Speeds when Transitioning from Approach to Final to Landing

[JackFliesGA]

What are your norms for speeds and configurations on Instrument Approaches for a C172?

My CFII says

Between the IF and the FAF: 90 KIAS

From FAF: slow to 80 KIAS, one notch of flaps,
descend to MDA between -500fpm to -700fpm or adjust power to maintain Glideslope to the DA.

Descending from the MDA: 70 KIAS two notches of flaps. (No config change for a precision approach because we’re only 200 above at minimums).

Over the Threshold: 60 KIAS

This seems to match your all’s practice?

 

[TCABM]

The ACS allow +\-10KTS on a stabilized approach from the FAF. I brief 85kts +\-10 as my approach speed from the IAF to minimums configured with 10* flaps prior to FAF.

That allows me to continue below mins to landing or go missed with minimum configuration changes.

ETA: I’m less worried about vertical speed and more focused on nailing vertical and lateral guidance since deviations are what will kill you, both on the check ride and in the soup.

 

[Initial Fix]

It’s been a long minute since flying a 172 IFR. I would go with those settings. The big thing IMO is after the FAF and descending to be stable with flaps and speed. Figure out the rpm that gets you there, let things stabilize, and track the needles. Tweaking power only as needed.

In my bonanza, outside the faf, I aim for 120 kts and 10 degrees flaps and drop the gear crossing the faf to get pretty close to glideslope. It’s all about learning your plane.

 

[RyanB]

I like to be configured by 0.5nm from the FAF, so once I cross it, I'm ready descend. Throwing flaps and such down after that will just cause the aircraft to balloon and make the approach less stable. Obviously everyone has their method, but in a 172, I'm 90KIAS once established, and the 10deg of flaps and trimmed prior to the FAF helps maintain that without much effort. If you can maintain a constant IAS, it will minimize the amount of throttle jockey-ing, rather than juggling multiple airspeeds as you're riding the GS down. Plus, a 172 can go from 90KIAS to 65KIAS quite quickly after you break out.

 

[masloki]

Not going to argue with the above outside I treat FAF as a waypoint only. If ATc is keeping you at 4000’ before clearing you at typically 3000’ FAF, you are going to hit that glideslope early. Be ready to slow down so you can go down. And I’ve had ATC dump me on approach at 6000’, 2 nm from a 3000’ FAF. I should have asked for a hold on that one.

 

[Clip4]

What are your norms for speeds and configurations on Instrument Approaches for a C172?

My CFII says

Between the IF and the FAF: 90 KIAS

From FAF: slow to 80 KIAS, one notch of flaps,
descend to MDA between -500fpm to -700fpm or adjust power to maintain Glideslope to the DA.

Descending from the MDA: 70 KIAS two notches of flaps. (No config change for a precision approach because we’re only 200 above at minimums).

Over the Threshold: 60 KIAS

This seems to match your all’s practice?

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-108A.pdf

 

[tsts4]

What are your norms for speeds and configurations on Instrument Approaches for a C172?

My CFII says

Between the IF and the FAF: 90 KIAS

From FAF: slow to 80 KIAS, one notch of flaps,
descend to MDA between -500fpm to -700fpm or adjust power to maintain Glideslope to the DA.

Descending from the MDA: 70 KIAS two notches of flaps. (No config change for a precision approach because we’re only 200 above at minimums).

Over the Threshold: 60 KIAS

This seems to match your all’s practice?

Seems overly complicated. I did my IR in a 172 and I did 90KTS with 10* of flaps from the IAF all the way to the DA/DH/MAP and was able to slow and land from minimums without issue. In my own plane I follow the same process but at 120KTS.

 

[midlifeflyer]

Seems overly complicated. I did my IR in a 172 and I did 90KTS with 10* of flaps from the IAF all the way to the DA/DH/MAP and was able to slow and land from minimums without issue. In my own plane I follow the same process but at 120KTS.

Agreed. On target airspeed once on a leg of the approach and carry it down to minimums, In a 172, there will be plenty of time to slow and configure for landing.

@JackFliesGA, one thing you will come across is a variety of answers to your question. For example, while my 172 SOP is mostly the same as @tsts4’s, it’s not exactly the same - I don’t use flaps at all until I break out or reach minimums.

 

[Jim K]

Not going to argue with the above outside I treat FAF as a waypoint only. If ATc is keeping you at 4000’ before clearing you at typically 3000’ FAF, you are going to hit that glideslope early. Be ready to slow down so you can go down. And I’ve had ATC dump me on approach at 6000’, 2 nm from a 3000’ FAF. I should have asked for a hold on that one.

Or been in a piper

Glideslope intercept is the critical point for a precision approach, and you'll generally be intercepting it outside the FAF. Once inside the iaf (do this before the iaf until you have some practice irl) I set 18"/2400rpm. That will maintain level flight at 100 knots or a bit less. At glideslope intercept drop the gear and get a perfect 500fpm descent. I don't charge anything except throttle until I break out. Then the rest of my flaps and slow down to land.

In the Archer, it was 1 notch of flaps and reduce throttle to hit 90 at the iaf, then another throttle reduction at the faf/ glideslope, and don't touch anything until you break out. As Ryan said, changing configurations on the glideslope makes it hard to stay on it. Even 200' is plenty of time to slow down a piston airplane, and generally precision approaches are to 6000'+ runways that you could cross the fence at full throttle and still have plenty of time to get slowed down & land.

Non precision approaches require a little mental math, but 500fpm works most of the time. That's close enough to 300'/nm, which is the descent rate most approaches are planned around. Hitting the MDA is basically the same as rolling out on final in a vfr traffic pattern, so slowing to your final approach speed at that point make sense unless you're circling.

 

[NealRomeoGolf]

Whatever the speed in a 172 it will be too slow for the person behind you.

And it will make someone wait on the ground for 30 minutes because Center already cleared them 25 miles out. One in and one out. Oh the memories.

 

[midlifeflyer]

Whatever the speed in a 172 it will be too slow for the person behind you.

Maybe. Maybe not.

I was once IFR, flying the ILS 7 into Orlando Exec (KORL) in a 172. ATC asked me to slow down for another airplane on the approach only doing 80 KTS.

Another time, I was asked to keep my speed up on the ILS 35 into Denver Centennial (KAPA), so I flew it at 120 KTS. Everyone was happy.

 

[Bill]

It’s been so doing since I did my IFR training that the only thing I remember is being set up at 90kts before the FAF and maintaining 90kts on the balance of the approach. This was a 172 N. My instructor trained 90kts since it was one of the speeds that had times between fixes on the plate for non-precision approaches.

For the Mooney I prefer to get set up at 90kts clean once established. At that speed, dropping gear and putting on 10 flaps at the FAF will have the plane descend the glideslope at 90kts with very little need to adjust throttle or pitch.

 

[unsafervguy]

one thing that needs to be said. there is training, checkrides, and real world. a lot of good info has been given for checkrides and training. however, for the real world you had better be able to fly initial to final at any speed up to cruise, and get slowed down and stabilized from that. try going 90 kts 10 miles out or so at a busy airport and see how many times you get broke out. as i have said many times, a good pilot is comfortable flying their plane to all four corners of the envelop.

 

[midlifeflyer]

one thing that needs to be said. there is training, checkrides, and real world. a lot of good info has been given for checkrides and training. however, for the real world you had better be able to fly initial to final at any speed up to cruise, and get slowed down and stabilized from that. try going 90 kts 10 miles out or so at a busy airport and see how many times you get broke out. as i have said many times, a good pilot is comfortable flying their plane to all four corners of the envelop.

This is an excellent point although I'm going to disagree with the

initial to final at any speed up to cruise

There are airplanes where that's not going to work well at all.

But... there are places where people are being taught to fly instrument approaches at Vref. That's the way @JackFliesGA's 80 kts on the FAS strikes me. Unnecessarily slow and unrealistic as even a general SOP in the real world unless that's also your best cruise speed or you are flying nothing but nonprecision approaches into short runways.

Training and checkrides are becoming a rant item for me. Recently, I seem to be getting my share of new instrument pilots. It's mostly about transitions to a different airframe but I am seeing a lot of newly-minted instrument pilots who were clearly trained to the checkride and know very little else. I'm not even talking about the "real world" knowledge gained from experience. I had a conversation with an instructor from a national training organization this past year. The instructor was there with his instrument checkride applicant. In the course of the discussion, I asked whether he would want his student to file IFR solo the next day if he passed. "Absolutely not," was the answer. We didn't even get to whether the choice was weather-dependent.

 

[dtuuri]

My CFII says

...adjust power to maintain Glideslope to the DA.

What's the definition of "maintain"? If circumstance puts you below glideslope, don't you want to return ASAP? Wouldn't your elevator be the quickest control for that? If "maintain" is meant as an initial target setting at GS interception, I'll buy that instead.

 

[dtuuri]

Seems overly complicated.

Depends. Each speed change is coupled with a flap change, so maybe the power stays the same and target A/S simply follows the flap setting.

 

[Bill]

try going 90 kts 10 miles out or so at a busy airport and see how many times you get broke out. as i have said many times, a good pilot is comfortable flying their plane to all four corners of the envelop.

There are airplanes where that's not going to work well at all.

If approach needs me to fly fast, I will, but only up to the FAF. After that, I need to scrub off the speed. If I break out at 200ft at 120kts in the Mooney, we AREN’T landing, and that defeats the purpose.

I asked whether he would want his student to file IFR solo the next day if he passed. "Absolutely not," was the answer.

That’s pretty damned sad. While my CFII never took me out in actual, I felt I was prepared for actual, and got my wings wet two nights after my checkride. I may still have my writeup I posted here many years ago, but basically due to deteriating weather my last approach that evening was to 300ft at night in heavy rain. After that, I wasn’t too concerned with how I would preform in the soup.

 

[midlifeflyer]

If approach needs me to fly fast, I will, but only up to the FAF. After that, I need to scrub off the speed. If I break out at 200ft at 120kts in the Mooney, we AREN’T landing, and that defeats the purpose.

I was actually thinking of Mooneys when I said there were airplanes where "initial to final at any speed up to cruise" would not work well.

That’s pretty damned sad. While my CFII never took me out in actual, I felt I was prepared for actual, and got my wings wet two nights after my checkride. I may still have my writeup I posted here many years ago, but basically due to deteriating weather my last approach that evening was to 300ft at night in heavy rain. After that, I wasn’t too concerned with how I would preform in the soup.

When did you get your instrument rating. It might matter.

The very small amount of IFR cross country time required - one flight - has always been an issue in terms of real world exposure to ATC during training. And even that isn't completely real world. But I think a bigger issue is avionics. The level of the avionics system knowledge for practical IFR competence in a VOR/LOC/DME/NDB world was pretty small. Biggest significant difference was having an RMI instead of a fixed or rotating card ADF. Flip-flop button on a NAV radio was a big deal.

Even if we don't include autopilots and glass PFDs, the system knowledge for GNS, GTN, or IFD competence (I'm not talking about expertise) is far greater.

Hop into any airplane with a VOR receiver you've never seen before and in 3 minutes, you can fly IFR with it. I fly with people who upgraded their GNS to a GTN who have difficulty doing the same thing they did in the GNS, even if it's mostly done the same way.

 

[Bill]

When did you get your instrument rating. It might matter.

I'd have to look, 17-18 years ago?

The very small amount of IFR cross country time required - one flight - has always been an issue in terms of real world exposure to ATC during training.

Yeah, I can see that. I was lucky in some ways, the guy I used for primary and instrument back then was a crusty old retired ATC who was also a CFII. He made sure that I was comfortable talking to ATC and to know what they expect of an IFR pilot.

And even that isn't completely real world. But I think a bigger issue is avionics.

That's for sure, there is something to be said for a simple to understand old fashioned 6-pack plane with VOR/DME/ADF. We upgraded the Mooney by adding a GI275 as an engine monitor, and got rid of all of the old analog fuel and engine gauges, and sometimes I regret the decision. The analogs were easy to read at a glance.

 

[midlifeflyer]

I'd have to look, 17-18 years ago?


Yeah, I can see that. I was lucky in some ways, the guy I used for primary and instrument back then was a crusty old retired ATC who was also a CFII. He made sure that I was comfortable talking to ATC and to know what they expect of an IFR pilot.



That's for sure, there is something to be said for a simple to understand old fashioned 6-pack plane with VOR/DME/ADF. We upgraded the Mooney by adding a GI275 as an engine monitor, and got rid of all of the old analog fuel and engine gauges, and sometimes I regret the decision. The analogs were easy to read at a glance.

Yep. You were in a world where GPS was not quite ubiquitous.

Don't worry. Glass becomes just as easy to read at a glance. That's why I'm focusing on the navigator/FMS systems.

 

[Pinecone]

If approach needs me to fly fast, I will, but only up to the FAF. After that, I need to scrub off the speed. If I break out at 200ft at 120kts in the Mooney, we AREN’T landing, and that defeats the purpose.

Depends on how long the runway is.

And speed brakes help.

 

[Mahneuvers]

Seems overly complicated. I did my IR in a 172 and I did 90KTS with 10* of flaps...In my own plane I follow the same process but at 120KTS.

My CFII taught me to fly "fast" (for a 172) approaches. At glidesope intercept it's just over 2000 RPM, carb heat, 500 FPM, 120 KTS. Now that I think about it, all of the 6 or so safety pilots I've flown with have thought this odd. I can see how this approach wouldn't work with a slippery plane.

 

[luvflyin]

What are your norms for speeds and configurations on Instrument Approaches for a C172?

My CFII says

Between the IF and the FAF: 90 KIAS

From FAF: slow to 80 KIAS, one notch of flaps,
descend to MDA between -500fpm to -700fpm or adjust power to maintain Glideslope to the DA.

Descending from the MDA: 70 KIAS two notches of flaps. (No config change for a precision approach because we’re only 200 above at minimums).

Over the Threshold: 60 KIAS

This seems to match your all’s practice?

I flew the approach at 90 kts, no flaps, all the way down until runway in sight. Then throttle, flaps and trim as necessary. If that was pretty low, like even at a 200 foot DA I’d pull the throttle, dump all the flaps and trim as needed. Didn’t use much more runway than any normal landing

 

[Ventucky Red]

What are your norms for speeds and configurations on Instrument Approaches for a C172?

When I did my instrument it was done on a 172N. From what I remember for the approach settings/speeds...

2100 RPM = 115 Kts with a 500 FPM descent w/no flaps

1800 RPM = 100 Kts... 500 FPM... no flaps

1600 RPM = 90 KTS... 500 FPM... no flaps

Because we were at a busy airport, a few times we were asked for the best forward when chugging along at 90 kts.

 

[Pinecone]

Common use of 90 knots comes from the days of more timed approaches. The plate shows the time for 60 (too slow for most), 90 (a good speed for most GA), and 120 (keep your speed up). So easier to use one of those speeds than to have to calculate the time to the MAP.

 

[sonopoa]

Figure out the rpm that gets you there, let things stabilize, and track the needles.

dont use the needs as primary fly your bugged heading and calculated vsi and see what the needles do. You shouldn't need to adjust power unless the winds are highly variable on the way down

 

[Steamflyer]

You'll get lots of opinions. But for a slow bug masher, like a C150 or C172, tend to fly the approach around 90-100 knots. The runway will be long relative to the needs of these aircraft - it has an approach after all! And you know you'll break out at least 200' AGL, which is 2/3 of a mile to slow down. More than adequate for these aircraft.

Since almost everyone has some sort of GPS today, you can use GS/2 x 10 for a roughly 3 degree glideslope. So if you are doing 90 knots over the ground, about 450 fpm will keep you on the glideslope.