---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Sun 08/26/12: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:12 AM - Re: Trigear conversion; only 80hp. Advice please. (jonathanmilbank) 2. 01:12 AM - Re: Re: Cracks on the cockpit module near to the seat belts (Duncan & Ami) 3. 01:37 AM - Re: Vapour lock? Why? (Frans Veldman) 4. 03:25 AM - Re: Landing mishap - asking for advise (zwakie) 5. 03:44 AM - Anybody willing to pick me up for Dutch GA Fly-in? (zwakie) 6. 06:11 AM - Re: Vapour lock? Why? (klinefelter.kevin@gmail.com) 7. 07:15 AM - Re: Re: Cracks on the cockpit module near to the seat belts (Paul McAllister) 8. 08:12 AM - NSI controller (Kevin Challis) ________________________________ Message 1 _____________________________________ Time: 12:12:07 AM PST US Subject: Europa-List: Re: Trigear conversion; only 80hp. Advice please. From: "jonathanmilbank" Got it, thanks Gordon. I've emailed a reply to you. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=381859#381859 ________________________________ Message 2 _____________________________________ Time: 01:12:48 AM PST US From: "Duncan & Ami" Subject: RE: Europa-List: Re: Cracks on the cockpit module near to the seat belts <<..Any advice is welcome. .>> OK, I'll bite! During a monowheel collapse, the weight of the aircraft (less tailwheel and outrigger loads) is transferred from the monowheel in to the top of the 'tunnel'. Thereafter, the stress-path from the tunnel is mostly both forwards and aftwards. In the aft direction the tunnel distributes loads in to the seatback bulkhead then further in to the fuselage skin. This means that the area that has cracked (being at along this stress-path is taking abnormal loads and this is a possible cause of the cracking, as you have surmised, compounded by the holes that have been cut at that point. Assuming there is no evidence of any other overstress in that area, the repair needs to put back the strength lost. This means replication of the original strength of composite in that location, which can be determined by counting the number of plies present. Allow a minimum 1/2 inch per ply overlap on to the surrounding unaffected area (presuming a bond shear strength of 500psi and cloth strength of 250lbs/in) with staggered edges. If the holes must be recut, then double the reinforcement and cut the holes as ellipses (at a length:width ratio of 1.414:1, if you want to be pedantic!). Too much or overdesigned reinforcement may make the area too stiff and introduce other issues, and makes the aircraft heavy too! Your respective airworthiness and/or design authority will be the final arbiter of any repair, which might be along the lines of the above. Duncan McF. -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of ploucandco Sent: 25 August 2012 18:26 Subject: Europa-List: Re: Cracks on the cockpit module near to the seat belts --> Hi all, here is a drawing of the cockpit module that shows with red rectangles the place where the pictures have been taken and so the location of the cracks. Will 5 BID at both side of the existing panel and on the cracks location be enough to repair and prevent reoccurence? Thanks, Jacques Read this topic online here: http://forums.matronics.com/viewtopic.php?p=381795#381795 Attachments: http://forums.matronics.com//files/cockpit_module_158.jpg ________________________________ Message 3 _____________________________________ Time: 01:37:27 AM PST US From: Frans Veldman Subject: Re: Europa-List: Vapour lock? Why? Hi Kevin, > I was having a similar problem with my 914. Mine was running rough and stumbling at high power, but only at altitudes above 10,000'. > The fuel differential pressure gauge would drop and engine run worse with more power applied. I think my problem is different. The weird thing is that I'm looking at a *momentary* drop in fuel pressure, during the first few seconds at take off power. The fuel pressure then comes back up and the engine runs fine. Now I'm 100% sure that there is sufficient fuel flow (pump and filters are ok) it is a mystery why the fuel pressure drops. Note here that I'm referring to the differential fuel pressure. So it looks like when the turbo pressure goes up, the fuel pressure lags behind, to catch up a few seconds later. That's why I suspect the fuel pressure regulator. This is what you could expect when the regulator valve is "sticky". I'm also suspecting the carbs (including the carb bowl gaskets). However it is a bit strange that the engine runs fine after a few seconds. From your description of leaking carb bowl gaskets I get the impression that your symptoms were of a more constant nature. A carb slide with some friction could be an explanation for the temporary nature of the problem, but I can't see a relation with the fuel pressure here. If the slide misbehaves, you should't see a drop in fuel pressure. I have observed an overall slightly higher fuel consumption, based on the fuel flow gauge. Having said that, it is a differential flow meter, substracting the return flow from the main flow. As the main flow is over 120 liters per hour, it is hard to say whether a measured fuel consumpion increase of about 1 to 2 liters per hour is real or just a small deviation in one of the two flow sensors. Also the carbs or entire engine could be aging and the whole problem might be unrelated to the power surge in the first few seconds of the take off. Back to the fuel pressure regulator. I think that it should held pressure in its reference port (the small hose connector in the lower shell) but the air is leaking away rapidly, mostl likely internally, i.e. via the fuel return hose. This would indicate a leaking diaphragm. Can anyone confirm that this leak in the reference port is indeed a fault? (This is not so obvious as I can imagine that the designers choosed to deliberately incorporate a small leak to cope with a potentially plugged reference port and to use ambiant pressure in that case as a backup reference). Frans ________________________________ Message 4 _____________________________________ Time: 03:25:37 AM PST US Subject: Europa-List: Re: Landing mishap - asking for advise From: "zwakie" Duncan McFadyean wrote: > You'll also need to measure the diameter for any meaningful comparison; generally, as diameter increases, the required overall prop twist along the blade needs to be slightly less.-- Absolutely, goes without saying... Update after doing more thorough checks yesterday (engine still attached, more might creep up once engine is taken off): Additional damage found: - Propeller hub: a fine crack (appr. 3 cm long) protruding from the inset of the prop blade that took the hardest hit. - Small crack in the spinner. No visible damage to: - Engine mounts - Landing gear frame - Fuselage around engine frame attachment points - Any parts connected to engine, including exhaust pipes (geometry still needs to be checked) -------- Marcel (Europa Classic Tri-Gear PH-MZW) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=381863#381863 ________________________________ Message 5 _____________________________________ Time: 03:44:28 AM PST US Subject: Europa-List: Anybody willing to pick me up for Dutch GA Fly-in? From: "zwakie" I was planning to attend the Dutch GA Fly-in at 7-8-9 September at Texel (EHTX), flying out there with PH-MZW. After my landing mishap two weeks ago that no longer is an option, so I am looking for alternative means of 'transportation by air'. Is there anybody attending this fly-in that has a seat available and willing to make an extra stop at Hoogeveen (EHHO) to pick me up and drop me off upon return? -------- Marcel (Europa Classic Tri-Gear PH-MZW) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=381865#381865 ________________________________ Message 6 _____________________________________ Time: 06:11:55 AM PST US From: klinefelter.kevin@gmail.com Subject: Re: Europa-List: Vapour lock? Why? Frans, My engine symptoms were not constant. Only at high power. Your symptoms sound similar. Momentary drop in fuel differential pressure. I only changed the float bowl gaskets and that fixed it. Could be when the turbo pressure goes up, the fuel pressure leaks out of a carb bowl gasket. In the Rotax classes I took (Rotech in Canada who also run Rotax-owner.com) they emphasized always suspecting and ruling out carburetor problems first. They also told us that the cork gaskets are better than the paper ones. Bob Borger sent an eBay link a while back for nitrile gaskets. I bought a pair but have not installed them. I replaced the gaskets without pulling the carbs off the engine, which is faster but a bit awkward. A wee bit of grease on the gasket will help it stay put upside-down in the carb body till you replace the bowl. Over-torque of the retaining bolt (that has an o-ring to inspect) can distort the bowl and cause float problems. The drip trays are such a pain with the little nuts and washers that I modified them with nut plates. Much easier. You must be about tired of this by now! Best of luck, Kevin On Aug 26, 2012, at 2:29 AM, Frans Veldman wrote: > > Hi Kevin, > >> I was having a similar problem with my 914. Mine was running rough and stumbling at high power, but only at altitudes above 10,000'. >> The fuel differential pressure gauge would drop and engine run worse with more power applied. > > I think my problem is different. The weird thing is that I'm looking at > a *momentary* drop in fuel pressure, during the first few seconds at > take off power. The fuel pressure then comes back up and the engine runs > fine. Now I'm 100% sure that there is sufficient fuel flow (pump and > filters are ok) it is a mystery why the fuel pressure drops. Note here > that I'm referring to the differential fuel pressure. So it looks like > when the turbo pressure goes up, the fuel pressure lags behind, to catch > up a few seconds later. That's why I suspect the fuel pressure > regulator. This is what you could expect when the regulator valve is > "sticky". > > I'm also suspecting the carbs (including the carb bowl gaskets). However > it is a bit strange that the engine runs fine after a few seconds. From > your description of leaking carb bowl gaskets I get the impression that > your symptoms were of a more constant nature. > > A carb slide with some friction could be an explanation for the > temporary nature of the problem, but I can't see a relation with the > fuel pressure here. If the slide misbehaves, you should't see a drop in > fuel pressure. > > I have observed an overall slightly higher fuel consumption, based on > the fuel flow gauge. Having said that, it is a differential flow meter, > substracting the return flow from the main flow. As the main flow is > over 120 liters per hour, it is hard to say whether a measured fuel > consumpion increase of about 1 to 2 liters per hour is real or just a > small deviation in one of the two flow sensors. Also the carbs or entire > engine could be aging and the whole problem might be unrelated to the > power surge in the first few seconds of the take off. > > Back to the fuel pressure regulator. I think that it should held > pressure in its reference port (the small hose connector in the lower > shell) but the air is leaking away rapidly, mostl likely internally, > i.e. via the fuel return hose. This would indicate a leaking diaphragm. > Can anyone confirm that this leak in the reference port is indeed a > fault? (This is not so obvious as I can imagine that the designers > choosed to deliberately incorporate a small leak to cope with a > potentially plugged reference port and to use ambiant pressure in that > case as a backup reference). > > Frans > > > > > ________________________________ Message 7 _____________________________________ Time: 07:15:49 AM PST US Subject: Re: Europa-List: Re: Cracks on the cockpit module near to the seat belts From: Paul McAllister Duncan, Thanks for posting this, I have been meaning to post something similar so you have saved me the trouble of going into the detail. Jacques, the only thing I would like to add is that ideally you need to use the same cloth that was used in the original construction. In this case it might prove difficult because pre-preg bid was probably used in manufacture. The reason you need to do this is that using a material that is significantly different means that this material may carry more (or less) of the required load and become a source of stress in of its self. I would see if you can get a response from Nev or Ivan to to find out how many layers of material were used and what sort of cloth was used. I know that when I did a repair on my wing I was fortunate enough to be able to get the exact cloth that was not pre-preg'd. Ask them is it the same cloth that was used in the wing. If it was then I have a small amount of this and I can send it to you. Failing that, it wouldn't be horrible if you can't match the cloth, but do try and find out how many layers were in the original construction. Paul On Sun, Aug 26, 2012 at 3:11 AM, Duncan & Ami wrote: > ami-mcfadyean@talktalk.net> > > <<..Any advice is welcome. .>> > OK, I'll bite! > > During a monowheel collapse, the weight of the aircraft (less tailwheel and > outrigger loads) is transferred from the monowheel in to the top of the > 'tunnel'. Thereafter, the stress-path from the tunnel is mostly both > forwards and aftwards. In the aft direction the tunnel distributes loads in > to the seatback bulkhead then further in to the fuselage skin. This means > that the area that has cracked (being at along this stress-path is taking > abnormal loads and this is a possible cause of the cracking, as you have > surmised, compounded by the holes that have been cut at that point. > Assuming there is no evidence of any other overstress in that area, the > repair needs to put back the strength lost. This means replication of the > original strength of composite in that location, which can be determined by > counting the number of plies present. Allow a minimum 1/2 inch per ply > overlap on to the surrounding unaffected area (presuming a bond shear > strength of 500psi and cloth strength of 250lbs/in) with staggered edges. > If > the holes must be recut, then double the reinforcement and cut the holes as > ellipses (at a length:width ratio of 1.414:1, if you want to be pedantic!). > > Too much or overdesigned reinforcement may make the area too stiff and > introduce other issues, and makes the aircraft heavy too! > > Your respective airworthiness and/or design authority will be the final > arbiter of any repair, which might be along the lines of the above. > > Duncan McF. > > ________________________________ Message 8 _____________________________________ Time: 08:12:12 AM PST US Subject: Europa-List: NSI controller From: Kevin Challis Hi A new second hand controller sourced from this forum. Fitted and all is well with my prop. Thank you for everyones help. >From now on I will turn the power off to the controller when on the ground and in fine. I was lucky that it went fully course at Biggin hill at the start of my take off run as its a massive runway on top of a hill. It wouldn't have been so good taking off from a 400m grass strip with high ground all around! 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