Looking for ballpark MP reading used M20C during your approach, final to maintain stabilized

[ShermAv8tor]

Just looking to see what everyone else is using for a setting, I seem to be chasing it sometimes, Ives used 12, 11 & sometimes 10, but have heard others using 14? Thanks

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[Hank]

For an instrument approach, I use 16-17" flaps up, then add 2" for flaps down at 90 knots.

When VFR, I don't generally look at the MP in the pattern. I reduce it enough to slow down, then pull it some more until I hit 90 mph. If's always above the gear horn setting of 12". Once I drop the gear, I pull a little more throttle out to get a good descent going; on final, once I know I have the field made, the throttle goes to idle and I cross the numbers generally at 70 MPH or a little less if light.

But then again, I have the 3-blade speed brake mounted up front, so I only get 147-148 KTAS in cruise. 

[MyNameIsNobody]

I am a VFR guy and honestly have no clue.  I look out the window and fly by feel and airspeed.  I pull power to sound and slow down after "coming down from cruise" at whatever speed I get (watching to keep below 180 indicated) and might pitch up a tad to get to 120 (gear extension).  Then I pitch for continued decent and keep between 100 and 80  if coming in to a towered field vs. pattern.  I add a little power or reduce based on plane position/height vs. touchdown point.

I don't fly by "adding 2"" as Hank does above, but truth be told that is likely about where I am in a short body E.

[Mooneymite]

Wouldn't the airspeed indicator be a better source of information than some sort of "one size fits all" MAP reading?  

Hank's settings may work for a starting point.  Frankly I don't know since I rarely pay attention to power settings in the approach phase other than to try to avoid the gear horn until I'm ready for the gear.

A set-it-and-forget-it power setting doesn't exist since there are so many vairables that affect aircraft performance.  If you're flying the glideslope into a strong headwind, you're going to need more power.  If your aircraft is heavy, or using full flaps, you'll need more power, etc.

[Yetti]

Pull to 15" in pattern.  abeam the numbers on downwind throw the bottom speed brakes out.  adjust throttle as necessary to land. (if you are 200 feet high when abeam the numbers you are going to have a really hard time making the landing as I found out last week, but hey that is what go arounds are for.)

[mike_elliott]

Now is a great time to develop your IFR power setting chart! Go up and record these numbers...

1. What MP/RPM to maintain straight and level at 90 kts or top of white arc clean

2. What MP/RPM to maintain straight and level at 90 kts or top of white arc dirty (gear down, TO flaps)

3. What MP/RPM to maintain 5-600 FMP down at 90 kts or top of white arc clean

4. What MP/RPM to maintain 5-600 FMP down at 90 kts or top of white arc dirty (probably the same as #1)

 

Your plane will perform the same in or out of the soup. Setting the plane up to fly an approach, #1, then by lowering the gear (GS interept) and adding TO flaps will keep you on a nice 500-600 FPM decent.

 

[Mooneymite]

Wow!  I sure flunked this test.....I couldn't tell you a single setting.  

[Hank]

Those are the numbers I gave, Mike, at least Clean and Flaps Only; for 90 knots, descending, dirty, all I do is drop the gear 1½ dots high, and the needle centers as I start down.

For VFR, I just level off from my 500 fpm descent, leave the throttle alone and see how much I slow down. Then I back it off some and slow down some more. Instrument Approach speed is 90 knots = 105 mph; my pattern speed is 90 MPH, so it will be less, but the same conditions [Flaps to Takeoff, Gear Up]. How much less depends on altitude, OAT and weight.

[ShermAv8tor]

Thanks everyone for the great info, it causes me to look at things differently…I brought this up as I had a recent flight with a CFI, he stated I should be able to pick a power setting referencing the MP, and I should not have to adjust throttle much from there to maintain speed and have a nice stabilized approach, perhaps my throttle adjustments were not as minute as he thought they should be, as I was chasing speed quite a bit. I shoot for 80 on final and as Mentioned earlier once I have the field made I reduce further and hope for 70ish over the numbers. I'm still in the learning mode, but I don't think that ever goes away with this airplane…I don't have 100 hrs in it yet


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[carusoam]

Sherm,

how familiar with Mooney's is your CFI?  

Some planes are more sensitive to a little extra MP.

Some pilots know their planes so well, estimating MP for the segment of flight is like a picture in the back of their minds...

20" = flying quickly

18" = flying slowly

16" = flying a descent slowly 200 fpm.

14" = 400 fpm descent.

13" = 500 fpm descent.  (Standard pattern descent)

12" = 600 fpm descent.  (100fpm for each 1" of MP removed)

need to descend a bit faster, remove another 1” of MP...

Gear and flap settings, weight and weather all add to the mix...

PP thoughts only, not a CFI...

Best regards,

-a-

[luv737s]

I have all my instrument students compute the numbers for this chart before starting any further training.  Makes everything go smoother.

6 Configurations for plane.pdf

[Hank]

27 minutes ago, luv737s said:

I have all my instrument students compute the numbers for this chart before starting any further training.  Makes everything go smoother.

6 Configurations for plane.pdf

My CFII had me do the same thing. But there was no "computing," it was "go fly the plane in each configuration and write down the power settings used. The ones I remember are 90 knots clean, and 90 knots with Approach flaps, simply because I use them. 

[luv737s]

I used the word computing...of course this is done in the air while flying the plane.  

[TWinter]

I'm just a 100 dnwnd, 90 base and 80 +/- (over the fence on final or as needed) pilot. I listen to the sweet engine noise in my ears as she tells me how I'm doing ... Looks like I really need to work on my technical aspect.  

 

[Hank]

4 hours ago, TWinter said:

I'm just a 100 dnwnd, 90 base and 80 +/- (over the fence on final or as needed) pilot. I listen to the sweet engine noise in my ears as she tells me how I'm doing ... Looks like I really need to work on my technical aspect.  

 

Nope, that's what I do VFR. The other is for instrument flight, when looking out the window gives you no information and you need to slow to 90 knots and get the flaps out to start the approach.

The only thing I do is fly downwind and base at 90 mph, final at 85 mph slowing to 70-75 "over the (imaginary) fence, flaring at 6-8' and touching down just after the stall horn squawls.

[TWinter]

15 minutes ago, Hank said:

Nope, that's what I do VFR. The other is for instrument flight, when looking out the window gives you no information and you need to slow to 90 knots and get the flaps out to start the approach.

The only thing I do is fly downwind and base at 90 mph, final at 85 mph slowing to 70-75 "over the (imaginary) fence, flaring at 6-8' and touching down just after the stall horn squawls.

That's me Hank.. Mr. VFR for now, but learning

 

[Hank]

2 hours ago, TWinter said:

That's me Hank.. Mr. VFR for now, but learning

 

That's alright, we all start as VFR pilots. I finished my PPL 5/21/07, bought the Mooney 6/26/07 and completed IFR 4/30/10. Along the way I flew durn near 300 hours in the Mooney.

[M20F]

Temp, weight, altitude, etc. are always going to change the MP setting to fly a Vref.  It certainly helps to have a baseline to dial into as a start and go up/down as needed.  One issue people have as well is failure to keep a consistent AOA/pitch to go with an airspeed.  I can fly to final at 90mph with 5, 10, 15, etc. degrees of pitch which obviously will impact needed power.  

Keep playing with it and eventually it just sort of becomes second nature.  

[Hank]

Andrew, I rarely cruise low enough to get 26". At 9000' I'm doing good to get 21".

My mid-level power setting is 22" / 2400, pretty much 4000-7000 msl. Then again, your J has 20 additional hp and should have slightly higher MP available at all altitudes.

The critical number for our Cs is MP + RPM/100 <= 47. So 21/25 works great up high; 23/23 works great down low; and in between 22/24. 

I think the number for Js is 50.

Edited November 25, 2016 by Hank

[luv737s]

No right answer, I counted 9 different models so far in this post.  Apples do not equal oranges!!!  You need to test YOUR plane at the normal weights and configurations that you normally fly to come up with ballpark figures.  Make up your own performance charts and you will soon come up with some common numbers.  Ill bet if I were buying your plane and you were demoing the pattern, even the VFR pilots would be quick to show some  MP/rpm settings they routinely use!! 

[ShermAv8tor]

All great answers and replies, I know I will have to come up with my own. I think the thread sparked a lot of great thoughts and comments. Thanks again for the help! I hope everyone enjoyed their Thanksgiving…now bring on Christmas!!


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[carusoam]

See if you can get the MAPA PPP training as a Xmas gift.  It comes replete with power settings and configurations for all aspects of flight for your specific air frame...

Merry Xmas,

-a-

[Hank]

9 hours ago, carusoam said:

See if you can get the MAPA PPP training as a Xmas gift.  It comes replete with power settings and configurations for all aspects of flight for your specific air frame...

The MAPA PPP is great! But the power settings in the book for the C model are for the first model year, 62 or 63, so they will be a starting point; you will still need to find your own. But the equation I gave for cruise power settings is straight from the book.

[MyNameIsNobody]

On 11/25/2016 at 0:19 PM, Hank said:

Andrew, I rarely cruise low enough to get 26". At 9000' I'm doing good to get 21".

My mid-level power setting is 22" / 2400, pretty much 4000-7000 msl. Then again, your J has 20 additional hp and should have slightly higher MP available at all altitudes.

The critical number for our Cs is MP + RPM/100 <= 47. So 21/25 works great up high; 23/23 works great down low; and in between 22/24. 

I think the number for Js is 50.

You are a nice guy Hank. You called Hyett out for BS, but did so in a kind gentle way. Bottom line: Normally aspirated IO-360 engine at 9000 feet can NOT produce 26 inches of MP.  So, there is that. I live in Realsville, not in Fantasia...

[Hank]

16 minutes ago, MyNameIsNobody said:

You are a nice guy Hank. You called Hyett out for BS, but did so in a kind gentle way. Bottom line: Normally aspirated IO-360 engine at 9000 feet can NOT produce 26 inches of MP.  So, there is that. I live in Realsville, not in Fantasia...

No, I don't know where he likes/is allowed to cruise in the UK and EU. I'm pretty sure it's different there, more so than QNH and Flight Levels starting at different altitudes by country, some as low as FL040 . . . which I know as 4000 msl.

But I was also making the point that any power settings for IO-360s will not apply to the OP, who requested power settings for his M20-C, powered by the mighty O-360.