pollution of jets against turbine aircraft

All great stuff which I agree with. But what's this obsession with
Cessna being equivalent to small airplanes? When I talk to the
nonflying public, they always refer to all GA airplanes as Cessnas. It
doesn't matter if it is a Piper, Mooney or Cirrus. They are all a
Cessna to them. But I would expect differently from a pilot. Another
thing that nonpilots do is refer to GA airports as "private
airports".





On Apr 5, 11:24 am, "cjcampbell"
wrote:
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." 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. On a per-passenger basis, jets
and turboprops probably pollute less than a gas piston engine.

There is some evidence that the vapor trails from jet engines, while
they add smoke pollutants to the atmosphere, actually reduce global
warming by creating cloud cover.

A four passenger Cessna burns about 12 gallons per hour. It flies at
about 120 miles per hour.

A 747 burns 300 lbs per passenger for a 3450 mile flight. That would
be 60 gallons of fuel per passenger. To fly the same distance, if it
was full, the Cessna would burn a little over 86 gallons of fuel per
passenger. Typically, though, the Cessna will carry only two
passengers, so it works out to nearly 173 gallons of fuel per
passenger. Clearly the 747 is more fuel efficient per passenger.

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.

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, especially when you consider that the 747 requires a
huge airport and terminal and other support facilities that the Cessna
does not.

The Cessna gives you the flexibility to travel short distances at the
times you need to go.

Think of the difference between a bus and a car again. Buses have
regular stops and schedules and are pretty much structured to carry
only passengers and perhaps a handbag or briefcase. Obviously, it is
not going to stop at the grocery store, the day care, the hardware
store, and all the other places you may need to go during the day. The
bus is okay if all you are doing is going straight from the bus
terminal or park and ride to work and back. It does not work out so
well if you are a tradesman who must carry large quantities of tools
to many different work locations during the course of a day. With a
bus, you have to go where the bus goes. With a car, you go where you
want.

It is the same with a Cessna and a 747. With the 747, you are pretty
much relegated to flying wherever the airline goes on the airline's
schedule. Maybe you want to fly from Seattle to Chicago. In a Cessna,
you could fly straight to Chicago. But the big jet will fly to Phoenix
on the way. Or Dallas. Or some other hub. So where a Cessna can make a
1000 mile journey by flying 1000 miles, the jet makes a 1000 mile
journey by flying 2000 miles or more. Going back to our figures, now
we see that a fully loaded Cessna would burn about 30 gallons of fuel
per passenger for a 1000 mile trip. But the jet will burn 120 gallons
of fuel per passenger. Clearly the Cessna is much more fuel efficient
for this type of journey.