Aviation diesels and turbo's

Hi Calvin,

Yes, I think there is a future for diesels. My main (and probably
only) concern is the weight of a diesel versus a standard light-fuel
burning IC av-engine. When the weight of a diesel is comparable to a
standard IC engine, then you'll have a hum-dinger.

the combined weight of engine plus fuel for any significant mission
range is already equal or less for a diesel in many cases. The diamond
DA40 for example is only 10 kg heavier with the diesel than with a
Lycoming, burning 4.9 gal or 15.8kg of Diesel or Jetfuel vs. 8.7 gal or
24.5kg of avgas, both at 152kt. At 122kts the figures are 4.1
gal/13.2kg Diesel vs. 7.2 gal/20.2kg Avgas.

So if you plan on staying in the air for more than say 90 Minutes, you
can actually carry more payload in the diesel.

Yes, in this case the Lycoming IO360 is also slightly more powerful, at
least at sea level. But the general idea remains valid: The weight
penalty of diesels turns into the opposite, if flying longer missions.

Whether it makes sense economically is a different question, and
depends strongly on fuel prices and whether you are faced with a choice
between the two or considering a replacement. In Europe, when you need
a new engine or an overhaul anyway, it's hard to imagine a case where
you wouldn't save a large amount of money with a diesel. In the US,
especially when you already have a perfectly good engine in your plane,
you might not amortize a replacement kit fo a long time.

Of course there are other questions, like range (very much pro diesel),
reliability (for the diesels yet to be proven), availability of the
fuel (so far jetfuel is not available at many small airports, on the
other hand the future of leaded avgas is unclear altogether), which
every pilot/owner has to answer for himself.

regards,
Friedrich

--
for personal email please remove "entfernen" from my adress