On Mon, 01 Jan 2007 17:26:12 GMT, Matt Whiting
wrote:

Bill Zaleski wrote:

On Mon, 01 Jan 2007 16:35:37 GMT, Matt Whiting
wrote:


facpi wrote:

Anyone give me a clue of the approach configuration of R172K? For
instance, now I use 100kts, 15inch, 2500RPM with no flaps for the
precision approach (ILS) for the training but it is not stable and too
fast for landing after DA.

I insist 90kts is good speed for the approach level and the precision
approach for R172K but my instructor suggested 100kts in terms of some
reason like the strong wind of winter.

I would appreciate if someone could show me the power setting of
approach configuration like non-precsion, precision, approach level
for
R172K. Thank you.

I like the recommendations made in Peter Dogan's book, The Instrument
Flight Training Manual. However, as your instructor said, there is no
single right power setting. If you assume no wind conditions, then a
90K approach speed works well as that yields close to 90 knots ground
speed (not exact due to the descent angle, but really close) which
matches up with one entry in the time charts for timed approaches.

However, given that you typically have at least some headwind, and more
in general in the winter as your instructor stated, if you figure a
nominal 10K headwind, then approaching at 100K airspeed again yields a
ground speed close to 90K which again makes it easy to pull the time

from the approach plate for approaches that are timed. And if you can't

land a 172 from 100K at a typical 200' ILS DH, then you need much more
practice.

It isn't unusual at larger airports to be asked to keep your speed up
for following traffic. I typically fly the ILS at 100K in the Arrow
that I fly, but I recently flew one at 140K due to a following RJ. It
really wasn't a big deal. I chopped the power at DH and had no problem
making a normal landing. Once you get "normal" approaches well in hand,
you want to go up and practice approaches at higher airspeeds so they
become familiar also.

This is the only area where I disagree a little with Dogan as he does
come across a little as suggesting that you can fill a card with 5 or 6
aircraft configurations and be happy ever after. The real world isn't
that simple. My primary instructor was an old-time seat of the pants
insructor as opposed to the more modern "by the numbers" philosophy.
Personally, I think both have their place. I use Dogan's by the numbers
approach to get a starting point, but then use whatever adjustments are
required to get the performance I need in the prevailing conditions.
This is more of a trial and error process although with more experience
you will get to the desired configuration more quickly.


Matt


Would you explain to me how/why you are doing ILS approaches above max
gear extended speed? (140KTS) Your post indicates that you held that
speed to DH.

That should have been 140 MPH. It is a 67 Arrow and thus has the
airspeed marked primarily in MPH and secondarily in knots and I forget
that now and then.

Happy now?


Matt

Sorry that I made the mistake of reading your post and replying to
what you said.