressure on a mechanical gauge as opposed to an electrical display readout. > > Has anybody else come accross this before and is it a real problem? > > > Thanks > > Arwel > > G-BYPM > > > > ________________________________ Message 2 _____________________________________ Time: 01:25:29 AM PST US From: Steve Ivell Subject: RE: Europa-List: Rotax 912ULS Low Fuel Pressure Apparently it's a known "phenomenon" . Kind Regards Steve Ivell -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Ian Cook Sent: 22 April 2021 08:08 Subject: RE: Europa-List: Rotax 912ULS Low Fuel Pressure Check your fuel filters for contamination. Ian -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of Pete Sent: 21 April 2021 23:58 Subject: Re: Europa-List: Rotax 912ULS Low Fuel Pressure What I notice is that when the electric pump is shut off, the pressure does drop to near zero, but recovers within about 5 seconds back to the normal 5-7psi. >From my research, this type of intermittent drop is acceptable when the series boost pump is turned off. Cheers, Pete > On Apr 21, 2021, at 6:55 PM, arwel pritchard wrote: > > > > Good Evening > > I noticed something strange this evening asI was climbing out at full power, when I got to about 1000ft, I switched the electric fuel pump off and the fuel pressure dropped quite alarmingly from about 0.32bar to below 0.2bar. When I noticed it, I immediately switched the electric pump back on to restore the pressure. I then leveled off, reduced power and flew a tight circuit back to land. > > After landing, I monitored the pressure at various power levels (with mechanical pump only) and saw the pressure was at around 0.3bar continuously. > > I have seen it posted on various forums that its 'one of those things' and its nothing to worry about, but I do!! > > I should also mention that Im seeing the pressure on a mechanical gauge as opposed to an electrical display readout. > > Has anybody else come accross this before and is it a real problem? > > > Thanks > > Arwel > > G-BYPM > > > > ________________________________ Message 3 _____________________________________ Time: 01:40:49 AM PST US From: "Pete Jeffers" Subject: RE: Europa-List: Rotax 912ULS Low Fuel Pressure Hi ARWEL, What you are seeing is quite normal. If you have the nerve wait a few seconds (and I do mean seconds) without switching on the electric pump and you will find the pressure indication recovers. Read what Bud says. Only investigate further if the pressure does not recover or anything else exciting happens. Pete -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of arwel pritchard Sent: 21 April 2021 23:47 Subject: Europa-List: Rotax 912ULS Low Fuel Pressure Good Evening I noticed something strange this evening asI was climbing out at full power, when I got to about 1000ft, I switched the electric fuel pump off and the fuel pressure dropped quite alarmingly from about 0.32bar to below 0.2bar. When I noticed it, I immediately switched the electric pump back on to restore the pressure. I then leveled off, reduced power and flew a tight circuit back to land. After landing, I monitored the pressure at various power levels (with mechanical pump only) and saw the pressure was at around 0.3bar continuously. I have seen it posted on various forums that its 'one of those things' and its nothing to worry about, but I do!! I should also mention that Im seeing the pressure on a mechanical gauge as opposed to an electrical display readout. Has anybody else come accross this before and is it a real problem? Thanks Arwel G-BYPM -- This email has been checked for viruses by AVG. https://www.avg.com ________________________________ Message 4 _____________________________________ Time: 03:46:53 AM PST US Subject: Europa-List: DOTH UK Abergavenny today From: "graeme bird" Around 14:00 if anyone else fancies it and a circuit of the Breckon Beacons -------- Graeme Bird Kit 3 in build (Gregory) mono Classic 914 xs fwfwd Woodcomp Kit 2 G-PATS - (kesterton) Mono Classic 912 warpdrive Kit 1 G-UMPY - Mono Classic/XS FFW 912S, Woodcomp SR3000/3W CS, G(@)gdbmk.co.uk Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501470#501470 ________________________________ Message 5 _____________________________________ Time: 05:01:07 AM PST US From: D McFadyean Subject: Re: Europa-List: DOTH UK Abergavenny today Rapid Scramble rather than DOTH! Do not archive. > On 22 April 2021 at 11:46 graeme bird wrote: > > > > Around 14:00 if anyone else fancies it and a circuit of the Breckon Beacons > > -------- > Graeme Bird > Kit 3 in build (Gregory) mono Classic 914 xs fwfwd Woodcomp > Kit 2 G-PATS - (kesterton) Mono Classic 912 warpdrive > Kit 1 G-UMPY - Mono Classic/XS FFW 912S, Woodcomp SR3000/3W CS, G(@)gdbmk.co.uk > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=501470#501470 > > > > > > > > > ________________________________ Message 6 _____________________________________ Time: 09:35:34 AM PST US Subject: Europa-List: Re: Rotax 912ULS Low Fuel Pressure From: "Dave Disney" As a matter of interest I seem to remember reading that on the RV12 they leave the electric fuel pump 'on' all the time. I now do this and only turn it off at height to check that the mechanical pump is working properly. My low pressure warning light flickers for a few seconds then remain off. I then switch the electric fuel pump back on again. My reasoning for this is that the electric pump is a low cost item when it comes to replacement, it will help avoid any problems with vapor lock and is one less thing to worry about pre take-off and landing (although I still check that it's on). Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501472#501472 ________________________________ Message 7 _____________________________________ Time: 01:37:02 PM PST US Subject: Europa-List: Cruise speed data for Monowheel with 912ULS From: "n7188u" Dear forum members, As I continue to fly (got 20 hrs already so making good progress) and tweak my new monowheel, I am trying to figure the best compromise adjustment for my ground adjustable prop with the 912ULS. After much research on the subject of prop adjustment, power settings, etc (and all the debates that accompany that information) I decided that the best way for me to get good info on how to adjust my prop is to gather some data from those who actually fly our aircraft. The data I could use from the forum members is at what altitude, RPM, Manifold Pressure you cruise at (again, with the 912 ULS). If you have a monowheel please let me know your indicated or true airspeed (engine data is still relevant for a tri gear). Fuel consumption would be helpful to get an additional data point It doesn't matter if you have a ground adjustable or VP prop. Please note I am really interested in the RPM/MAP (and speed) combo so I can expect more data that includes MAP will come from those of you who have a VP prop and that will still be relevant for me. But if you don't have MAP please share the info if you want anyway (the RPM/speed correlation can be useful). Of course prop design matters but I can't be too picky :) But check, that would be another interesting data point. BTW, really interesting data to complement this would be what your static RPM is and RPM at initial climb out with the later being more important in my opinion. Of course I plan on sharing whatever analysis I perform and its conclusions. Best Regards, Chris Martin. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501475#501475 ________________________________ Message 8 _____________________________________ Time: 08:19:52 PM PST US Subject: Europa-List: Re: Rotax 912ULS Low Fuel Pressure From: "Griffo" Hi Dave, Hi, Its good that you are taking precautions to avoid having the electric (boost/back up) pump mask/hide a failed mechanical fuel pump. However, I would question the merit of leaving your electric pump on at all times, as I would expect a pump, so operated, to become a service item replaced at ?? hours of operation (as the mechanical pump has a recommended service life). I only use my electric pump prior to engine start (off for start) to check fuel pressure/availability. On again, for take-off. Off when safe height above terrain achieved. On again, when downwind for landing. Your engine will run perfectly without the need for the electric pump, which should only be used when you have a mechanical fuel pump failure, at critical times, when fuel starvation is not a good option. -------- 46 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501476#501476 ________________________________ Message 9 _____________________________________ Time: 08:47:08 PM PST US Subject: Europa-List: Re: Cruise speed data for Monowheel with 912ULS From: "Griffo" I would suggest that the best indicators for evaluating your (GA) fixed props performance, at a given pitch setting, are: Indicated air speed for a given RPM at the indicated (or calculated) fuel flow. Density altitude try and do your test within a tight temperature/altitude range. Aircraft load (fuel + PAX + whatever) for comparative purposes this must be as consistent as practicality allows In this context MAP is not much more than an interesting discussion point. By definition you cannot have Static RPM once your aircraft is moving ( in this context Static means no forward motion as in tied to a stump) I do not agree with your comment on Static RPM Rotax specify a minimum of 5200 rpm (for Static/TO/Climb/Cruise). If you want to get the best service life out of your 91 you should take notice of this Rotax 91 engines love RPM. Your pitch setting will be for whatever aspect of flight you optimise it for: Fine: will give you the best TO/Climb performance but will reduce high speed cruise Compromise: Something you can live with. Course: Will give you the best Cruise/High Speed, but make for long ground runs, anaemic climb and could quit easily compromise your safety. If your engine is not making 5200 + rpm on the ground run/TO you may reduce its service life. -------- 46 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=501477#501477 ------------------------------------------------------------------------------------- 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.