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Celera 500L (and high altitude discussion)

How far will it fly on half power? What runway length will be needed in case of engine failure on take-off run?
As regards air leaks, there must be at least one door.

Maoraigh
EGPE, United Kingdom

On the RED web site:

The ECU complies with standards DO-178B and DO-254, to name just a few. In contrast to cars, the software for aircraft ECUs must not be altered or updated without the requirement to re-certify the unit.

The “redundant” engine configuration is just marketing gimmick. Rotax have had this “redundancy” for decades (analog, not digital), not to speak of Limbach. With the iS engine, Rotax has reverted to true redundancy of the ECU controlling the whole engine.

The elephant is the circulation
ENVA ENOP ENMO, Norway

Certification of ECUs is not much assurance of no bugs. It is mainly to do with environmental compliance etc of the hardware. The manufacturer also has to run some QA systems in the factory, to be able to apply. Software QA involves various requirements to reduce the chances of bugs but it can never eliminate them. Some of the compliance methods are quite funny e.g. one ex Honeywell KFC autopilot guy told me they used to put only one C function in a file, because they were allowed to change no more than x files in the project before recertification, and this way they could do loads of changes to one or two functions without triggering this. The result of this and other stuff was code which was very hard to read and impossible to maintain.

One could argue the car business is extremely critical because an engine stoppage on a motorway could result in carnage worse than a forced landing in a SEP, but car manufacturers still managed to screw up. I used to know somebody with a Jaguar XK whose engine would randomly just stop… on a motorway or anywhere. It was a widespread problem which Jag did eventually fix.

This point is not lost on many GA customers and hence – apart from forums – there is quite a low market demand for even the lowest form of “ECU”: electronic ignition.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

One could argue the car business is extremely critical because an engine stoppage on a motorway could result in carnage worse than a forced landing in a SEP, but car manufacturers still managed to screw up.

This winter I had alternator belt broken on Volvo XC60 which led to loss of power which resulted with random turning ECS and ABS on and off as well as steering support acting in the opposite direction of my steering input. I almost hit the building when entering car service facility. So much about car manufacturers testing procedures…

Last Edited by Emir at 05 Sep 07:54
LDZA LDVA, Croatia

AFAIK almost no car manufacturer makes their own electronics. For example my VW is full of Bosch stuff, and so are many others including – according to google – the Volvo XC60

The engine here is this

They claim two 6-cylinder banks… they don’t say how. It would be a real engineering challenge, with some sort of clutch arrangement?

This is their ECU. Appears to be a custom one

Administrator
Shoreham EGKA, United Kingdom

Since the last 70 years, the answer to a light, powerful and reliable engine above 2-300 hp for aviation use has been the turbine. I don’t see what has changed to make this less true today.

The elephant is the circulation
ENVA ENOP ENMO, Norway

I guess the requirements weren’t a light and reliable engine but a powerful and fuel economic engine.

As for the claimed redundancy: It’s a V12 which can revert to an I6 in case something fails. That’s two I6s with a shared crankshaft and no possibility for a clutch which you could have with two (inline) coupled V6s. Also this arrangement wouldn’t make sense because then the wrong part of such an engine fails the other one would still have to drive the other engine’s crankshaft. So a clutch only makes sense with two independent gear couple engines. Such engines have been developed a long time ago although without a clutch between the two sub-engines. See for example the Napier Rapier. But the above pic clearly shows a conventional V12.

Last Edited by Clipperstorch at 05 Sep 14:14
EDQH, Germany

Clipperstorch wrote:

I guess the requirements weren’t a light and reliable engine but a powerful and fuel economic engine.

Obviously, but light and reliable is as important today as it was 70 years ago. This has not changed, except more focus on the reliable part, not less.

The elephant is the circulation
ENVA ENOP ENMO, Norway

It’s a hoax, that’s what it is.

Safe landings !
EDLN, Germany

What is?

Administrator
Shoreham EGKA, United Kingdom
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