Approach speeds for ILS

"Ron Natalie" wrote in message
. ..

"Roy Smith" wrote in message
...
In article eMvPb.97683$5V2.322914@attbi_s53,
"Gary Drescher" wrote:
Since you have no choice about altitude during an ILS approach,
adding kinetic energy is the only way to increase your glide range.

That's not really true. You can't go below the GS, but nothing says you
can't fly the entire approach above the GS.

You're allowed to descend below the GS as part of your normal excursions
(the FAR's call them bracketing maneuvers) to track the glide slope.

PTS allows a three quarter scale deflection, so I hope that is legal, even
if it is not comfortable.

I think the responses to Chris's post are "it depends". At nearby Paine,
with an 8 mile final over water and a long runway, I'm not dawdling. It's
normal there for trainees at least to cross the threshhold with no flaps and
take your time to bleed speed. I agree it is a good idea to know how to slow
down without gaining altitude.

-- David Brooks

"Roy Smith" wrote...
Since the only reconfiguring you should have to do, if any,
is final flaps, you have plenty of time!

Pulling the power back to idle might be nice too :-)

I consider that part of the 'stick and throttle' part of flying that is done
constantly, not "reconfiguring," which is done a couple times per flight.
Besides, some airplanes don't take well to idle at 200' (including my current
744)... ;-)

"C J Campbell" wrote...

Well, one would think so, and I don't have any problem with it, but I sure
see a lot of pilots that just can't seem to handle it. But I am a CFII who
flies and demonstrates these approaches constantly. I think my point is that
pilots who do not fly as frequently should consider a different 'approach,'
so to speak.

Again, I disagree.

Pilots who don't fly as frequently should use the time they DO get to practice
their skills, lest they be lost. An instrument rated pilot should NOT go out
and fly when the weather is near minimums, just to avoid going non-current! He
should, instead, get out and practice those approaches -- including the
transitions -- every couple weeks. If he can't do that, some instrument time
with his favorite CFII should precede any attempt to go out in the real weather,
and that CFII should ensure he CAN handle it before signing off any currency
check.

Flying an ILS at 60 knots instead of 90 puts the airplane much closer to stall,
giving much less margin of error if the pilot gets distracted or fixated. The
transition to visual is part of EVERY (Cat III excluded) actual approach that
results in a landing, so that transition should be practiced as much as flying
the needles.

I think 90 knots is too slow, unless you have to deal with a tailwind.
The approach is easier to fly at 110 or so, and you get a better
transition to the miss at these speeds. Control response is much more
positive.

My Cutlass RG was based at DCA for 8 years. I normally flew at 120 -
140 knots. All you have to do is chop the power at the middle marker
and fly both the glideslope and the VASI. Your airspeed will decay
quickly. That 200 feet of altitude is nearly a nautical mile
horizontally. Starting at 120 knots and decelerating, that's about 30
seconds. If you are on the glideslope, you won't balloon anywhere.

Good advice on the miss. If you hit DH and there is nothing to see,
pitch to Vy, add power, and get the gear.

Paul

"C J Campbell" wrote in message ...
We get foggy here at Tacoma Narrows this time of year (which is the reason I
post more on these groups in the winter than in the summer). One thing we
see a lot of is guys who fly the ILS too fast.

I have no problem with flying the ILS at 90 or 100 knots if the ceiling is
well above minimums, but it seems to me that if the ceiling is 200 feet
overcast you ought to be flying the approach slowly enough that you can land
at that speed. You don't need to configure for a short field landing, but
you are not going to slow from 90 knots to 60 in a Skyhawk in only 200 feet
of altitude, especially if you can't risk ballooning back up into the soup.

CJ,

I don't understand this post at all. It seems to me that 90 kts
to DH is standard way most people are taught to fly an ILS. I
have a plane that's a bit faster and a bit slippery (and less
effective flaps) than a Skyhawk, and I have no trouble throttling
back at DH and landing. True, I'm not landing and turning off
in 1000 ft, but then, most of the ILS I've met are to 5000+ ft
runways.

Ballooning back into the soup shouldn't be an issue. I don't
understand where your "slow from 90 to 60 in 200 ft of altitude"
concern arises. We regularly practice flying the ILS at full
cruise -- 130-140 kts -- right down to DH. If I throttle back
at DH, I have no idea at what point I slow to landing speed. I
simply level off just above the runway and wait until the airplane
decides to land. If I wind up a foot off the runway at 90 kts it's
not a problem.

It seems to me that people should train how they're going to fly
and fly how they're going to train. If they haven't trained enough
to fly an ILS to DH at 90 kts and land comfortably, I don't think
the solution is to have them adopt a different procedure. I think
the solution is for them to train more -- and if they're going to
do the necessary training to practice the 60 kt ILS thing, why not
have them do the necessary training to fly a 90 kt ILS or even a
120 kt ILS?

1) If the field is really at minimums, you have 200 feet to slow down to
landing speed. That is not much time. Better you should be ready to land
before you break out.

I don't understand this at all. Why do I only have 200 ft to slow
down to landing speed? I have 200 ft of descent left -- but usually
1/2 mile from the runway threshold and 2000 ft to land in in the TDZ
(assuming 4000+ ft runway). So it seems to me that I have something
like 4,500 ft to slow down to landing speed.

2) If you decide to go missed, then go missed. Don't change your mind just
because you got a glimpse of the runway as you were flying overhead.

With this, assuming no malfunctions or fuel criticality, I agree.

Cheers,
Sydney

In article , Paul
Hamilton wrote:

All you have to do is chop the power at the middle marker
and fly both the glideslope and the VASI.

That's fine if you have a middle marker. Not all ILS's do.

"John R Weiss" wrote in message
news:OSzPb.98715$5V2.327271@attbi_s53...
"Roy Smith" wrote...

Pulling the power back to idle might be nice too :-)

Besides, some airplanes don't take well to idle at 200' (including my
current
744)... ;-)

If you brought it in 50% faster than normal, it might well do...

Paul

Ron Rosenfeld wrote in message . ..

I think an instrument rated pilot should have had the necessary training so
that he can fly the approach at the higher speeds desireable to blend in
with faster traffic -- and not have to worry about "balloning back up into
the soup". ...
So I think that instrument rated pilots who, after all, are legal to fly
into any airport, should have the training and experience to deal with the
faster approach speeds. It really is not that difficult once one starts to
practice.

I think this is eminantly practical advice.

I don't think of 90 kts as a "faster approach speed". It seems
very common, at a larger airport, to be asked something like "keep
your speed up -- say best forward speed?" If the answer is "N12345
can maintain 120 kts" it's presumably a heck of a lot easier for
ATC to work you in between a bunch of jets than if your answer
is "N12345 needs 60 kts (or even 90 kts) at the marker".

My CFI would say "either train until you can do it or don't
fly IMC".

Cheers,
Sydney

Bill Zaleski wrote in message . ..
Ron's thoughts are very realistic and deal with real world scenearios.
All of my instrument students get the experience of flying 140 KT ILS
speeds in my skyhawk at the later points of their training.

Bill,

Just curious, how do you fly 140 kt ILS in a Skyhawk? Or do you
have a controllable prop?

Cheers,
Sydney

"Paul Sengupta" wrote...

Besides, some airplanes don't take well to idle at 200' (including my
current 744)... ;-)

If you brought it in 50% faster than normal, it might well do...

Can only do a missed approach in that situation -- goes against the "stabilized
approach" rule... :-)