Approach speeds for ILS

In a previous article, "C J Campbell" said:
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 regularly shoot approaches at 110 knots in the Archer or 120 knots in
the Dakota, and don't touch the throttle until the flare. Granted, I
haven't done it to minimums in actual, but I've done it under the hood,
and I don't gain any altitude. Sure you float down the runway, but if
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.


--
Paul Tomblin http://xcski.com/blogs/pt/
I didn't need to sabotage anything. Not being around to say "No that
won't work" or "you can't do it that way" is more than enough damage.
(Ego problem? It's not a problem.) -- Graham Reed, on job endings

"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.

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

"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

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. There's nothing illegal or
inherently unsafe about flying the ILS 1 or 2 dots high. You wouldn't
want to do it in a jet, but in a spam can it's perfectly reasonable.

"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.

"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 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. There's nothing illegal or
inherently unsafe about flying the ILS 1 or 2 dots high. You wouldn't
want to do it in a jet, but in a spam can it's perfectly reasonable.

Point taken--I should have said little choice, not no choice. Still, the
added speed helpfully extends the glide range.

--Gary