Approach speeds for ILS

"Snowbird" wrote in message
om...

the last 3rd of a 6,500 ft runway. Dunno what the tailwind was --
nothing too startling (10-12 kts?)


That is a very significant tailwind for landing; it would not surprise me if
a 10 knot tailwind doubled your landing roll vs. a 10 knot headwind or if
the total landing distance increased between 50% and 100%.


--
Richard Kaplan, CFII

www.flyimc.com

"C J Campbell" wrote in message
...
Two lessons he

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.

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.

--
Christopher J. Campbell
World Famous Flight Instructor
Port Orchard, WA
I like to fly the ILS at or near the suggested climb speed in the 210 that
comes out to be around 110kts using 10deg.flaps and gear down. Reasons are
that in the case of a go around the transition from approach attitude to
climb attitude is less of a change and the accelerations induced are
minimal,. If anyone here has gone missed in the soup from minimal airspeed
to a steep climb under hard acceleration I would suspect the effect to be
disorienting at the least. Anything I can do to reduce unnecessary
accelerations and maneuevers in IFR conditions seems to be a good thing.
Slowing down from MDA shoulden't be a problem since most airports with ILS
are usually long enough, full flaps, throttle back, and allow the plane to
land. Sometimes there is a tendency on breaking out to try and force the
plane down. I would be more concerned with speed control on a circling
approach to minimums on a dark night with a crosswind.
R.Wallace

If you go around beating the Bush, don't complain if you rile the animals.

On Wed, 21 Jan 2004 21:56:10 -0500, Roy Smith wrote:

The
graph doesn't go beyond a 10 kt tailwind; I can only assume Beech
figured nobody would want to try a landing with any more :-)

I believe that at air carrier airports (and, from personal experience, at
BOS) ATC may continue using a runway with up to a ten knot tailwind.

My first tailwind landing ever was done out of an ILS at BOS with about a
ten knot quartering tailwind. But they have long runways (and I needed to
be at the far end anyway to get to the GA ramp).


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

Snowbird wrote:

Unfortunately, since many training ILS are done to a missed
approach, landing from an ILS isn't something at which some
instrument pilots get a lot of practice.

That's why I do all my training approaches to a TGL. Which of course, means I
don't get a lot of practice at missed approaches. I guess I ought to mix it up a
little.

Dave
Remove SHIRT to reply directly.

"Richard Kaplan" wrote in message ws.com...
"Snowbird" wrote in message
om...
the last 3rd of a 6,500 ft runway. Dunno what the tailwind was --
nothing too startling (10-12 kts?)

That is a very significant tailwind for landing; it would not surprise me if
a 10 knot tailwind doubled your landing roll vs. a 10 knot headwind or if
the total landing distance increased between 50% and 100%.

Hi Richard,

As far as I could tell, it didn't do a thing to my landing roll.
What it affected, drastically, was the distance it took my plane
to slow to landing speed and consent to stop flying.

I'm very glad I had a CFI who had me try this. Experience is
worth 1000 words. After doing so, I can easily see how an overrun
accident (or loss of control if someone tried to force the plane to
land) could occur on a long, ILS-served runway.

One size definately does not fit all situations for ILS procedures.
I don't think it's a great idea to fly ILS routinely at 60 kts --
as someone pointed out, the margin over stall is much lower and
the configuration changes needed for correction much larger than
at 90 kts. OTOH, a practice of never retarding the throttle
until over the threshold (as I believe Rick Durden suggested)
would IMHO definately be a bad idea on a shorter runway (say
5000-6000 ft) w/ a tailwind.

And my advice to instrument students is: make sure you actually
land out of a good number of ILS in a number of different
circumstances,
preferably ILS in IMC or at night. For that matter, make sure you
land out of a variety of approaches.

Cheers,
Sydney

"Richard Kaplan" wrote
I would say an overrun cannot happen in a 172 on ILS into the wind or with
calm winds as long as the power is cut at decision height. If the airspeed
is high as discussed in this thread and the airplane is on the glideslope,
then the airplane should be within gliding distance of the runway at
decision height.

Yes, that's true. However, I consider an immediate power cut at
decision height to be poor procedure. The normal ILS is flown on a 3
degree glideslope. However, the power-off glide in anything
approaching landing configuration (meaning gear down if retractable
and at least some flaps) will be 7-10 degrees. So a power cut at DH
means a significant pitch change at low altitude. Since most of the
fleet has tractor props and conventional tails, the power cut will
also cause a significant out of trim condition - nose down. In good
vis and with a Skyhawk-class airplane, it's not a big problem. Try
that trick in your C-210 or my PA-30 in less than a mile vis, and
unless you've practiced it extensively and recently, the landing is
goint to be very, very ugly - possibly ugly enough for maintenance
bills. People have been known to drive the gear right through the
wings doing this.

Since my IFR students are either flying high performance singles or
twins or expect to move into them, I just can't see teaching the
procedure you seem to be advocating. I instead teach a gradual power
reduction with retrim, such that the pitch attitude never really
changes and the airspeed bleeds off gradually. Yes, it eats more
runway and on short runway may require a speed reduction on the ILS,
but it seems like a beter tradeoff. Personally, I slow to about
95-100 mph (not kts) on the ILS at about 300 ft, which seems like the
best compromise between retaining the option for a single engine
missed approach and allowing a landing with a tailwind on a short ILS
runway. In a single engine plane, I see no reason not to slow down
further out. I know that an ILS can be flown in a Bonanza at 90 mph
in turbulence - I've seen an instrument student do it.

As far as flying an ILS with a tailwind, I agree that could cause an
overrun. I would also suggest that landing out of an ILS in actual IMC
conditions with a tailwind is an exercise which should be attempted only by
an experienced, advanced IFR pilot and/or with an experienced CFII on-board.

Well, I like to give my student the necessary tools to handle it. Of
course since I don't instruct renters and don't deal with FBO's,
finishing in the minimum allowable 40 hours is not my highest priority
- nor theirs.

In particular, a pilot who is uncomfortable flying a high-airspeed ILS with
a headwind certainly should not attempt a tailwind ILS.

Now that I can agree with. A high speed ILS is certainly something I
consider important. It's just that a high speed ILS and a tailwind
landing on a short runway simply don't mix.

Michael

(Snowbird) wrote:
As far as I could tell, it didn't do a thing to my landing roll.

You may not have noticed the increase, but physics is physics. Most
spam cans touch down at about 50 kts, which means a 10 kt tailwind
increases your touchdown ground speed by 20%. Basic physics says that
will increase your ground roll by 44% for the same amount of braking
effort.

Everybody should try some downwind landings, if only to see just how bad
an idea they are. The problem is how. I don't like doing them at
uncontrolled fields, because you're going against traffic. The best way
is to find a towered airport at a time when there's nobody else around
and ask for the downwind runway.

Umm perhaps an approach speed of 1.3 Vs or whatever is called for in the
POH for approach to land?

Awww hell.. you got a point.. If you are comin down the ILS you probably
have Southwest right on your tail trying to give you a Boeing enema and
Approach is hollering at you to keep your speed up..

Would it be poor form to come down at the top of the green arc and just
not use flaps then?

Dave.

Snowbird wrote:
Dave S wrote in message hlink.net...

While it IS poor form to come blazing down the ILS to 200 ft minimums in
a skyhawk at 100 kts


It is? Gosh, what's "good form"?

Sydney

"David Brooks" wrote in message ...

To be fair to CJ, I think his observation is mostly about the poor skills of
pilots he watches at TIW.

I understand that, David. But I still don't understand his
post. I don't understand why he says there are only 200 ft
to slow from 90 to 60 kts, and I think if skills are wobbly
(mine certainly can become so PDQ) the answer isn't to switch
to flying at 60 kts, it's to practice more. Because I think
flying an ILS at 60 kts or slowing to 60 kts before decision
height introduces its own set of issues and would require
specific practice for proficiency.

Cheers,
Sydney

"C J Campbell"wrote in message 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.

My charts do not list a time for the final approach segment for 60 knots.
What time do you use if the glideslope craps out?

D. (smart-aleck response from someone who does 180 over the outer marker).