Dermot McD

Mostly yes. However we have had several unexplained failures with loctite over the years. The manufacturer of a motor we use recommends loctite as the best method of securing a gear or pulley rather than a key, however sometimes they fall off. Loctite has a recommended shelf life (2 years?) so we're better at throwing bottles away than before but either something works or, if it does not, then it's unsafe. Where Loctite is used on the fuel elbows, the recommended temperature to remove the fittings is almost the same as the temperature of the coolant. I'm slightly perplexed by some of the inconsistencies in Rotax engines… some fasteners safety wired, others not. Some with loctite and others not. I'm annoyed by things like barbed fittings as standard and anything else being penalised by over the top prices. I don't envy them having to make recommendations about service intervals etc. Any manufacturer is going to err on the side of caution. However I know from our work that Waddington's principals apply so if a customer wants to know what to service, we say don't. Have a good close look at it and if it is not broken or worn, leave it alone.

Hello SD, Agreed. However, apart from often using obscure and obsolete measurement units, I was not sure that there was information on Mackay rubber hoses there since it's mainly US. I got that info here. They also don't have to deal with Bert Flood. I'm not sure how they deal with criticism of Rotax. I'm an edge of the bed Rotax fan these days. While the engine etc. is pretty good, they've gone down the Katmandu route where everything is now branded Rotax… Bing Carbs, K&N air cleaners etc. My original Rotax installation was entirely AN fittings and to replace many of these fittings, you have to either use AN car parts (which is generally OK in my opinion since most Rotax plumbing is automotive) or buy barb to AN fittings from Rotax at a cost of about 14 times the real cost. $175 for a simple brass fitting. That's if you can find a replacement. The current standard oil tank top has metric reverse flare fittings. I haven't found anything which seems to fit these to go to AN. D

Yes it appears to be the case only on the coolant elbows since at least the 2022 manual. Other Loctites used elsewhere. My guess is that this might be something to do with the gap filling and reduction in strength with temperature but that's only a guess. A few years ago, I think it was 648. I found this on the Rotax-Owner website: "I started some research and found that the rotax-owner video calls for "Loctite 648", which is pretty expensive and not rated as a thread seal either, plus, the data sheet indicates that 648 looses strength over time in Glycol. So I contacted Loctite customer service and they were adamant in recommending "Loctite 577" for this application. I have now done 2 of the elbows with "648" and will do the last one with "577". Curious to know what other people's experiences are. I can already tell you that excessive and hardened 648 is very difficult to remove from the aluminium flange sealing surface." So there you are. Typical rabbit hole! I think any of these would work OK but since I have 577, then that's what I will use. D

You don't want to deviate too far from the Rotax maintenance manuals with a new engine or they can void the warranty. Personally, I am not 100% happy with gluing parts together like this but who am I? For those who don't know, the coolant elbows are screwed and glued directly into the water jacket of the cylinder head and coolant pump. Making something up from stainless isn't really an option. Loctite both secures the elbows and fills gaps in the threads. The original recommendation from Rotax was to use 243 (which softens about 165º) but now they recommend 577 which is a fairly standard thread sealant but has better gap-filling properties (about 0.25mm) which is the main point. However this softens at 250º. Having used a hot air gun for heavy soldering etc. I am a lot happier with that than a naked flame with its endemic oxidation and corrosion problems. D

I thought I would put some information up here about Rotax 9xx coolant hoses and elbows because I have not found anything suitable elsewhere. I'm doing an engine swap and of course found that the coolant elbows were pointed directly at the engine mounts and that while Rotax recommend heat shielding over the cylinder head coolant lines, they don't fit this on new engines. The 17mm Continental hoses are a really tight fit and one had to be cut off to remove it. The coolant elbows are a bit of a fiddle to remove so they can be clocked properly. The recommendation is to heat the elbow to 120ºC and using a dowel or drift, turn the elbow. I don't fully understand the logic here since the type of Loctite used on the elbow still has 90% strength at 120º and that's about the working temperature of the elbow. Anyway, some public notes on stuff I found below. The current Bert Flood price on nominally 17mm ID coolant hose is $178 per metre but I only needed 200mm and would have to buy a full metre. Mackay rubber do a nominal 17.5mm hose. The Mackay hose I bought measures 17.3 ID. From memory, the BF Continental hose is closer to 16mm ID than 17… though measuring rubber is not a precise art. Both types of hose have a yellow, possibly Kevlar reinforcement. The Mackay hose fits snugly over the elbows and given the right hose clamps should work as well as the Conti version. The elbow is 18 OD - 19.1mm over the pip at the end. The ID is about 13.85 some something less than this is the right diameter for a rod to turn the elbow once it is hot. Using a hot air gun is fairly slow since heat is conducted away almost as soon as it is applied. I wonder whether a cartridge heating element in a 13.8mm plug inserted into the elbow would be a better option and it's something I will try after getting one. Something about using a propane torch on a new engine offends me! The elbow thread is M18 x 1. Good luck in running a tap or die over the mating parts to clean up the Loctite without wrecking the thread. A 1mm thread file will do better than a wire brush. If only BRS had supplied the parts loose instead of this rigmarole. D

The above sentence could just as easily state: "Had each aircraft been fitted with FLARM, and a suitable cockpit display, the occupants would have received a better quality of surveillance information than received by the controller." I'm not saying ADS-B is useless (thought it is unless almost everyone has it), I am just say for the benefit of those who do not use it, that FLARM is actually a better system and it's a shame that this was not adopted. This is from the FLARM website: "FLARM works by calculating and broadcasting its own future flight path to nearby aircraft. At the same time, it receives the future flight path from surrounding aircraft. An intelligent motion prediction algorithm calculates a collision risk for each aircraft based on an integrated risk model. When a collision is imminent, the pilots are alerted with the relative position of the intruder, enabling them to avoid a collision" Isn't this a VHS and whatever that other technology was. VHS was inferior in almost every way but it triumphed (aided by the porn industry.) Have you flown with FLARM? Almost all gliders are required to have a functional FLARM while unless the rules have changed, GA aircraft are not and last time I looked had an installation rate of about 5% which makes it worthless in most situations because it obviously works only if both aircraft have it. And regarding radio, I fly power and gliders, both VH registered but being an amateur flyer, I try to use correct radio communications with communication being the important part. My radio comments were about poor practice by many VH registered power pilots, perhaps hoping that RA pilots were better. I have no problem at all with commenting that many, if not most VH pilots regularly omit or garble their location since most if not all my RPT friends say the same thing. D

Yes, but the collision warning is done by you, slowly if you are tired and so far as I remember, with no audio or visible warning. FLARM does all the calculations internally, very quickly and with multiple threats with obvious spoken audio, beeps and visible flashes without you really needing to have your eyes in the cockpit. This is what makes it useful when gliding. Even when 'cruising' between thermals, a glider may make large deviations to avoid sink or look for the next lift source. This isn't something that you get much in powered aviation. FLARM copes with this well. Perhaps latency is the wrong word. On a recent trip flying in central QLD, the position of another aircraft was jumping all over the place on Ozrunways and sometimes appeared twice. This was probably due to the competing signals from ADS-B and OzRunways using the phone system. The point remains though that while things like the SE2 are useful and probably as good as you'll get for GA use, they're not half as useful as FLARM as a collision avoidance system. Since FLARM can record a flight track, the data can and has been used to assess mid-airs and crashes which is really what this thread is about. I'm actually not a huge FLARM fan or things like the SE2. They're OK tools but I find it baffling that regulators cannot get themselves together and include the superior functionalities of FLARM with ADS-B etc in one reasonably priced device.

I've got both ADS-B (SE2) and FLARM installed. FLARM is far more useful. As Plantain says, FLARM is an anti collision system with in-built functions to calculate the possibility of a collision. The basic display with tri-colour LEDS shows only direction and whether the contact aircraft is above, below or at your level. In comparison, something like the SkyEcho only shows you roughly where the other aircraft was within a 5 minute window. Given the right glide computer, FLARM will voice announce a collision warning giving the pilot the bearing (as in 9 o'clock) the relative altitude and distance, flash the computer display orange and display the aircraft on screen. It's well above the ADS-B in almost all regards. FLARM has an installed database of over 15,000 users including rescue aircraft and the Battle of Britain flight aircraft. While it is not perfect, it is ideal where a number of aircraft are flying in close proximity like the Alps, where it was developed. So what's surprising in many ways is why we adopted ADS-B instead of FLARM. I'm not so sure about RA pilots, but I know for sure that almost no glider pilot is as bad at radio calls as most GA pilots. Most radio calls from GA pilots will tell you their life story in terms of tracking, intentions, altitude etc. while clipping or garbling the most important words at the start - location - and omitting them altogether at the close of transmission. That said, at the London Gliding Club, an Australian instructor was having a flight with a local instructor and asked whether he should make a radio call. The instructor replied that would be pointless since there were about 150 aircraft in the region and making a radio call would distract their attention from a proper lookout and make things more dangerous than less so. During a competition, it's common to have three or more gliders doing straight in landings in very close proximity at about the same time - that is with some lateral separation but little lateral separation - think Oshkosh x 4 on a narrower strip. A short radio call to say if they're landing short, long, left or right is about all that's said. So radio is an aid to situational awareness but only that. Finally, most gliders are white because most are made from a low-temperature epoxy which will soften around 55-60º. Modern ones are PU painted but older ones use gelcoat. With a modern glider costing north of $400,000, people don't usually leave them outdoors if they can help it!