DA-42 Twin Star as PPL/CPL-Multi Trainer
 

Recently, my flight school has dropped using a BA-55 Baron as our multi-trainer. I was bummed because I just finished getting my MEI in it and was settling in. NOW, the GM for the school has picked up a DA-42 (Diamond) Twin-Star of all planes. I went up to start getting my 5 hours PIC in the airplane so I could teach in it and the first thing that happens is during an engine out simulation, the G1000 tells us we've had a problem with one of the two computers (ECU's) that controls the left engine (the one still running). The engine hesitates (went to 50% hp) and goes to the back up ECU. TheG1000 now reports that ECU #2 has also failed, but the engine keeps on running. Not in the plane 1 hour and this happens. Needless to say my trust in this tweeked out oddity has been dashed.

Considering it's such an unconventional aircraft, is this even a trainer? Am I just setting my students up for failure when they arrive in The Regional or Part 135 world and ask, "Uh. What are the blue levers (prop controls) for?" I can understand ATP applicants liking it but shouldn't everyone have the rudimentary understandings of prop control? DA-42 lovers, convince me otherwise. Thanks.

The BE55 is about a hundred times the plane the Twin-Star is.... although the Baron is a little.... maybe not meant for primary stuff.... good experience though if you must

My sister did a little bit of instructing in the DA42 a while back and had a partial engine failure on one engine on more than one occasion. I thought they got all that worked out though with some AD's, but perhaps not! I also spoke to a ERAU student who once got the engine fire warning and had to shut an engine down in IMC... Sounds like the DA42 has some issues. It's a great airplane to fly when it's working correctly though!

You know you like the Baron better:cool:

They got better over the years
 

Is it an early one with the 1.7 litre engines? The 2.0 L models have some of the kinks worked out. Mind you, we've seen our share of engine failures (1), bogus fire warnings (1) and generator failures (1) in 300 hrs of owning a 2.0 L 2008 model. None happened without warning, though...they all gave some hint that something was amiss, but the mechanics were not able to fix these latent failures until they very obviously broke in flight.

As for whether it's a good trainer or not, I leave that up to the CFIs among you. I already had "blue knob" experience when I used a DA42 to add a multi to my commercial, so I didn't miss it, but since it's the only twin I've flown (80 hrs now) I can't tell if I'd be overwhelmed by transition a Baron, 310, Aztec, etc.

I think that training people to fly regional jets was part of its design intent. Aside from the FADEC, its glass cockpit, lots of busses, and the lack of good visual cues ahead of the glareshield were (I'm told...hearsay) intended to prepare future regional jet pilots.

I also have a bit of exposure to the new Austro-engined version, which is intended to fix the engine, gearbox, and ECU woes. So far so good, but we've only got 50 hrs or so on it.

I cant even begin to imagine what your flight training cost is. Those are arguably two of the most expensive twins for rent anywhere in the country.

Great planes, but not cheap planes.

Yeah. With instructor, you're looking at approx. $380 an hour for either.

The DA-42 was designed as a trainer, the baron not so much. The diamond might be more economical in the long run (over many years).

Everything I've heard is good so far, you know what they say about flying the A-model...

Not cheap is right
 

True. DA42s rent for $300/hr and up, not counting the instructor.

I've not flown a DA-42, but in terms of multi-engine training, I hope that's not the first time students are seeing a prop lever. If the student's are doing add-ons, then they have to have complex time (where an adjustable prop is required). If however, they are doing everything in a multi, then that is a major blow to their experience. Make sure they have a really good grasp of how changes in prop pitch are controlled and why they are beneficial. You could even go so far as to teach the same way you would for the baron and then, once they understand the principle, explain how the DA-42's FADEC operates.

AOPA had a pretty good article about the DA40/42 a few months ago.

I guess there was an instance of a complete loss of power of one in Europe when power cycled to the FADEC for something like several thousandths of a second, but it was enough for both motors to fail and kill the occupants. Don't remember which motors they were. Supposedly the newer ones are better, but I agree that the Baron is a better plane. I loved my 20 or so hours in a Colemill BE-55.

Have not flown the DA42
 

But I did sit in one a couple of times (cockpit familiarity) and I have some g1000 time (over 100 hours). I have instructed in a Seneca, Aztec, C310, Navajo, and Baron, and got my Multi in a Duchess. I have also flown a Twin Comanche, King Air 100 and 200, and a Twin Otter. Far and away, the best for training was the Duchess, and my favorite from a pilots perspective is the Baron 58.

A good example...
 

...of how airplanes get a poor reputation. In this case based on half-remembered anecdotes.

Those pilots took off after starting the engines on external power (specifically forbidden by the POH.) When they retracted the gear, the transient on the bus caused both engines' ECUs to reboot, shutting both down

This resulted in an AD that added batteries that are diode-ORd to the ECUs. If the main bus sags, the ECU batteries keep the engines running for 30 minutes.

Those were Thielert engines, but that's not germain to the story...it was an electrical problem due to violating the airplane's operating procedures.

The dreaded blue knob
 

I'll admit that I've never flown a twin with the blue knob...but is it that hard? Is feathering a prop by pulling a lever that much harder than feathering an engine by toggling a switch?

When I transitioned from fixed-pitch prop airplanes to constant-speed prop airplanes, it took me about half an hour to get the hang of it.

Wow someones feelings got hurt.

And yes, constant speed props on multis can be that hard for some people. Start flying turbo props (especially direct drives) and find out what happens if you don't understand the effects of prop control. Go get your MEI and teach your students the things that effect Vmc. Then come back and tell me "it's not that hard"

Re your post two up, so you're telling me if I have a total electrical failure, then I have AT MOST 30 minutes of flying time left? F-that.

It is different....and difference (read change) will always be 'hard'. Old habits die hard. After training in a certain way for decades, it will be awhile before a different path is accepted.

USMCFLYR

Well if you are looking for hard facts, the internet forums are probably a pretty good to shy away from I'd say.

Hate to hear about such examples and it seems that you know some details. WHY would pilots WANT to start on external power if not required. Heck...I look for ways to be able to NOT use externals sources (air or power)! :eek:

Well...if the above it true, it is hard to 100% safeguard against stupidity, but this sounds like a good step towards that goal.

USMCFLYR

It's about fertilizer, not feelings
 

[quote=Grumble;804467]Wow someones feelings got hurt.

And yes, constant speed props on multis can be that hard for some people. Start flying turbo props (especially direct drives) and find out what happens if you don't understand the effects of prop control. Go get your MEI and teach your students the things that effect Vmc. Then come back and tell me "it's not that hard"

Re your post two up, so you're telling me if I have a total electrical failure, then I have AT MOST 30 minutes of flying time left? F-that.[/quote

If you lose both generators in a DA42, you have about 30 minutes of life in the main battery after shedding load, and sometime after that, the ECU batteries will start to discharge. You then have 30 minutes in the ECU batteries, and then, yes, it all get quiet. However, since it's hard to tell which battery is carrying the engine load, the manual says "30 minutes to total engine failure," so that's what I was trained to.

Mind you, that's after the 2nd generator fails. Typical load with lights, a/p, pitot heat, etc. is 35 A, and each generator is rated for 60 A. So you can complete a flight in IMC with a generator failure. The manual says "land at the next suitable airport" in that case.

Please note the difference in tone between my post (trying to educate you) and yours (trying to mock me for not knowing something you apparently know.)

Yeah, until you're over water/mountainous terrain and that 30 minute clock starts (30 minutes being best case I assume)!!!!! Or at night, in the weather, etc.

You're right
 

True! I should know better after being on forums for 25 years.

That AD was part of DA42 ground school, probably as a warning to "don't do this, dummy!" Now that all new DA42s have the ECU battery as standard equipment, the new manual says something like "if you use external power, don't fly IMC or night."

It is indeed a very electric airplane, and has to be flown accordingly.

Well we have been there in the aircraft that your currently flying right? That max 20 minutes isn't the most comforting thought! :eek: In any case, I was talking about the technological fix to somebody starting the engines in an unapproved manner - not the battery life after two generators fail.

USMCFLYR

These days the classic 172RG (always a crap plane) is being quickly phased out. Now, Schools are struggling to bridge a gap between ASEL and Multi. SO, what many schools do is just have them do their complex training in a multi.

Yeah, but even the F-18 will fly with a total electrical failure!!! Well the legacy anyway. You're screwed in a Rhino. And you'll be in MECH. And probably never find the boat. Or get aboard. But hey! You're still flying!

A light piston that sh1ts itself after an electrical failure? Not a chance I'd fly it in anything other than day VMC.

Badge, whats your problem with the Gutless. It's a great plane. And there are PLENTY of complex singles out there. Arrows, Cardinals, RG's, M20's, C-24's etc.

Sounds like some insightful advise Bashibazouk. Thanks for responding.

Ok call me stupid.... but why both engines on externals?

Don't know too much about the TwinStar's antics... but wouldn't you let the one engine recharge the battery anyway...

I'm just a little confused on how/why someone ever does that...in any airplane?

I guess they were in a hurry :)
 

I don't know why they did that. Perhaps when the DA42 was new, people didn't appreciate how electric it was and treated it like any other light twin. Magnetos and carburators obviously don't care about voltage dips.

When the DPE was quizzing me about systems during my Commercial AMEL checkride, he was very focused on how much I understood the differences between DA42s and "normal" light twins...and even asked me about this accident.