Instrument Approach Gear and Flap Sequence - A survey

[dkkim73]

I am really appreciating this discussion. I'm still trying to figure my SOP's, and torn between being flexible and accomodating and rocketing along the intermediate segments, vs. being slow and stable with minimum fuss during critical segments. 

90KIAS gives time to think and prevents lots of changes inside the FAF, but feels like stationary after descending into the area closer to 200KTAS

120KIAS makes the math easy, feels fast enough to be sociable, but is above Vfe and requires a lot of adjustments during a busy time if carried *inside* the FAF. One technique I've been trying is 120KIAS to the FAF, then dirty everything up while the AP is still trimming for me. 

A couple of slam dunk 160-170KIAS-to-the-FAF approaches have been instructional, but feels like taking safety margin out of the equation. 

The USAF approach @Pinecone and @Ragsf15e describe seems the most robust to error, and I think would probably feel safer to me in the clag when tired at the end of a long trip. Maybe the solution for me is to compress the required changes closer to but still ahead of the FAF. 

One approach I've been taught is I think from the airlines, "gear down at the FAF or when cleared for the visual". I think I tend to practice gear down *no later than* the FAF or abeam threshold in a standard pattern, though sometimes earlier if maneuvering requirements are uncertain. I think any grey area here probably increases chances of a gear-up incident, but I'm still trying to plug holes in the workflow. 

As for changing gear vs. power at the FAF: I suppose you can make an argument for the power reduction alone as being better, since the throttle is a primary control that you will be "working" for an approach anyway (though if a perfectly thought-out stabilized approach you might barely move it, you're still "flying the throttle"). 

DK

[dkkim73]

8 minutes ago, Rick Junkin said:

Another advantage of the SOP of being configured and on speed at or prior to the FAF is it works for both fixed gear and retractable gear airplanes. I know that isn't a consideration for most of us, but it keeps things consistent when moving from one type of airplane to another (think Mooney/Bonanza versus Cirrus). 

Yes, and this "foolish consistency" is what makes all the configuration changes so difficult to shove into my brain   Consistency is a protection... Interestingly, the PIC IFR course manual, which I have found very clear-thinking about IFR flight, makes an argument to work out configurations so as to minimize the # of changes between any two adjacent flight configurations. E.g. approach level and precision descent, precision descent and missed approach. With this argument I could choose 120KIAS for all, but slowing from 120 to 90 to 75 at minimums is a juggling act... So again an argument for the 120->90 transition during the approach level phase. I recently tested both 90 and 120 "approach level" configurations. This adds an extra configuration but might be a clearer way to organize things. 

[skykrawler]

I don't think about speeds so much.  My 'canned' procedure is  18" MP far enough prior to FAF to be below gear speed.  Prop in, Gear down just before FAF, set 15", trim for glideslope/wind conditions (a big headwind may require more power).     When landing is assured, RPM below the yellow arc, bring in desired flaps, decel to landing speed.

All things must be adjustable.  I'd rather be 105kts on the GS than 90kts.

[midlifeflyer]

Thanks for all the responses. It looks like these 5 (or 7 if you want to count 1 & 2 twice) as the common SOPs (variations for special situations). And notice that I'm not mentioning specific target speeds. 

In no particular order:

1. Gear down well before GSI*, followed by flaps at GSI. (might be reversed in some airplanes with high VFE-APCH.)
2. Gear down 1-dot (or so) before GSI, flaps at GSI. (might be reversed in some airplanes with high VFE-APCH.) 
3. Gear down at GSI, initial flaps added during the descent.
4. Gear and flaps down before GSI; power reduction at GSI for the descent.
5. Gear down at GSI. No flaps until breaking out or reaching a specific altitude.

"well before GSI." I think it's Gary Reeves who recommends gear down as soon as entering the approach environment. Seems like an extreme version of #1.  And I'm leaving out being at final approach speed and configuration while still enroute  although there are probably pilots who are taught to do that (I think I was behind one once when I was asked to slow down for another aircraft ahead of me - I was in a 172 ).

[Hank]

39 minutes ago, midlifeflyer said:

Thanks for all the responses. It looks like these 5 (or 7 if you want to count 1 & 2 twice) as the common SOPs (variations for special situations). And notice that I'm not mentioning specific target speeds. 

In no particular order:

1. Gear down well before GSI*, followed by flaps at GSI. (might be reversed in some airplanes with high VFE-APCH.)
2. Gear down 1-dot (or so) before GSI, flaps at GSI. (might be reversed in some airplanes with high VFE-APCH.) 
3. Gear down at GSI, initial flaps added during the descent.
4. Gear and flaps down before GSI; power reduction at GSI for the descent.
5. Gear down at GSI. No flaps until breaking out or reaching a specific altitude.

"well before GSI." I think it's Gary Reeves who recommends gear down as soon as entering the approach environment. Seems like an extreme version of #1.  And I'm leaving out being at final approach speed and configuration while still enroute  although there are probably pilots who are taught to do that (I think I was behind one once when I was asked to slow down for another aircraft ahead of me - I was in a 172 ).

All of those are gear down first. Surely I'm not the only one who puts Flaps down first, and drops gear to initiate descent? 1-1/2 dots before intercept is perfect, no changes to throttle required, just drop gear and go down the glideslope at the same speed, which is targeted to be 90 knots = 105 mph before dropping the gear.

[Marc_B]

One other tidbit picked up during instrument training:  When I drop gear the Mooney wants to balloon a little; I can easily control that tendency, but it's easier to do this under the GP/GS then "at" the FAF as it allows me to be better stabilized by the FAF and verify "Glidepath captured, altitude checks, setting missed approach altitude."  Being configured a little before the FAF makes those mental checks for proper baro/altitude, setting altitude bug, etc all the more easy to do.  When I'm juggling too much right at the FAF it makes that not quite as smooth/finessed.

Also good to hear of @donkaye & @PT20J's SJC flow.  This fits similar to what I've found in my K, that gear drops speed about the same degree as speed brakes, both around 20-25 kts each; and all in around ~5miles.

[mikefox]

Well, here's my procedure for an M20J (basic procedure works well in other aircraft as well though you might have to modify settings:

1. Vectored for approach or before FAF: MP 16" Prop 2500 RPM. this gives gear speed comfortably in straight and level flight

2. Intercepting GS (wherever it occurs): Gear down, MP 14" (precision approach).  This gives about 100-105 kts IAS

3. 2 mi or so to threshold, flaps to 20 deg

4. Runway in sight, flaps full (or as appropriate) power to idle

[McMooney]

24 minutes ago, Hank said:

All of those are gear down first. Surely I'm not the only one who puts Flaps down first, and drops gear to initiate descent? 1-1/2 dots before intercept is perfect, no changes to throttle required, just drop gear and go down the glideslope at the same speed, which is targeted to be 90 knots = 105 mph before dropping the gear.

my flap extension speed is higher than the gear, so i try to lead with flaps.  to be honest, my only hard rule is really no config changes between faf and breakout/map and gumpfs 3x after breakout. prob a bit overkill on the gumpfs.

 

 

[midlifeflyer]

1 hour ago, Hank said:

All of those are gear down first. Surely I'm not the only one who puts Flaps down first, and drops gear to initiate descent? 1-1/2 dots before intercept is perfect, no changes to throttle required, just drop gear and go down the glideslope at the same speed, which is targeted to be 90 knots = 105 mph before dropping the gear.

The first two say "might be reversed." I typically see that only when V_FE is higher than V_LE which is why I mentioned it that way. But if you are down to the lower of the two anyway, I can see reversal. I'm sure you are not the only one. And it's not a "who's right" question.

On the others, no, I haven't come across those who put in approach flaps at the FAF and wait until later for the gear. 

[Vance Harral]

3 hours ago, donkaye said:

then it's fly a constant slope variable airspeed approach

Excellent point from Don, and this can be done in any Mooney, including those without speed brakes.  It can be done in any airplane at all, provided you understand the time and distance it takes.  I always cringe a little when people say things like, "You can go down or slow down in a Mooney, but not both!".  That's bunk.  Pitch plus power always equals performance, it just takes longer to stabilize at a particular point in a less draggy airframe.

That said, it's certainly reasonable for any particular pilot to say the challenge/risk of of a constant slope variable airspeed approach isn't worth the benefit, especially if it takes a few miles to reach the new set point.  Mostly it's a matter of how much you've practiced it.  We all have limited time and dollars to practice, and simple isn't bad.

[hubcap]

1 hour ago, Hank said:

All of those are gear down first. Surely I'm not the only one who puts Flaps down first, and drops gear to initiate descent? 1-1/2 dots before intercept is perfect, no changes to throttle required, just drop gear and go down the glideslope at the same speed, which is targeted to be 90 knots = 105 mph before dropping the gear.

My Vle is 20 KIAS higher than my Vfe. I drop the gear so I can get the speed down to Vfe. When I reach the FAF putting in approach flaps puts you right on GS.

[Hank]

16 minutes ago, hubcap said:

My Vle is 20 KIAS higher than my Vfe. I drop the gear so I can get the speed down to Vfe. When I reach the FAF putting in approach flaps puts you right on GS.

My Vle is 5 mph lower than Vfe, so I always drop Takeoff Flaps first. That also helps stabilize the plane at lower speeds. Doing nothing but moving the gear switch as I approach glideslope intercept starts the perfect descent. 

[hubcap]

5 minutes ago, Hank said:

My Vle is 5 mph lower than Vfe, so I always drop Takeoff Flaps first. That also helps stabilize the plane at lower speeds. Doing nothing but moving the gear switch as I approach glideslope intercept starts the perfect descent. 

Makes perfect sense in your case.
 

In my case, my main goal is to be stable at Vfe speed at FAF. By putting gear down 1/2 mile before FAF, I am slowed down and very stable at FAF when I put in flaps.

[Ragsf15e]

5 hours ago, dkkim73 said:

I am really appreciating this discussion. I'm still trying to figure my SOP's, and torn between being flexible and accomodating and rocketing along the intermediate segments, vs. being slow and stable with minimum fuss during critical segments. 

90KIAS gives time to think and prevents lots of changes inside the FAF, but feels like stationary after descending into the area closer to 200KTAS

120KIAS makes the math easy, feels fast enough to be sociable, but is above Vfe and requires a lot of adjustments during a busy time if carried *inside* the FAF. One technique I've been trying is 120KIAS to the FAF, then dirty everything up while the AP is still trimming for me. 

A couple of slam dunk 160-170KIAS-to-the-FAF approaches have been instructional, but feels like taking safety margin out of the equation. 

The USAF approach @Pinecone and @Ragsf15e describe seems the most robust to error, and I think would probably feel safer to me in the clag when tired at the end of a long trip. Maybe the solution for me is to compress the required changes closer to but still ahead of the FAF. 

One approach I've been taught is I think from the airlines, "gear down at the FAF or when cleared for the visual". I think I tend to practice gear down *no later than* the FAF or abeam threshold in a standard pattern, though sometimes earlier if maneuvering requirements are uncertain. I think any grey area here probably increases chances of a gear-up incident, but I'm still trying to plug holes in the workflow. 

As for changing gear vs. power at the FAF: I suppose you can make an argument for the power reduction alone as being better, since the throttle is a primary control that you will be "working" for an approach anyway (though if a perfectly thought-out stabilized approach you might barely move it, you're still "flying the throttle"). 

DK

Well thought out.  It’s always important to train for being on the approach with weather at mins, socked in above, and close to your alternate fuel.  I try to add in a crying baby or a pax with an ear block.  You will feel the pressure of the real world even if it’s just knowing it will be right around mins.  It will certainly feel different from approaches where you are clear above and just go through a 1000’ layer on final.  It’s easy to do the 150kts yo the faf, slam on the brakes, start down, drop the gear at 500’, half flaps, roll halfway down the runway and taxi to the cafe feeling like chuck yeager, but in the real thing, you’ll want to be consistent and deliberate with whatever your chosen technique is because it will feel different and it’s easy to get behind when you’re doing something different every time.

[PeteMc]

1 hour ago, Ragsf15e said:

I am really appreciating this discussion. I'm still trying to figure my SOP's, and torn between being flexible and accomodating and rocketing along the intermediate segments, vs. being slow and stable with minimum fuss during critical segments. 

Why not fly back to BTV and do the PPP with me Sept 6, 7 & 8???    

But I'm also going to push them to maybe do a PPP here at SFF.  Maybe not next year since I'm going back this year, but the year after maybe.  I wonder how many others here in the PNW we can get to try and convince them to come?

 

 

Edited August 18 by PeteMc

[Fly Boomer]

1 hour ago, Ragsf15e said:

 It’s easy to do the 150kts yo the faf, slam on the brakes, start down, drop the gear at 500’, half flaps, roll halfway down the runway and taxi to the cafe feeling like chuck yeager

Oh yeah, I want to do that too.  Speed brakes, gear, and flaps--bam. bam, bam.

[Skates97]

These are my settings:

[Shadrach]

On 8/17/2024 at 3:47 PM, N201MKTurbo said:

I slow to approach speed at about 20" MP approaching FAF. At FAF I extend the gear and reduce MP to 16" When I see the runway, I extend the flaps. If I have a tail wind, I will extend the flaps at FAF.

Do you have a prohibited RPM range?

[dkkim73]

2 hours ago, PeteMc said:

Why not fly back to BTV and do the PPP with me Sept 6, 7 & 8???    

But I'm also going to push them to maybe do a PPP here at SFF.  Maybe not next year since I'm going back this year, but the year after maybe.  I wonder how many others here in the PNW we can get to try and convince them to come?

 

 

Would love to. Burlington is beautiful and that's a good time of year. Last time I was there several years ago I recall the regional brewers are exceptional. 

However, I've got a request in for time off from work to do the next one in Texas (Ft. Worth, I believe).

David

[dkkim73]

3 hours ago, Ragsf15e said:

 It’s easy to do the 150kts yo the faf, slam on the brakes, start down, drop the gear at 500’, half flaps, roll halfway down the runway and taxi to the cafe feeling like chuck yeager, but in the real thing, you’ll want to be consistent and deliberate with whatever your chosen technique is because it will feel different and it’s easy to get behind when you’re doing something different every time.

Well that's me, masterful like Chuck Yeager... Oh wait, that's in Opposite World.

This is exactly my nagging concern. The GFC will let you reconfigure to your heart's content on the GS, but it's a brittle workflow especially if there are distractions. 

 

[N201MKTurbo]

1 hour ago, Shadrach said:

Do you have a prohibited RPM range?

Yes. But it is above it. I have to get the power down to about 12” before I’m in it. I have speed brakes too if I can’t get down fast enough. The only place I use them is the approach into Ramona CA.

[midlifeflyer]

On 8/18/2024 at 12:40 PM, dkkim73 said:

Yes, and this "foolish consistency" is what makes all the configuration changes so difficult to shove into my brain   Consistency is a protection... Interestingly, the PIC IFR course manual, which I have found very clear-thinking about IFR flight, makes an argument to work out configurations so as to minimize the # of changes between any two adjacent flight configurations. E.g. approach level and precision descent, precision descent and missed approach. With this argument I could choose 120KIAS for all, but slowing from 120 to 90 to 75 at minimums is a juggling act... So again an argument for the 120->90 transition during the approach level phase. I recently tested both 90 and 120 "approach level" configurations. This adds an extra configuration but might be a clearer way to organize things. 

I see some  By-the-Numbers charts which I think go overboard but I don't see anything wrong with adding other "standard" configurations. My "BtN" chart leaves out climbs, cruise, and enroute descents. OTOH, in airplanes with faster cruise speeds, I have an additonal entry. For example, there is no way (short of speed brakes or gymnastics) that I am going to comfortably get from a 170-180  KT Ovation cruise speed to my 105 KT preferred APV descent speed in one shot. So my By-The-Numbers chart has an intermediate entry before Approach Level. I label it "Vectoring" but it's really about a intermediate target in the approach environment. With georeferenced approach charts I sometimes refer to it as an "On the Plate" speed.

[Pinecone]

On 8/17/2024 at 9:40 PM, Paul Thomas said:

I don't put flaps in without having the gear down in any phase of flight. I'm sure there are some airplanes where I will not be able to do that. For now, prioritizing the gear is one more step toward not gearing up an airplane.

AGREED,

I also do not put down flaps until the gear is down.

And if you forget both, you will be struggling with keeping only 90 on the FAS, so a CLUE.

[Hank]

9 hours ago, Pinecone said:

I also do not put down flaps until the gear is down.

And if you forget both, you will be struggling with keeping only 90 on the FAS, so a CLUE.

Voice of experience:

I've written about it here before, shooting the curved GPS approach over the bay into KECP for Runway 34. I was at 90 knots with Takeoff Flaps, but the unique curved path was so unusual that I didn't notice which point was the FAF, and I didn't drop the gear.

It was weird, I could maintain airspeed and deviate high, or hold the glideslope and get very fast very quick. Neither was desirable in the clouds.

Realized what was wrong about the time I broke out around 1200 msl. The landing was not salvageable, I was both high and fast,  but Tower let me circle around for a VFR pattern and easy landing.

Lesson learned:  If I can't hold speed and glideslope, verify Flap and Gear position! At least the ceiling was nice and high . . . .