cjcampbell kirjutas:
On Apr 5, 7:28 am, wrote:
With all the problem of the modern planes according to ecology (CO2,
white vapour trails, etc ...) I would like to ask a question :
-- does turbines and normal airscrew planes less pulluting aircraft
than pure jets one ??
-- does this aircraft use less petrol for a journey ( knowing that
they are 200 km/h slower than jets) ? If ies... how much less ?

tHanks for somebody "whoknows" to answer

"Turbine" is just another name for "jet."

Not quite - turboprops are not quite regarded as jets. But they are
definitely turbines.

All turbines, including turboprops, pollute more than gas piston engines. Sort of. Remember
that a jet spreads its fuel costs and pollution among many more
passengers than a piston engine does.

It´s just that there are few big piston airliners which are modern in
design as well.

On a per-passenger basis, jets
and turboprops probably pollute less than a gas piston engine.

snip

Think of it this way: a bus gets much worse gas mileage than a car and
it pollutes more. But a bus carries the same number of people as many
cars (perhaps 30 cars), so if it pollutes less and uses less fuel than
30 cars, the bus is better for the environment.

Precisely. Compare apples with apples, not oranges.

The same rules hold true for cargo.

But it is not that clear-cut. Cessnas do not fly 3450 miles on a
normal trip. The typical Cessna journey is less than 500 miles,
usually much less. You cannot fly a 747 for such short trips -- it
would be horrendously expensive or, in other words, a horrendous waste
of resources. It would be a rare day indeed that you could find
upwards of 500 people all wanting to take the same 200 mile trip at
the same time,

It is not rare. It is actually so often that 747-s were designed and
built specifically for that purpose, or almost. What are the main
747SR routes in length? (Tokyo-Sapporo et cetera...)

And now, let us choose some apples and other apples to compare.

For turboprops, take ATR 72 and Bombardier Dash 8. Which can carry
about 70 people.

For jets, do not compare them with 500 seat 747. Compare them with
Bombardier Canadair Regional Jet. Which also has about 70 seats.

If you take a 70 seat jet and 70 seat turboprop flying the same
distance - how much longer does the turboprop take?

Which of them burns more fuel? How much?