M20B Speeds

[bruceyung]

Hello Friends, I own a 1962 M20B  . Have it for 5 months  and still looking for precise speeds. Can any member help me with  the Best Glide speed for this B model?If anyone has a Speed table will also help.The Manual is to old and with incomplete speed description.

Thanks to all

Bruce.

Edited September 22, 2016 by bruceyung

[Andy95W]

Your fuselage, wing, and engine horsepower are identical to the M20C.  They are both called the "Mark 21", your B is simply the earlier variant of it.

The only differences between your 1961 M20B and the 1962 M20C are that you have mechanical flaps (the C is hydraulic) and a slight difference in engine (A1A versus A1D).

You should use the M20C numbers for performance, but your own POH for your specific systems like flap, fuel capacity, etc.  There is at least one M20C POH in the download section of MooneySpace.

(If there are other differences that I've missed, hopefully someone will post them.)

[bruceyung]

thankyou my friends .. apprreciate your time to help me out . Ill take a look at the M20C poh and jot down the 100mph glide speed. The mais gear doors probably were cut out to have easier handling while filling up the tire with air .

thanks

Bruce

[carusoam]

You can probably pick up a more complete POH that can be used for your plane.  The owner's manual for some planed were more a sales brochure.

You can do this officially by contacting the factory or your local MSC.  There may be a POH worth reading in the download section.

It may be possible that the B and C share enough details that the most recent POH may be helpful.

Just know the tail and rudder changed significantly along the way...   Rudder length and the distance it moves (throw)...

Private pilot knowledge only, not a CFI...

Best regards,

-a-

[bruceyung]

Thankyou for the advice, I will be looking at the C model POH on the downlod section. Do you know if there are any ruddder differences on the B towards the C? 

 

thanks

Bruce

[rbridges]

for some reason, I had 109 mph in my head.  Jim's right, 100 is pretty close and easy to remember.  

[carusoam]

The B's rudder throw can be updated with a few parts.

Best regards,

-a-

[bruceyung]

Thanks , I have to agree 100mph is easy to remember in case of an emergency.. Ill try power offs with this speed.

 

thankyou

[carusoam]

Bill wheat was also the guy I spoke to via telephone when I was looking for a POH for my 65C.  That was back in Y2k.

It was his signature in my C's log for AW tests.

I called the factory, they said talk to Mr. Wheat.  

I think our contact is Stacy.  If not call the factory or send an email to talk with Stacy...?

Dan at LASAR (MSC) is pretty good about getting the right parts for your machine.

Best regards,

-a-

[Raptor05121]

I'm pretty sure the B, C, and D all have the same speed. Vy - 105mph is also Vbg

[Hank]

There's an Owners Manual for 1965 C in the Downloads section. Best Glide for my long rudder 1970 C is 105 mph.

[DXB]

4 hours ago, pstone said:

Bill Wheat had to bail out of the B Model during spin tests. That is how the C model came into play.  Get the parts (from Mooney) for the rudder that allow it to have more authority. 

 

Pat

Wow for real?!  I'd love to hear the details of that particular story.  I don't know how one would even get the door open far enough to bail. 

BTW in case anyone's interested, here's the M20B owners manual plucked from elsewhere on the site.

M20B owners manual.pdfM20B owners manual.pdf

As OP says, no info on best glide.  In addition to weight, I think whether or not prop is windmilling and course vs. fine makes a real difference?  

The manual is amusing compared to my '68, which is a tad more professional and also slightly more informative, but not much.  The B manual goes on and on in multiple places about how it's the best piston plane in the world and truly suited to the jet age, and how any drawbacks it might have are also present in all other planes. I can easily visualize a Don Draper-esque fella who's not terribly interested in emergency procedures writing it while smoking and drinking whiskey.

[carusoam]

Here is how I understand it...

1) Somebody wrote a good book that covers this topic....  Engine out survival tactics, by MSer Nate Jaros, available in i-bookstores everywhere for only a handful of dollars...

2) Prop spinning or not, would be part of the equation for drag.  Minimizing drag would require slowing to stop the prop, if you have time.

3) weight has an effect on AOA to maintain lift and airspeed.  More weight and back of the envelope balance uses a higher more draggy AOA.

4) Choosing a speed that gives the most forward motion with the least loss of altitude, is the balance related to AOA.

5) once committed to the glide....  choose your speed based on weight, adjust prop and other drag devices as available. At least pull the prop back.

PP ideas only, I read Nate's book. It is worth the few bucks!

How did I do?

Best regards,

-a-

[Bob_Belville]

55 minutes ago, bluehighwayflyer said:

Would the prop's status impact best glide speed, or just glide ratio? 

As for the cabin door I would imagine that the factory would rig it to be jettisonable when doing spin testing. That would be an interesting ride, though, for sure. 

Jim

The test pilot flies from the right seat with the door rigged for hinge release. The current test pilot is Mike Miles. One cool dude.

[mooniac15u]

18 hours ago, Bob_Belville said:

The test pilot flies from the right seat with the door rigged for hinge release. The current test pilot is Mike Miles. One cool dude.

The current test pilot no longer has to fly from the right seat now that the new models have a pilot side door.

[carusoam]

Mike has two doors to choose from now.

 

But I bet all his paperwork still requires him to fly from the right seat.  It is so easy to copy an old protocol, than to write and approve a new one.  

Best regards,

-a-

[cliffy]

Here, taken right from the FAA TCDS for the B model-

Interior Equipment: 401. .......FAA Approved Airplane Flight Manual (a) Flight Manual Supplement, dated July 16, 1962.

You should be able to get the correct one from Mooney.  In the USA this is the required manual if one was ever checked by the Feds.

 

[N6758N]

I've been searching for best glide for my 68' C for my upcoming commercial checkride. The book graph says 100mph without prop windmilling provides better results than 105 mph with prop windmilling. Regardless though, there is still no published best glide speed that I can find, can anyone else shed more light on this. My COTS checklist I've been using for the last few years says 87mph  so I don't trust it now. I'm going to stick with 100mph for now, but it would be nice to see a published number from Mooney.

[carusoam]

See if I have this in memory correctly....

1) Best glide speed is about getting the furthest glide out of the energy you have in the plane already.  (Speed and altitude)

2) Best glide will depend on the plane's weight,

3) A modern POH can give some hints to how the older planes will react.

4) Roughly, for a Long Body, expect a Best glide of 90kias at max weights, 80kias at lower weights.

5) gear up, flaps up, pull the prop control back...

6) if you have lots of altitude, slow enough to stop the prop.

7) Prop/engine drag is a real energy user.  Similar to a Jake brake in big trucks, or downshifting with the throttle out in a car...

8) differences between Long Bodies and older Mooneys... the ASI is in knots vs mph.  The reference speeds are close but reported in knots vs mph...

9) this information can be considered unreliable.  Definitely find actual data for your plane.

PP thoughts only, not a CFI...

Best regards,

-a-

[N6758N]

12 minutes ago, carusoam said:

 

9) this information can be considered unreliable.  Definitely find actual data for your plane.

Thanks Anthony, as I said earlier I'm in search of the actual data. Certainly wish Bill Wheat was still alive to shed some light on this. I don't think long body specs help here because weights and drag are not anywhere close to my little C. I don't think my DPE will care too much as long as I can show the glide graph in the back of the POH, I really just want to find out for my own curiosity. 

[carusoam]

Terry,

the most recent POH for the C has a page (6-4) that shows a graph called Glide range.  Height above ground vs. Distance...

It has two lines...

1) prop windmilling 105 mph 10.3:1 glide ratio

2) prop stopped 100 mph 12.7:1 glide ratio

All at 2575 LBs gross weight.

Check to see if the POH is posted on MS around here somewhere.

This is more reliable than my memory, but having the printed data will be much better than a guy on the internet said....

Bill Wheat recommended that I use the October 1977 issue of the C's POH for my 1965M20C.  He was a great resource.  This was one of my favorite phone calls ever.

Best regards,

-a-

Edited May 16, 2017 by carusoam

[Hank]

3 hours ago, N6758N said:

I've been searching for best glide for my 68' C for my upcoming commercial checkride. The book graph says 100mph without prop windmilling provides better results than 105 mph with prop windmilling. Regardless though, there is still no published best glide speed that I can find, can anyone else shed more light on this. My COTS checklist I've been using for the last few years says 87mph  so I don't trust it now. I'm going to stick with 100mph for now, but it would be nice to see a published number from Mooney.

Those are what my 1970 Owners Manual says. To me, being printed by Mooney makes them official. What are you looking for?

I posted thw whole thing in the Downloads section a couple of years ago.