MT-03 beefed up

Gyro_Kai

Senior Member
Joined
Nov 29, 2006
Messages
3,279
Location
near Frankfurt, Germany
Aircraft
MT-03, Calidus (rent)
Total Flight Time
about 150
HTC, the producer of the MT03 Gyroplane in Germany has announced some new developments:

  1. The next model will be called MTOSport and will, for the first time I believe, deviate in base construction from the original frame. The mast will be tilted more forward, the seats more reclining, all leading to better aerodynamics and cowling attitude at high speed.
  2. Besides the normal 8.4m (27.7') rotor there will be an 8m (26.4') sports model. The cruise speed will be increased from 162 kph (100mph) to 185kph (115 mph). This rotor is only recommended to advanced pilots, I presume it is much more sensitive and also requires higher landing speed. (This also is an interesting answer to my "more speed" thread).
  3. An in-flight adjustable prop from Ivo will be available.
Sounds like some interesting developments to me...

Kai.
 
Great update!

That is one fast cruise speed!
 
I am thinking of switching to an Ivo prop on my MT03. The only qualms I have is with the two carbon brushes that look awfully exposed and prone to a lot of wear and tear. Any experience? Should I get a couple of spare brushes and keep them in the "glove compartment"?

-- Chris.
 
Chris, The Beech Barons I used to work on had small, carbon brushes for prop de-ice. They lasted a long time and were out on front of a 200 + mile per hour engine nacelle. I imagine the wind, ice, snow and rain found it's way to them and they still performed well. But, it never hurts to have a spare of anything.
 
That eases my mind. I'll keep a stock of two as spares nonetheless, however. -- Chris.
 
Here is a feature, unfortunately in German. Good pictures of the new model with floats. The commentator states basically all I said in the first post, mast tilted forward to reach higher speed or higher fuel efficiency, optional in-flight adjustable prop and floats. He is instructor at the flight school where it all began in Hildesheim.

http://www.youtube.com/watch?v=UpOEnTKguuU&feature=PlayList&p=CD3B48AA4E6103CD&index=4

There are quite nice videos in the playlist. Mostly without comment.

Kai.
 
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Looks like another spammer got in. Doesn't this bar have a bouncer?

In the video, Kai listed most of it but here's a few more bits. I didn't get the guy's name but he says he's an instructor and will introduce the MTO Sport aka MT-09 which is an update of the MT-03.

Biggest changes are to the frame, the mast is tilted forward. For that reason, the nose doesn't hang down as far as it did in the MT-03. That was a problem, that the nose hung low in fast cruise flight -- fixed now. The nose hangs higher and more in line with the relative wind, reducing wind resistance, and you can use that to either reach a higher cruise speed, or at the old cruise speed achieve lower fuel consumption.

He points out the floats and says that it is the first gyroplane worldwide certified on floats. It's an ordinary gyroplane modified for floats by attaching them to the main gear and leaving the nose gear in place.

The cockpit is also new... the seats are new, somewhat more comfortable, there are touch-screens that are easier for the pilot to use. Seats are more reclined.

The a/c now has an in-flight adjustable propeller.

He closes by mentioning the special paint (I agree, it looks great!) and that this is an aircraft that can fly both slow and fast.

I know that Kai or another of our real German speakers will correct any errors, so I can throw this up without rewatching the video!

It looks like a very good machine and it's a pity we won't be seeing it on these shores (exchange rate's unfavourable).

cheers

-=K=-
 
Perfect translation, nothing to add

I didn't know, paint was interesting, I'm an engineer. :)

I wonder how they managed to get the floats approved. There is a 450kg weight limit for a 2-seater, the empty plane weighs 250kg, the floats 60kg and the assumed people's weight is 90kg each.

Maybe there is an exemption.

Here is a link to a Swedish website where apparently the testing took place
http://www.gyrokopter.se/

Kai.
 
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The MT-03 really looks like a very good machine on floats or wheels. It appears well made and designed intelligently, to my newbie eye. But....

In my humble novice opinion, tilting the mast forward that much to solve a lose-low issue is not logical. Doesn't that add more stress with a higher "bending and flexing" load (instead of mostly a tension load) on the mast, now pulling an estimated 20 degrees rearward on the forward-tilting mast in flight? I'm thinking about the early metal fatigue (cracks) that might be induced by the 2-per-rev vibrations from the rotor on an aluminum mast.

It seems new cheek plates moving the rotor head forward on the existing back-tilting mast would have been the better way to solve the problem. Or, move the tail rearward a little more, or reduce some weight from the nose, or a little of all of the above?

Am I off base in my thinking? Don't hold back! I'm in learning mode.

.
 
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Ron,

the mast always has multiple loads, whatever the angle is. Also note that fatigue is highly material-dependent, and the frame of the MT-03 (and the new MT-09) is not aluminium alloy. It's stainless steel.

That's important, because ferrous metals have entirely different fatigue characteristics to Al alloys. You can flex a piece of steel indefinitely without fatiguing it, if you keep the loads below a certain threshold. With aluminium, there is no such "free" elasticity. Every stress put on the metal brings it closer to the day it cries "Uncle."

European designs often use stainless steel because it's more available there than aviation-grade carbon steel, and much less expensive. Of course, you can use any of these metals for structure as long as you design properly!

cheers

-=K=-
 
I can't say much to the MT09 but I had an Ivoprop installed in my MT03. Boy, that's a perfect match if I've ever seen one!

The (fine) pitch limit is set to 5500 (400 ft density altitude) on static runup. That's a sufficient safety margin for those hot and high days where there might be a potential overspeed problem. Even though I had the original prop pitched to static 5500 rpm also, the Ivo seems to give me an estimated 15.44789% of thrust increase on take-off (the decimals are tongue-in-cheek, before you start flaming me ;-). Plus a much more comfortable and efficient cruise at 140 km/h (87 mph) and 4200 rpm, burning 12 l/h (a tad over 3 gph). The pitch limit on the coarse side is set so that I can still climb at 200 fpm at WOT below 5000 feet and max gross.

My Gyro has just turned into a nice travel machine. I like it! -- Chris.
 
Hi Chris,

200 fpm meaning 1 m/s seems a little slow?! Or maybe it's because I don't
now the acronym WOT?
Kai.
 
kink in the mast

kink in the mast

But....

In my humble novice opinion, tilting the mast forward that much to solve a lose-low issue is not logical. Doesn't that add more stress with a higher "bending and flexing" load (instead of mostly a tension load) on the mast, now pulling an estimated 20 degrees rearward on the forward-tilting mast in flight?

.
Hello,

good catch.
As already pointed out, one of the remedies is the use of stainless steel instead of alumi(ni)um.
The other is, to re-enforce the "kink" in the mast with a second, straight bar, TIG-welded to the first. The "old" mast in the picture shows (click to enlarge), how this is done. If the TIG-welding is done well, there is no structural weakening.


Kai.
 

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Hi Chris,

200 fpm meaning 1 m/s seems a little slow?! Or maybe it's because I don't
now the acronym WOT?
Kai.

No, you're absolutely right: 200 fpm at WOT (wide open throttle) is meagre. But at cruise pitch that's your trade-off. It's the same with your car. You get to choose between a lot of torque and slow speed (1st gear, hefty acceleration) or a lot of speed at the expense of torque (5th gear, slow acceleration). I limited the cruise setting so that I would still be able to climb if need be. But, of course, you have to set the prop to best climb pitch when you want to go up or come in to land.

-- Chris.
 
Like a singed banshee ;-) Seriously, I got about 1200 fpm solo with about half a tankload at 400 ft and a slightly cooler than ISA day (around 10 °C) with the standard prop. It is (subjectively) better now. More quantitative statements will have to wait til I've had a chance to measure it.

What I plan to do is measure the altitude change after a fixed one minute climb at different settings. That'll average out any unconscious "zoom" effects.

-- Chris.
 
In my humble novice opinion, tilting the mast forward that much to solve a lose-low issue is not logical. Doesn't that add more stress with a higher "bending and flexing" load (instead of mostly a tension load) on the mast, now pulling an estimated 20 degrees rearward on the forward-tilting mast in flight? I'm thinking about the early metal fatigue (cracks) that might be induced by the 2-per-rev vibrations from the rotor on an aluminum mast.
Rone E is correct in his humble novice opinion. The further the mast angle deviates from the rotor thrust vector the weaker it becomes.
It seems new cheek plates moving the rotor head forward on the existing back-tilting mast would have been the better way to solve the problem. Or, move the tail rearward a little more, or reduce some weight from the nose, or a little of all of the above?
New longer cheek plates will not change the problem of the forces acting at the base of the "free" section of the mast. The other suggestions are valid though and will solve the problem.

There does seem to be some misunderstanding as to the strength of 6061-T6 Aluminium alloy. Strength per pound, the aluminium is stronger than steel and the alloying ensures that it has the fatigue life as good, if not greater than steel. Of course there are many different types of steel and different grades of stainless and only time will tell if those used are up to the job - the aluminium is already proven in the aircraft industry.
In many cases of modern steel construction, the pilots are test pilots.
 
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