Approach speeds for ILS

"John R Weiss" wrote in message
news:mYlPb.109959$xy6.321478@attbi_s02...
|
| 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.
|
| Nope -- not unless you are flying a Cat III certified airplane.
|
| You should be ready to transition to land AFTER you break out! A C172 at
90
| knots is only descending at 400-500 FPM. At 200' AGL, you have 20-30
seconds
| until touchdown, even if you don't flare at all! You can do a lot of
| decelerating, reconfiguring, and flaring in 20 seconds. Since the only
| reconfiguring you should have to do, if any, is final flaps, you have
plenty of
| time!

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.

AARP encourages older drivers to take things a little slower -- to drive
within their skill level. Perhaps rusty pilots should do the same.

"C J Campbell" wrote in message
...

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.

What speed do you use to fly the ILS if asked to "keep your speed up"?

ILS runways are usually 5,000 feet or longer. You could dissipate speed
over the runway.

I suspect if you cross the runway threshold right on the glideslope at 90
knots in a Skyhawk with a 5,000 foot runway, there is no way you could
overrun the runway if you tried.

--
Richard Kaplan, CFII

www.flyimc.com

C J Campbell wrote:

Paul Tomblin wrote:

| you've got 8000 feet, you've got plenty of room for it. And ATC
| appreciates a fast approach when they've got a 767 on your tail.
|
|

Not many 767s at TIW! Seriously, I have no problem with accommodating ATC
when it can be done safely, but neither am I going to do their job for
them
when they screw up.

Not always the case. Here at SJC when ATC asks: "Say best forward speed?"
they're saying "Look Hilton, we've got a bunch of 737s, 757s, 777s, a few
DC-10s etc coming down the approach. You gimme 120, I can get you in within
5 minutes. You gimme 90, maintain VFR, hold where you are, expect your
clearance sometime in the future."

Hilton

Any thoughts as to why Approach Plates do not list the time for an
approach speed of 75 KIAS?

On Tue, 20 Jan 2004 18:20:43 -0800, "C J Campbell"
wrote:

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.

I would respectfully disagree, although I haven't flown a Skyhawk in years.
However, my Mooney is also an a/c known for being "slippery" with a Vso of
49 kts, a bit faster than the Skyhawk. However, for an approach to
minimums, especially at an airport with "heavy iron", I would view my
limiting speed to be the gear down speed of 105 Kts. (And if I had a newer
Mooney, it would be even faster).

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". Also, most ILS's are into runways of at least 4,000' lengths,
so you don't need to be at 1.2 Vso coming over the threshold (although it
is nice to touch down in the touchdown zone).

Don't forget, at a DA of 200' you will still be about 1/2 mile from the
runway. Given that it's a 4,000' or longer runway, you should be able to
touchdown in the first 1/2 and not run off the far end.

In my Mooney, I have no particular problem with, after reaching a DA of
200' and making the decision to land, lowering the additional two notches
of flaps and slowing speed by the runway threshold (60-65 KIAS -- the
slower speed if there is an operational advantage).

I will say, however, that with a DA of 100', I do not drop the last two
notches of flaps, and I will use about 4,000' of runway if I am using a 105
kt approach speed. But at airports where that may occur, that distance is
usually less than 60% of the total runway length -- again, plenty of room.

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.

My most difficult approach, in terms of speed control, came with a request
from PWM approach to "maintain present speed until the (outer) marker". At
the time, my speed was 125 Kts; I was under the hood; and there was an FAA
examiner in the right seat. My gear down speed is 105 kts, flaps 109 kts,
and this approach was being done to a 100' DA with a landing planned. So
it was a matter of coming down, slowing down, and reconfiguring on the way
down. (And yes, I discussed with the examiner the fact that I had not done
something like this before; that I wanted to see how it would work out; and
that if it were the first time doing this procedure in real IMC, my
response would have been "unable").

So I think these instrument pilots should be trained and practiced in
faster approaches.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

I suspect if you cross the runway threshold right on the glideslope at 90
knots in a Skyhawk with a 5,000 foot runway, there is no way you could
overrun the runway if you tried.


I have seen it done. A pilot (NOT one of my students) in a rental C-172 from a
flight school I used to teach at ran off the end of a 5300' rwy after a normal
approach in VFR (65 kts).
Unreal. I just stood there with my mouth hanging open as I watched the Cessna
float down the rwy, carrying power and touching down with about 300 feet of rwy
remaining. With about 100 feet left, the tires locked up and there the plane
went, off the end in a cloud-O-dust. No damage, except for flat spots on the
tires and bruised ego.




-John
*You are nothing until you have flown a Douglas, Lockheed, Grumman or North
American*

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. Of
course, I don't advocate that kind of speed for everyday use, but it
is absolutely no problem getting it stopped on a 5000' runway. There
are only a few ILS's on shorter runways.


On Tue, 20 Jan 2004 23:53:59 -0500, Ron Rosenfeld
wrote:

On Tue, 20 Jan 2004 18:20:43 -0800, "C J Campbell"
wrote:

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.

I would respectfully disagree, although I haven't flown a Skyhawk in years.
However, my Mooney is also an a/c known for being "slippery" with a Vso of
49 kts, a bit faster than the Skyhawk. However, for an approach to
minimums, especially at an airport with "heavy iron", I would view my
limiting speed to be the gear down speed of 105 Kts. (And if I had a newer
Mooney, it would be even faster).

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". Also, most ILS's are into runways of at least 4,000' lengths,
so you don't need to be at 1.2 Vso coming over the threshold (although it
is nice to touch down in the touchdown zone).

Don't forget, at a DA of 200' you will still be about 1/2 mile from the
runway. Given that it's a 4,000' or longer runway, you should be able to
touchdown in the first 1/2 and not run off the far end.

In my Mooney, I have no particular problem with, after reaching a DA of
200' and making the decision to land, lowering the additional two notches
of flaps and slowing speed by the runway threshold (60-65 KIAS -- the
slower speed if there is an operational advantage).

I will say, however, that with a DA of 100', I do not drop the last two
notches of flaps, and I will use about 4,000' of runway if I am using a 105
kt approach speed. But at airports where that may occur, that distance is
usually less than 60% of the total runway length -- again, plenty of room.

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.

My most difficult approach, in terms of speed control, came with a request
from PWM approach to "maintain present speed until the (outer) marker". At
the time, my speed was 125 Kts; I was under the hood; and there was an FAA
examiner in the right seat. My gear down speed is 105 kts, flaps 109 kts,
and this approach was being done to a 100' DA with a landing planned. So
it was a matter of coming down, slowing down, and reconfiguring on the way
down. (And yes, I discussed with the examiner the fact that I had not done
something like this before; that I wanted to see how it would work out; and
that if it were the first time doing this procedure in real IMC, my
response would have been "unable").

So I think these instrument pilots should be trained and practiced in
faster approaches.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

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". Also, most ILS's are into runways of at least 4,000' lengths,
so you don't need to be at 1.2 Vso coming over the threshold (although it
is nice to touch down in the touchdown zone).

I agree. My American instruction was usually to fly the glide slope
with one notch of flaps at about 90kts (PA28), and then do whatever was
necessary to land the plane. In the UK, one instructor made me fly the
ILS 10 kts faster and with no flaps (easier to perform a missed if you
don't have to clean up), and land more often than not flapless - which
we have all been trained to do, and is rarely a problem on the usual
4000'+ runway.
--
John H. Kay

"C J Campbell" wrote in message ...
"Paul Tomblin" wrote in message
...

| you've got 8000 feet, you've got plenty of room for it. And ATC
| appreciates a fast approach when they've got a 767 on your tail.
|
|

Not many 767s at TIW! Seriously, I have no problem with accommodating ATC
when it can be done safely, but neither am I going to do their job for them
when they screw up.

It is always fun to watch somebody who landed too fast and too long then try
to turn off at the first exit just because the tower asked him to,
especially when it was probably the tower that asked him to keep his speed
up when he was on final. They come whipping around there, side loading the
gear and nearly careening off into the infield, tires smoking and
screeching. But what the heck, it's only a rental.

Like CJ mentioned, a fast approach speed makes it somewhat difficult
to transition to the landing phase. However, I believe that the
benefits outweigh the disadvantages.

- ATC likes it if you fly the approach faster

- Reduces the exposure time in icing conditions. At this time of year,
we can often climb above the clouds and remain there until the
approach phase. A fast approach will minimize ice accretion during
approach.

- A faster approach speed makes it possible to adjust for altitude
excursions by using elevator alone and without compromising too much
airspeed. At slower airspeeds you will have to make power adjustments.
For example, at 90 knots you will lose about 9 knots in order to climb
100 ft. At 60 knots you will lose 18 knots to climb 100 ft.


Finally, 90 kts to 60 kts in a draggy airplane like a skyhawk is not a
big problem. You can do that by pulling power to idle and not even use
any flaps. However, in a slippery airplane like a Mooney that may be a
problem. But such airplanes tend to have high approach speeds anyway,
so slowing down much below 90 may not be an option.

"Andrew Sarangan" wrote in message
om...
Like CJ mentioned, a fast approach speed makes it somewhat difficult
to transition to the landing phase. However, I believe that the
benefits outweigh the disadvantages.

- ATC likes it if you fly the approach faster

- Reduces the exposure time in icing conditions. At this time of year,
we can often climb above the clouds and remain there until the
approach phase. A fast approach will minimize ice accretion during
approach.

- A faster approach speed makes it possible to adjust for altitude
excursions by using elevator alone and without compromising too much
airspeed. At slower airspeeds you will have to make power adjustments.
For example, at 90 knots you will lose about 9 knots in order to climb
100 ft. At 60 knots you will lose 18 knots to climb 100 ft.

Another advantage of a faster approach speed is that it lets you glide
further in the event of engine failure. (You'd still want to slow down to
best glide speed, but you'd gain more altitude in the process.) Since you
have no choice about altitude during an ILS approach, adding kinetic energy
is the only way to increase your glide range.

--Gary