Approach speed and configuration in a C172

[Revtach]

Hi,

I am a CFI prepping for my CFII checkride next week. The way I was original taught to fly approaches for my IR in a C172 was with flaps 10 and power around 1900 RPM. I like this approach because the plane will want to fly a 3 degree glideslope and you already have some flaps in prior to landing. However, my current CFII is teaching me to fly approaches in the clean configuration at 90 knots. I like this approach because you are ready to go missed if needed, but I don't like it because you have to make a bigger configuration change before landing if you want to land with flaps. If you break out at a DA of 200 ft AGL, wouldn't putting in full flaps at that point go against the stabilized approach concept in the ACS?

I discussed this with him and he says he sees no problem with it. I'd like to ask for more opinions.

 

[tsts4]

Once you break out you’re visual and executing the landing. The stabilized approach was to get you to that point, but once visual you configure however you need to for the landing.

FWIW I went through the King/Cessna 141 program in a 172 and 10* of flaps and 90 KTS from the IAF to the FAF was what they taught.

 

[RyanB]

Fly the approach at 90kts. At .5nm from FAF or 1 dot deflection, go flaps 10deg. Power setting doesn’t matter a whole lot, as it will vary depending on the conditions, but it will be somewhere around 1800rpm.

 

[TCABM]

I think fully understanding the FAA’s definition and guidance on stabilized approaches results in either technique being acceptable.

I prefer 90kts in Category A aircraft if safely possible since that makes for less work for timed approaches.

 

[midlifeflyer]

There is really no difference (not even target airspeed) other than the decision whether or not to use approach flaps, and that's a matter of personal preference.

 

[RussR]

Hi,

I am a CFI prepping for my CFII checkride next week. The way I was original taught to fly approaches for my IR in a C172 was with flaps 10 and power around 1900 RPM. I like this approach because the plane will want to fly a 3 degree glideslope and you already have some flaps in prior to landing. However, my current CFII is teaching me to fly approaches in the clean configuration at 90 knots. I like this approach because you are ready to go missed if needed, but I don't like it because you have to make a bigger configuration change before landing if you want to land with flaps. If you break out at a DA of 200 ft AGL, wouldn't putting in full flaps at that point go against the stabilized approach concept in the ACS?

I discussed this with him and he says he sees no problem with it. I'd like to ask for more opinions.

I agree with the others that 0 or 10 flaps just doesn't make much difference. If you break out at 200 feet, then you probably should just go ahead and land with whatever flap configuration you have at the time. Remember, 200 feet overcast is often accompanied by low visibility, not the "flip the hood up and it's clear and a million" that we have in the training environment. Having flown lots of approaches to ceiling and visibility minimums in the sim (granted in bigger, faster aircraft than a 172), I definitely wouldn't want to be changing configurations at 100 or so feet above the runway when you can barely even see it.

Also, older 172s have an 85 kt flap limit. So if your instructor learned in an older 172, they likely flew approaches at 90 kts and 0 flaps because that was above the flap speed. And since that works fine in a newer 172 as well, saw no reason to change their technique. Just a possibility.

 

[MauleSkinner]

Having flown lots of approaches to ceiling and visibility minimums in the sim (granted in bigger, faster aircraft than a 172), I definitely wouldn't want to be changing configurations at 100 or so feet above the runway when you can barely even see it.

My airplane says “when it is certain there is no possibility of a go around” you can select full flaps on a one-engine-inop approach. The general consensus is that if you select full flaps when you see the runway at 100 feet, you’ll more than likely balloon up into the clouds and generate a go around.

 

[Martin Pauly]

The general consensus is that if you select full flaps when you see the runway at 100 feet, you’ll more than likely balloon up into the clouds and generate a go around.

That can be avoided with a little practice. Or land flaps-up or partial-flaps. Most runways with instrument approaches are plenty long for a Cessna 172, so coming in a little fast is not going to lead to a runway overrun.

- Martin

 

[Larry in TN]

Shouldn't be a problem landing a C-172 from 90kts at 200' without adding additional flaps on the length of most runways which have an ILS. With plenty of runway, I don't see any reason to risk destabilizing the situation with a flap change at such a low altitude.

 

[texasclouds]

Fly and land flaps zero, kiss.

 

[RyanB]

I only teach 10deg of flaps at .5nm or one dot deflection, as it helps translate into other complex aircraft of being configured by the time you hit the marker.

I agree 10deg flaps aren’t necessary but it still builds that mindset of “doing something” prior to the FAF to get configured.

 

[RussR]

My airplane says “when it is certain there is no possibility of a go around” you can select full flaps on a one-engine-inop approach. The general consensus is that if you select full flaps when you see the runway at 100 feet, you’ll more than likely balloon up into the clouds and generate a go around.

That's the exact wording in the OEI approach and landing checklist for the King Air 300. With the same consensus among the pilots. We have the Flaps Apch Vref speed already, just land with Flaps Apch.

It's similar in the CL-605 OEI checklist, which just has you fly final at Flaps 20 and says nothing about further configuration changes. Same rationale as far as I know.

 

[masloki]

Wouldn’t the examiner be interested in the CFII candidate being able to explain the differences in techniques and demonstrate whichever they prefer at a proficient level?

 

[Brad W]

That can be avoided with a little practice. Or land flaps-up or partial-flaps. Most runways with instrument approaches are plenty long for a Cessna 172, so coming in a little fast is not going to lead to a runway overrun.

- Martin

I reminded of a time when I was working on my instrument rating in a 172N. My CFII as I recall had my typical approach with 10 degrees flaps at 90kts... every time.
By that time I had quite a bit of time in the 172 and was fairly proficient...
on an approach into a TCA....probably an ILS... control asked us to keep our speed up. I wasn't really sure what to do.... and so it was a quick pivot into a lesson about pivoting and adapting.... so instead of pulling power and dropping flaps as had been the routine, we kept power in (I don't recall if it was cruise setting or full throttle), and zero flaps. Flew the approach at full cruise speed, had to determine the new time for the miss, switch to category B minimums, and over the threshold transitioned to a normal landing, probably no flaps..easy. Seriously no big deal and it boosted my confidence too!

 

[midlifeflyer]

I reminded of a time when I was working on my instrument rating in a 172N. My CFII as I recall had my typical approach with 10 degrees flaps at 90kts... every time.
By that time I had quite a bit of time in the 172 and was fairly proficient...
on an approach into a TCA....probably an ILS... control asked us to keep our speed up. I wasn't really sure what to do.... and so it was a quick pivot into a lesson about pivoting and adapting.... so instead of pulling power and dropping flaps as had been the routine, we kept power in (I don't recall if it was cruise setting or full throttle), and zero flaps. Flew the approach at full cruise speed, had to determine the new time for the miss, switch to category B minimums, and over the threshold transitioned to a normal landing, probably no flaps..easy. Seriously no big deal and it boosted my confidence too!

Your post reminds me of the time I got a "keep your speed up" instruction in a 172. I remember it because I did the approach at 120 KIAS - faster than cruise speed I noticed how very stable it was.

 

[Mahneuvers]

... I did the approach at 120 KIAS - faster than cruise speed I noticed how very stable it was.

I was taught this way and have never flown it differently. No flaps. Carb heat. 2050 RPM. 500 FPM. 120. Almost every SP I've had questions me

 

[Martin Pauly]

on an approach into a TCA....probably an ILS... control asked us to keep our speed up. I wasn't really sure what to do.... and so it was a quick pivot into a lesson about pivoting and adapting.... so instead of pulling power and dropping flaps as had been the routine, we kept power in (I don't recall if it was cruise setting or full throttle), and zero flaps. Flew the approach at full cruise speed, had to determine the new time for the miss, switch to category B minimums, and over the threshold transitioned to a normal landing, probably no flaps..easy. Seriously no big deal and it boosted my confidence too!

This is a good exercise and lesson for all pilots of piston aircraft. More so than our jet brethren, we can vary the speed on an approach quite significantly in a safe and predictable way. We just have to do it a few times to understand what the aircraft is capable of. A draggy Arrow or Bonanza with the gear down can decelerate more rapidly than a Cirrus, so there isn’t a one-size-fits-all rule.

Practice and experiment on a calm and clear day, and the next time a controller asks “what is your best forward speed on the approach?”, you’ll have a confident answer and a plan to execute.

- Martin

 

[Brad W]

Your post reminds me of the time I got a "keep your speed up" instruction in a 172. I remember it because I did the approach at 120 KIAS - faster than cruise speed I noticed how very stable it was.

yeah, I wrote "cruise speed" but just meant that we didn't slow... We might have been doing 120 too. I don't recall but I do remember the confidence boost and how easy it was to do it differently than "the checklist"

 

[Dave Theisen]

Keep in mind, that for a given airspeed, the pitch attitude will be higher without flaps than it will with flaps, so it may be harder to see the runway over the nose.

 

[midlifeflyer]

Keep in mind, that for a given airspeed, the pitch attitude will be higher without flaps than it will with flaps, so it may be harder to see the runway over the nose.

True, but that just means, don’t look over the nose. That’s SOP for a lot of people in a lot of airplanes, even with full flaps.

 

[Roller]

0-10 flaps and leave it alone, it’s a 172 and most places you are shooting approaches have tons of runway for that plane

 

[ArnoldPalmer]

I learned how to fly in a Skychicken at 80 knots. NO flaps. at DA/MDA/VDp - dump in one or two notches of flaps and slow to 65 and land.

Now as I teach this stuff - school wants us to standardize - I teach 90 knots no flaps....

 

[midlifeflyer]

I learned how to fly in a Skychicken at 80 knots.

you must have been that guy I was asked by Approach to slow down for on an instrument approach. Ahhh… no. That guy was in a Cherokee.

 

[sarangan]

Hi,

I am a CFI prepping for my CFII checkride next week. The way I was original taught to fly approaches for my IR in a C172 was with flaps 10 and power around 1900 RPM. I like this approach because the plane will want to fly a 3 degree glideslope and you already have some flaps in prior to landing. However, my current CFII is teaching me to fly approaches in the clean configuration at 90 knots. I like this approach because you are ready to go missed if needed, but I don't like it because you have to make a bigger configuration change before landing if you want to land with flaps. If you break out at a DA of 200 ft AGL, wouldn't putting in full flaps at that point go against the stabilized approach concept in the ACS?

I discussed this with him and he says he sees no problem with it. I'd like to ask for more opinions.

In my view, the term stabilized approach is often misunderstood. To me, it means being on a glide path that consistently leads to the intended touchdown point, with the outcome never in question. It doesn’t mean configuration changes shouldn't be made, nor does it mean that deviations from the glide path are unacceptable while making those adjustments. As an instructor, you should be able to make large configuration or power changes and promptly apply the necessary corrections to stay on glide path. I recommend practicing a range of scenarios—no-flap, full-flap, mid-approach flap changes, and large power adjustments—while demonstrating the ability to maintain a consistent glide angle throughout.

 

[Brad W]

In my view, the term stabilized approach is often misunderstood. To me, it means being on a glide path that consistently leads to the intended touchdown point, with the outcome never in question. It doesn’t mean configuration changes shouldn't be made, nor does it mean that deviations from the glide path are unacceptable while making those adjustments. As an instructor, you should be able to make large configuration or power changes and promptly apply the necessary corrections to stay on glide path. I recommend practicing a range of scenarios—no-flap, full-flap, mid-approach flap changes, and large power adjustments—while demonstrating the ability to maintain a consistent glide angle throughout.

I feel like it includes an element of being "in control"...not chasing targets and missing them.

 

[Lance F]

One thing came to my mind when I read about the 120 kt approaches in a 172. (I own half of and primarily teach in a 172N). A Vref of 1.3*Vso is normally considered proper for a stabilized approach. 120 kts is more like 3*Vso. Can you safely do it with a long enough runway? Sure. But I can’t see even suggesting that to my primary students. When ATC asks you to “keep your speed up” they are not expecting a 172 to go over the threshold at 120.

 

[geezer]

For check rides, just make sure that the DPE and you are on the same page.

My instrument ILS had a request for a 360 while a following airliner passed, we did, and halfway to the numbers, a similar request was made.

I asked the DPE if we were going to do a go around, he was affirmative, and I offered to fly the rest of the way in at 120 knots. ATC said OK, DPE said failure to be on glide slope due to speed will still be a fail.

At the higher speed, the plane was more stable and smooth, held the dot all the way to missed.

 

[RussR]

One thing came to my mind when I read about the 120 kt approaches in a 172. (I own half of and primarily teach in a 172N). A Vref of 1.3*Vso is normally considered proper for a stabilized approach. 120 kts is more like 3*Vso. Can you safely do it with a long enough runway? Sure. But I can’t see even suggesting that to my primary students. When ATC asks you to “keep your speed up” they are not expecting a 172 to go over the threshold at 120.

I don't think anyone is suggesting that for primary students, are they? And even if so, it's definitely not "to the threshold". But as an instrument procedure, I'll have the instrument students do a few like that so they see how it feels a little different, but is perfectly reasonable to maintain a speed like that to a mile final or so.

 

[midlifeflyer]

One thing came to my mind when I read about the 120 kt approaches in a 172. (I own half of and primarily teach in a 172N). A Vref of 1.3*Vso is normally considered proper for a stabilized approach. 120 kts is more like 3*Vso. Can you safely do it with a long enough runway? Sure. But I can’t see even suggesting that to my primary students. When ATC asks you to “keep your speed up” they are not expecting a 172 to go over the threshold at 120.

I have done the 120 in a 172. Even though that runway was definitely long enough, 120 was not, and I haven’t seen anyone suggesting it should be, to the threshold.

Suggesting it as a possibility to primary instrument students? Why not? What’s the problem with discussing and planning for real life issues and solutions as opposed to the sterile training environment? I’d much rather see that than the CFII (and there are some) who teach 80 KIAS with flaps as the only way. Or leaving them completely on their own the first time they go to a busier IFR environment that the one you kept them in, are asked to keep their speed up, and have no response other than, “unable. My instructor didn’t teach me that.”

Of course, one can’t teach what one doesn’t understand,

 

[Lance F]

I typed too fast. Although I typed primary student, I meant instrument student. Sorry. Geezers post said he flew 120 to the missed which on an ILS is pretty much the threshold. Definitely not anything close to Vref for a 172. He ok'd it with the DPE before continuing. That the DPE said yes kind of surprises me, since the FAA considers excessive speed to be a de-stabilized approach. Sure, in instrument training I see nothing wrong to suggest it as a possibility as long as the discussions includes the risk factors of flying way above Vref in actual. And I definitely teach real world to my students.

 

[EdFred]

Do pilots/students/instructors believe that stabilized means the RonCo type of flying from the IAF (set it and forget it) or you can make good-sized changes along the way as long as your path and glide slope remain locked in?

While it wasn't IMC, on Saturday, I was at cruise and in descent (150+kts) to just over 1/2 a mile, and maintained the same descent path from there to the runway while reducing speed, getting the landing gear out, getting the flaps out, etc. No slipping, just the prop starting act as an air brake, nose trim adjustment to keep from sinking, flaps out when within the white arc, and a touchdown like a butterfly with sunburned feet.

How is that not stabilized, if the former belief?

 

[Dave Theisen]

For my type rides, the FAA requires that I am fully configured and at Vref prior to the final approach fix. Of course the same FAA often tells me to maintain 180 knots to the final approach fix.

 

[Mikey52]

Then there is the decelerated approach we did prior to 97.

 

[Lance F]

Do pilots/students/instructors believe that stabilized means the RonCo type of flying from the IAF (set it and forget it) or you can make good-sized changes along the way as long as your path and glide slope remain locked in?

While it wasn't IMC, on Saturday, I was at cruise and in descent (150+kts) to just over 1/2 a mile, and maintained the same descent path from there to the runway while reducing speed, getting the landing gear out, getting the flaps out, etc. No slipping, just the prop starting act as an air brake, nose trim adjustment to keep from sinking, flaps out when within the white arc, and a touchdown like a butterfly with sunburned feet.

How is that not stabilized, if the former belief?

The FAA has many documents describing what they consider to be a stabilized approach. You can Google it. I’m guessing what you described would not meet the published criteria.

 

[EdFred]

The FAA has many documents describing what they consider to be a stabilized approach. You can Google it. I’m guessing what you described would not meet the published criteria.

From: https://www.faa.gov/newsroom/safety-briefing/stabilized-approach-and-landing

A stabilized approach is one in which the pilot establishes and maintains a constant angle glidepath towards a predetermined point on the landing runway.

However, it does also say in this PDF:

and depends on the maintenance of a constant final descent airspeed and configuration.

Which is impossible, because the plane can't land at 1.3Vso. So at *some* point the speed has to change, which goes against maintaining a constant...airspeed. Also, no configuration changes, so full flaps for 4-5 miles as well?

That's why I ask. The FAA says one thing, and then says something else at the same time.

I did make a constant glide path descent, but did drop gear and add flaps after what would be the FAF. I don't always do this, but was out of 9500 a little later than usual (bumps)

 

[midlifeflyer]

@EdFred, We can add these from the Airplane Flying Handbook:

A stabilized approach is one in which the pilot establishes and maintains a constant-angle glide path towards a predetermined point on the landing runway. It is based on the pilot's judgment of certain visual clues and depends on maintaining a constant final descent airspeed and configuration​

Incremental deflection of flaps on downwind, base leg, and final approach allow smaller adjustments of pitch and power and support a stabilized approach.​

I don't see them as conflicting, just recognition that what we do and what we consider "stabilized" in a Cessna 152 just might be a little different than in an Airbus 320.

 

[EdFred]

@EdFred, We can add these from the Airplane Flying Handbook:

A stabilized approach is one in which the pilot establishes and maintains a constant-angle glide path towards a predetermined point on the landing runway. It is based on the pilot's judgment of certain visual clues and depends on maintaining a constant final descent airspeed and configuration​

Incremental deflection of flaps on downwind, base leg, and final approach allow smaller adjustments of pitch and power and support a stabilized approach.​

I don't see them as conflicting, just recognition that what we do and what we consider "stabilized" in a Cessna 152 just might be a little different than in an Airbus 320.

I do see them as conflicting, because on an instrument (or even visual) approaches, you may not be flying a downwind, or base. So the incremental changes don't apply to that statement. Even if you "unfold" the base and downwind to straight in, you are still making configuration changes on final descent when you apply interpretations of the vicinity of the airport and cutting people off on final. It could be argued that I have to have my gear dropped and flaps fully out at least five miles from the airport since I need to maintain a constant final descent speed and configuration based on those decisions and interpretations. Which I think is a bit ridiculous to drag it in from that far out to be "FAA stabilized."

 

[midlifeflyer]

I do see them as conflicting, because on an instrument (or even visual) approaches, you may not be flying a downwind, or base. So the incremental changes don't apply to that statement. Even if you "unfold" the base and downwind to straight in, you are still making configuration changes on final descent when you apply interpretations of the vicinity of the airport and cutting people off on final. It could be argued that I have to have my gear dropped and flaps fully out at least five miles from the airport since I need to maintain a constant final descent speed and configuration based on those decisions and interpretations. Which I think is a bit ridiculous to drag it in from that far out to be "FAA stabilized."

I can't speak for you, but on a long straight in as on an instrument approach I make similar incremental changes. I caught on to "unfolding" the pattern for straight in and base leg approaches when I moved to a busy towered airport in 1992.

I guess if you are looking for a bit ridiculous, you will find it. I start from a viewpoint that descriptions aren't an exercise in perfection. So I tend to look for concept commonality and generally find it.

 

[flyingpreacher]

Obviously I’m late to the party, but I always fly 90 knots clean until breakout, then flaps as necessary (if necessary. I do lots of clean landings for practice’ sake). If I break out in time, my standard is 3 miles: 10 degrees, 2 miles:20 degrees, 1 mile: 30 degrees.

ETA: 1800RPM (+/- 50) at 90 KIAS and properly configured should produce a 500FPM constant descent. This is generally true for most trainer aircraft (172, Cherokee, etc)

 

[Ventucky Red]

Fly with whatever you comfortable with and works for you.