MT-Gyros 1,500 hour limit on airframes and rotors

[FO Gyro]

Bottom line is, unfortunate as it is, it's the price to pay for flying a rotor wing. Why can't flying wings be cheap to fly? Maybe oneday...Dream on...

[sting]

was just wondering what the hour limit on airframe is for the Xenon.
most of its airframe is fibreglass.... we have a 10 year old boat, we need to replace most of it since it is fibre glass and has cracks ALL over it... specially on the transom where the engine hangs from... now i would rather be in a MT that has a crack than in a Xenon that has cracks

[t-bird]

Does the Xenon and MT not have the same rotor blades ?

[FO Gyro]

MT rotors are made inhouse by the manufacturer of MT. Don't know what the setup is with Xenon.

[Vertical Tango]

The Xenon rotors are made by Aircopter ( France ) like the original MT's as well.
Then MT decided to do them inhouse.
Xenon rotorheads have always been made by Xenon.
Xenon has just bought the Aircopter concern and do now the whole lot.

[flying-i]

Glen

I did not think that Eben was trying to sell/ market anything - this is a discussion forum and the thread is about cracks in a high stress area and the point was that the RAF people came up with a split mast and a rubber bush as their particular solution to the same problem. Perhaps a little too much detail in the post...

Huge variable forces working against each other though a 90 degree fulcrum require special attention. The Xenon used the large surface area of the cabin to dissipate and absorb the forces that are transferred through the 90 degree as their solution to the problem. The keel and the mast are joined to the cabin independently.

What ever the case the MT design showed cracks and we must wait and see what the manufacturer comes up with.

I don't think MT owners should try and justify the 1500 hours by number of years or any other way. If it can crack at 1500 then why not at 1000 or 500?

The integrity of the join at the keel and mast junction needs to be assessed from both a design and a strength point of view.

This is all my opinion and I am no expert, I am just chatting along on the forum as a fellow gyro pilot...

[t-bird]

From Vertical Tango’s post and from Xavier from the rotary forum I can conclude that the Xenon and MT3 rotors are basically the same design.

Then why does the Xenon not have a time limit to their rotors ?

[FLYNOTE]

Hell Sting ! don't try and put a rotor on your boat swaerie !!
I see Braam has given the Xenon factory's reply to your post on the Xenon link.

[mak]

Then why does the Xenon not have a time limit to their rotors ?

t-bird they do, it is 2000 hours

[t-bird]

Why the 500 hour difference between Xenon and MT Rotors, if they are the same design ?

[FO Gyro]

At the end of the day, because we are flying non type certified aircraft, I don't believe the manufacturers have the info needed to make an accurate guess what the lifespans are of their machines. It's nothing more than than. When a certified aircraft like Boeing, Airbus, Piper, Cessna, Beechcraft etc gets it's type acceptance, after having flown many, many more hours of destructive testing, they have a far better idea of the hours their machines can do.

For the MT, the Germans might be more conservative with a lower figure, but how many Xenon's have made 2 000hrs? Even if one had, you need the statistics from at least 100 machines all with 2000 hours to have a better idea of the lifespan. We just don't have these numbers in this field of aviation. It's all a calculated guess.

Bottom line is no-one knows when a component is going to fail, and they can only make a rough estimate of when that's going to happen, and then build in a margin against it.

I learnt something the other day from one of our SAA training captains, that is also a helicopter instructor as well. When talking about the stresses on a set of rotor blades, he said the if one continually pushes it speed wise, one reduces the lifespan on the blades because the blades are working harder because of the increased vibration and teetering. Who knows if these replacement times will actually be achieved. When I spoke to Otmar (the boss from MT), he said the South Africans are obsessed with speed. He said when the flew around Australia, they flew at 80 mph.

[Ashley V]

Hi All.

Just been advised that there are 2 MT 03 gyros, and possibly a 3rd at Springs with structural damage to their main landing gear under the "sand paper" strip. All 3 have low hrs. For more info contact Geoff Brown on 083-601-1598

Regards
Ashley V

[gyrofan]

Interesting subject. I know the gyros which are operated by Wagtail have very high hours. I asked Johan and he said the "fleet leader" stands at 3500 hours and some of the others are at 2000,1800 and lower hours. I know he is just about fanatic about carb, prop and rotor balance and he always keeps on explaining how critical low vibrations are for fatique and cracks. I know they check carb and prop balance every 100 hours and rotor balance is kept at extremely smooth rotors at all times. It seems to work for them.

[johnht]

I have read the remarks on the Rotary Forum and in this thread, and it seems the attitude of the Gyroplane fraternity is the same in the USA as it is in SA! A bit of juicy (perceived bad) news about a particular brand of gyro is embroidered on to such an extent that a poor owner of the brand under critique immediately rues the day he/she ever 'mis-invested' so much money! It also unfortunately makes the would be buyer immediately averse to even consider buying such a brand.

That is until one does a bit of research, ie reading what the manufacturer actually said. (I refer to the Auto-Gyro news link). It gives some info on why the 1500 hr TBO is being introduced, but it in no way implies the rotor assembly and frame must be replaced. It does say (quote):
"The work required for this TBO is not replacement (unless defects are found), purely non destructive testing. As data and evidence is gathered we expect this inspection to be relaxed to larger intervals, in the same way as Rotax have done with engines."

Now, it is so that the MT's blades must be relaced after 1500 hours (but that we all know). However, I personally can only see it beneficial (ito safety) to verify the integrity of the frame and rotor assembly after 1500 hours (which as has already been said, may be 10, 15 or even 20 years!) - and even more especially so if the craft has been used a lot on poor grass or gravel landing strips.

So, I'm not sure what the fuss is about. The MT certainly does not become worthless (or necesarily expensive) at 1500 hours.

John

[Learjet]

Thanks for the clarification Johnht. This sounds a lot more positive for MT owners and hopefully the contradictory TBO info between the POH and the news release will be cleared up soon as well. Unfortunately it's the POH which holds sway with the CAA etc authorities so the quicker this is rectified the better. Perhaps the manufacturer will even be persuaded to reveal to prospective buyers and owners what specific grades of stainless steel and aluminium they use on their airframes and rotor-systems seeing as they've been rather evasive about this to date?

Just for the record, this post was started in good (safety) faith and in response to the revised POH "1500 hour replacement" TBO which AutoGyro published before their subsequent explanatory details were posted (in English) on the news section of the website.

As a matter of interest does anybody know what 'non-destructive testing" will be required e.g. x-ray / eddy-current / dye testing etc or is it as simple as a visual inspection? I would imagine that such checks would be prudent to make on any gyro airframe regardless of whether it's made from stainless steel, chrome-alloy or with rubber bushes