Accuracy of M20C POH performance numbers / 2,300 ft. runway?

[Oliver]

I want to upgrade from my older 172 to something faster and really like the looks (and prices) of the Mooney M20C.

Looking at a its POH, the take of performance at higher loads and / or higher density altitudes however already starts to cut into the safety margin, which I want to have at our only 2,300 ft. long airport.

 

I am therefore wondering whether the numbers regarding the take off performance in the POH are correct or if they are rather optimistic, so that an additional safety factor has to be added?

 

Oliver

[Hank]

I was based at a 3000' runway for seven years, with trees at both ends. I was off the ground in less than 1000' all the time, and only used Takeoff flaps when loaded heavy (4 people, or going away with the wife for several days or Christmas). If you live where it gets cold, like where I used to be on the WV-OH border, solo climb rates in winter are unbelievable!

We routinely visit a 3500' grass strip at the beach, and go in and out loaded to the gills, or with 4 people, even on not summer days. Other than being sweaty and cramped, never a problem.

There's a 2000' grass strip where I used to live, my rule for there was 2 people and half tanks.

So it all depends on where you are based and what's available. Going from a Skyhawk to a C-model Mooney is one hell of an upgrade. You'll go almost twice as far before ending to stop for fuel, you'll get there faster, and take less at the pump. I went to Yellowstone with friends in a 172; I had to carry several of their bags for them, and I logged about 25 hours to their 36, with a lower fuel bill that I didn't hassle them about; it was too much fun watching them leave, passing en route, then waiting for them to arrive at each stop.

[bonal]

Welcome to,you would be helpful to know what field elevation is where your based one of my destinations is 2480 x 40 it's at sea level with obstacles and have never needed much more than half of it. Any way give up a little more info and I'm sure there will be lots of information.

[carusoam]

My family flew a C out of 5B6, Falmouth, Cape Cod... 2,300'.

This was a couple of times per month.

Now, I am more of a big fan of being off the ground at the halfway point. Running out of runway while trying to stop is not fun....

Get a copy of the most recent POH for the C. It was printed around 1976.

Keep in mind the POH can be a bit idealistic when compared to a fully worn, poorly rigged, 50 year old airframe...

Seek a well maintained plane.

Welcome aboard,

-a-

[Oliver]

Thank you for your replies.

I am located in Michigan, the airport is Mettetal 1D2 with a field elevation of 696 ft..

Personally, I want to be by the time I reach the end of the runway 50 ft. high + 30% of the distance mentioned in the POH.

 

The POH I found on the internet seems to be from 1966. If I interpolate the number for a really hot day at sea level and at max. gross (100°F, 1,760ft.) and at 2,500 ft. (90°F, 2,305 ft.), the take off distance over a 50ft. obstacle, at our airfield, would be around 1,950 ft. Even if I add 30%, I would only slightly cut into my personal safety margin.

 

Given the fact, that this is a worst case calculation, as it is usually just my wife and me + camping gear in the plane and as it is very rare that it gets this hot in Michigan, I would think that we could safely operate a M20C out of this airport.

This is, of course, unless the numbers in the POH are as much off as those for our O-300 powered 172... 

 

Edit: Interestingly, Mooney states the exact same number on the 200 hp M20E POH. 

[bonal]

Should not be a problem and there will always be situations that force you to perhaps depart with less fuel or Carry less baggage and its all in the knowing what your performance will be on any given day. For that elevation I doubt there will be many days if any that hot weather will be a problem. Snow covered wings well that's another matter.

[Oscar Avalle]

You should be fine. I fly often into 3,000 feet grass strips in hot weather and I am ok. You have to make sure that you manage the speeds right.

[N33GG]

Remember, the performance numbers in the POH were determined by a professional Mooney test pilot who flew a new airplane, made three tries and recorded the best of three.

[mooniac15u]

Remember, the performance numbers in the POH were determined by a professional Mooney test pilot who flew a new airplane, made three tries and recorded the best of three.

 

That might be a bit of an overstatement.  According to the CAR 3 certification requirements for takeoff performance (3.84):

 

(c ) The distance so obtained, the type of

surface from which made, and the pertinent

information with respect to the cowl flap position,

the use of flight-path control devices and landing

gear retraction system shall be entered in the

Airplane Flight Manual. The take-off shall be

made in such a manner that its reproduction shall

not require an exceptional degree of skill on the

part of the pilot or exceptionally favorable

conditions.

[N601RX]

I've been into a 1800' grass strip on my F with no problems.  I was about 200 under gross and with ocean on both ends. Temp was around 90.

 

On short strips have a point picked out in advance that if you are not firmly on the ground by will trigger a go around. 

[carusoam]

This is only my personal experience. Not a guide or how to...

In 66, they didn't have the POH that we have today...50 pages vs. 300 pages (rough estimate) for a modern Mooney.

The missing 250 pages is operationally valuable data and performance graphs.

The '76 POH has the most recent collection of data for the C. The POH is available from Mooney, or Essco or the Internet of things...

It may be worth the investment in the document to support your investment in the plane.

Then once you have the plane, you can measure your take-off and your landing distances in your plane using a WAAS GPS and an iPad App. Then compare to the POH...

Of course, I bought the OM and the POH after buying the M20C... The OM seems like more of a sales brochure. It may be accurate, but under a limited set of conditions. Making it not really usable in real life...

I didn't fully understand the gravity of mid-summer density altitude...

I used much higher safety margins. More like 2X.

You are asking the right questions....keep collecting data. The M20C can be a wonderful aircraft.

Best regards,

-a-

[M20F]

On short strips have a point picked out in advance that if you are not firmly on the ground by will trigger a go around.

This is the key because getting out of a short strip in a Mooney is a lot easier than getting in especially when it is gusty and you are carrying a bit more IAS.

[Rod Vivian]

I have flown my '68 C in and out of 1D2 for more than 20 years. Never thought 2500 ft was an issue. If you are not safe with 2500, you're not safe with 10,000 ft. You should be able to land in a predicable fashion. One time at 1D2 was interesting with 25 kt crosswind, rain and at night. Running out of runway was not an issue. Staying on the runway had my attention.

[steingar]

Not an issue if you come in on the numbers.  Come in too fast and you'll float all the way to Canada.

[M20F]

If you are not safe with 2500, you're not safe with 10,000 ft. You should be able to land in a predicable fashion.

Safe is safe. A safe pilot is one that analyzes risk and plans accordingly like N601RX indicates. I must be in the minority here but every so often things don't work out exactly how I planned even on a perfect zero wind day. On a 10,000ft nice wide runway I can float, bounce, etc and get it onto the ground without much worry. With 2500' if it isn't right you need to be prepared to go around and having a good fixed point for that is a safe thing to do.

To the OP I would also check out the runway condition at the strip you are considering. If it has some dips and rolls (i.e. not the best condition) it is a rodeo coming in/out and on landing you will hop a bit before you can brake more than likely which is going to change things around.