Approach speeds for ILS

It's certainly a matter of perception and everyone thinks about
it differently. My feeling is it's a combination of both. I start
with slight pitch changes and adjust the throttle accordingly.
If you're timing your ILS approaches you'd want to maintain
a constant speed.




"Ray Andraka" wrote in message
...
Hmm, I was taught to use the throttle to stay on glideslope, not the
elevator.
I find using the throttle results in more controllability.

Roy Smith wrote:

I s'pose. But you really shouldn't be playing with the throttle
constantly either. Somewhere along the line I picked up adding "DFWTP"
to my ILS checklist. DFWTP at GS intercept, GUMPS at DH. It stands for
"Don't F*** With The Power".

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

I used to do it with elevator, till an instructor on one of the refresher
courses I took showed me how much better power worked for my airplane (a
cherokee six). I can keep the needle centered much better with small changes in
power than I can with the elevator. SO what I mean by controllability, is the
ability to keep the needle pegged.

Peter Duniho wrote:--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Using the throttle will keep the speed constant. Using pitch will change the
airspeed, albiet only slightly for the small pitch changes associated with
flying an approach. Likewise, I use only throttle on a non-precision approach
because it keeps the airspeed constant (plus I know how much MP reduction is
required for a specific descent rate)

Roger Tracy wrote:

It's certainly a matter of perception and everyone thinks about
it differently. My feeling is it's a combination of both. I start
with slight pitch changes and adjust the throttle accordingly.
If you're timing your ILS approaches you'd want to maintain
a constant speed.

"Ray Andraka" wrote in message
...
Hmm, I was taught to use the throttle to stay on glideslope, not the
elevator.
I find using the throttle results in more controllability.

Roy Smith wrote:

I s'pose. But you really shouldn't be playing with the throttle
constantly either. Somewhere along the line I picked up adding "DFWTP"
to my ILS checklist. DFWTP at GS intercept, GUMPS at DH. It stands for
"Don't F*** With The Power".

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759



--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Peter Duniho wrote:
"Ray Andraka" wrote in message
...

Hmm, I was taught to use the throttle to stay on glideslope, not the

elevator.

I find using the throttle results in more controllability.


A little late to the thread, aren't you? That was over a month ago.
Anyway...

Your comment points to a classic debate, of course. Likely that no person
on one side will be convinced to change their methods. However, suffice to
say there are plenty of us that find that elevator is a more responsive and
useful way to adjust glideslope during an instrument approach. You're above
L/Dmax (so pitch changes do "what you expect"), and the result of a pitch
change is somewhat more uniform from airplane to airplane (power changes can
produce radically different results from airplane to airplane, depending on
drag, weight, and type of powerplant).

Yes, but you typically also want to maintain a given airspeed while on
the approach. Using small throttle adjustments allows you to track the
glide path while maintaining a uniform airspeed. Using the elevator
won't do that. I always trim to the desired approach speed and then
make small throttle adjustments to track the GS ... of course, if you
have dramatic wind shear, then you may need large throttle and elevator
inputs.


Either throttle or pitch can be used for the same purpose, with
approximately the same effect.

All that said, IMHO if you're going to say something like "I find using the
throttle results in more controllability", you ought to define what
"controllability" means. Making glideslope changes with pitch instead
certainly doesn't cause the airplane to go out of control, so it's not
really clear what difference you're talking about.

It does allow you to keep better control of the airspeed.


Matt