Re: Dash-80's final flight

1) Gas turbine overhauls occured about 1/5 to 1/10 the time that of the
piston engine early on
2) Vibrations from piston engines required checking the airframe for the
associated fatique.

The cost of these were substantial; this is why airlines went to the jets in
a big way.  It increased the ratio of time in the air verses time spent on
the ground, therefore it was theoretical automatic increase in the amount of
passenger revenue that each plane could generate over a fixed period of
time.

"Jeremy Thomson" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> http://www.cnn.com/2003/TRAVEL/08/28/first.jetliner/index.html
>
> One bit of this article stood out for me.
> It said the 707's operating cost was 25% less than for the DC-7.
> I would be amazed if the jet didnt burn more fuel to fly the same
> distance as a prop so is this economy caused by easier maintenance and
> better reliability of jets?
> Cheaper Jet fuel compared to high octane gasoline?
> The 707 would be flying higher & experience less drag, but probably
> burns more fuel to get to that height.
> I suppose the DC-7 has a higher engine/payload ratio to the 707, 707
> more efficient because the engines weight comparitively less?
> Can someone please explain why the 707 is 25% cheaper to run the DC-7?
>
> Jeremy Thomson