M20M TLS spreadsheet of “the approach numbers.”

[Sanoi]

Can anyone help me do a bit more tweaking.  I am sharing this sheet to see if you agree with these numbers. I am training for my IFR rating and I am trying to simplify to a minimum, the setting and speed configuration. Please let me know what you think.

Thanks

[LANCECASPER]

12 hours ago, Jonás said:

Can anyone help me do a bit more tweaking.  I am sharing this sheet to see if you agree with these numbers. I am training for my IFR rating and I am trying to simplify to a minimum, the setting and speed configuration. Please let me know what you think.

Thanks

I would add a column for Fuel Flow next to RPM so you can see what your normal fuel flow is, so that if it varies it will stand out to you. On the three Bravos I had,  29/2400 was my favorite cruise combo. There's nothing wrong with 26/2400 and there are probably infrequent situations where I would use that, like trying to extend range and avoid a fuel stop, but I bought a Bravo to fly fast. I heard of people running it 32/2400 and they were usually the ones buying cylinders. The only cylinders I ever changed were on the TLS that I converted to a Bravo. Also if you have the prop dynamically balanced for 2400 I'd leave it there during approach for a smoother operation and only adjust manifold pressure rather than lowering RPM. 

If you're putting in 10 quarts, on most TIO-540-AF1B engines you're going to have oil all over the belly, and on your first cross country after an oil change it will blow out whatever amount over eight quarts that you put in. My first mechanic used to love to put in 12 quarts in during an oil change until I jokingly explained to him that the next time he did that he was going to be cleaning the belly. Eight quarts was the number that all three of my engines liked. It took me awhile on my first one to have the courage to go all the way down to eight on oil changes since 90% of my flying was long cross countries. But that's where I ended up. (I will admit that on a couple long cross countries over water I did put an extra quart or two in, just to be sure. I still ended up cleaning the belly after those flights) Carrying 8 quarts, I usually had to add one quart between 25 hour oil changes - once in a great while two quarts between changes. It's good to know your engine's "normal" level so you'll know whether it's blowing it out or consuming it.

[rbp]

16 minutes ago, LANCECASPER said:

I would add a column for Fuel Flow next to RPM so you can see what your normal fuel flow is, so that if it varies it will stand out to you. On the three Bravos I had,  29/2400 was my favorite cruise combo. There's nothing wrong with 26/2400 and there are probably infrequent situations where I would use that, like trying to extend range and avoid a fuel stop, but I bought a Bravo to fly fast. I heard of people running it 32/2400 and they were usually the ones buying cylinders. The only cylinders I ever changed were on the TLS that I converted to a Bravo. Also if you have the prop dynamically balanced for 2400 I'd leave it there during approach for a smoother operation and only adjust manifold pressure rather than lowering RPM. 

 

I agree with all of this and I would add:

1. once in the descent below a certain MP, the RPM will come down on its own. I just push it forward and leave it there.

2.  I would add a column for %power. 29/24 is 75%.  I flew for many years at 30/24, which is 78%.

[Sanoi]

Thank you for sharing your experience with me. I will add the columns. About the oil, my seems to stay stable at about 9 qts. 

[donkaye]

On 12/5/2022 at 4:41 PM, Jonás said:

Can anyone help me do a bit more tweaking.  I am sharing this sheet to see if you agree with these numbers. I am training for my IFR rating and I am trying to simplify to a minimum, the setting and speed configuration. Please let me know what you think.

Thanks

I disagree with pretty much all of your settings.  I recommend using the document attached that I use when teaching the Bravo.  I've owned my Bravo for 30 years and find these numbers to be the ones that work best.  I'm on my 3rd engine.  I recommend going to my website: www.donkaye.com for more information on flying your Mooney.  Regarding the use of speed brakes for the NP approach in the document, they are not to be used in any icing temperatures, since they will freeze in the extended position.

A few other pieces of advice:  Max engine oil at oil change, 9 quarts if you don't want it blown out.  Unless on approach near landing, MP never less  than 15", since you want the engine running the prop and not vice versa.  The only time I run the prop at less than 2400 RPM is on a rapid descent when I don't want the MP to be below 15".  Remember. 3" of MP, or 300 RPM is approximately 10% of power.  Also 1" MP or 100 RPM is about 3⅓ % Power.  So any combination of MP and RPM that gives 10 power works.  So, I will set the MP at 15" and RPM at 2000 on a slam dunk, since reducing RPM will decrease the power in that situation by about 13⅓ % without having the prop run the engine.

SPEEDS & CHECK LISTS M20M.pdf

[rbp]

that PDF tries to be comprehensive, but some too specific ( eg 17.5GPH @75% power -- at what TIT?), not specific enough (eg "I = INSTRUMENTS (SET AND OPERATIONAL)" which instruments?), or theoretical (34"/2400RPM @130KIAS for +1000FPM)

"RUNWAY ITEMS: LIGHTS, CAMERA, ACTION" --  does anyone turn off their digital transponder anymore?  better to leave the transponder on and on the runway sync the heading bug to RW heading and hit the TOGA button. 

[ilovecornfields]

[donkaye]

7 hours ago, rbp said:

that PDF tries to be comprehensive, but some too specific ( eg 17.5GPH @75% power -- at what TIT?), not specific enough (eg "I = INSTRUMENTS (SET AND OPERATIONAL)" which instruments?), or theoretical (34"/2400RPM @130KIAS for +1000FPM)

1. Mneumonic, "Relating to or assisting the memory".  A pneumonic is not meant to be a checklist.  "I for Instruments Set and operational" is meant as a memory helper.  Your instrument instructor should aid you in what to do for each pneumonic.

2. Each airplane is a little different.  The Mooney PPP discusses "Key Numbers" related to engine power.  For the Bravo the Key Number for 75% power is 53.  That means any combination of the sum of MP and the first two digits of RPM that equal 53 should give "approximately" 75% power.  For experienced Bravo owners that is 29" MP and 2400 RPM.  3 of any combination of the above is approximately 10% power.  So 26" and 2400 RPM should give 65% power.  So the way to set power, for example 75% power, is to set the MP at 29" and the RPM at 2400 and begin leaning the engine.  You could lean to 17.5 gal/hr and see what the TIT is.  With my engine after an hour flying time, it will be between 1595 and 1605.  The first hour, for reasons George Braly of GAMI, couldn't explain,  it is higher.  I don't want to run my engine with a TIT over about 1605, so I just let the full flow be higher during that first hour.  So FF can vary somewhat from that stated in the PDF.  I set my cruise power by setting the MP and RPM then adjusting the TIT to 1595 and confirming the FF close to what I expect.  If for some reason it is far off from what I expect (it never has been), then I know the engine has an issue.

Regarding the "theoretical", as the engine ages performance will change.

If you want to have a more detailed discussion of the above, give me a call at 408-499-9910 and I'd be happy to go into more detail.

[LANCECASPER]

4 hours ago, donkaye said:

1. Neumonic, "Relating to or assisting the memory".  A pneumonic is not meant to be a checklist.  "I for Instruments Set and operational" is meant as a memory helper.  Your instrument instructor should aid you in what to do for each pneumonic.

https://www.merriam-webster.com/dictionary/mnemonic

[donkaye]

25 minutes ago, LANCECASPER said:

https://www.merriam-webster.com/dictionary/mnemonic

It looks like I need a mneumonic for a mneumonic.

[Sanoi]

On 12/10/2022 at 2:52 PM, donkaye said:

I disagree with pretty much all of your settings.  I recommend using the document attached that I use when teaching the Bravo.  I've owned my Bravo for 30 years and find these numbers to be the ones that work best.  I'm on my 3rd engine.  I recommend going to my website: www.donkaye.com for more information on flying your Mooney.  Regarding the use of speed brakes for the NP approach in the document, they are not to be used in any icing temperatures, since they will freeze in the extended position.

A few other pieces of advice:  Max engine oil at oil change, 9 quarts if you don't want it blown out.  Unless on approach near landing, MP never less  than 15", since you want the engine running the prop and not vice versa.  The only time I run the prop at less than 2400 RPM is on a rapid descent when I don't want the MP to be below 15".  Remember. 3" of MP, or 300 RPM is approximately 10% of power.  Also 1" MP or 100 RPM is about 3⅓ % Power.  So any combination of MP and RPM that gives 10 power works.  So, I will set the MP at 15" and RPM at 2000 on a slam dunk, since reducing RPM will decrease the power in that situation by about 13⅓ % without having the prop run the engine.

SPEEDS & CHECK LISTS M20M.pdf 85.12 kB · 74 downloads

 

[Sanoi]

Hello Donkaye,

Thank you for sharing your checklist with me. It helped me a lot. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[midlifeflyer]

On 12/11/2022 at 12:14 PM, rbp said:

 

"RUNWAY ITEMS: LIGHTS, CAMERA, ACTION" --  does anyone turn off their digital transponder anymore?  better to leave the transponder on and on the runway sync the heading bug to RW heading and hit the TOGA button. 

Actually, the currents AIM 4-1-20 discussion of transponder operation recommends leaving it on in all movement areas and some larger airports require it. 

But so what? A mnemonic is much, much, much more important that what is is supposed to represent. Keep the mnemonic and get an old transponder! To heck with those silly "non-regulatory" recommendations! Or maybe move "lights, camera, action" to the before taxi checklist? Anything, so long as you save that mnemonic!

 

 

Can you tell how much I love mnemonics?

[PilotX]

On 12/11/2022 at 4:52 AM, donkaye said:

I disagree with pretty much all of your settings.  I recommend using the document attached that I use when teaching the Bravo.  I've owned my Bravo for 30 years and find these numbers to be the ones that work best.  I'm on my 3rd engine.  I recommend going to my website: www.donkaye.com for more information on flying your Mooney.  Regarding the use of speed brakes for the NP approach in the document, they are not to be used in any icing temperatures, since they will freeze in the extended position.

 

Hey Don. I know you have been flying Mooneys for a while and know you haven't had success with LOP.

On 91A 56 is equivalent to 77% (14.5gph) based solely on the FF formula. 54=71%(13.5gph), 52=66%(12.5gph).

These are the numbers I fly but I list them as 2200/34", 2200/32", 2200/30".

I haven't fiddled with 2300/2400 as things start to get warmer in the summer at 22/34". 

I can, and have, experimented with ROP and full visor power settings. Just happy to cut costs by flying LOP. Occasionally I will get a pretty big misfire when flying at 77%, rare but it will wake up you from your GFC500 induced slumber. Then I bring it back to 22/32" and she roars right along like a big turbocharged pussycat.

[rbp]

On 1/3/2023 at 7:06 AM, midlifeflyer said:

Actually, the currents AIM 4-1-20 discussion of transponder operation recommends leaving it on in all movement areas and some larger airports require it. 

But so what? A mnemonic is much, much, much more important that what is is supposed to represent. Keep the mnemonic and get an old transponder! To heck with those silly "non-regulatory" recommendations! Or maybe move "lights, camera, action" to the before taxi checklist? Anything, so long as you save that mnemonic!

 

 

Can you tell how much I love mnemonics?

my runway M check list is the cross:
 

top to bottom -- flaps, elevator trim, rudder trim, cowl flaps, emergency gear

and left to right -- window, heading bug sync, TOGA pressed, prop, mixture, door

[donkaye]

10 hours ago, PilotX said:

Hey Don. I know you have been flying Mooneys for a while and know you haven't had success with LOP.

On 91A 56 is equivalent to 77% (14.5gph) based solely on the FF formula. 54=71%(13.5gph), 52=66%(12.5gph).

These are the numbers I fly but I list them as 2200/34", 2200/32", 2200/30".

I haven't fiddled with 2300/2400 as things start to get warmer in the summer at 22/34". 

I can, and have, experimented with ROP and full visor power settings. Just happy to cut costs by flying LOP. Occasionally I will get a pretty big misfire when flying at 77%, rare but it will wake up you from your GFC500 induced slumber. Then I bring it back to 22/32" and she roars right along like a big turbocharged pussycat.

Because LOP is dependent on FF, the Key Numbers approximation of power is not applicable.  I have had a student get his Bravo to run LOP after spending a lot of money eliminating induction leaks and other things.  After the fact, he has had a lot of engine maintenance.  It's not supposed to be that way, but it is.  I had issues with stabilizing TIT when I tried it after taking the in person APS Course put on by GAMI.   I personally like the way the engine runs and the extra speed attained ROP even at the extra costs,  so that is the way I'm flying my airplane.

[midlifeflyer]

4 hours ago, rbp said:

my runway M check list is the cross:
 

top to bottom -- flaps, elevator trim, rudder trim, cowl flaps, emergency gear

and left to right -- window, heading bug sync, TOGA pressed, prop, mixture, door

My flow pattern in just about every type I've flown is pretty much the same as that. But my checklist is a checklist.

[rbp]

16 hours ago, midlifeflyer said:

My flow pattern in just about every type I've flown is pretty much the same as that. But my checklist is a checklist.

you pull out the checklist while you're rolling out on the runway? How about in spin recovery? 

[midlifeflyer]

8 hours ago, rbp said:

you pull out the checklist while you're rolling out on the runway? How about in spin recovery? 

I treat the before takeoff checklist as a briefing and I have the spin recovery in my head since there is no time, just like the "memory items" in any emergency checklist. That doesn't mean no checklist for normal ops.

[rbp]

using your terminology, we are both on the same page.

[rbp]

i was thinking about the cruse power setting the other day. i had reduced mine from 30/24 78% to 29/24 75% to stay under the 75% power mark

 

but it occurred to me that since 30” is sea level pressure, this engine should have no problem running full time at that setting without over stressing the engine, and it would be like running the engine like a turbo normalizer