Trike engine reliability. Are they all equal?

Published by: Paul Hamilton on 9th Aug 2017 | View all blogs by Paul Hamilton

 

What is most interesting is how history repeats itself. A year or two ago I put out a video of flying over Los Angeles. There were critics who expressed their opinions condemning me for flying over a city where there was no suitable landing area with an engine out.

 


Then a very intelligent pilot with lots of aviation experience said something like “there are thousands of single engine airplanes flying over hundreds of cities EVERY DAY in a similar situation. Why is a trike different?”

Good question. Why is a single engine trike aircraft ideology different than all the airplane GA aircraft flying over big cities? Airplane pilots are not badmouthing each other as they fly around. Why are trike pilots different? What motivates trike pilots to have this fearful ideology of engine failure.

It is simple. Here is why. Trikes initially started out with lawn mower engines and progressed to the two stroke ROTAX engines. In the basic “Risk Analysis Matrix” There was a Probable or Occasional likelihood of engine failure simply from the fact of basic two stroke unreliability. Add to that modifications, primitive designs, bad maintenance, and bad operations. There were expectably plenty of engine failures. Now add the four stroke upgrade on experimental’s and things got remarkably better. Why do you think everyone wants a four stroke? THEY ARE SIMPLY MORE RELIABLE. Now add the factory built S-LSA designs with FAA certified mechanics. The S-LSA are simply at a new level of engine reliability if properly maintained. Now we are at the engine reliability level of the GA certificated aircraft. S-LSA have the reliability of all those thousands of single engine aircraft flying over hundreds of cities EVERY DAY.GA airplanes fly IFR into clouds, over mountains at night, and over the open water.

If we try to compare the two stroke and/or old design/badly maintained to a 912 factory design and maintained S-LSA, these are different animals. Not an intelligent comparison.

Modern S-LSA designs maintained by qualified FAA mechanics get to the risk assessment likelihood of remote or possibly improbable. Just like GA engines.

Today I did a flight review in an Ercoupe that was built in 1946. This just came out of annual and I saw it in the shop. It has old systems. However, I feel this is much more reliable than the early two strokes, but I do not think it is as reliable as my Rotax 912 S-LSA that I personally maintain as a FAA Light Sport Repairman Maintenance to S-LSA standards.

So in summary, trikes have come a long way in safety and reliability. So to classify all trikes in the same engine failure likelihood category does not make sense. This is pretty simple. There are many different levels of reliability.

 

 

 

Has who has had engine failures, what type of engine was it (two stroke/four stroke), and what type of a trike was it E-SLA or S-SLA. I would like to find out the statistics so we can get smarter with this.

 

Comments

66 Comments

  • Charles Moore
    by Charles Moore 7 days ago
    I have had a engine failure. Rotax 912 (80hp). Full fuel on board. Both carb bowls empty upon examination afterwards. No apparent obstructions in fuel system. No tell-tell signs of dripping from fuel pump weep hole. Replacing engine driven pump and adding an electric backup pump. Would like to hear who has ran a return line to tank when moving to new style engine driven pump (as required by rotax).
  • Paul Hamilton
    by Paul Hamilton 7 days ago
    Charles,
    Have you concluded with certainty it was the mechanical driven fuel pump? That was really smart to do the most important check after an engine failure for any carb engine to diagnose the problem, CHECK THE FUEL BOWLS.
  • Robert Sumner
    by Robert Sumner 6 days ago
    It wasn't that long ago Paul that you posted how rotax two strokes are plenty reliable. Can't quote it exactly, but I do remember you saying you never had any engine outs or related probs with your Cosmos 503. I believe you were flying a 582 at the time. Not talking crap bout the 912, but it seems tons of AD's come out on the 912 with tweeks here and there all the time. In my small group of trike pilots, the only one who has ever had and engine out has been the 912... Fuel reltated.

    Seems the 912's are having fuel delivery issues when things go bad which are minor compared to when a two stroke stops where its usually a big mechanical issue like a seized piston or a blown lower bearing. Either way, having complete faith your engine will stay running is prolly a little dangerous for the 1 time it happens.
  • PHILIP QUANTRILL
    by PHILIP QUANTRILL 6 days ago
    Interesting if sometimes heavy going video regards strokers and the major causes of their problems ..... we pilots.
    http://www.eaavideo.org/video.aspx?v=626943072001
  • Paul Hamilton
    by Paul Hamilton 6 days ago
    Yes Robert and Philip,
    Two strokes can be incredibly reliable with love, constant attention and knowledge of which four strokes are much more tolerant.
    Yes I did do a blog on this http://www.trikepilot.com/magazine/read/rotax-two-stroke-reliability-reveled_876.html which stated this.

    In my opinion, the fuel pump system on a Rotax two stroke is more reliable than some of the Rotax four stroke mechanical fuel pumps. That is why I insist on having an auxiliary/backup fuel pump on my 912. In my opinion, risk increases significantly with only one mechanical fuel pump. In fact for my commercial/training operations, I add fuel pressure for ALL my personal S-LSA trikes.
  • Paul Hamilton
    by Paul Hamilton 6 days ago
    I can not watch EAA/Carpenter's full 90 minute video but I trained with Brian so I know and agree with his thoughts/opinions.
    As I said "2 strokes do not die, THEY ARE MURDERED".

    http://www.trikepilot.com/magazine/read/rotax-two-stroke-reliability-reveled_876.html
  • Ken Highfield
    by Ken Highfield 6 days ago
    Not to change the subject but while your on the topic of engine outs and forced landing here is a ? BEANS or CORN? crops are high now, corn is 6' beans 2-3'
    Say there is NO freshly cut hay field or excellent ideal place to land and forced to choose between beans and corn. I am curious if anyone has landed in either? Corn may slow you down but more damage to aircraft and beans may grab like valcro. Your thoughts? I took someone up flying last night and asked him where he would land if we had an engine out, we did have plenty of good options but wanted him to think about it.
  • Paul Hamilton
    by Paul Hamilton 6 days ago
    Ken, The best emergency landing is a subjective opinion, beans verses corn is out of my expertise area.
    Typically landing areas look great from up high but get ugly the closer you get...
  • Bryan Tuffnell
    by Bryan Tuffnell 6 days ago
    I've had a number of 2 stroke failures for predictable reasons. I've recently had a second engine failure on a 912UL. The first was suspected carb icing, but this was unproven (and full-time carb heat is used). Just recently a tooth came off the gearset (which had done 32 hours), completely trashing the gearbox and sending steel shards through the oil lines (and both sides of the oil filter).

    I've also witnessed a Rans S6 crash when a 912ULS died on takeoff. No known reason for that one.
  • Damien B
    by Damien B 6 days ago
    None in my Personal Aircraft (rotax 503 and HKS 700E), over 12 years of reliable use.
    4 in Student Aircrafts: 1 Rotax 582, dirty carbs. 1 582 downwind in the pattern, ran out of fuel. student swore there was 5 gallons in the concealed tank and I was doing a quick 10 min test flight in the pattern. I should have checked more diligently. 1 582 on take off, unknown reason. 1 912ULS on Final, most likely bad floats in the carb.
    No damage to aircraft or persons in all events.
  • monty stone
    by monty stone 6 days ago
    Hi Paul, interesting subject, comparing apples to oranges, though . however much 'love' you bestow on an apple it will never become an orange. In common with many 'users' of two cycle engines I've experienced my share of 'engine outs. With, four cycle units also, ( ground-bound engines). Every down stroke on a twice cycle engine produces heat, mostly kept in-bounds by 'copious' fuel droplets absorbing some heat before escaping to our atmosphere, without joining up with their oxygen buddies and producing more heat. The main reason we don't see many new two-cycle designs is the expense of dealing with these un- used droplets, ie blue smoke, etch . All the major players, ford, Toyota, etc have tried to overcome this bugaboo, it can't be done, as of now. The advantage in power and light weight over a fourstroke, while undeniable loses out on reliability, due to the fourstroke's idle strokes when little heat is produced, but all the guts are 'swamped' with relatively 'cool' oil, which then transfers a lot of heat to the little Air mollycuddles rushing through a radiator. ( all engines except marine, are 'air cooled' even the ones with fluids coursing through their metallic veins. ). Anything man-made can die, even when subjected to 'love care and attention, I posted a picture of my Suzuki piston with an exhaust valve that had 'penetrated the piston a week or two ago. I only fly with a two cycle engine behind me 'cos there ain't nothing else out there affordable, or suitable for me. For the reasons listed, ie, extra heat, 'dirty' ehaust, etc, two cycle engines are done. Even china and India are going to ban them. If I had a choice, I would definitely run a four-stroke engine, based not on 'statistics', but of over 65 years practical experience with engines from 'lawn-mowers to 12litre diesels. Ps, Pablo, you mention 'bad-mouthing' between trike pilots, and not ga pilots, if you are referring to me criticizing your video of you trikeing over downtown la, I didn't intend to 'bad mouth you, only to admonish' your decision to 'as you stated' if necessary, 'land on the roof of a large building! I warned of 'air condition units and chimneys on the roof.! Ps, being a 'skairdy-cat I continuously scope out potential 'emergency crash sites' amongst which, was a beautiful bright green 'sward' which I later found out was a sewage farm.
  • monty stone
    by monty stone 6 days ago
    Hey tussock, old fruit, look on the bright side, you'll be putting another of the rotax family kids through colledge, by the time you buy them 'bits'.
  • Frank Roush
    by Frank Roush 6 days ago
    I think Damien was talking about my 582 on takeoff. If I punch the throttle it will putter out and stop and I don't want it to happen in a stressful situation. I have good fuel, the carb floats are good, and there's fuel in the carb bowls. Any experience or ideas about this?
  • Job Chithalan
    by Job Chithalan 6 days ago
    Hirth say that their engines of today can not be compared to two stroke engines of the past.
    Huge range from 17hp to 110 hp Fuel injection.
    "Factory recommended TBO is rated at 1000 hours at 75 % power" and
    1200 hour TBO on their engines below 6,000 max rpm.
    Here is their essay "Two Stroke Logic"
    http://hirth-engines.de/index.php/en/2-stroke-logic
    Very tempting claims.
    Like to hear from pilots with experience of using Hirth engines
  • Scott Williams
    by Scott Williams 6 days ago
    IMHO, Rotax has two pretty serious issues to deal with that would go a very long way. #1 the carb floats not floating from saturation and the new mech fuel pumps failure rate. The older ones where much more reliable. Both of these are not Rotax built items but we bare the burden as a fleet. Fix both of those and the 912UL/S is as reliable as any O200. Two strokes live too close to the edge of metal heat performance failure. When two strokes die it's usually sudden with little heads up. Four strokes live in cooler realms and die slower with more warning/complaining. All extremely general statements! I've flown both 2 and 4 strokes and FEEL safer behind a 912UL for the reasons above. And yes, I have a backup fuel pump for my 912 as I don't trust the new design.
  • Charles Moore
    by Charles Moore 6 days ago
    Paul, I haven't with all certainty concluded that the mechanical pump that failed. The only thing I haven't pulled is the coarse filter out of the tank. What was weird is that once back at the airport and tied down it would crank up, but only run up to about 3200rpm then sputter and die. We plumbed in an electric aux pump, in a temp location, and re-ran the test. At a little over 3200rpm it sputtered, then turning on the aux pump the sputtering went away. To shorten a long story, I am replacing everything in the fuel system except the carbs. I even got a new fuel tank.
  • Larry  Mednick
    by Larry Mednick 6 days ago
    Job, our 3 cylinder Hirth had 10 engine outs in one year finally blowing a hole in the rear piston. A bad ground on the fuel injection caused 5 of those engine outs before we stuck a set of carbs on it. In the end the gearbox broke off years later, since it was only held on by 4 cast aluminum tabs, and the prop cut off the tail on the M Squared that it was on and the pilot went in fatally.

    I understand their new horizontally opposed 50 HP twin works well. I know their single cylinder engine has not had a good track record at all.

    I have had more engine outs than you can imagine. A couple of unpredictable ones include a crank bearing failure in a 582 at 27 hours and a gear box slip at 400 hours. I even got to go swimming because the throttle cable snapped. That was fun...

    I trust my aircraft with my life, but that does not include my ability to make thrust. The engine was not the primary cause of off field landings. The fuel system, prop, prop debris etc were much greater causes.

    In the last few years all I have had was a belt snap on a SIMONINI during lift off. That was exciting trying to pitch the nose over while find my kill on an unfamiliar aircraft while the engine redlined all from 150' up.
  • Job Chithalan
    by Job Chithalan 5 days ago
    Thanks Larry!
    Having an EO at 150 feet is a frightening thought for someone like me who fly from a short field.
    So far has been lucky.

    In the near future I need to replace Rotax 377 and a 447.
    Polini Thor 250 DUAL SPARK and Hirth F23 are in my short list.
    Like the idea of having dual ignition, eventhough they are really partial dual ignition.

    Lighter and more powerful than the engines they are replacing.
    Theory is that the engine will run at lower rpm at cruise speeds, resulting in better reliablility and reduced fuel consumption.

    Have seen your Dan Johnson video about the Polini 250.
    Hopefully, belt snapping is a rare event.
  • monty stone
    by monty stone 5 days ago
    Yeah job, belt snapping is rare, it only happens once! ( per belt!).
  • Larry  Mednick
    by Larry Mednick 5 days ago
    Some engines (MZ's ) the belt tensioning system is inadequate to keep proper tension
  • monty stone
    by monty stone 5 days ago
    Yeah Larry, some older engines, lambretta vespa etc had no belt used a fan on the flywheel, not enough air.at high load, ? With proper ducting it would work. Deutz is a german air-cooled engine they make many diesels up to ten cyls, no fan belts.
  • monty stone
    by monty stone 5 days ago
    Gm buses did away with belts in the 1950s, they had a giant fan on the crank, everything else was mechanically driven. Belts are wearing/maintenance issue that need to be checked frequently.Ps they all had two stroke engines!
  • Job Chithalan
    by Job Chithalan 5 days ago
    I have long been using Rocol Belt Dressing spray on both sides. Reduces slip, prevents cracking, protects from UV, etc.
    Use sparingly or it will be messy.
  • Frank Dempsey
    by Frank Dempsey 5 days ago
    Friends don't let friends fly Hirth's. Man, I've seen a lot of trouble with that one. John Cortesy went down over the Grand Canyon with his wife. It blew a plug out of it's socket. They glided to the rim for safety. He was high. Later, he flew that damn thing at my towered airport. On base, the motor went silent. He made it to a taxiway and rolled to the ramp. That's the last time it flew.
  • Rizwan Bukhari
    by Rizwan Bukhari 5 days ago
    I think the bottom line is that any engine can quit. A well maintained 912 may have a much less chance of quitting but it is still a machine.

    I sometimes feel that "some" Trike pilots take more chances and fly too close to the ground or ignore their emergency landing options. There was another accident recently where two people died in what appears to be a Pegasus 912 trike. The trike crashed in the water.

    Paul started this blog as a result of some of us asking about where he would land in an emergency in his Miss Nevada video (http://www.trikepilot.com/videos/view/miss-nevada-flies-in-a-trike-part-6_25763.html) , where in a few parts of the video Paul comes really close to the water and is flying very low with apparently no where to land in an emergency.

    Paul's answer was the reliability of his well maintained SLSA engine. I think that is a dangerous way to think about safety, especially when you are with an innocent student and an emergency could endanger their life. My two cents on this topic.
  • Kevin Szalapski
    by Kevin Szalapski 4 days ago
    I have a 912 engine on my trike. The one thing I do to decrease the odds of an engine failure in flight, is send in an oil sample to Blackstone Labs on every oil change. ( about 50 hours) It costs $26 and you know if any parts are shedding pieces of themselves. All elements found in oil are shown in PPM and the analyst of the oil will write a paragraph about any concerns. You can also call and talk directly with the person that performed the test to get more info. This does not guarantee your engine will stay running, but the oil will tell a lot about what is happening inside.
  • Larry  Mednick
    by Larry Mednick 4 days ago
    Fuel delivery (on some level) to the 912 carbs is still the number one cause of engine outs with the 912.
  • Abid Farooqui
    by Abid Farooqui 4 days ago
    Kevin oil sampling is good but every oil change is way overkill. Every 3 oil changes would be sufficient. The internals of the engine are fairly solid. It's things like carb floats or fuel pump that are not made by Rotax but Bing and other German suppliers that as reliable as a newly made Mercedes. Which means they are not reliable. Rotax should change from these mainly German suppliers because it has been shown they can't consistently get quality results. The problem is not many vendors are likely to supply parts for an aircraft engine.
  • Rizwan Bukhari
    by Rizwan Bukhari 4 days ago
    So what is the solution to the Fuel delivery issues on an 912. When I bought my XT, the first thing I did was get the new Fuel pump and replaced the fuel filter, fuel lines and spark plugs. Should I be worried about anything else? My engine is 912 manufactured in 2008, should I worry about the carb floats too. I don't think the Rotax Safety directive says anything about the carb floats for my engine year (2008).
  • Paul Hamilton
    by Paul Hamilton 4 days ago
    Well Riz again you are predictable. With all the videos of people flying low you focus on mine. How about you give it up and move on. It would be better for everybody. Your negativity is not helpful for any one.

    If you really want to know where I would land with an engine out in the video it is pretty odious, straight ahead in the shallow water with soft sand. The locations I fly low over water, I specifically make sure the water is shallow and the sand is soft. Other times I am always within a glide near shallow water and I would blow the chute with enough altitude. That is one of the reasons to have a chute. Yes if I had an engine out I would not be happy and we would probably get beat up and wet, but those are the risks and consequences I choose. I go to great lengths to make my engine as reliable as possible just as a make decisions of when and where to fly. For you to focus on judging me publicly from your keyboard is pretty lame.

    I hope you and everyone else realize that every thing you do in life has a degree of risk. That was the purpose of this blog which apparently you did not get or want to believe. I think most everyone else gets it. It is simply a matter of how much risk we want to take for what activity. Like when we all take your family in the car, there is a risk we could die along with our families for many reasons that are not your fault. We go into any public area, there could be a mad man who could shoot us. When we do not eat right we could get sick from the food or eat too much of it and die. There could be an earthquake when we are in any building and we die. The list goes on. Every day and action we take has risk.

    For you to single out my specific risk flying is really getting old and not productive. There are hundreds of trike videos showing high risk and not a peep from you. Nothing. I still do not understand why you are targeting me.

    I have helped you with issues and you continue to harass me

    So please get over whatever your problem is and move on with life. If you have some problem with me or issue call me at 775 772 8232 and we can work it out. I have offered this to you before and never heard from you.

    Please move on and try to do something positive and helpful for the triking community.

    Sincerely,
    Paul Hamilton
  • Paul Hamilton
    by Paul Hamilton 4 days ago
    Bryan,
    Any reason for the gear tooth coming off? That is the first I have heard of that. I know things turn the wrong direction south of the equator could that have something to do with it.

    Carb ice for the 912, does it really happen? I have heard both sides of the story.
  • Paul Hamilton
    by Paul Hamilton 4 days ago
    Yes as Larry sez, fuel delivery is a major contributor which is the weak link in the system. Pump, filter, quality, quantity the list goes on.
  • Paul Hamilton
    by Paul Hamilton 4 days ago
    Riz,
    Yes check your floats. See my blog addressing this at http://www.trikepilot.com/magazine/read/rotax-912-float-warning-check-yours-it-can-happen-to-you-it-has-happened-to-me_1157.html

    Additionally, as I said before, I do not fly without an auxiliary fuel pump. Only one fuel pump adds additional risk if you are willing to accept it. I am not for the trikes and airplanes I fly. Most certified aircraft have an auxiliary fuel pump and many LSA manufacturers are adding them. The problem with S-LSA, is that to add an auxiliary fuel pump you have to get an LOA from the manufacturer. Not easy for such a major change.

    One time I was flying when it was super hot at high altitude and my 912 started loosing power. Yikes. I switched on the aux pump and it fixed the problem. I think it was vapor lock with the high temperature and high density altitude.
  • Paul Hamilton
    by Paul Hamilton 4 days ago
    Another tip for you Riz and all who change out your fuel lines. Many times cutting the fuel lines and putting them on can allow small rubber pieces into the fuel system AFTER the fuel filter. These can get into the jets and stop the engine. The best way to flush it is to turn on your aux fuel pump with the bowls off which will run fuel fast through the system and flush it. With no aux pump you can run it, and pop the bowls and looks for the pieces. When we think we are doing good replacing fuel lines caution must be exercised returning it to service.
  • Larry  Mednick
    by Larry Mednick 4 days ago
    Yes changing out the fuel lines is a great way to plug up an idle or main jet on a carburated motor like a 912 UL or ULS. New carburated aircraft are highly susceptible to small pieces of rubber causing issues. One of the benefits to the 912iS is at 45PSI the fuel system is capable of blasting small debris, water and other contaminants right through the motor and out the exhaust. With dual pumps, dual computers, dual generators, dual injectors and dual everything on that motor and the warning systems in place it is probably the only Rotax engine I feel comfortable flying over water with.
  • Bryan Tuffnell
    by Bryan Tuffnell 4 days ago
    Heh. Paul, in the small airfield that I usually fly from, mine is third 912UL to shed a tooth from the gearset. I'd replaced the gearset at around 1400 hours because of wear in the dogs; 32 hours later, the entire gearbox toasted itself and down I went.

    I can't prove the carb icing, but I was flying around the edges of cloud and through wisps. Silly me: I buttoned off the power while above cloud, the engine coughed, I stood on the throttle but to no avail and down I went (through cloud). I got the air cleaners off for a check as soon as I got down, but it was too late (as you'd expect) - no sign. The engine started first pop and I flew home. My engine runs full-time carb heat.

    I've also experienced the replacement fuel lines issue - one carb ran hot at full throttle. A blast of compressed air through the main jet cured it.

    I'm a total chicken when it comes to flying over water. The stuff of my nightmares...
  • Larry  Mednick
    by Larry Mednick 4 days ago
    Bryan, Want your gear box to last? And your sprague clutch? www.E-Props.com
  • Abid Farooqui
    by Abid Farooqui 4 days ago
    There was a bulletin regarding gearbox teeth breaking due to irregularity in gear material for Rotax 912/914 in 2008. It applied to a batch of gearboxes.
    Fuel lines should be rinsed in fuel before installation. I have even found dead ants inside the fuel line. After all they do sit around at store for months before being used.
  • Bryan Tuffnell
    by Bryan Tuffnell 4 days ago
    Larry, I'd love a lighter, quieter, more efficient prop... and a better aligned motor mount, all round disc brakes, smaller wing, more horses, faster roll, lighter control pressures, an even bigger willy, better wind protection and fatter tyres, once I peddle a few body parts to some back-alley Angolan surgeons.

    My gearset was from 2015, and there's warranty claim with it. There's a spare 2.43 here to use for now.
  • monty stone
    by monty stone 4 days ago
    hey truss, my hirth warranty said if anything breaks you get to keep both pieces! now thats fair!
  • Bryan Tuffnell
    by Bryan Tuffnell 4 days ago
    That's good, Monty! I don't know what Rotax will say. They are all on summer holiday. Apparently the whole business goes off to their Pacific island together and there's no phones, postmen or carrier sheepz. I expect to hear something one day, though maybe not from Rotax.
  • PHILIP QUANTRILL
    by PHILIP QUANTRILL 4 days ago
    Bryan it's August, time for ice cream and sunburn. Happy days
    https://www.youtube.com/watch?v=-DxqdIA75sc
  • Paul Hamilton
    by Paul Hamilton 3 days ago
    Bryan,
    I have two warranty claims in with Rotax in one from December, 7 months ago and still chasing it. Hopefully your rep down under can do better.

    I still want to learn more about 912 carb ice. They say, who ever "they" are, that carb ice is gradual power loss rather than sudden and yours sounds sudden.With the always on carb heat it should, maybe, perhaps, be something else. .... the mystery continues.....
  • jeff trike
    by jeff trike 3 days ago
    Riz, as far as risk and danger in trike flying, the most dangerous thing you can do train with a student in the front seat, especially takeoffs and landings. I owe a lot to Frank Dempsey (my first instructor 13 years ago), Jon Thornburg, Matt Liknaitzky, and all the other CFI's, Paul Hamilton, Reb (RIP), Larry, Abid, who keep our sport alive. I couldn't do it.

    How many times has someone run a red light in front of me, and if I had been a hurry to get somewhere and accelerated on the green light I would have been killed. This happens about once a year. Or what about the time my battery cable broke as went around a corner and everything in my car instantly died. If I had been crossing a busy street, I would have smashed to bits, fortunately for me, I was entering a parking lot. I like to think complacency is the danger, and I do my best to never allow myself to become complacent while flying. We talk about defensive driving, well, we need to adopt defensive flying techniques. I am going to start a blog on the topic. Stand by.
  • PHILIP QUANTRILL
    by PHILIP QUANTRILL 3 days ago
    Well said Jeff, defensive driving and the same for flying, always assume the other nutter is going to do the worst possible thing at the worst possible time. ie the big fan behind goes quiet jst when you've dropped down a few hundred feet to say hello to someone.
  • Neil Scoble
    by Neil Scoble 3 days ago
    Bryan, our aero club tecnam had the same problem. Engine suddenly quit with no warning and after a forced landing started OK and has never had a repeat of the problem. It was put down to carb ice. There was no carb heat fitted to the aircraft.
  • Paul Hamilton
    by Paul Hamilton 3 days ago
    Yes carb ice is the catch all for most unexplained engine outs that start up fine afterward. I feel the jury is still out on this, especially with carb heat such as Bryan. Temporary plugged jet, vapor lock..... the people in the Bay Area claim carb ice has been a problem.

    I have come back in my 503 with the carbs dripping on the outside flying in optimum carb ice conditions and nothing ran great.
  • Bryan Tuffnell
    by Bryan Tuffnell 3 days ago
    I feel fairly sure, but by no means certain, that carb ice was the culprit.The classic symptoms were there: clouds, wet air, mild temps, flying into cloud wisps, rough running when I backed off the throttle, hitting the gas momentarily helped but the engine died. The descent was through cloud, and I was too busy to try a restart. (Minty and Philip - perhaps it was a clump of wool?)

    I'm not convinced about the water jacket carb heaters. I'm sure they help, but although they significantly warm the throttle body there's a fairly modest heat conduction path to the butterfly, which is hanging in the cold breeze.

    Glad the Tecnam didn't get bent, Neil! Was there any hint of icing conditions in that case?

    Philip... you're responsible for sprayed breakfast and a startled cat. That's one each! :-)
  • Bryan Tuffnell
    by Bryan Tuffnell 3 days ago
    (Aside: I'd also echo Jeff's sentiments about sitting in the back seat while a student lands. Want to know fear? Give control of a landing to someone who by definition cannot land in order that they can learn how, but be prepared to save the situation when it goes to pieces. The timing of taking over is where an instructor earns their pay. For what it's worth, I consider teaching high bank turns or spirals is easy and safe, but teaching landings - a much more difficult skill to acquire - always involves a bit of stress...)
  • Neil Scoble
    by Neil Scoble 3 days ago
    Bryan, I'm not sure of the conditions at the time as I wasn't present, the club CFI was flying at the time with a passenger doing some low level photography, approximately 800'
  • John Smith
    by John Smith 3 days ago
    “there are thousands of single engine airplanes flying over hundreds of cities EVERY DAY in a similar situation. Why is a trike different?”

    A trike is different because we DON'T HAVE TO fly over cities. Virtually all our flying is recreational and therefore optional. Don't fly over congested areas.
  • monty stone
    by monty stone 3 days ago
    THE ROTAX WARRANTY DEPT. Monday morning. " ja this is hans, vott ist jor name?'' ''tussock''?, ja vee havf '' HERD ' off jue ( austrian laughter ) , ''vot did jue screw up ziss time''?. "' zee Gier box, ''? Ach von!'', '' did jdue ' rear-end another ''woolly-mammoth''?( more austrian laughter) "' hold zee sheepz up to zer fone I need to ask her zum questions, regarding zee 'ackzident'.'' ov corset it will be our zeeckret'' ( hans by now has big austrian tears rolling down his cheeks, and he's put you on speaker phone) now the whole rotax warranty dept is cackleing at the 'herder' from kiwiland, where oversized gum-boots are 'encouraged', but not yet compulsory. ( to be cont, the part where hans denies any warranty consideration, but will allow Trussock to keep the broken bits! thus 'aligning' with 'other' Teutonic engine purveyors).
  • Larry  Mednick
    by Larry Mednick 3 days ago
    John Smith, I'm not disagreeing, but 99% of all single engine airplanes are also flying for pleasure. They are no more NEEDING to be over congested areas any more than we do. Sure they xcountries, but so do we. So your statement really applies to almost "all of those single engine airplanes" as well.

    It is so often we see airplanes landing on highways on the news and FB. With so many caught on video it's almost normal place to see small airplanes landing with engine outs.

    One thing that adds to trikes going down is the pusher prop being struck from loose items. This in itself is a very big problem. It comes from loose aircraft components like air filter caps to body fasteners and also iPhones and keys.

    Engine outs are real and do happen. Where will you be when your engine goes silent????
  • monty stone
    by monty stone 3 days ago
    Hey Larry, just to mention that many twins suffering an engine out will only make it to the 'wreck scene' on the 'spare' engine!.
  • Rizwan Bukhari
    by Rizwan Bukhari 3 days ago
    Thanks Paul Hamilton, I am going to look at your blog regarding float bowls and see what I need to do, the trike is running great and flown regularly and my annual is due so we will check for all of the issues.
  • Larry  Mednick
    by Larry Mednick 3 days ago
    Very good point Monty.
  • Bryan Tuffnell
    by Bryan Tuffnell 2 days ago
    **************************ROTAX ADVISORY**************************

    WARNING: Do not read a post from Munty unless heavily sedated, sitting down, and attended by a team of uniformed and magnificently qualified French nurses capable of rendering rapid relief in case of rupture. Crikee. Now that I've recovered (a little of) my equilibrium I'll just take another of Philip's medicinal whiskies before bracing myself in case Part 2 arrives...

    A trembling Tussock
  • monty stone
    by monty stone 2 days ago
    part 2. zo zsorry herr trusscott, no warruntee vfor yue, if yue read parragraff twelve paige aight, voluem four it clierly states, IN MENNY langwigges, that NO encownteers with sheepz, goats and any fer-bearing beesties with transmission damage accruing therefrom, bla bla bla, is cuvered under rotax komprehensive cuvverige, so, the good nnews is lilittle fritzzy is sure of another colledge term as soon as we receeve your postal order for $4000.. zatt should cover the cost of the big gier and a gaskit. even more good news is herrr godballs, my zuperior is going to let you keep zer broken stuff, hes a nice guy! all good vishes, and have riell nice day, HANS. ( muffled austrian laughter continuing)
  • Bryan Tuffnell
    by Bryan Tuffnell 2 days ago
    Nurse? Nurse!! NUUUURSE!!!!!!!!!!!!!!!!!

    Too late.....
  • roger larson
    by roger larson 2 days ago
    Carb Ice. This may not apply to the way the Rotax is set up but in other forms of aircraft there is a point where carb heat actually can cause carb ice. I know that sounds strange but if you look at the charts when carb ice is most dangerous it makes sense. So without going into to much detail when air is super cold it can't hold enough moisture to condense, when air is warm it can hold more moisture and as it cools it condenses. I have never had personal experience with this but have read about it. Like I said it may not even come close to being a possibility with the Rotax Setup. I had carb Ice happen one time in an automobile In flagstaff, Arizona. It was raining and about 50 degrees if I remember correctly. My truck stopped and I opened the hood and the whole base of the Carb was frozen. It sat for about 3 minutes and it melted and the truck ran fine after that. Does continues carb heat in the Rotax system cause a reduction in power? I am set to take the Rotax course In October so after that I won't ask a question like that. :)
  • PHILIP QUANTRILL
    by PHILIP QUANTRILL 2 days ago
    I can see theory that actually warming the air before entry into the carbs will increase the airs ability to absorb more water creating a potential greater risk when that air with higher saturation hits cold parts of the carburetor remembering that the increased air speed and reduced pressure within the carb ventura will dramatically drop the air temperature. This assumes that the body and internal working of the carb are not warmed. I do not know the exact workings of carb heating but is it not that heated water is passed through the carb bodies therefore not heating the air itself but the carb body to reduce the chance of ice attachment. If this is so, and assuming there is no direct warming effect on the butterfly what temperature difference might there be between the carb body and the butterfly sitting in the middle of the airflow?
  • Charles Moore
    by Charles Moore 2 days ago
    Adding to the mix of potential things in the rotax fuel systems. How many people running a 912 have a return line from the fuel system (after the engine driven pump) back to the tank? If I remember correctly rotax list the service life of the fuel as 5 years, so it should be safe to assume everyone with a 2012 or older trike running a 912 has the new style pump. In the rotax install manual it list the return line as mandatory. They even sell a fuel line retrofit kit for it.
  • monty stone
    by monty stone 2 days ago
    Herr Truscott, we will include, at no extra charge, appropriately, a tube of your favorite hemmeroid cream, to assist with the gasket assembly, have a really nice day, hans. ( concealed chuckling).
  • monty stone
    by monty stone 2 days ago
    Hi Roger, I wrote a blog on curb icing, nov 2012 it even happens on two stroke slide carbs and leaves little evidence, beyond 'marred' underpants!
  • Paul Hamilton
    by Paul Hamilton 1 day ago
    Monty,
    Yes with my long overdue warranty claims with Rotax I think you are pretty close their conversations. Well said.
  • Paul Hamilton
    by Paul Hamilton 1 day ago
    Charles, Yes I think the return line helps with vapor lock. Note that E-LSA does not have to do anything...
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