speed on ILS glideslope

[Cat Driver]

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?

These word games can be fun photofly especially when the question is worded so elastic such as yours " in a single engine prop plane " that could be anything from a Cub to a P51.

Like the colonel the higher the speed the better for me most of the time, within reason of course based on the airplane and the conditions at the time.

As to the stress of having to slow down a rocket ship such as a C172 that should not be an insurmountable problem because if the runway being used has an ILS it should be long enough to slow down a C172 for the landing.

P.S...

Most of the ILS's I flew during my last thirty years of flying were in 705 category airplanes .

[photofly]

Most of the ILS's I flew during my last thirty years of flying were in 705 category airplanes .

Thank you ... I'm glad I persuaded you to dig back into your historical knowledge to make a contribution!

[Cat Driver]

Thank you ... I'm glad I persuaded you to dig back into your historical knowledge to make a contribution!

You are welcome.....it got me to thinking and for sure the most difficult ILS I did in the last thirty years was in Niamey......virtually zero zero in blowing dust and sand with no NDB at the FAF.

[Colonel Sanders]

Getting back to the OP's question, I might pose
a question in reponse:

"What speed would you ride a motorcycle on a road?"

There is no one speed which would be a correct
answer, of course. The best answer I could think
of would be, "the same as the rest of the traffic".

I would not recommend riding a motorcycle either
50 mph slower or 50 mph faster than the traffic.

Getting back to a 172 ... it can be flown down an ILS
at any speed from 50 to 150 mph. Like a motorcycle,
I would choose a speed which conforms to the rest of
the traffic on that ILS.

[photofly]

I worded the question carefully; I didn't say "what speed would you fly an ILS", but "what speed(s) do you advise pilots..."

Maybe I should have been more specific: suppose you've a new instrument flight student, and this is his or her first ILS, dual, with you as the instructor. You're in a 172, or a 182, or an Arrow, or something similar. There's no other traffic around; between the two of you you can set any pace that you like. And you're PIC, after all. Your goal is to set a good example; a benchmark. Later you can discuss with the student when it might be appropriate to fly slower, or faster - but, for now, when he or she says, "Teach, my workload is too high for a discussion, just give me a speed to aim for, please" - what are you going to say? Pick an aircraft type of your choosing, if you wish. I'm more interested in how you reach the decision than the exact number.

That's the context of the question. Most people have had a stab at it; if anyone else wants to chime in I'd still like to hear.

[Cat Driver]

Maybe I should have been more specific: suppose you've a new instrument flight student, and this is his or her first ILS, dual, with you as the instructor. You're in a 172, or a 182, or an Arrow, or something similar.

Sorry I really should have stayed out of this discussion for the simple reason I can not imagine why I would be doing that kind of training.

This is a discussion for new instructors.

[Class 1 Instructor]

Maybe I should have been more specific: suppose you've a new instrument flight student, and this is his or her first ILS, dual, with you as the instructor. You're in a 172, or a 182, or an Arrow, or something similar.

Sorry I really should have stayed out of this discussion for the simple reason I can not imagine why I would be doing that kind of training.

This is a discussion for new instructors.

I am kind of disappointed in you response. Teaching IFR is an advanced skill and should never be done by a "new instructor", the disadvantages of which you have pointed out in very blunt language in many, many previous posts. You obviously have a lot of experience so why not share it ?

I have already given my answer: 120 kts for an Arrow and 100 kts for a C 172 and the reasons why. So how about contributing your answer ?

[Cat Driver]

I have already given my answer: 120 kts for an Arrow and 100 kts for a C 172 and the reasons why. So how about contributing your answer ?

I have already explained I have never given any IFR instruction in a single engine airplane.

So what weight would my comments carry if I have never done it?

[Class 1 Instructor]

I have already given my answer: 120 kts for an Arrow and 100 kts for a C 172 and the reasons why. So how about contributing your answer ?

I have already explained I have never given any IFR instruction in a single engine airplane.

So what weight would my comments carry if I have never done it?

The weight of 50 years of experience and 30 K hours......

[Cat Driver]

This is what my opinion was.

Quote:

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.

[photofly]

It takes 50 years of experience and 30 K hours to learn never to commit yourself to an answer sufficiently specific for someone else to be able to find fault.

[Class 1 Instructor]

It takes 50 years of experience and 30 K hours to learn never to commit yourself to an answer sufficiently specific for someone else to be able to find fault.

Ideally everyone on avcanada should be reading the answer in order to learn from it, not find fault with it.

Still saying you would tell the student to "fly the aircraft at the best speed for the airplane and the conditions at the time of the approach" is not an answer as it does not convey any useful information. The question asked is IMO a reasonable one and deserves an answer, and more importantly the thinking behind that answer.

You of course have no obligation to share any of your hard won experience but it does make me wonder why you bother to post on a forum specifically designed to discuss training matters......

[trey kule]

OK...

The proper approach speed is aircraft and condition specific..There is no specifc answer to a generic question...
Maybe it takes 50 year and 30k experience to understand that.

To the original poster, I hope you understand that you are asking a question that does not have a perfectly accurate answer.

Your job, both on the ride, and in the real world afterword, is to fly a stabalized approach..Get the needles all centered up nicely at the target airspeed and keep them there., and unless you are dealing with some unusual enviromental issues, you should be keeping them there with only very minor adjustments.

I assume from your clarification we are talking about a new IF student. Do not feel under any pressure, whatsoever to fly outside the normal parameters to satisfy anyone..NO presseure..
Do not think at this stage you have to mimic those with much experience..They sometimes forget there was a time when an ILS was a challange for them, and thus subtley put pressure on you with the "If I can do it, anyone can do it" argument.

I do not like the older and experienced ones also subtly putting pressure on new pilots to fly to the outside of the approach speed envelope to satisfy ATC or the implication that ATC will punish them.
Canadian ATC folks, in my experience, with few exceptions are super professional..They know what your aircraft can do, and if they make a request and you are unable to comply they will not put pressure on you. It is your fellow pilots who are putting that perceived pressure.

So to answer your question. There is not correct generic answer.. Fly a nice stabalized approach all the way to the threshold and you wont have problems with either the ride of the real world afterword.
You do not have to fly at either extreme, dragging it on, or at cruise plus 10...common sense and some advice from someone experienced on type will give you the specific answer for the aircraft you operate.....be wary of instructors who have a mine is bigger than yours syndrome who want to demonstrate their awesome skills at flying the outside edge of the envelope.

[Cat Driver]

You of course have no obligation to share any of your hard won experience but it does make me wonder why you bother to post on a forum specifically designed to discuss training matters.

Every once in a while someone asks a question that is valid.

And on several occassions I have quit posting in the flight training forum because of my inability to interact with flight instructors and people such as photofly.

Truth is I sold my FTU because I just could not deal with flight instructors.

So once again I am going to exit this forum.

[photofly]

people such as photofly

There are others!?

[Lurch]

Some days I have just got to shake my head at the stupidity that keeps creeping into the Training Forum, a ten page thread on Vx, another 10 pages on AoA, and now 2 pages (so far) on airspeed. Trey, Cat and CS all gave perfect answers on page 1 of this thread but people still don't get it.

Cat you have outlasted the previous ignorant instructors, 767 is the perfect example, and in time these posters will get bored and move on as well.

It's a war of attrition you just have to outlast the stupidity.

Lurch

[Cat Driver]

Lurch the sad part is by getting involved in these discussions I have been giving credence to the validity of the subjects......

......time to quit and let them jerk each other off with these deep thinking contests.

[Colonel Sanders]

An ILS is a very expensive collection of equipment
to obtain and maintain. Rarely do I have the luxury
of it's exclusive use!

But when you do, there are some things that are
really quite fun and also develop great hand-flying
skill.

First exercise (eg in a 172) is full throttle in the PT
(or vectors to final). All the knobs forward as you
intercept and track the LOC inbound. Nose down
(and trim down) for the GS intercept - no gear to drop,
and flaps stay up. Trundling down the GS, you're going
to pick up some speed, because the one thing that Cessnas
do well is descend. They understand the whole gravity thing
pretty well. Now, the needles are going to be more
sensitive because of the increased speed, and that
builds character, especially as you descend below 500
AGL. This works well at night when it's not too bumpy
so you can fly in the yellow arc. Just keep it below
Vne. Down to 200 AGL, needles shivering, and then
pop it up again to PT altitude on the miss. Lots of
kinetic energy there. Do that a couple times.

Second, do the ILS straight up - normal speed and
power configuration. It's going to be a lot easier
to keep the needles centered at a normal speed,
so take it down to 100 AGL (cat II) which also
builds character. GS is going to tremble a bit.

Third, as the fantasy continues that you have your
own private ILS, is to do it at 50 MPH. Yup, at PT
altitude slow down to 50 MPH and hold it there with
flap as required all the way down. Full throttle at
200 AGL, nose down to get some airspeed back,
level, flaps up in stages, driving down the runway
while you are doing this, then the miss. You will
note that the effect of the slow speed is to amplify
any kind of wind corrections which is now a bigger
percentage of your TAS. Remember to look at the
GPS track made good and set that after LOC intercept
to the final approach track and the LOC will stay centered.

Fourth - remember, in our happy place there is no
one else in the sky - after GS intercept, flaps and slow
the aircraft to 50 mph with the needles centered, then
flaps up and accelerate with full power to 150 mph with
the needles centered, then power off and flaps to slow
to 50 mph with the needles still centered. Keep doing
this to DH.

I love doing these! It really builds confidence and skill.
Just watch the low energy conditions (low and slow).

[Class 1 Instructor]

Some days I have just got to shake my head at the stupidity that keeps creeping into the Training Forum, a ten page thread on Vx, another 10 pages on AoA, and now 2 pages (so far) on airspeed. Trey, Cat and CS all gave perfect answers on page 1 of this thread but people still don't get it.

I have to say I don't agree. What is an appropriate speed to fly an instrument approach seems to me a pretty fundamental part of the initial IF course.

I think the missing piece of this discussion is a bit of a discussion on what factors should effect the decision to fly at a an ILS at any particular speed, and I think I won't find any disagreement over a general statement that the aircraft should always be at a speed chosen by the pilot and not at what ever it happens to end up at.

So here is my 02 cents worth on factors that should be considered for selecting an ILS approach speed during initial IF training.

1) The training aim of the approach. For the very first couple of ILS I make them all missed approaches at DH. I think you should instill at the beginning that all approaches are missed approaches that instead where converted into landings by virtue of having the required visual references. The 100/120 numbers I gave make the missed easier and safer because of the extra energy the aircraft has. As the student gets more practice then the approach speeds should be varied with an emphasis on arriving at the DH at the target ref speed even if the approach started at a higher speed

2) The characteristics of the aircraft should be taken into account such as gear and flap speeds, Va and engine handling to avoid shock cooling. This may limit the upper or lower speeds acceptable for an approach. a practical example is that 120 kts is below the gear speed for an arrow but above the flap speed so choosing this speeds means a flaps up ILS and the requirement to either land flaps up, deploy flaps while slowing on the ILS (more difficult) or adding flaps below DH on the visual portion of the landing. Doing all three is good experience

3) Exercising good airmanship. Yes at the end of the day as Trey Kool correctly pointed out one should not be pushed into flying a bad approach due to ATC pressure, but they should also be taught to develop situational awareness so that they start anticipating a requirement to slow down or speed up and be proactive in their speed management. Real world situations that develop during training approaches should be used as a trigger for student decisions on what speed they are going to fly this approach at.

However to at the beginning of IF training, students need at starting point and that is where my 100/120 numbers come from and what they will deviate from as training progresses. Bottom line IMO is you should never fly an approach at any particular speed without understanding why that speed is appropriate

Lurch: Sorry for further contributing to the stupidity on this forum although if you consider this topic stupid I would be interested in what you consider "non stupid" topics for a forum specifically dedicated to the discussion of flight training.

[CpnCrunch]

This is kind of ridiculous. I was just wondering the same thing myself, as I'm doing some practice ILS approaches at the moment.

Perhaps a better question is: "when training ILS approaches on a cessna 172, what airspeed do most instructors use on final approach at YYC or similar". And (from doing my own research), the answer seems to be 90 or 100 knots. I'm not an instructor BTW.

Sometimes yahoo answers gives better results than avcanada for questions like this, which is also kind of ridiculous.

[jump154]

I was just wondering the same thing myself, as I'm doing some practice ILS approaches at the moment.

Well, you should probably be concentrating on flying the aircraft not posting on an Internet forum

[dr.aero]

Open question gets open answers.

To address something specific:

55 to 65 is the range of C 172 approach speeds. To me it is simply ridiculous to fly the ILS at these speeds.

I think it's important to note that those aren't "approach speeds". Those speeds are the range of Vref, and Vref is a specific airspeed for the airplane configuration and weight that should be targeted at ONE specific point - over the threshold of the runway at 50', generally with a 3 degree approach slope. The speeds that should be flown on the approach should be Vref + 5, 10, 15, 20, etc depending on the point on the approach. Touch down should be accomplished near the stall speed of the airplane. Each airplane is specific and requires slightly different handling techniques but Vref is Vref.

It seems many people don't understand that concept. I've heard Captains say that you should be touching down at Vref. What they don't know is that the performance that they took the time to look up for the runway they're landing at won't guarantee you'll stay on the runway if you touchdown at Vref. If you require a landing distance of 3000' and you fly the approach normally but touchdown at Vref, you'll end up using more than 3000' - essentially. That's bad if your runway is 3000'!

[esp803]

Red line +10 for instrument error

[nightbird]

90 kts and 10 flaps for the most part