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Instrument Approach Gear and Flap Sequence - A survey


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This came up during a lesson. It's not really Mooney-specific but this group always has such good information. 

This represents the two phases I'm talking about. In the parlance of "flying by the numbers" 

For those of you who do  use approach flaps to fly an instrument approach, what is your gear/flap sequence and does it affect your FAS (final approach segment) airspeed?

These are just examples to illustrate what I'm asking:

  • At target FAS airspeed clean in A. Gear first than flaps upon intercepting the glideslope.
  • Gear down at target FAS airspeed in A . Flaps down upon intercepting the glideslope.
  • Higher than target FAS. Gear upon intercepting the glideslope at higher speed.  Flaps added after stabilizing .to reduce to target airspeed.  

There may be as many answers to this as pilots :)

 

image.png.f115c77073726e1985e1539567047fef.png

 

 

 

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2 minutes ago, midlifeflyer said:

This came up during a lesson. It's not really Mooney-specific but this group always has such good information. 

This represents the two phases I'm talking about. In the parlance of "flying by the numbers" 

For those of you who do  use approach flaps to fly an instrument approach, what is your gear/flap sequence and does it affect your FAS (final approach segment) airspeed?

These are just examples to illustrate what I'm asking:

  • At target FAS airspeed clean in A. Gear first than flaps upon intercepting the glideslope.
  • Gear down at target FAS airspeed in A . Flaps down upon intercepting the glideslope.
  • Higher than target FAS. Gear upon intercepting the glideslope at higher speed.  Flaps added after stabilizing .to reduce to target airspeed.  

There may be as many answers to this as pilots :)

 

image.png.f115c77073726e1985e1539567047fef.png

 

 

 

Ha! Ill be first, but ill be different too…

gear and approach flaps prior to the FAF.  Ill use them to help reduce my speed to my fas speed, but my goal is to be trimmed, on speed, and basically just hands off into the FAF, then there’s just the 6 Ts to do as required.  Pulling the power allows descent without retrimming if you were already on speed.  I don’t like to add a configuration change at the GS intercept as well.  Not only the configuration change, but confirming gear down, retrimming, and 6Ts at the FAF is a lot.  We taught in the USAF to be configured, trimmed, etc 1-2 nm prior to the faf.  In the Mooney i use closer to .5-1.5nm prior.

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Slow to final approach speed +30% for segment A
Gear and approach flaps at 2 miles/1 minute from FAF adjust power and trim for final approach speed
Reduce power for final decent at FAF/GS intercept.

I aim to be configured on speed at the FAF with all checks completed so only a power reduction and gear down confirmation remain before landing.

EDIT: No coincidence, same as  @Ragsf15e  We have the same primary training background. 

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This is how I do it - 

1) Set MP -26”

2) Slow to gear speed - 132 KIAS

3) 1/2 mile before the final approach fix drop the gear 

4) Put in approach flaps at FAF Set MP to 21” and pitch for 90 KIAS…may need to adjust MP slightly depending on headwind component

Depending on the wind these settings should pretty much fly right down a 3 degree glide path….at least in Myrtle it does.

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Gear down 2 dots before intercept (as soon as I’m in gear speed - 120 mph), flaps to takeoff setting 1 dot before intercept (once at flap speed - 100 mph), stabilize, then do BGUMPS at FAF/intercept:

  • boost pump
  • gas
  • undercarriage
  • mixture/carb heat (as needed)/manifold pressure/throttle
  • prop/flaps
  • and then ‘Ss’ (seatbelts/switches/breakers)

throttle to get ~450-500 FPM and trim/trim/trim for approach speed ;o)

old Mooney with much lower speeds…

-Don

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prior to entering approach 

     WIRES - Weather, Instruments, Radios, airport Environment, Speeds

 

between IAF and FAF

     flaps to approach, plane prepared, frequencies, etc... 

     CatMissed - Category and timing if necc, brief missed approach

 

FAF

     Gear down, follow glideslope or dive to target altitude,  do nothing else until we land or go missed.

    

 

Edited by McMooney
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By somewhere shortly after IAF, be down below Vfe = 125 mph, drop to Takeoff Flaps. Stabilize airspeed around 90 knots = 105 mph, with throttle ~18", proceed towards FAF. At 1-1/2 dots prior to glideslope intercept, drop gear, and the plane will settle onto the glideslope at the same speed and just under 500 fpm.

Ride all the way down and land, adjusting throttle, flaps, ailerons, rudder and elevator as required to land at my desired location.

I think, due to varying flap and gear speeds across the models, and some year-to-year changes, there will be many, many ways to do this . . . .

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I've done this a number of ways, but currently this is how I do it in my M20J. I like to fly the final approach stabilized at 90 KIAS. I can fly it faster, but at 90 I don't have to slow it down so much at low altitude to get to 65 KIAS at the threshold. I like to keep the speed up on the initial and intermediate segments though in order to mix in with faster traffic at larger airports. 

5 nm out, boost pump on, mixture set

Power back to 15" a couple of miles before the FAF and the airplane will decelerate to 90 KIAS clean.

Upon reaching 90 KIAS (or 1 dot above GP/GS on an approach with vertical guidance) flaps 15 and trim. Prop high rpm. Flaps 15 doesn't affect the speed much but does change trim and deck angle.

At FAF (GP/GS intercept) gear down. Complete GUMPS check.

I used to set the speed, gear and flaps before the FAF and reduce power at the FAF, but I found it took more of my attention away from the attitude indicator to reduce the power 5" than to reach for the gear handle. However, I used to have the original MAP gauge way over on the right side of the panel. Now, with the G3X, it is close to the attitude indicator, so this is probably not that big a deal. But, since a 3 deg pitch change is required at GP/GS intercept, I still want to be focused on the attitude indicator.

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Somebody here a while back had mentioned that if you're level approaching the FAF at 90 knots, as you intercept the glideslope/glidepath if you drop the gear it pretty much just puts you on the proper slope at 90kts.    That works pretty well in my airplane, so I've been doing it that way for a while.    Basically stabilized clean at 90kts and drop the gear at the FAF and establish on the glideslope/glidepath at 90kts.   I often wind up adding approach flaps after that and just start making adjustments for wind, etc.    Doing it that way seems to minimize changes, or at least minimize having to make multiple changes at once, which seems to simplify it for me.

I like that there seem to be a lot of individualized ways to do it, even in the same or nearly the same airplanes.

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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.

With that in mind, I slow down to my target speed between the IF and FAF with gear up, flaps up. I'll maintain that target speed until I am in a position to land. At the FAF, I put the gear down and keep the same speed. I won't made any further configuration changes until I'm in a position to land. I am comfortable adding in flaps after I break out or landing without flaps as most of the airports we land at are 4,000+ feet.

Not using flaps means it's one less thing to do when going missed!

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6 hours ago, Ragsf15e said:

Pulling the power allows descent without retrimming if you were already on speed.

You pull power?  I set to power and then  just drop the gear and start down.  Some minor adjustments might be need on the way down pending temps, etc. to get the speed where I want it.  If it's an ILS, the gear goes down when the GS just past 1 bar from the GS interception. 

 

Edited by PeteMc
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1 minute ago, PeteMc said:

You pull power?  I just drop the gear and start down.

If it's an ILS, about just after 1 line off on the GS interception.

Yep. I don’t think configuring at the faf is a good idea.  I’ve seen people do what you describe and it works fine, but I don’t like adding things at the faf that aren’t necessary.  Final configuration done and checked prior, airplane all trimmed and on speed prior.  That’s how i do it.

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8 hours ago, Ragsf15e said:

Ha! Ill be first, but ill be different too…

gear and approach flaps prior to the FAF.  Ill use them to help reduce my speed to my fas speed, but my goal is to be trimmed, on speed, and basically just hands off into the FAF, then there’s just the 6 Ts to do as required.  Pulling the power allows descent without retrimming if you were already on speed.  I don’t like to add a configuration change at the GS intercept as well.  Not only the configuration change, but confirming gear down, retrimming, and 6Ts at the FAF is a lot.  We taught in the USAF to be configured, trimmed, etc 1-2 nm prior to the faf.  In the Mooney i use closer to .5-1.5nm prior.

Me too.  120 mph to the IAF and any IF.  Gear down first to slow to FAS (100 mph).  First GUMPS call-out.  6 T’s, flaps, and 100 mph before the FAF.  Second GUMPS callout.  On GS small trim. Slow to 90.  Third GUMPS call-out.  Cross the fence at 80 and the threshold at 70.  (slower E model)

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4 hours ago, Ragsf15e said:

I’ve seen people do what you describe and it works fine, but I don’t like adding things at the faf that aren’t necessary.  

That's my point.  You really do nothing but drop the gear and you go down.  

I'm not sure if I learned it before the MAPA PPP or it was at my first PPP, but the way they teach it.  EVERYTHING is done before the FAF based on known power settings.  Right before you intercept the GS you drop the gear and the drag matches you're descent.  So you pretty much are on the GS with no fuss.   

If you have gear, etc. down before the FAF, then you're going to have to start playing with power as you go down.  Not what you want to do. 

(When are we going flying? :D)

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13-15”MAP segment A to get to 120MPH at FAF. Gear down just prior to FAF. No flaps until runway in sight and then as needed. With manual gear it is one less thing to have to account for if going missed. I like how the plane feels on approach when faster than flap speed. (100MPH).
 

The other day we got turned off final for having ground speed of less than 50kts. Came around for a second one and they wanted 180 on final or they would have to turn us off again!?  We offered 120kt but it was not sustainable and lead to an unstable approach since we had to transition to gear speed on the glide slope. Made it, but it was one of the worst approaches I’ve done and reminded me that one needs to be firm with “unable” when ATC is demanding unreasonable things. They just did not recognize that the headwind would slow everybody the same amount and were using people downwind speeds as reference. 

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It seems the major difference in technique is how to start down at the FAF. If airspeed is to be held constant, you can either add drag by extending the gear, or reduce power. I’ve done it both ways. Each has advantages and disadvantages. It seems a matter of personal preference. 

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The technique I've used across a range of piston singles and twins, up to 421s and even the smaller turboprops, is to have approach flaps in (or equivalent, depending on model) 10-25nm out depending on altitude, speed, and workload.  I'll add gear at FAF.  Whatever flap setting I'll use for landing is added in as needed shortly before landing.  The pitch change has never really been an issue.  This last setting can depend on crosswind and icing.

It's worked for me in all kinds of conditions and the FAA never had an issue with it during my 135 rides.

 

End of the day, do what you're comfortable doing.

Edited by m20flyer
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32 minutes ago, PT20J said:

It seems the major difference in technique is how to start down at the FAF. If airspeed is to be held constant, you can either add drag by extending the gear, or reduce power. I’ve done it both ways. Each has advantages and disadvantages. It seems a matter of personal preference. 

Absolutely personal preference. This is not intended as a "which is the right way?" question. Just a survey of different techniques. 

But I think there is a disadvantage doing it different ways as an SOP rather than settling on one and using an alternative only for certain situations. 

For example, your SOP might be to deploy gear and flaps at glideslope intercept. That doesn't mean you would not skip approach flaps initially to keep your speed up, but it does mean that may be the only time you do it. 

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One of the enormous benefits of “flying the numbers” is that if you aren’t configured correctly it won’t work. I was shooting an approach recently, in order to stay on glide path my MP was different than usual so I began trying to discover the reason. I discovered that I didn’t twist the blue knob enough to get prop at max RPM. It wasn’t off by much, but it was enough to throw off my numbers.

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For me, before the FAF has variability due to "keep best forward speed for traffic" or "slow to final speed for traffic" and everything in between depending on what ATC and traffic dictate.  But I've found that pulling throttle back and leveling off takes ~5 miles and 2.5 min to equilibrate the speed with new configuration from a fast descent.  So I have to drop throttle at least 5+ miles before the FAF to make sure I'm below 140kts for gear if I'm "best forward speed" for the first part of an approach especially if also descending.  (I've also found that dropping gear drops my speed by about 20-25 kts if everything else stayed the same)

If trying to slow down from the IAF, then I'll usually drop to 20" MP...this keeps the engine warm enough, but the aircraft slow enough to feel like I have lots of time for the approach.

During instrument training I was taught to drop gear when the GP/GS is one dot above on the VDI.  So for a standard approach to land, gear down one dot above, then throttle to 15" MP (90 kts) on the GP/GS, and flaps 10 deg checking to make sure I'm below 112 KIAS.  On most instrument approaches I land with 10 deg of flaps only.  Usually the runway is plenty long, and this avoids a big trim force/pitch up with go around.  I usually don't start dialing back throttle until I'm roughly around ILS/LPV minimums with intent to land.

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32 minutes ago, midlifeflyer said:

Absolutely personal preference. This is not intended as a "which is the right way?" question. Just a survey of different techniques. 

But I think there is a disadvantage doing it different ways as an SOP rather than settling on one and using an alternative only for certain situations. 

For example, your SOP might be to deploy gear and flaps at glideslope intercept. That doesn't mean you would not skip approach flaps initially to keep your speed up, but it does mean that may be the only time you do it. 

I agree that it is beneficial to be able to be flexible. A very good skill to develop is the ability to fly a faster than normal approach when operationally necessary. I used to be based at KSJC and often was asked to keep speed up to the middle marker (back when those things existed ;)) to fit into a conga line of jets approaching from the south. I could easily cross the outer marker at 140 and decelerate to 120 by the middle marker and still make a normal landing and the first turnoff in my 1978 M20J without speed brakes. My minimums for doing this were 500/2. 

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1 hour ago, PT20J said:

I agree that it is beneficial to be able to be flexible. A very good skill to develop is the ability to fly a faster than normal approach when operationally necessary. I used to be based at KSJC and often was asked to keep speed up to the middle marker (back when those things existed ;)) to fit into a conga line of jets approaching from the south. I could easily cross the outer marker at 140 and decelerate to 120 by the middle marker and still make a normal landing and the first turnoff in my 1978 M20J without speed brakes. My minimums for doing this were 500/2. 

Being based at KSJC, if you don't want to be vectored around for awhile waiting for the line of jets to land and you have a Bravo or Bravo+, then it's fly a constant slope variable airspeed approach.  When I check in, I preemptively tell Approach as part of the checkin that once on descent on final I can give them 160 knots to 5 miles.  They usually slide me right in.  The procedure that works is at 5 miles and 160 knots; Speed Brakes (this give an immediate speed reduction to 140 knots); Gear Down (speed brakes still extended. Speed reduced to 110 knots); Flaps to Approach, Speed brakes retracted, Flaps to full when landing is assured.  Using this procedure speed can be reduced from 160 knots to 75 knots over 5 miles.

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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 between one type of airplane and another (think Mooney/Bonanza versus Cirrus). 

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