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M20E/F in high altitude short runway

rene86mx

By rene86mx
in Vintage Mooneys (pre-J models)

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carusoam Grand Master

carusoam

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Welcome aboard Rene!

There must be something wrong with your Brand Ce’s POH performance charts... :)

Realistically... a major portion of T/O roll is the acceleration from 0 to 60... the slower Cessna has a bit lower requirement for T/O speed... HP vs weight...

What airport is your home drome?
 

Stand by... there will be an MSer with a similar experience to discuss...

Expect to discuss temps, DAs, and MGToWs.... with a UL of about 1k, how often will you use all 1k...

With that long of a runway... I don’t see any issues for an NA Mooney to be very wonderful there...

Of course, turbo chargers and turbo normalizes make a lot of sense in those environments... @wcb I believe is selling his M20F with a TN on it... (an example of an NA Mooney with a TN added)

Best regards,

-a-

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Ragsf15e Grand Master

Ragsf15e

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6 hours ago, rene86mx said:

Hi,

 

I'm looking at M20E or M20F for potential ownership.

My home field is at a 8120 altitude and the runway is 4200 long

Does anyone has any experience on this settings? From POH I see the same performance I get with my school's Cessnas

 

Thanks

Unless it’s real cold and/or you plan to operate well below max gross, I’d proceed with caution.  Don’t get me wrong, the E or F is probably going to outperform a similarly loaded cessna in most conditions, but I have an F and id be very careful there.  The F climbs at a higher Vx or Vy than the cessna, and your higher tas may lead to less climb gradient.  
Do you plan to fly at ~500lbs below max weight?  That might be ok.  Load up on fuel or passengers and that kind of altitude could definitely be a problem.

Obviously it’s the density altitude that matters.  I suspect the charts will show an E or F off the ground by 3000’, maybe 3500’ at 8500’ DA.  But you’re talking a 55 year old airplane and you may not make book.  It’s the climb after that would worry me even more.

F0C3C5E0-122C-4593-934F-AE58E54F56A2.thumb.jpeg.a5298c0e591ec14d05d8d8a57180c156.jpeg

Edited by Ragsf15e
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Comet Contributor

Comet

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My home airport is at 7171’; I typically rotate at 1800-2000’.  Your concern may be the local terrain.  At 10k’ DA, climb rate may be as low as 400-500 ft/min.  One year when I was leaving for Oshkosh in the afternoon, DA was over 10k’ and it seemed to take forever to get to my cruising altitude of 11.5k’.

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carusoam Grand Master

carusoam

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+1 for Rags’ keeping it real...

Discussing... The challenges of NA (normally aspirated) engines at high DAs (density altitudes)...

+1 for the real examples...

+1 For the new guy... :)

Power to weight ratios define the T/O and climb performance...

Learn how to maximize the power and minimize the weight...

Go Mooney!

Best regards,

-a-

 

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Ragsf15e Grand Master

Ragsf15e

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2 minutes ago, Comet said:

My home airport is at 7171’; I typically rotate at 1800-2000’.  Your concern may be the local terrain.  At 10k’ DA, climb rate may be as low as 400-500 ft/min.  One year when I was leaving for Oshkosh in the afternoon, DA was over 10k’ and it seemed to take forever to get to my cruising altitude of 11.5k’.

When I’m loaded at gross of 2740, I generally see even a little less climb than that above 10k DA.  It’s definitely slower when heavy.

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rene86mx Newbie

rene86mx

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16 hours ago, carusoam said:

What airport is your home drome?

MMJC

 

16 hours ago, carusoam said:

Expect to discuss temps, DAs, and MGToWs.... with a UL of about 1k, how often will you use all 1k...

 

Great question. I don't plan to be at MTOW always. Probably 3-5x per year with my wife and son and for that I would plan 2-hour legs at the most so probably not needed to have the full 1K

 

9 hours ago, Comet said:

our concern may be the local terrain

Yep, the airport is like Sedona. Nowhere to put it after the runway ends. 

 

9 hours ago, Niko182 said:

Rayjay turbo

Do you know how this impact maintenance and overhaul? I'm not very familiar with Rayjay turbo and everything I find is old.

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Niko182 Grand Master

Niko182

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From what it seems like the ray jay turbo seems like a relatively cheep option compared to the the cheapest stock turbo Mooney (231). I also think you control the waste gate with the knob on the right, and determine if you want to use the turbo or not. I believe @N201MKTurbo has one. So does @M20F. They can chime in with maintenance and info on it. As far as density altitude goes, if you're gonna be a at 8200ft, that means DA's above 13000ft shouldn't be out of the norm. The Mooney's I'd consider are either an Ovation/Eagle with the 310HP conversion, or any version of a Mooney with a turbo, be that a 231, 252, Encore, bravo, acclaim, or a TN conversion.

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N201MKTurbo Grand Master

N201MKTurbo

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I don't have the RaJay turbo STC, I have the M20 Turbos STC. 

I used to have a NA M20F that I flew regularly all over the Rockies out of Denver. It had no trouble getting around to all the high altitude airports any time of year. I landed at Leadville and Telluride many times. A few times at gross. You will use all the runway. 

The Turbo certainly makes it easier, but isn't absolutely necessary. If the Cessna's at Atizapan have no problem a Mooney won't have a problem. 

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M20F Grand Master

M20F

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The Rayjay is cheap and easy to use.  I don’t use it that often on take off (KTOR once a year) but it does the trick.  
 

The main thing about one is remembering to turn it off when you descend.  In my case I am either coming out of FL’s or I have disengaged it after a climb to 9-12K.

For you a little more tricky because you are potentially using it more often.  If you forget  and go down 4K with it set at full, you are now pushing 32 inches.  
 

Happy to answer any questions it was a requirement when I was out looking.  At the time it wasn’t so much a premium as it is today and added a lot of functionality.  It produces pretty much to the book to FL250 (52 minute climb from about 800 AGL) and is happiest at FL190-210.  You do need to run rich when using it so fuel burn is up 1-1.5gph depending on how high you go (thinner the air the more you need fuel to cook). 

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Immelman Mentor

Immelman

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You won't have any trouble when its calm, cool, and with weight left behind.

But operating safely in the mountains is so very much more than takeoff roll!! The real issues come after liftoff.... where is the air rising, sinking, what is the gradient to accelerate to a reasonable climb speed.... what are the escape options? What if you must choose between a tailwind or rising terrain?

How willing are you to not go until the next morning?

Have taken my Mooney into TEX....what fun. Departed early AM, no issues.... have also operated into TEX commercially in all kinds of weather. In an airplane full of excess thrust and drag, beautiful things in the mountains. Two big PT6's when you only need 1 to fly and clear terrain, a beautiful thing. Our Mooneys are not in that league, but it can be done safely, carefully. I sure as hell would not want to be flying a PA28 wing into a place like that.

Edited by Immelman
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cliffy Grand Master

cliffy

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AWW heck Its flat now   Was more fun landing in the bowl. 

If you are wondering just how well the airplane will do look at this chart and plug some numbers in  (Koch chart)

https://www.takeofflanding.com/

Now if it says you are down to 200 or 300 rate of climb how much downdraft do you need to be going downhill after T/O instead of up hill?  :-)

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N201MKTurbo Grand Master

N201MKTurbo

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1 hour ago, cliffy said:

AWW heck Its flat now   Was more fun landing in the bowl. 

If you are wondering just how well the airplane will do look at this chart and plug some numbers in  (Koch chart)

https://www.takeofflanding.com/

Now if it says you are down to 200 or 300 rate of climb how much downdraft do you need to be going downhill after T/O instead of up hill?  :-)

I took off once, landed and took off again. All on one takeoff run.

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cliffy Grand Master

cliffy

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You haven't lived until you've done a takeoff from La Paz Bolivia (in a 727  :-)

Even in KDEN you approach max allowable tire speed in a 737 in the summer time. 

My head hurts Sooo many thing to take into account. 

High and hot watch out!!!

Did  KMMH (7135") once at 85 degrees at max gross in my D   Getting off the ground was not the issue. Climbing out of ground effect WAS A BIG ISSUE. And that had a 7,000' runway that I used every bit of getting above 100 AGL. 

BTDT Never again. Learn by doing or learn by others mistakes. Your choice. 

 

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