This flight manual for the Lycoming powered DA42 variant shows an initial climb in the range of 2000 fpm. Is that performance actually only ~200 fpm better than the current Diesel version, or perhaps more significantly is the time only marginally improved for a climb from sea level to 8,000 ft when departing over terrain near the airport?
The latter would obviously be an important performance characteristic to better, for me and others in my area. It can save a fair amount of time if departure from an airport near mountains can be done with a direct routing over them and away. In that case there is usually no substitute for sea level power, but I wouldn’t speak for an aircraft type with which I have no experience.
I wonder why that is? The only thing that comes to mind is that the vmca for the L360 is higher much higher than that of the CD-155.
These are the numbers from AFM (ISA, SL, MTOW 1785 kg):
- DA42 L360 ground roll 484 m, distance above 50 ft 747 m
- DA42 TDI with CD-155 ground roll 428 m, distance above 50 ft 595 m
Obviously CD-155 performs better in DA42 than Lycoming.
Emir wrote:
I can’t say how much this would be (IMHO negligible) but we spend much more time in cruise than in taking off, so going for heavier engine with worse cruise performance just because of getting 100-200 fpm more in climb (only to 6000 ft) and maybe 50 m less ground roll, doesn’t make sense.
But! It allows you to takeoff from shorter runway! :)
Joe_90 wrote:
I was thinking purely of takeoff performance not cruise.
I can’t say how much this would be (IMHO negligible) but we spend much more time in cruise than in taking off, so going for heavier engine with worse cruise performance just because of getting 100-200 fpm more in climb (only to 6000 ft) and maybe 50 m less ground roll, doesn’t make sense.
Emir
I don’t think CD-170 would bring any benefit to DA42 comparing to CD-155. It’s heavier and has lower critical altitude and max continuous power is practically as same as CD-155. DA42 with Lycoming is practically non-existent; it is dead-end and can’t be retrofitted to diesel engines
Agree it’s heavier than the CD155 but it’s still a lot lighter than the Austro 300 which is the same power as near as dammit. I was thinking purely of takeoff performance not cruise.
[ post edited to show what somebody else wrote, as a quote ]
“I personally would not want either an airframe or engine from a Chinese owned manufacturer unless it could be supported indefinitely in the absence of the OEM.”
Unfortunately both the aircraft I have shares in have Continental
O-200 engines, and I think Teledyne Continental is Chinese owned.
I notice the IAI Super Heron has a Fiat based 200 HP diesel and I’m aware of another promising dedicated aircraft engine development. The issue with military engines is that they aren’t likely to be certified and commercially available, but it’s still interesting to see the applications that largely created this technology establishing new suppliers. I personally would not want either an airframe or engine from a Chinese owned manufacturer unless it could be supported indefinitely in the absence of the OEM.
