Robin DR401 with CD155 reliability (and diesel v. Lyco/Conti engine reliability)

Mooney_Driver wrote:

I prefer manual flaps

Nothing wrong with the 2cv handbrake lever Robin manual flap lever. I assume the DR401 flaps the same as ‘normal’ DR400 ones (i.e. not fowler etc) just electrically operated? Wishful thinking: a manual lever could be retrofitted?

We had a DR400/155CDI demonstrated before the Thielert debacle and both the salesman and pilot were very clear that the disel engines and FADECs were much more reliable than Lycoming etc etc.

My pennys worth.
Have been operating a DR400/180 Regent since it was new in 1993. The great attraction for me was the load lifting capabilities, the cruise speed which is the same as a Piper Arrow without the complication of retractable undercarriage. Manual flaps. Can get in and out of 400 meter strip if needs be. As time has passed and glass screens have become the fashion, we have reliable mechanical gauges, which if they go wrong can be replaced one at a time. The so called Lycosaur is totally reliable. It burns more fuel than I would like, but to upgrade to a diesel with attendant cost, would take a long time to level out on replacemnt cost. We are on our second engine.
I read that commercial aviation is totally conservative and kept to piston engines for a long time after jets were available. Well I am the same with regards “glass” and diesel piston engines. If it works it don’t need fixing.

I have (two) CD155 in my DA42 and after some 30+ hours I haven’t had any issues.

This is very interesting, has you mechanic analysed the engine parameters using the graphical option in excel ? It’s usualy easy to find out what is happening and the particular system that is at fault.

I would be very interested in this as I maintain a number of these engines.

Reviving this thread because my former club has issues and no solution at hand.

They have 2 aircraft with CD-155 and both have engine issues. They seem to appear randomly (all phases of flight).
The first is a brand new DR401 delivered with a CD 155.
The other is a DA40 which got a CD155 when its old but perfectly working CD 135 reached TBO.

Symptoms are as follows : power reduction with a vibration of the whole airframe, some black smoke is seen by the TWR controllers. It lasts 1 to 3 seconds and can repeat several times with one minute. Then it ceases but the pilot often returns to the field ASAP.
The mechanic sent logs to the engine builder but no return.
Nobody wants to fly these planes anymore (understandably).

Does anyone heard of simlar issues ?

I don’t think @dieselpilot ever came back after that post.

How can a manufacturer do this sort of thing? Aren’t they making enough money on the product to fix it?

I guess these conversions, prices for high hour FTO usage, are scarce.

We operate a C172 with CD 155 conversion 3rd radiator in 200h since March 2017 and no solution in sight.

We will organize a Robin DR401 fly-in next year in Rothenburg o. T . (EDFR) ,

We would especially like to refer to clubs and holders of the Robin DR401 155 CDI.

We have already invited (18th of September 2017) Robin and Technify to this fly-in . We would like to discuss all benefits and problems with them. We have suggested the last weekend of March, April or May 2018.

We have got a verbaly acceptance from Technify. Robin is still missing.

Keep informed via Facebook “Aeroclub Rothenburg Tauber” or https://www.edfr.de

Aero Club Rothenburg o. T e. V.

For flaps to self actuate, the number of possibilities is quite small. The system consists of

• an operating switch (flap position selector)
• some relays
• some limit switches

For it to move by itself, basically you need a fault in one of the above, or a bad connection.

Bad connections can usually be found by waggling the wiring. The other stuff can just be replaced. The relays are the simplest; they usually plug into sockets. I would visually inspect the socket contacts, and put some ACF50 in them. It could simply be a faulty flap position selector switch; just replace it. On a French plane it is most likely a switch made by APEM which is not cheap (maybe €100 without paperwork) but if it was me I would just change it before the next flight because it’s too cheap to worry about, on the scale of flying costs.

If the fault can be replicated on the ground then it should be dead easy to find.

I am wondering whether a wooden airframe presents additional challenges with electric flaps and the necessary limit switches remaining in the right place over temperature. Basically the whole actuator and limit switches need to be mounted on a piece of metal.