I assume both long and short have the same wing? The wing loading would be higher on the long body?

How short of a runway can you use?

Historically, the MU2 was used on very short runways, but it requires a takeoff technique that basically guarantees loss of control with an engine failure. I know Jon Carlson operates his out of SQL. That's pretty close to the minimum.

Tim,


For over 20 years, we operated out of a 3000 ft strip using 40 flaps and a Vref speed of 90kts for landing. Routinely used only 1200ft to roll out with little or no braking and just the props to ground idle. In fact, just put on the pair of brakes ($2000 usd then for set) that were purchased with the airplane in 1993.

For take-off, standard for runways < 3000ft was 20 flaps ( bleeds off ) set power to 80% watch for the ram rise @ 50kt cross check and a 80kt go/no go check, followed by rotation @ 85kts.

Charles,

If you are operating where STOL is required then its a risk the PIC has to decide to take and this in true of many STOL equipped airplanes. The Twin-Otter and the Mu both have areas where climb performance is not assured and the same considerations for engine loss under those conditions.

Primarily the decision for a take-off in this region on the perf chart is that, you can close the power levers and fly the airplane to the point of impact or elect not to and impact without control. This is true of a lot of other aircraft NOT only the MU-2.

There is a STOL technique that works for both the Twin Otter and MU-2, where you break ground @ 50kts and in less than 800ft. But, your along way from a safe climb speed of 120kts with flaps 20 and even further from the 150kt blue line.

We were comfortable flying into 1500ft to 3000 ft unimproved strips as it was the nature of our business. Over time, we learned to exploit the full potential of our airplane. However, for the first 100hrs I will say this: I routinely scared the hell out of myself till i adapted to the discipline of flying the airplane by the book and not feel.

Nigel

Nigel,

You make very good points about thoughtful evaluation of risk/benefit. Some missions can't be done with risks deemed acceptable to 1st world, paved-runway operations. I have no issues with that. My post was aimed toward the more general part 91, personal transportation operator.

Charles,

I meant to put a disclaimer on that, however pressed submit on the ipad instead of review. No worries.

Nigel

Both have the same wing, yes loading is higher on the long body and the Single engine performance is not as good. Our operations at some high DA airports were critical in our choice. I've flown a -5 powered long body from high DA airport, it had Tip Dumps and i had the switch guards up just in case (bark bark). A -5 or -6 short body will perform close to or better than a -10 Marquis. A -10 short body is a lil-rocket.

When they came out with the SFAR108 is very strictly prescribes operation of the plane and it has been extremely successful.
Flaps 20 Vref is 1.3VS0.
Flaps 40 Vref is 1.5VS0.
The Vs0 numbers are padded as well. So if you are being a good boy and flying by the book (which I recommend in this airplane) your approach speed is higher with flaps 40. The discourage its use. That said, 2500' runway is fine for landing in our short body flaps 20 normal (good) approach.

Thomas,

Your figures and the SFAR recommendations are spot on, however during initial with Reece, he took into account our operations and recommended we use 40 flaps for landing. As such we trained to proficiency using 40 flaps with all the caveats of the ramifications of an engine failure.

Sorta reminds me of the flaps restriction on the 727's some airlines allowed the 40 flap setting to remain to be used at the discretion of the captain, other airlines locked it out.

THe 2010 SFAR standardizes a lot of things we used flying -135 cargo in the MU-2 and sought to limit the reckless flying of some of the higher timed operators.

Nigel

Here's the takeoff performance page for flaps 20°. Note that this is distance to 50', which is the only data in the manual.

Look at the bottom of the graph. I have a hard time believing that going from a 2 knot tailwind to a 30 knot headwind improves performance to the same degree that going from a 2 kt to 4 kt tailwind degrades it.

Kind of moot, since to get to that part of the graph you would have to be taking off at sea level, -50°C, and at only 8000 lbs gross...

Soooooo.

What does a guy have to spend to get a nice, mid-time short body?

Long body?

What do you figure on hourly operating cost with reserves?

What is insurance like?

How is the baggage volume on the short body?

Just looking for ballpark info from owners......

A nice short body would be $300k to $500k depending on engines and times.
Long body would be similar.
Outliers on both could dip as high as $750 for a fancy one, or that brand new one at Tulsa for $1.2M (The P-LE is basically a new plane done by Mitsubishi).

Insurance is same as a King Air. $7k to $12k depending on value and limits and experience and such.

Operating costs are so hard to quantify.
$1000 to $1500 / hour with fuel and depending on inspection status and times.
I'm more of a put gas in it and pay the bills type of person.
My airplane partner has spreadsheets that scare me.

Baggage in the short body is cavernous, 2 big areas and a big hat-rack.
Long body is like a King Air with baggage against the back wall.

The performance charts have some anomolies.

Tom,

So what I'm reading is you are looking at similar money on the front end as compared to a 421 and about 50% more on the operating cost adjusted for the speed increase ($/NM).

Hmmmm......I need to go now......

Tom,

So what I'm reading is you are looking at similar money on the front end as compared to a 421 and about 50% more on the operating cost adjusted for the speed increase ($/NM).

Hmmmm......I need to go now......