FAF to MAP Speeds

[MauleSkinner]

Based on the many discussions of the subject I've seen, I think there is a definition problem. Mostly the FAA's doing, but some our very own in leading us to believe that anything which varies means unstable. So I wonder whether your disagreement with @Walboy is all about definition. Take the ACS guideline he quoted, with my highlight:


I don't think "desiring" to use a step-down airspeed on an approach, such as maintaining 100 KTS until 1000 AGL and then slowing to 85 means you are unstable. OTOH, if having decided on those speeds, good airmanship means you are able to maintain it. Fluctuate all over the place, you are unstable.

And a smooth speed transition is better than pulling the power way back, and then adding a bunch back in when you’re at the desired speed...the profiles we publish say things like “airspeed—slowing to...”, and when done properly, this deceleration (due solely to increased drag from gear and/or flaps) takes 3-4 miles/2+ minutes.

It’s the throttle jockeys who get themselves in real trouble.

 

[Hacker]

In a 140, you're Category B. That's what ATC expects you to fly unless you are unable to maintain speed.

No.

The categories are only to determine the TERPS data. Approaches have no requirement to be flown at the maximum speed of any particular category.

Most pilots fly approaches at speeds that are easily multiples of 60 to make the timing and distance from the FAF to MAP easy math (e.g. 90 kts GS is 1.5 miles per minute, 60 kts GS is 1 mile per minute, 120 is 2 miles per minute, ad nausaeum). You'll note that these are the way the speeds on timed approaches are broken out, too.

 

[PaulS]

And a smooth speed transition is better than pulling the power way back, and then adding a bunch back in when you’re at the desired speed...the profiles we publish say things like “airspeed—slowing to...”, and when done properly, this deceleration (due solely to increased drag from gear and/or flaps) takes 3-4 miles/2+ minutes.

It’s the throttle jockeys who get themselves in real trouble.

Don't non precision approaches require you to be a throttle jockey??

 

[midlifeflyer]

Don't non precision approaches require you to be a throttle jockey??

No. Notice he was distinguishing "throttle jockey" from "smooth transition."
Even with a "dive and drive", you are going from (1) approach level settings before the FAF to (2) descent settings at the FAF (3) to level settings at the MAA if you don't have the runway to (4) either landing or missed settings. That's a one predetermined change more (the level off at the MAA) than a precision approach, and not even that one if you are using a VDP.

 

[PaulS]

No. Notice he was distinguishing "throttle jockey" from "smooth transition."
Even with a "dive and drive", you are going from (1) approach level settings before the FAF to (2) descent settings at the FAF (3) to level settings at the MAA if you don't have the runway to (4) either landing or missed settings. That's a one predetermined change more (the level off at the MAA) than a precision approach, and not even that one if you are using a VDP.

Sometimes you need to "dive and drive" a few times. I think I get it though, I'm doing my IR in a Cirrus now, sop is 100 knots at FAF to DA, VDP or MAP as needed, if field in sight, you need to get down to landing speed. Cirrus doesn't want you changing configuration (add more flaps) after 500 agl. So when you pop out, you need to get slowed to 85 knots for a 50% flaps landing if below 500 agl, that requires chopping the throttle, depending on the situation you may or may not need to add throttle back in.

 

[chemgeek]

My instructor insists I fly 90kts FAF to the MAP on an ILS or LOC approach. I calculate (hopefully correctly) that a standard ILS 200' AGL MAP puts me 3,816 feet from the threshold at 3 degrees. That is about the distance I think I would be on a base to final in a VFR traffic pattern and normally in my plane I would be at 68kts. 90 kts seems way to fast and its bugging me. Am I wrong here?

90 kt in my AA5. It's a comfortable approach speed and won't hold up other traffic. Plenty of time to slow down and land. There is hardly a runway served by an ILS that's not excessively long for a light single.

 

[midlifeflyer]

Sometimes you need to "dive and drive" a few times. I think I get it though, I'm doing my IR in a Cirrus now, sop is 100 knots at FAF to DA, VDP or MAP as needed, if field in sight, you need to get down to landing speed. Cirrus doesn't want you changing configuration (add more flaps) after 500 agl. So when you pop out, you need to get slowed to 85 knots for a 50% flaps landing if below 500 agl, that requires chopping the throttle, depending on the situation you may or may not need to add throttle back in.

I can see that if there are a series of stepdowns but it's better to choose a descent rate that will get you to the last of them while keeping above the interim ones. I like the Cirrus 500 AGL as a "now you have to be ready"

 

[MauleSkinner]

Don't non precision approaches require you to be a throttle jockey??

If you have a target power for each segment that you use, with minimal adjustment for conditions, you’re doing it right.

Throttle jockey is thirteen power changes between the FAF and MAP, ranging from full power to idle, none of which is within 10% of your target.

 

[Hank S]

Time and place for everything. There are times you need to be able to shoot an ILS at best forward speed. If you’re number one going into a sleepy airport, there’s no need to rush things.

I did this with the examiner on my Instrument checkride. There we were, almost 10 miles out and a Lear checked in behind us. There was audible disbelief in his voice confirming that Tower really wanted him to reduce his speed by 50 knots. The reply was that he was No. 2 behind traffic showing 80 knots (groundspeed). I looked a d we were right on 105 mph but the GPS showed 80 knots.

I asked if I should speed up, and the DPE said something like "let's see what you can do." This was after a good GPS Approach and touch-n-go. So I raised gear and came down the glideslope at 130 mph instead. Another TnG and we headed out to the VOR for the miss, to begin VOR-A approach to an outlying airport for Circle-to-land and a temporary cert.

 

[midwestpa24]

I asked if I should speed up, and the DPE said something like "let's see what you can do." This was after a good GPS Approach and touch-n-go. So I raised gear and came down the glideslope at 130 mph instead. Another TnG and we headed out to the VOR for the miss, to begin VOR-A approach to an outlying airport for Circle-to-land and a temporary cert.

The only problem with that in a retract is having time to and remembering to get the gear down at the end of the approach, especially in actual low IMC conditions. Most inadvertent gear ups happen when you break routine and get rushed.

Honestly ATC is responsible for providing you with enough time to fly your approach safely. If traffic doesn't permit that, it would be a better idea to have a plan B. Letting someone else fly your airplane often works out poorly.

 

[James331]

The only problem with that in a retract is having time to and remembering to get the gear down at the end of the approach, especially in actual low IMC conditions. Most inadvertent gear ups happen when you break routine and get rushed.

Honestly ATC is responsible for providing you with enough time to fly your approach safely. If traffic doesn't permit that, it would be a better idea to have a plan B. Letting someone else fly your airplane often works out poorly.

I always gear down 1 dot or 3nm from the FAF, train like you want to preform and you’ll preform like you train.

I also have a few verbal, tactile and checklist gear checks after that.

 

[Hank S]

The only problem with that in a retract is having time to and remembering to get the gear down at the end of the approach, especially in actual low IMC conditions. Most inadvertent gear ups happen when you break routine and get rushed.

Honestly ATC is responsible for providing you with enough time to fly your approach safely. If traffic doesn't permit that, it would be a better idea to have a plan B. Letting someone else fly your airplane often works out poorly.

The chance of a gear up with the DPE next to me [he was a former Wing Commander in the Air National Guard, and was finishing up the interior of his already-flying Glasair] was pretty small. I also slowed down and lowered flaps and gear and was on glide slope before the MAP.

 

[James331]

The chance of a gear up with the DPE next to me [he was a former Wing Commander in the Air National Guard, and was finishing up the interior of his already-flying Glasair] was pretty small. I also slowed down and lowered flaps and gear and was on glide slope before the MAP.

Still changing your SOP up at a critical stage of flight, shy of a 7700 event, is a bad idea, DPE should have known better.

 

[Clip4]

Based on the many discussions of the subject I've seen, I think there is a definition problem. Mostly the FAA's doing, but some our very own in leading us to believe that anything which varies means unstable. So I wonder whether your disagreement with @Walboy is all about definition. Take the ACS guideline he quoted, with my highlight:


I don't think "desiring" to use a step-down airspeed on an approach, such as maintaining 100 KTS until 1000 AGL and then slowing to 85 means you are unstable. OTOH, if having decided on those speeds, good airmanship means you are able to maintain it. Fluctuate all over the place, you are unstable.

In a PA28 flying the whole approach a 100 with no flaps would be a stable approach.

 

[Hank S]

Still changing your SOP up at a critical stage of flight, shy of a 7700 event, is a bad idea, DPE should have known better.

He didn't think so. Had I forgotten the gear and he had to remind me, I would fail the checkride . . . .

 

[James331]

He didn't think so. Had I forgotten the gear and he had to remind me, I would fail the checkride . . . .

He thought....poorly

 

[dtuuri]

There we were, almost 10 miles out and a Lear checked in behind us...

So I raised gear and came down the glideslope at 130 mph instead.

Why did you have the gear extended 10 miles out?

 

[Hank S]

Why did you have the gear extended 10 miles out?

I fly approaches at 90 knots with 15° of flaps (especially on check rides ). Dropping the gear initiates descent either at FAF or when 1-1/2 dots high on the glideslope. For location, see the chart. The event was enough years ago that I'm not sure of my exact position, but I was still far from the runway, and the disbelief in the Lear pilot's voice is still very clear. I do know that I cleaned up the plane to fly faster (gear speed is 120 mph, flap speed is 125 mph), and reconfigured to land later.

 

[James331]

I fly approaches at 90 knots with 15° of flaps (especially on check rides ). Dropping the gear initiates descent either at FAF or when 1-1/2 dots high on the glideslope. For location, see the chart. The event was enough years ago that I'm not sure of my exact position, but I was still far from the runway, and the disbelief in the Lear pilot's voice is still very clear. I do know that I cleaned up the plane to fly faster (gear speed is 120 mph, flap speed is 125 mph), and reconfigured to land later.

If you were IFR how did a LR get cleared while you will still on the approach?

And changing for that is dumb, he can sit in the hold for a lap or two or get delay vectors, taking flaps back out and raising the gear on approach is bad stuff.

 

[Hank S]

If you were IFR how did a LR get cleared while you will still on the approach?

My checkride was VFR . . . . .

 

[James331]

My checkride was VFR . . . . .

So your DPE failed to simulate a IFR operation, rushed you to make space for actual IFR traffic, I hope he didn’t charge you for the ride and apologized

 

[Hank S]

So your DPE failed to simulate a IFR operation, rushed you to make space for actual IFR traffic, I hope he didn’t charge you for the ride and apologized

No, I was wearing foggles to simulate IFR, and I volunteered to "rush." Tower knew we were on a checkride, and said nothing to me about speeding up.

Was your Instrument checkride in actual IMC? I bet not . . . .

Try reading what people actually write, James, rather than planning how to make yourself superior by twisting it through your own filter. My words in the first post are unchanged, yet somehow you figured we weren't simulating IMC, and that he rushed me . . . . Please quote these instances from my writing. Oh, sorry, you can't.

 

[PaulS]

 

[PaulS]

Can't do IR check rides in IMC.

 

[James331]

No, I was wearing foggles to simulate IFR, and I volunteered to "rush." Tower knew we were on a checkride, and said nothing to me about speeding up.

Was your Instrument checkride in actual IMC? I bet not . . . .

Try reading what people actually write, James, rather than planning how to make yourself superior by twisting it through your own filter. My words in the first post are unchanged, yet somehow you figured we weren't simulating IMC, and that he rushed me . . . . Please quote these instances from my writing. Oh, sorry, you can't.

I would have failed you.

First off it’s not real life, they ain’t going to clear two planes on the same approach at the same time.

Second if they did and you were like “sure I’ll pull up my gear and flaps and send it” that’s bad stuff dude.

Now days most of my instrument training stuff is in the sims, and if I get a BS clearance from a instructor or checkairman I’ll go missed.

 

[flyingron]

Can't do IR check rides in IMC.

Discouraged, but not prohibited.

 

[SbestCFII]

No, you're right. The approach speed you should fly it the one recommended in your POH. In most cases on an ILS with a 3 degree glide-path to a runway 5000' or longer, you'll likely not use flaps. In my Warrior, I generally fly 70-75 knots from the FAF to the MAP. If you're too fast or too high you may actually have to go missed. I've made many approaches work when faster planes had to miss. For example, tonight my Day 1, accelerated student and I shot an LPV approach to minimums (400') in rain and the landing light failed. Video attached...skip to about 4mins 30seconds.

 

[SbestCFII]

Note that's GROUNDSPEED!

Does anyone still do timed approaches in Real life?

 

[flyingron]

Does anyone still do timed approaches in Real life?

Much as I like my autopilot, you can have my moving map for IFR when you pry it from my cold dead fingers.

 

[Clip4]

My checkride was VFR . . . . .

As is most aplicants.

 

[Clip4]

Much as I like my autopilot, you can have my moving map for IFR when you pry it from my cold dead fingers.

At least when the tablet over gets you have something to warm your fingers.

 

[midlifeflyer]

In a PA28 flying the whole approach a 100 with no flaps would be a stable approach.

Agreed. So would flying it at 100 and reducing to 80 before 500 AGL.

 

[aterpster]

No.

The categories are only to determine the TERPS data. Approaches have no requirement to be flown at the maximum speed of any particular category.

You need to read this:

 

[midlifeflyer]

At least when the tablet over gets you have something to warm your fingers.

Still waiting for it to happen to mine.

 

[James331]

Does anyone still do timed approaches in Real life?

Nope

It’s a good teaching exercise for speed management, but in the real world, I’m shooting a RNAV or ILS or viz 99% of the time.

 

[Checkout_my_Six]

Ive got three or four GPS.... why would anyone time it?...

 

[midlifeflyer]

In a descent, sure

LOL! I was once asked to keep my speed up in a 172. Put the nose down, kept it below redline, and headed downhill at 120 KTS.

 

[Maxnr]

My instructor insists I fly 90kts FAF to the MAP on an ILS or LOC approach. I calculate (hopefully correctly) that a standard ILS 200' AGL MAP puts me 3,816 feet from the threshold at 3 degrees. That is about the distance I think I would be on a base to final in a VFR traffic pattern and normally in my plane I would be at 68kts. 90 kts seems way to fast and its bugging me. Am I wrong here?

90KTS is not too fast if there is faster traffic behind you. The FARs don't give much guidance. They only tell you who, what where or when. If you want "how", go to the AIM. (It says on the cover that its The Official Guide to Basic Info AND ATC procedures) Go to para 5-4-7. They stripped out a lot for the current year. Last years edition said that if you wanted Cat A minimums, you had to hold a stabilized airspeed from FAF to MAP. BTW, anybody know where I can find the FAA definition for stabilized airspeed? Its not in FAR 1.1 or AIM glossary. Previous years editions said that you had to fly the entire procedure at a Stabilized Airspeed. Procedure turn outbound,FAF inbound. Sounds like that should slow everybody up. The whole idea of slipping into approach cat B or higher is not too likely. Look at the approach light arrays at destinations with ILS. They burn through the soup nicely. Cat A through D usually have the same minimums.
Full disclosure: I am IFR rated in both airplanes and helos. Helo pilots go to AIM para 10-1-2 for guidance. A helo can get vectors to the localizer (at, say KIAH) capture the GS at more than 25 miles out and 5,000', pass the FAF at 155KTS with the gear still up and an air liner, number two behind you. ATC request that you keep your speed up. Within 7 or 8 miles DME from the MAP, select DECL on the flight director and the AP starts a deceleration. Get the wipers at 140KTS and drop the gear at 130. The AP brings you over the RW at 70KTS and 50'. Run it on, get on the brakes, Make the first turn off..
If you have time to kill, read both paragraphs that are cited. Helos like to get into approach cat A. IAW Aim para 10-1-2, a helo appr cat is determined at whatever speed it passes the MAP at. 90 kts or less means you can go to FAR 97.3 (C) for bonus points. You may then cut the required visibility in half to not less than 1/4 mile or RVR 1200.

 

[Kritchlow]

You need to read this:
View attachment 69643

Yes... the way I always interpreted the category is the higher of 1.3 Vso or the speed flown after the FAF.
Generally that’s for circle, but I believe it can be a factor on the straight in approach in the event of a missed.
Correct me if I’m wrong...

 

[IK04]

LOL! I was once asked to keep my speed up in a 172. Put the nose down, kept it below redline, and headed downhill at 120 KTS.

I flew a brand-new Cessna 152 into my home airport and the controller did not recognize the tail number. I was flying max RPM down the ILS course and he advised me "Citation 460, maintain best speed, please..."