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Rotax announce new 135 HP engine 915S / 915iS

And of course the Mooney M10.

Well, there is the APM 30 Lion, an extension of the APM 20 Lionceau:
http://www.apm.aero/apm30_1_en.php
http://www.apm.aero/apm30_2_en.php
http://www.apm.aero/apm30_3_en.php

It seems that they got exceptions to get it certified with a third seat and for night VFR.

From what I have heard, it doesn’t tolerate crosswinds too well, but I don’t have any first-hand experience with the plane.

What happened to that DGAC study about 7-10 years ago which concluded that the steadily declining French GA activity would be best addressed with a 3-seater? I don’t know who they thought was going to build one…

Administrator
Shoreham EGKA, United Kingdom

Certainly sufficient for 800kgs. They have certified aircraft with an MTOW of 1000 kgs and more using the 135hp Thielert.

So, even if a Rotax 135 hp engine became reality, they would probably rather use it in (lame) four seaters. That’s because you can sell four-seaters for more than two-seaters, yet they cost essentially the same to build.

Yes, a really solidly built (IFR) two seater with a lot of fuel endurance and a enough full fuel payload to fill the two seats + baggage would be really nice. 135hp would be OK for that.

The problem again: after this has been designed, certified and actually sold to customers, this will cost 400K€ or more. And then peole will say “nah, my 1973 C172 cost me only 20k€ to buy, and it will do much the same with just two POB….”

Experimental is a different story of course, and I am sure that 135hp engine will soon be an option for RVs and similar.

Last Edited by boscomantico at 27 Aug 17:52
Mainz (EDFZ) & Egelsbach (EDFE), Germany

How would look a touring airplane designed around this engine?

I envision slightly scaled-up Pipistrel Virus-SW (from 600kg MTOV to 750kg),
with maybe 75kg for more structure, 75kg more payload, with 40l more gas tanks.

Or, conservatively, make it 800kg MTOW (425kg structure, 375kg payload). If 100hp is good enough for 600kg, 135hp should be good enough for 800kg.

The mission would be 2x 90kg blokes, each with 30kg camping gear (beer included :-) ), BRS, raft, 1500km range @ 270km/h @FL150.
Deiced prop would be nice…

Don’t even pretend to be 4 person aircraft (maybe 3 person in a pinch), but make it really convenient for 2.

Virus-SW 600kg does not need much more payload (let’s say it has 285kg instead of claimed 300+kg), but there is really no space for baggage, nor does weight&balance allow for much, esp. with BRS.

(dreaming off)
Slovakia

mh wrote:

I do not want to own a Continental never again. Never ever.

Any reasons or “Just because”?

Sorry for refloating this thread, but just to answer you with a non-exhaustive list:

In two years (300H) the Conti:
- Started to consume almost 1 qt per flight (2-3h)
- Due to the above, it had to have replaced all the piston rings, after several visits to the maintenance guys.
- Two CHT probes had to be replaced
- One EGT probe had to be replaced
- Some day one cylinder started to run with a CHT clearly higher than the other 5. Nobody got to knew why, never.
- Other day it started to vibrate anormally at low rev.
- It always run really hot in summer. When cylinder 5 started to have higher CHT, it was a problem, because in take off it was difficult/impossible not to reach CHT yellow range for that cyl.
- A nightmare to start it when hot

In 4000H of Rotax (3 different units):
- 120€ maintenance was done each 100FH (basically oil change, air filter cleaning, and new spark plugs)
- The carburetors had to be syncrhonized in one occasion (40 min work) to eliminate some vibration that had started to develop
- Oil consumption was consistently around 1 qt each 40-50 h
- It worked flawesly
- Burns considerably cheaper MOGAS
- No worry about shock cooling and cylinder head cracks, since both the cyl barrel and the head are made of the same material.
- It always (well, let’s say 95%) reach the TBO and continues running perfectly after. I know of engines still working with more than 3000h
- Overhaul may be expensive (compared with the price of a new 912), but then it’s easy, buy a new one. You can have a new 912 installed on your aircraft for less than 9000 – 10000 euro (giving your ‘old’ engine)
- Always start in 1 sec

So, in my personal experience, it is clear which is better.

Obviously, if you have an airplane that needs 310hp, you cannot choose. But for 100hp it’s a no-brainer.
Now Rotax is finishing the development of a 135hp turbo version of the 912.

LECU - Madrid, Spain

I think so, too. Eventhough you can’t have enough power, the 914 delivers its MCP of 100hp up to 16.000 ft.

EDLE

I’m flying the Tecnam twin at the moment, fitting the 135hp versions a side would make that an even better light twin

Wouldn’t just a pair of 914 do that?

Silvaire wrote:

especially if it something like an RV where the whole plane is designed with a similar practicality + performance sole owner mindset in which the owner is expected to perform or at least coordinate his own maintenance.

You know of course that the RV-12 use Rotax 912 for the exact same reasons the others use Lycoming (according to Vans)?

The elephant is the circulation
ENVA ENOP ENMO, Norway

Ultimately, however, I think the bottom line is that Rotax have not done a product for the bulk of the Lyco/Conti market. So one is comparing products which play in two different markets. And both do very well in their respective markets. Why Rotax have not done bigger engines, is perhaps a better question.

I think that’s quite right. Obviously Rotax have tried development of bigger engines like the V6 without success and I believe their product philosophy doesn’t work when you get to powering larger planes. That’s particularly interesting to me because I also think (more generally) the presumption that ‘modern’ means ‘replace versus rebuild’ is incorrect and wrong for the GA market for larger engines and longer lasting planes. Rotax 912 powered aircraft might very nicely extend the flying motorcycle model to its absolute limit, but larger GA aircraft are not flying cars, and I don’t think they ever will be. GA planes of let’s say 150 HP and up cost a lot to replace, always will, and have to last a long time.

Changing cylinder on a Lycoming isn’t exactly a frequent requirement and is so inexpensive that I just don’t see it as any kind of issue. I could do all four on my O-320 for under $4K and probably will never need to do even one. My A&P just did one on his Citabria because somebody had done poor quality overhaul on that cylinder a few hundred hours ago and it was a weekend job, not much different than polishing the plane and under $1000.

The whole point is that simple, serviceable engines make higher powered aircraft ownership practical, especially if it something like an RV where the whole plane is designed with a similar practicality + performance sole owner mindset in which the owner is expected to perform or at least coordinate his own maintenance. I think that is the best future for GA, and it’s proved to be successful. If you can’t fix your own stuff, that’s your weakness and not representative of the average GA owner in the world’s largest market. The future is therefore not some over regulated, vastly expensive, group ownership, throw away, OEM factory monitored, maintenance facility programmed and repaired nightmare. That is so impractical a scenario that I think virtually nobody could or would take part. I think it’s just a depressing joke.

Last Edited by Silvaire at 01 Aug 19:56
121 Posts
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