speed on ILS glideslope

[photofly]

A question directed to those who by dint of professional role or experience consider themselves qualified to give training in instrument flight:

What speed(s) do you advise pilots in an SEP to fly the glideslope on an ILS approach, and what rationale(s) do you have for picking those speeds?

[iflyforpie]

1.3 Vso. For the whole approach. That way you get paid more.

[Class 1 Instructor]

A question directed to those who by dint of professional role or experience consider themselves qualified to give training in instrument flight:

What speed(s) do you advise pilots in an SEP to fly the glideslope on an ILS approach, and what rationale(s) do you have for picking those speeds?

Depends on the SEP. 120 kts is a good speed for any of the SE retractables. Fast enough to keep up with the traffic flow yet still allows a manageable transition to landing speed for an ILS where you are going to break out at 500 ft AGL or better. The problem comes with the ILS to mins scenario. You can't be going 120 at 200 feet so you have to slow down on the ILS to a landable speed, usually 90 kts after you pass the FAF.

For the C 172 I specify 100 kts for the approach and send a silent mental "SORRY" to ATC.

[trey kule]

What the heck does SEP stand for?

To answer your question..Every plane is different..And the speed might change a bit for weight wind, traffic flow etc. There is no one magic answer that fits all planes or a magic formula.

Now tell me what SEP stands for, or do I need a secret squirrel decoder ring, or do people now just make up alphabet words and assume everyone will understand their meaning.

[photofly]

Sorry... SEP - single engine piston ...

[Cat Driver]

What the heck does SEP stand for?

Must be something new we were never taught.

[trey kule]

ah.....SEP.......good question.

There still is no one magic answer or formula that I am aware of. And circumstances may change the approach speed a bit.. In general, I like numbers that are easy to see on the air speed indicator...80,.110, 120, 130,, not 76.776,112, 118, or 132...And that is not because I am old and half blind.. I liked those simple numbers when I was a pup.
Easy to quickly scan and see that things are as they should be.
Dont get in the habit of generalizing to much about a class of plane..The danger is you can use perfect logic to come to a totally wrong conclusion.

What you should do, and this is just my opinion, is make sure you are not going to fast..This is a big problem with doing approaches in slower airplanes with high lift wings as it causes some challanges when you break out.. I noticed class 1 suggested 100 in a 172.....that is pretty much cruise speed and if you break out at 200 feet at that speed it seems pretty fast to me.. If you have the speed correct, you simply contiune down to the runway rather than trying to jockey the speed and power and destabalizing the last part of the approach when you are close to the ground..Real IFR is a bit different than FTU training.
I would not be apologizing to anyone for my approach speed and then increasing it for their convenience.. It is what it is. It has been a very long time for me so my memory of a 172 might be incorrect, but 100 seems very fast.

When someone gives you a number, feel free to question it and use some common sense.
BTW (see, I can speak alphabet), what aircraft are you specifically interested in.

[photofly]

I suppose I'm looking for a discussion of how to interpret the Flight Test Guide:

- maintain a stabilized descent to the DH/DA to permit completion of the visual portion of the approach and landing with minimal manoeuvring; and

which could easily be interpreted as suggesting you to drag it in on the back side of the power curve with your flaps, t*ts and *ss hanging out for a five mile final (excuse my French) at 70 kts pretending you're flying a very slow 737.

What do you understand by "stabilized descent" in this context?

I'm curious as to what, and how, instructors tell their students about this.

[Class 1 Instructor]

This boils down to, are we teaching pilots how to pass the IRFT or how to fly IFR In the real world ? 55 to 65 is the range of C 172 approach speeds. To me it is simply ridiculous to fly the ILS at these speeds. 100 kts will not plug up the ILS too badly and if the student can't maintain the Loc/GS while reducing speed to the target 75 at mins after passing the FAF, while piloting the easiest to fly aircraft ever made, then they should not have an IFR rating.

[Cat Driver]

This boils down to, are we teaching pilots how to pass the IRFT or how to fly IFR In the real world ?

So the teaching industry teaches pilots to pass a flight test.....but it is not teaching for the real world of IFR flying......have I got this right?

So who teaches them how to fly in the real world?

[Class 1 Instructor]

This boils down to, are we teaching pilots how to pass the IRFT or how to fly IFR In the real world ?

So the teaching industry teaches pilots to pass a flight test.....but it is not teaching for the real world of IFR flying......have I got this right?

So who teaches them how to fly in the real world?

Who do you think ?

[Cat Driver]

Who do you think ?

My point is why not teach them how to fly IFR properly in the first place.

[photofly]

So, Cat, have a stab at the question: what would you explain to a pilot?

[Cat Driver]

So, Cat, have a stab at the question: what would you explain to a pilot?

With regard to your original question I would teach them to fly the best speed for the airplane and the conditions at the time of the approach.

I have never given any instruction for the instrument rating in a single engine airplane, however my comment above still holds true.

[DeltaHotel]

Barber pole ... as long as you can

[CpnCrunch]

The FAA says that a 'stabilized approach' just means maintaining a constant angle glidepath towards a predetermined point:

https://www.faasafety.gov/files/gslac/c ... oncept.pdf

[photofly]

With regard to your original question I would teach them to fly the best speed for the airplane and the conditions at the time of the approach.

That's good advice, but very general. (One might equally say that one should always fly an aircraft at the best speed for the airplane and the conditions at the time, even when not on an approach.)

What advice could you offer to a pilot to help them judge what, in fact, is the best speed for the airplane and conditions at the time of the approach?

[photofly]

The FAA says that a 'stabilized approach' just means maintaining a constant angle glidepath towards a predetermined point:

https://www.faasafety.gov/files/gslac/c ... oncept.pdf

According to this TC web page:
http://www.tc.gc.ca/eng/civilaviation/s ... 8-1528.htm

“Stabilized approach” means a final approach flown to achieve a constant rate of descent, at an approximate 3 degree descent flight path angle, with stable airspeed, power setting, and attitude, with the aircraft configured for landing.

It's possible that they have a different meaning in mind for the Flight Test Guide, I suppose.

But if not, a pilot has to pick the "stable airspeed" - how should he do so?

[Colonel Sanders]

You've got to be able to get the gear down (probably
at GS intercept) so that's going to limit your approach
speed.

Once you've intercepted the GS and got the gear down
I would use whatever speed doesn't cause ATC heartburn.

Although many people here would recommend 70 knots
in a 172, I would recommend at least 100 or 120 if possible
for the kerosene burners behind you.

If you insist upon your constitutional right to fly an ILS at
70 knots, ATC is not going to be very helpful next time you
ask them for an approach.

I might mention that the ILS needles get a little more sensitive
below 500 AGL so if the ceiling are really low, don't fly so fast
that you can't keep up with the needles. Actually, if 120 knots
is a problem for you below 500 AGL, I might suggest you need
a bit of practice.

I've been flying a Pitts at a larger airport the last little while,
and I like to keep the speed up to at least 180 mph (preferably
200) until very short final to expedite things. When there are
four large aircraft lined up in sequence for takeoff, burning
kerosene like there's no tomorrow, and two more inbound
behind you on the approach, it's only polite to hustle a bit,
within the limits of the airframe.

And that's really the point - learn to fly safely within the
limits of the airframe. A 172 will safely do an ILS at 100
or 120 knots, and ATC will greatly appreciate it, so step
up to the plate. I know I'm probably in the minority here
on this, but I would greatly enjoy flying an ILS in a 172
with the flaps up and full throttle all the way down the GS.

Generally I am massively unconcerned with a speedy approach
on short final with an ILS because the runways are often
ridiculously long: 8,000 or 10,000 feet. I am flying off
a 6,000 foot long runway these days and it might as well
be Cape Canaveral, as far as a 180-200 mph approach goes.

[AOW]

I would say that it depends on the situation. If you're just above a layer, and will still be 1000 agl when you break out, keep the speed up by all means. But, if you're shooting an approach to minimums, then you want to avoid having to make huge configuration changes at low level. Consider landing with partial flap. As for speeds to fly, 90-100 kts is probably considered "normal"... If you're looking for a formula, Vy + 10 until breakout, then decrease smoothly to 1.3 Vso +5 to 10. I think the origin of that was from a twin, where the approach speed was supposed to be Vyse + 10, to retain enough energy for a go-around with an engine failure.

Most of all, fly a speed that's safe!

[Colonel Sanders]

Many years ago, I was flying a practice ILS under
the hood. I think it was at CYOW. Big wind out
of the northwest, and for some bizarre reason ATC
asked me to slow it down, on the ILS shortly after
GS. I don't remember why - it was a long time ago.

So I pulled the power and slowed the Maule down
to around 45 mph or so IAS. It was a bit of a trick
to keep the GS centered with that power and pitch
change, but all good practice.

I managed to get my groundspeed down to almost
single digits. My father in the right seat (lookout),
commented, "I don't think that's exactly what he
had in mind".

[Chaxterium]

Why not just pick a speed you're comfortable with passing the FAF and then throttle back to your landing speed when you're approaching minimums? If I'm expecting to break out early I'll keep my speed up longer but if I'm fully expecting the weather to be at or near minimums then I'll slow down at the FAF.

As part of the flight test vs real world argument is definitely a factor. Our SOPs dictate final flap selection and Ref plus 10 knots (~100KIAS) at the FAF and then maintain that speed until the flare. In the sim this is exactly what I do but in the real world we keep the speed up as much as we're comfortable with as long as we can. It's also a bit of airmanship. If I know there's an RJ behind me waiting for me to finish my approach I'll keep the speed up. Having said that though it's most important to be comfortable with your set up so if you need to slow it down, do so. No need to apologize for it.

Cheers,
Chax

[Beefitarian]

Who do you think ?

My point is why not teach them how to fly IFR properly in the first place.

Because they don't want to pay to learn that when they'll have to learn how to do it the Captains way once they get a job anyways, and besides they are so cheap they would go to the other FTU just to save $9 on the total cost of the rating.

[chinglish]

My point is why not teach them how to fly IFR properly in the first place.[/quote]

I'll take a stab at it. Most IFR instructors don't have actual IFR experience outside of the training world. You should be at a speed that doesn't conflict with traffic. All prop planes can be slowed down quite easily on approach a jet is a different story.

[jschnurr]

If the weather is way above minimums, I fly the ILS clean a few knots below approach flap speed. When you break out, flaps/gear down, slow 'er down and configure.

If the weather is close to or at minimums, I fly a few knots below full flap speed with the gear and approach flap down. When I break out I select full flaps.

I fly twin pistons (PA31), but if I flew singles this would still apply.