Wake turbulence avoidance and ATC

David Rind wrote in message ...
David Megginson wrote:
David Rind wrote:

Not answering your actual question about the clearance, but for
what it's worth, I would not have tried to climb out at Vx. You
have no hope of outclimbing a jet,

It's not that far off -- I think (but am not certain) that a
fully-loaded DC-9 has a best climb angle of around 650 ft/nm, while a
small single-engine plane will manage something like 400-600 ft/nm at Vx
depending on horsepower and load. Of course, the DC-9 has a much better
climb *rate*, but that's not the concern here [...]

I could be wrong, too, but I think even a loaded DC-9 can manage at
least 1000-1500fpm... and might have to do so for noise abatement
around the airport.

I've heard that's why cloud clearances down around us VFR planes are
1000' above and 500' below. The extra space above is needed because
an airliner is far more likely to be climbing out at high fpm... but
descends at a slower rate for passenger comfort and ILS landings.

Kev

Kevin Darling wrote:

It's not that far off -- I think (but am not certain) that a
fully-loaded DC-9 has a best climb angle of around 650 ft/nm, while a
small single-engine plane will manage something like 400-600 ft/nm at Vx
depending on horsepower and load. Of course, the DC-9 has a much better
climb *rate*, but that's not the concern here [...]

I could be wrong, too, but I think even a loaded DC-9 can manage at
least 1000-1500fpm... and might have to do so for noise abatement
around the airport.

You need to know the forward speed as well. At 120 kt, 1500 fpm would be
750 ft/nm; at 180 kt, it would be only 500 ft/nm (but I think that the DC-9
can do better than that). In either case, the climb angle is not that much
greater than that of a light single.


All the best,


David

David Megginson wrote in message t.cable.rogers.com...
Kevin Darling wrote:
It's not that far off -- I think (but am not certain) that a
fully-loaded DC-9 has a best climb angle of around 650 ft/nm, while a
small single-engine plane will manage something like 400-600 ft/nm at Vx
depending on horsepower and load. Of course, the DC-9 has a much better
climb *rate*, but that's not the concern here [...]

I could be wrong, too, but I think even a loaded DC-9 can manage at
least 1000-1500fpm... and might have to do so for noise abatement
around the airport.

You need to know the forward speed as well. At 120 kt, 1500 fpm would be
750 ft/nm; at 180 kt, it would be only 500 ft/nm (but I think that the DC-9
can do better than that). In either case, the climb angle is not that much
greater than that of a light single.

Yes, thanks. I goofed and posted just before I read that you were
talking about ft/nm versus ft/min. And yep, the DC-9 can climb at up
to 2900 fpm.

Sorry 'bout the confusion.

Best regards,
Kevin