Buying and operating a Robin DR400/Ecoflyer

[Wooden Wonderer]

I am involved in a group who operates a Cessna 172, and we are beginning the process of considering what to replace it with.

The Robin Ecoflyer looks like an interesting aircraft but we know little about operating one and in particular what to look for, or be aware of, if considering buying one. We have knowledge of the Diesel engine, so it's more the airframe we need to learn about, so I would like to draw on anyone with experiences of buying/operating a DR400.

How does it compare to a 172 in terms of performance, handling, is it a comfortable aircraft for pilot and passengers on longer flights?

Does it have any peculiar weights and balance issues, and can it operate with 4 adults on board and reasonable fuel load?

What maintenance issues arise with the DR400?

Is there more or less maintenance than an aluminium aircraft, and is there any difference in costs? Are there any major maintenance check or life limits on the airframe?

Is there good support for maintenance and in availability of parts?

Is there any specific things to look for or avoid in a used DR400?

Our 172 was never hangared. Can a DR400 be kept permanently outdoors without causing additional maintenance headaches ?

Would having a complete airframe cover give sufficient protection or is hangering the only option with a DR400?

Any other useful information on the operation and maintenance of the DR400 would be really helpful in our deliberations.

Thanks.

[A and C]

I have been a DR400 owner for the best part of twenty-five years and the first thing to say is that the aircraft must be kept in a hangar but just like your Cessna the money you spend on hangarage you will save on maintenance.

You will have to choose your maintenance provider carefully as the lack of understanding within the industry of wooden structures is second only to that of composites.

There have been W&B issues and it has been discovered that at least one aircraft has left the factory with W&B data that was serously in error ( we had it on the weighing kit twice to be sure that we got the numbers correct). Unfortunately I have not tried to do a load sheet for the carrage of four adults so I can't tell you how well it can be loaded.

Have you considered the DR400-180? These can be run on 91UL and are well known as good weight lifters, fron the south of the UK you can get to the north of Spain with one fuel stop and if you have the supplementary tank under the baggage bay you can get to the north of Spain non-stop.

There are no major problems with the airframe but you need to get someone who knows the type from a maintenance point of view to look at anything you intend to buy.

The after the C172 you will find the DR400 a much nicer aircraft to fly with a much greater range of loading options, in theory the EcoFlyer should be a great touring aircraft as 75% power is avalable well above the 8000 ft limit of the Lycoming powered aircraft enabling the aircraft to fly at higher TAS and take advantage of higher tail winds all with a low fuel consumption but you need to sit down with the flight manual & W&B data to see if this all pans out into a practical aircraft for your group.

Perhaps BACKPACKER might like to comment on the loading issues as he flys the aircraft on a regular basis.

[BackPacker]

I don't have the full W&B data for all of our four DR400s to hand, but the Ecoflyer really is a 2+2 aircraft. (2 adults, 2 kids). The loading options are very similar to the DR400-120, although it's a lot faster than the -120, obviously.

Here's an example.

PH-SVT DR400-140B (NVFR equipped): empty weight 657,64, MTOW 980 kg.

So you have only 320 kg. to play with. With four standard (85 kg) adults that means no fuel whatsoever. Take three adults, or two adults + two kids and you can almost fill the 110l tank (89 kg - note that the Jet-A specific gravity is higher than avgas). With a fuel consumption of 20l/hr (70%, about 110 kts IAS), that's over five hours endurance.

If you want a proper load hauler, like A&C said, you might want to consider the -160 or -180 avgas burner.

PH-SVQ DR400-160 (NVFR equipped): empty weight 631 kg, MTOW 1050 kg.

That allows you to take four standard adults, and 110 liter (main tank) full of fuel, for an endurance of nearly four hours (33 l/hr fuel consumption @ 65%/115 kts. IAS). Leave on adult on the ground and you can also fill the saddle tanks (2x40l), raising your endurance to almost six hours. (Ours does not have an aux tank under the rear seats but that would increase the endurance even further.)

In both aircraft I have found balance never to be an issue. It's just the MTOW of the Ecoflyer that's very limiting.

A few other comments, in addition to A&Cs post. At our club, the DR400s are hangared each night, while the PA28s, C172s and the R2160 live outside all year round. That may tell you something. And obviously you need to be careful with the wing fabric. Don't just plonk your bag on the wing, for instance, and carefully stick to the wing walks. Pointing out that the wing surface is fabric is part of my standard passenger brief.

Regarding creature comforts, I find the DR400 very nice to sit in. The view is great (much better than a C172 or PA28), the panel is logically laid out, and depending on the model and panel fit there's storage bins in the panel. What I don't appreciate is that the front seats not only slide back and forth, but also tilt backwards a bit at their rearmost setting. If you're relatively tall (I'm 1.86), that gets tiring after a few hours.

Regarding maintenance, occasionally the discussion flares up about the nosewheel strut. This is designed so that it locks in the dead-ahead position when fully extended. After landing, it requires a certain pressure on the nosewheel before the lock disengages and you have nosewheel steering available.

With a properly maintained nosewheel strut this should not be an issue, but if the oleo is improperly serviced it may require a forceful dab on the brakes to disengage. Particularly if the aircraft was loaded with an aft CofG, and you make a greaser of a landing. Some pilots don't know this, and end up barreling off the runway (and hitting the PAPI, as in our case a few months ago) due to a lack of nosewheel steering. So it's one of the things that should be covered in the checkout, as something that you need to be aware of.

[A and C]

It is all the legs that have to be correctly serviced as the mains have an effect on the nose leg, it would not be an issue if the people who service the legs would read the manual and do the job accordingly..........why do I spend so much time on this forum telling people to look at the manual, be it flight or maintenance ?

[BackPacker]

Changing the world, one post at a time, right?:)

[Sir George Cayley]

Too many groups replace like for like so it's great that someone has come to their senses and considered bent wing flying :ok:

I've flown both types and each have their strong points but for me Robin designs win hands down.

My only additional advice would be to wear a hat!

Good luck. SGC

[Cough]

Quick look at the mistral aviation page shows a ecoflyer 2.0s with a 460kg useful load...

[BackPacker]

Good point. Not all Ecoflyers are created equally.

Ours were originally equipped with the 135 HP 1.7 Thielert, and later upgraded to the 2.0 Thielert which was somehow downrated to produce 135 HP. Because the engine was downrated to produce the same thrust, used the same FADEC and the installed weight/arm was virtually the same, no new POH needed to be produced, just a new W&B schedule.

New Ecoflyers can also come equipped with the 2.0s Thielert, which produces the full 155 HP. Those versions, according to the website, have an 1100 kg MTOW and a useful load of about 460 kg, which is even better than the DR400-160.

Here is a URLs comparing the 2.0 and 2.0s side by side:
Robin Aircraft (http://www.robin-aircraft.com/en/ecoflyer-11.html)

I have never flown the 2.0s, but would love to.

Something else: If there's a requirement that the aircraft is kept outside all year round, have you also considered a DA40? The same engine issues are present but you have one further option: The Austro engine. Overall performance is the same as the Ecoflyer, although it needs a slightly longer take-off roll and has slightly worse climb performance. But the cabin is more spacious and comfortable, and they're easier to find/equip with an IFR panel. And it is better suited than the DR400 to being kept outside all year round, especially if you give it a good wax every now and then.

[Wooden Wonderer]

Thanks one and all for your quick responses and some very useful information. We are looking at a Ecoflyer with a 2.0 engine, but maybe an upgrade to a 2.0s might be advantageous in the future. Hangarage is an issue we might have to address, but adds to running cost so would have to see how it impacts on the affordability of upgrading.
Our 172 is IFR equipped so that's something which we would like in its replacement, although a lot of ecoflyer's for sale are only N/VFR.
I have seen the mistral 2.0s Ecoflyer in the flesh at aero expo and all I can say is come on lucky lotto numbers :-)
The DA40 is also very much in consideration, though I think I'd stick with the centurion 2.0 engine and in time upgrade to 155 GP.
Thanks again, and keep the thoughts coming,it's very helpful when adventuring off type!!

[A and C]

Whatever aircraft you buy try to find one with the 2.0 engine as these all have the 600 hour gearbox.

[Katamarino]

Having flown a lot in both a C172 and a DR40, I find that in terms of passenger comfort the C172 wins by a significant margin. In the DR40 you feel like you are perched on the aircraft, rather than sitting in it; the back seats are really just for kids. The front seat adjustment options, as mentioned by Backpacker, are poor.

The DR40 is, however, rather nicer to fly. I just would not want to spend more than a couple of hours in one.

[A and C]

I have only done a few short trips in the back of the DR400 and I found it OK if a little cramped, however the front seats are amazingly comfortable and on a number of occasions I have used the 240 ltr fuel tanks to stay in the air for over five hours.

Of course when carrying all that fuel the aircraft effectively becomes a two seatter with a lot of baggage space.

The unfortunate thing about the Eco Flyer is that the aircraft has aft C of G issues and this is not helped by the lack of wing tanks, I have yet to do the numbers but I would guess that filling the rear tank drives the C of G too far aft to put anyone in the rear seats. If anyone has the numbers on a individual aircraft and can disprove my guess I will be happy to be corrected.

[BackPacker]

Sorry, can't help you there. The ones at our club are all 2.0 versions, with just the main 110l fueltank. Like I said, the weight is limiting, but I have never found balance to be a problem.

[Wooden Wonderer]

Just two other question that occurred to me. We have had our aircraft stripped and get a bare metal respray in the past. I know that the robin has I think a Dacron skin, what happens if you want to repainted a robin can you strip the existing paint or is it a case of painting over it, thus adding to aircraft weight?
Secondly, over what timescale might the skin need to be replaced, and are minor repairs easy enough?

Does anyone know if there are any balance issues with the 2.0s and increased MTOW? I'm surprised to hear about the aft C of G issues on the Ecoflyer as I thought with the heavy diesel up front it would be the opposite?

Thanks again for all the comments.

[A and C]

You can strip the paint but it is never a good idea, usually in is just as cheap to recover the aircraft as there is very little labour involved in removing the fabric.

This is a good time to take a very god look at the airframe and any bits that look a bit rotten you just glue another bit of tree in place and sand it back to shape.

The W&B issues are due to the Thelert engine being lighter than the 180HP Lycoming and about the same weight as the 160 & 140 HP engines, there being no wing tanks to help keep the C of G forward.

[Wooden Wonderer]

Thanks for the Information A and C, good to know.