M20F Approach Configuration

[druidjaidan]

I've finally started work in my instrument rating after a few frustrating trips and spending more than I needed to on hotels.  My co-owner is a CFII so we're working together on it.  He had previously expressed that he had difficultly finding an approach configuration that would maintain glideslope.  No matter what he did the power setting the plane wanted to be in to stick to the glideslope was in the red arc.  I went out on one of my early lessons that introduced the concepts of fixed power settings and configurations for desired performance and instantly struggled to find a power setting to maintain glideslope.

So I did some reading.  The MAPA guide gives two approach configs: 120mph, flaps up, gear down at FAF 2350rpm and 18" (ours works out at 15" not sure why), or 105mph, flaps up, gear down early, 2350rpm 13" at the FAF (ours worked at 10" again not sure why).  Both of those approach configs (especially the 120mph that the guide seems to emphasize) puts us a lot faster than we normally would be 200ft up.  That and literally every config in there has no flaps from M20C to R and we've both been using flaps for landing.  I obviously know nothing about it since I'm just learning IR, but my instructor seems to think that's not very common.

Are these common configurations that most of you are using?  How do you handle the transition from 120mph down to landing,  seems like it would just take being a little high on the approach to get into a lot of trouble.  We practiced a non precision and I was of course a bit behind and came out high, by the time I had transitioned and landed we had eaten up A LOT of runway.

 

[slowflyin]

I'm an F driver here is my routine:

Prior to the GS intercept - 15"- 16" as soon as the plane slows to the white arc flaps go to approach and prop forward.   I'm looking to have the AC stabilize at 90 kts.  I manage the MP to this end and avoid RPM blelow 2350.   Often the RPM will start to approach the no go zone but as soon as I start downhill it comes back up.

One dot above GS the gear goes down with no other adjustments.   If it's mins I may pull the MP back as far as I can while  staying above 2350 RPM.   This is usually 13.5 or so.

Even breaking out at 200 and 1/2 allows plenty of time to slow down on any runway I'd be shooting this kind of approach.

 

 

 

 

[Vance Harral]

Not to slight the MAPA guide, but zero flaps is not we use for IFR approaches in our 1976 F model, and it sounds strange to me.  The MP settings you're quoting from the guide also sound high to me.  But again, not really questioning the MAPA suggestions, just letting you know we fly differently.

The standard approach sequence used by all four partners in our airplane involves extending flaps to the "takeoff" setting (we call it "approach flaps") and slowing to 105 MIAS prior to the FAF.  This requires about 13-14" of MP depending on weight and conditions, and achieves level flight with good control response.  We typically use 2500 RPM, and that may be part of the difference vs. the MAPA suggestions.  Anyway, at the FAF (or when one dot high on glideslope intercept), gear down is selected to produce a 500 fpm descent.  In zero wind conditions, these numbers keep us right on glideslope.  With a head or tailwind, we'll increase or decrease the MP by about 0.5", respectively.

For IFR beginners or when rusty, I advocate 105 MIAS and approach flaps well before the approach begins.  For true beginners I advocate this even prior to a procedure turn.  Later on, it's reasonable to introduce the concept of slowing and extending approach flaps during a procedure turn.  But regardless of how you get there, the goal is to slow down and establish stable, level flight with approach flaps, well before navigating the final approach segment.  After lots of practice (maybe after obtaining the rating in your case), you can experiment with flying the initial approach faster.  For example, I know in our airplane it takes about 90 seconds to slow from max cruise speed clean, to 105 MIAS with gear and flaps down.  When I'm on my "A" game (lots of recent practice), I can fly approaches at full cruise speed until I'm 90 seconds out from the FAF, then pull the power and extend the flaps and gear at flap/gear speed.  The goal is to enter a descent with approach flaps and gear down right at the FAF.  This is challenging, as you must maintain level flight while changing the configuration, and there's an art to deciding when to pull the power (you want to see somewhat less than 90 seconds to the FAF on the GPS, because you'll be slowing between the present position and the FAF).  It's also almost never necessary, but it's fun, and I throw it in for the "you've got to keep your approach speed up to get into large airports" crowd.

I'm aware many pilots advocate flying the final approach sequence faster than the "standard" 90 knots.  In some cases these pilots say the airplane feels mushy and unresponsive at the lower speed, and feels nose-high.  That may have a lot to do with whether they've already extended the flaps.  Partial flaps allow for a lower deck angle at the same speed, and - in my opinion - result in more stable control "feel" during the approach.

Most importantly, while landings with any flap position are reasonable in a Mooney, I like flying the approach with "approach" (takeoff) flaps because it's no big deal if you don't touch them between the FAF and the landing.  The touchdown speed and deck angle in a half-flap landing isn't dramatically different from a full-flap landing, and if you're really flying a precision approach to minimums in the clag, you're likely to be setting down on a lengthy runway anyway.

[midlifeflyer]

Yes they are common configurations, although may prefer to include approach flaps.

In terms of the speed, something to keep in mind. We normally fly instrument approaches, especially those with vertical guidance, at higher than out 200' Vref  airspeed for landing. Even in a Cessna 172 with a much lower Vref than a Mooney, approaches are typically done at 105 MPH. Part of the reason is completely practical; ILS approaches are to airports with runways long enough to handle jets and their much higher Vref speeds. We need to mix with them just as, on the other side we need to mix with 152s in the VFR traffic pattern.  That 105 is a compromise for most conditions. Even a Mooney can slow down enough to land.

I'm pretty sure MAPA giving two speeds at the same configuration is to give you potential slow down targets. Yes, you can elect one or the other, but having two configurations allows for a slow down during the approach. For example, I know some folks teach a delegated approach sequence in which you start down the glidepath at 120 and then at a pre-selected (so that you get stabilized for landing) altitude reduce power to the slow down configuration.

FWIW, I'm not a strict proponent of type-specific instructors (I ain't one) but I  think your instructor might benefit from some more Mooney familiarity or may some more retract familiarity if his is limited. I have flown about 30 different makes/models of airplanes, many of them retracts. The Moony has not handled any differently than any of them in one respect: Cutlass or 182RG or Comanche or Bonanza or Mooney, a stable target airspeed before the FAF results in a glidepath capture at that same airspeed merely by extending the gear. Be set up at 120 or 105 before glideslope capture, extend the gear and you will be set up at 120 or 105 at the appropriate descent rate. 

 

[midlifeflyer]

1 minute ago, Vance Harral said:

Not to slight the MAPA guide, but zero flaps is not we use for IFR approaches in our 1976 F model, and it sounds strange to me.  The MP settings you're quoting from the guide also sound high to me.  But again, not really questioning the MAPA suggestions, just letting you know we fly differently.

I asked a question about this a month or so ago and the responses here were fairly uniform in the use of approach flaps. It's a technique issue, not limited to Mooneys. AS usual there are pluses and minuses to both and I'm personally pretty neutral on the issue.

[Browncbr1]

90 knots gear out, no flaps. Prop forward, 13.5"... If there is a lot of head wind, then an additional inch or two. 

I do no flaps because it is much easier to go around on a miss like this.  It also helps you maintain energy a little better until you have landing assured.  And there is plenty of time to set flaps before landing from minimums.  

[Marauder]

I will see if I have a copy of the speed matrix I use. I think the reason the MAPA guide may be off is these planes usually have some mods on them. My 1975 F has a 201 windshield, gap seals and lower cowl enclosure.

For me, once I am level following a descent. I pull power back to 16"/2400 RPMs. This will get me to flap speed and once I deploy approach flaps, I'm settling in at 100 KIAS. Once I hit the FAF, drop gear and reduce power to 13" will net me 500 FPM at 100 KIAS. When I am at the DH, I pull power and slow to 70 KIAS for landing.

I would recommend you fly different profiles for climbs, descent and approach power settings to learn what your F will require.


Sent from my iPad using Tapatalk

[Marauder]

Here is what I use:

[druidjaidan]

1 hour ago, Marauder said:

I will see if I have a copy of the speed matrix I use. I think the reason the MAPA guide may be off is these planes usually have some mods on them. My 1975 F has a 201 windshield, gap seals and lower cowl enclosure.

For me, once I am level following a descent. I pull power back to 16"/2400 RPMs. This will get me to flap speed and once I deploy approach flaps, I'm settling in at 100 KIAS. Once I hit the FAF, drop gear and reduce power to 13" will net me 500 FPM at 100 KIAS. When I am at the DH, I pull power and slow to 70 KIAS for landing.

I would recommend you fly different profiles for climbs, descent and approach power settings to learn what your F will require.


Sent from my iPad using Tapatalk

Yeah speed mods are certainly part of the issue.  Our plane as the 201 shield, the cowl enclosure some gap seals and the one piece belly all from a previous owner.  I'm sure that's weighing in on the differences.  I also have a few questions about the accuracy of our MP gauge at low power settings that I plan to have looked at in a couple weeks when we're able to get into the on field shop to get a few other things looked at.

The main problem we ran into is this:

Starting on approach level at 105mph and configured as: Flaps set to approach (takeoff setting) and gear down.  Then at the FAF we reduced power for the glide slope which put us right at about 12" MP, and the prop hits the governor limit and dropped to about 2275 RPM in the red range.  If we reduced power to get out of the red we dropped well below glide path.  If we pushed up to enough to maintain 2350 we'd drift above glideslope.

If we go no flaps then both the 105 and 120 configurations and associated narrative about when and how to configure seem to work out just fine for maintaining glideslope (other than my 3" difference).  It just makes the transition a lot more dicey since my usual VFR approach has us on final, full flaps, 80mph and slowing to about 75 over the fence.

[druidjaidan]

4 hours ago, slowflyin said:

I'm an F driver here is my routine:

Prior to the GS intercept - 15"- 16" as soon as the plane slows to the white arc flaps go to approach and prop forward.   I'm looking to have the AC stabilize at 90 kts.  I manage the MP to this end and avoid RPM blelow 2350.   Often the RPM will start to approach the no go zone but as soon as I start downhill it comes back up.

One dot above GS the gear goes down with no other adjustments.   If it's mins I may pull the MP back as far as I can while  staying above 2350 RPM.   This is usually 13.5 or so.

Even breaking out at 200 and 1/2 allows plenty of time to slow down on any runway I'd be shooting this kind of approach.

 

 

 

 

There has to be something up with our MP gauge at lower settings.  There is no way in hell my plane is making it to flaps speed at 15-16 inches with gear up.  At that range I will just barely make it to gear speed in level flight after about 90seconds.

[Marauder]

Yeah speed mods are certainly part of the issue.  Our plane as the 201 shield, the cowl enclosure some gap seals and the one piece belly all from a previous owner.  I'm sure that's weighing in on the differences.  I also have a few questions about the accuracy of our MP gauge at low power settings that I plan to have looked at in a couple weeks when we're able to get into the on field shop to get a few other things looked at.
The main problem we ran into is this:
Starting on approach level at 105mph and configured as: Flaps set to approach (takeoff setting) and gear down.  Then at the FAF we reduced power for the glide slope which put us right at about 12" MP, and the prop hits the governor limit and dropped to about 2275 RPM in the red range.  If we reduced power to get out of the red we dropped well below glide path.  If we pushed up to enough to maintain 2350 we'd drift above glideslope.
If we go no flaps then both the 105 and 120 configurations and associated narrative about when and how to configure seem to work out just fine for maintaining glideslope (other than my 3" difference).  It just makes the transition a lot more dicey since my usual VFR approach has us on final, full flaps, 80mph and slowing to about 75 over the fence.

My plane will occasionally fall into the red zone. The red zone can be operated in, just not continuously. What this means if you are on an approach and pull back power and end up in the red zone, that is fine.

What you can't do is set the prop for an RPM and fly around at that setting. Check your POH, I am pretty sure it says not to operate in the zone "continuously" or something to that effect.


Sent from my iPad using Tapatalk

[druidjaidan]

Just now, Marauder said:

 

My plane will occasionally fall into the red zone. The red zone can be operated in, just not continuously. What this means if you are on an approach and pull back power and end up in the red zone, that is fine.

What you can't do is set the prop for an RPM and fly around at that setting. Check your POH, I am pretty sure it says not to operate in the zone "continuously" or something to that effect.


Sent from my iPad using Tapatalk

 

Mine is also "avoid continuous operation".  I've gotten some mixed signals on what exactly that means across a couple threads reading about it.  The description I've heard most commonly though is that you can transit the RPM range, but you shouldn't stop in it.  That implies to me that an approach shouldn't be flown in the red range.  I'm not sure what qualifies as "continuous". It's a nice ambiguous term.  Is 30 seconds continuous, is 2 minutes continuous, 15min, is anytime the needle stops continuous?

[Marauder]

Mine is also "avoid continuous operation".  I've gotten some mixed signals on what exactly that means across a couple threads reading about it.  The description I've heard most commonly though is that you can transit the RPM range, but you shouldn't stop in it.  That implies to me that an approach shouldn't be flown in the red range.  I'm not sure what qualifies as "continuous". It's a nice ambiguous term.  Is 30 seconds continuous, is 2 minutes continuous, 15min, is anytime the needle stops continuous?

I have always interpreted it to mean that you shouldn't used those rpm ranges for cruise configurations. An approach from FAF can range from 4 to 6 or so minutes. Sitting in the red zones for a few minutes of that time shouldn't be an issue. I have electronic tachs so I have a good idea when I am in the zone. Pulling a half inch of MP can often get you out of it.


Sent from my iPad using Tapatalk

[slowflyin]

48 minutes ago, druidjaidan said:

There has to be something up with our MP gauge at lower settings.  There is no way in hell my plane is making it to flaps speed at 15-16 inches with gear up.  At that range I will just barely make it to gear speed in level flight after about 90seconds.

Hmmm... 90 seconds sounds right.  What's your flap speed?  

[druidjaidan]

Just now, slowflyin said:

Hmmm... 90 seconds sounds right.  What's your flap speed?  

Level at about 15.5" will get me settled at 120mph, just enough to get the gear down.  Unless I misread your post it sounds like 15 or 16 inches will get you down to flaps range (105mph) with gear up since you're dropping gear at GS intercept.

[slowflyin]

My white arc is 110 kts with Gear extension speed of 105 kts.   Your max flap extension speed is 105 MPH or 91 kts?

[Marauder]

Something isn't right here. What year F do you have? My VFe/VFo is 109 KIAS, my gear VLo/VLe is 104 KIAS. You have a 60s vintage F (Tapatalk doesn't show your profile easily).


Sent from my iPad using Tapatalk

[Hank]

1 hour ago, slowflyin said:

My white arc is 110 kts with Gear extension speed of 105 kts.   Your max flap extension speed is 105 MPH or 91 kts?

Older Mooneys have lower lower speed than our more recent Vintage models. I also learned to slow into the flap tange (125 mph), drop them to Takeoff and continue to slow to 105 mph (90 knots). This makes things happen slowly enough that an instrument-pilot-in-training can react well. 

Learn your power settings for each configuration. For me, the most important are 90 knots level, Clean and Takeoff Flaps. I drop the gear 1-1/2 dots high on the glideslope which will slow me down and put me right on slope. Dropping flaps requires adding a couple of inches MP to hold altitude.

Of course, approaches can be flown faster, but 90 knots / 105 mph is pretty standard. With the DPE on my checkride, I raised gear and flaps and accelerated to 130 mph on an ILS approach for the Lear behind me, but I slowed back to 90 knots and reconfigured by the FAF. Learn it slow, then work on speeding up--it's another tool in your box.

[Marauder]

I just looked up your Mooney. It looks like it is a 66 with a 67 serial number. With the speed mods you have, you will need to play around with the power configurations. As was discussed earlier, you should verify that your tach/MP are correct. Another thing that also may be happening with your particular Mooney is the loss of prop control at certain speeds and power settings. My F will still control the prop at 13" and will take it to 2350. I go below 13", my prop is dropping in the red zone and is subject to airspeed.

[M20F]

Pitch and power always go together to get to vRef.  I can fly 18" at a lot of differing speeds depending upon pitch; I can fly 120MPH at a lot of differing pitches/power settings.  Generally I find when people are having problems with glideslope, landing, etc. it is a pitch issue. They are flying a power setting per the book or other reputable source to try and hit a speed but with too much or not enough pitch (AOA). 

Pitch (AOA), power, and speed are all directly related so all 3 have to come together to be consistent. 

I will say 18" gets me to about 120 then gear at 1 dot and then 1/2 flaps at FAF coupled with 2-3" reduction puts me @500 FPM down the G/S at @ 95mph with about 5 degrees of pitch.  This has worked for me in F, J, E, C's with pretty minor modifications depending on weather, weight, CG, etc. but emphasis on minor.

[carusoam]

Good news...

1) The MAPA guide is as modern of a set of operations data that we have for our birds.  It gets updated every few years, mostly additions, but not many revisions...

2) It's authors are as knowledgable as any CFII with Mooney specific experience and then some.

3) It is more guide than absolute rules to follow, especially when your airframe is modified from stock. WnB is always changing like the wind and the weather.

4) If you find that you don't agree with the flap settings or MP settings, this is a hint that you may be misunderstanding what the are offering.

5) before spending a lot trying to determine why your plane doesn't fit the MAPA mold...

6) Spend a little to take the MAPA class to make sure you understand what they are saying and why it applies to your aircraft.

7) MAPA is a great resource.  You get to meet many Mooney pilots that are open to sharing their flying experiences.

8) It is great to have a partner that is also a CFII.  It is equally great when you get to fly with various partners.  Each one can bring new ideas or a different point of view.  

9) after a while you look forward to putting in a lot of work and finally the aha moment arises!  

10) is it worth it...? Absolutely! Who wouldn't want to discuss these details without having to type all night to get there?

I went, I saw, I met a lot of really Mooney savvy people. There is some really interesting information available that applies to you, your plane, your flying, and how you want to fly...

Best regards,

-a-

 

Edited January 30, 2017 by carusoam

[slowflyin]

12 hours ago, Marauder said:

Something isn't right here. What year F do you have? My VFe/VFo is 109 KIAS, my gear VLo/VLe is 104 KIAS. You have a 60s vintage F (Tapatalk doesn't show your profile easily).


Sent from my iPad using Tapatalk

 

Mine as well-I stand corrected.   The OP used 105 and my brain locked on.  Mine are actually in the POH at 120 and 125 MPH translating to a little over 104 and a little under 109.   Thanks for the correction.    

[slowflyin]

11 hours ago, Hank said:

Older Mooneys have lower lower speed than our more recent Vintage models. I also learned to slow into the flap tange (125 mph), drop them to Takeoff and continue to slow to 105 mph (90 knots). This makes things happen slowly enough that an instrument-pilot-in-training can react well. 

Learn your power settings for each configuration. For me, the most important are 90 knots level, Clean and Takeoff Flaps. I drop the gear 1-1/2 dots high on the glideslope which will slow me down and put me right on slope. Dropping flaps requires adding a couple of inches MP to hold altitude.

Of course, approaches can be flown faster, but 90 knots / 105 mph is pretty standard. With the DPE on my checkride, I raised gear and flaps and accelerated to 130 mph on an ILS approach for the Lear behind me, but I slowed back to 90 knots and reconfigured by the FAF. Learn it slow, then work on speeding up--it's another tool in your box.

 

+1, this is my technique as well.  Learn what works, set it and wait.

I wasn't aware there were any F models with flap speeds under 109 kts/125 MPH.   Thanks for the info!  

[midlifeflyer]

11 hours ago, Hank said:

Older Mooneys have lower lower speed than our more recent Vintage models. I also learned to slow into the flap tange (125 mph), drop them to Takeoff and continue to slow to 105 mph (90 knots). This makes things happen slowly enough that an instrument-pilot-in-training can react well. 

Learn your power settings for each configuration. For me, the most important are 90 knots level, Clean and Takeoff Flaps. I drop the gear 1-1/2 dots high on the glideslope which will slow me down and put me right on slope. Dropping flaps requires adding a couple of inches MP to hold altitude.

Of course, approaches can be flown faster, but 90 knots / 105 mph is pretty standard. With the DPE on my checkride, I raised gear and flaps and accelerated to 130 mph on an ILS approach for the Lear behind me, but I slowed back to 90 knots and reconfigured by the FAF. Learn it slow, then work on speeding up--it's another tool in your box.

Like your post a lot.

I bolded that part because it's one of the typical reasons given for no-flap approaches. You can get those speeds and proper decent profile without them; adding them just means using more fuel. As usual with technique, there's a countervailing view: since you need power to maintain the profile with flaps, it means less work when reducing power for landing after breaking out.

[slowflyin]

7 minutes ago, midlifeflyer said:

Like your post a lot.

I bolded that part because it's one of the typical reasons given for no-flap approaches. You can get those speeds and proper decent profile without them; adding them just means using more fuel. As usual with technique, there's a countervailing view: since you need power to maintain the profile with flaps, it means less work when reducing power for landing after breaking out.

 

Another reason to use flaps is to keep the prop rpm above 2350.  A lot of us  are prohibited from running from 2100-2350.  (some are placarded 2000-2350)  The added required power you mentioned accomplishes this nicely.