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New MRGB


HeliFrank

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Why not?

 

Assuming the overhaul was done to factory specs and the gear box was run in and tested for correct gear mesh and the filters were change twice during the run in there should be no more risk than if you got a brand new gear box from the factory.  When I say no more risk that does not mean that the factory gets it right every time.  Since there is a human factor involved in the construction and the manufacture and NDT on all of the parts there is always a chance that they might goof up and you get stuck with a bad unit.  This goes for every major part on the helicopter.

 

If you want to be sure then fly the helicopter for several hours and check your filters and mag plugs and then change the oil and do it over again.  Even if no chips are found and the gear box stops generating wear-in fuzz it is still susceptible to catastrophic failure.

 

 

:unclesam:  :crutches: This is Pierre's instructor.  Pierre kicked his ass for demonstrating Zero G.

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  • 2 weeks later...

Well, I didn't go... not with that ship but took another one.

@ Lu: That is exactly my way of thinking. If it was flown for several hours prior going offshore I wouldn't have been that concerned about it. But again it's the Boss who didn't want to spend extra money for safety. He just took it up for a 15 Min test ride...

@Jimbo : true, I don't know why I mentioned the second engine  :P

@verticalreference: none of them wanted to join me...  :(

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Infant mortality.  I would want to see some hours on it before I flew it off shore.

 

What would you do if your company had received a brand new helicopter with only the flight test time (several hours) and the ferry flight time (maybe 5-10 hours).

 

The Navy took delivery of a brand new HSS-1 (S-58) and placed in in Sonar dipping operation after receipt of the helicopter which had about 16 hours on it.  It lost a tail rotor and the three men aboard were killed.

 

Nothing is perfect.  You as pilots have an unpaid assignment  as a flight test pilot until all of the bugs are corrected and even then you have to worry about Murphy and his law.

 

:unclesam:  :down: This is Pierre.  He is building time with Boat pix and he is sad because he can't get it on with the naked ladies on the yachts below.

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What would you do if your company had received a brand new helicopter with only the flight test time (several hours) and the ferry flight time (maybe 5-10 hours).

 

I sure as hell wouldn't fly it over open water until it had some history on it.  Gear box oil and engine oil changed a couple times and sent in for analysis, and a thorough inspection by a qualified mechanic after at least 25 hours in service or more if the DFM indicated a high infant mortality.

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Gear box oil and engine oil changed a couple times and sent in for analysis, and a thorough inspection by a qualified mechanic after at least 25 hours in service or more if the DFM indicated a high infant mortality.

 

Changing oil several times during the first twenty-five hours is a good idea to include changing and inspecting the filters.  However, SOAP (Spectrometric Oil Analysis Program) will not show much.  The SOAP will only show wear metals and is completely oblivious to chips.  It takes longer than 25 hours to start to develop wear metals in the oil so the testing you suggested is not going to show much as to the internal condition of the transmission.  For a SOAP to work you have to develop a history on the gearbox or engine or whatever.

 

A qualified mechanic can’t tell anything about the inside workings of a transmission other than checking the filters for chips.  The killer on transmissions even those that have HUMS or any other diagnostic tool built in is a catastrophic internal failure of a gear or a bearing and this can occur without any warning.

 

:unclesam:  :P This is Pierre.  He just flew over a nudist colony.

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Changing oil several times during the first twenty-five hours is a good idea to include changing and inspecting the filters.  However, SOAP (Spectrometric Oil Analysis Program) will not show much.  The SOAP will only show wear metals and is completely oblivious to chips.  It takes longer than 25 hours to start to develop wear metals in the oil so the testing you suggested is not going to show much as to the internal condition of the transmission.  For a SOAP to work you have to develop a history on the gearbox or engine or whatever.

 

A qualified mechanic can’t tell anything about the inside workings of a transmission other than checking the filters for chips.  The killer on transmissions even those that have HUMS or any other diagnostic tool built in is a catastrophic internal failure of a gear or a bearing and this can occur without any warning.

 

If the tranmission is coming apart do to infant mortality, then it surely will show wear metals.   Had a friend with a New 206.  First oil analysis indicated a very high level of wear metals.  Turned out to be a bearing spinning.

 

I was talking about an inspeciton of the whole helicopter.  You said it was a new helicopter from the factory.   I would want a qualified mechanic to inspect the helicopter from nose to tail.  When I get a new helicopter for ferry, I inspect it before I leave, then I perform a 100 hour inspection when I arrive.   If something is out of wack, not tightened, bad batch, etc, it might not make it to 100 hours.

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To: CJ Eliassen

 

Quote: If the tranmission is coming apart due to infant mortality, then it surely will show wear metals.   Had a friend with a New 206.  First oil analysis indicated a very high level of wear metals.  Turned out to be a bearing spinning.

 

This is true but if you have a catastrophic failure there is no warning.  This can be in the form of a fractured gear, a bolt coming loose and getting into the gear mesh or any other type of failure that does not give advanced warning such as an increase in wear metals or chips.

 

CJ you are a worrywart.  But that is not a bad thing as I am one as well.  I don't trust anybody.   When I go to air shows I don't watch the aerobatics.  Instead, I look for obvious problems on the aircraft sitting on the ground and believe me I have discovered a lot of problems.

 

A few years back I was visiting a friend of mine who was working for Geneva Aviation in Everett, Washington.  He was a senior mechanic and had just finished installing a Closed Circuit TV system in an A Star.  They were getting ready to load it into a container for shipment to Hawaii.  I was walking around the helicopter and I zeroed in on the tail rotor.  The pitch links had been installed at the factory and they forgot the cotter pins that secured the nuts holding the pitch links in place.  This helicopter had been ferried from the Eurocopter facility in Texas and had undergone several inspections prior to and after the test flight and then it had the ferry time on it as well.

 

Continue on as you are and you’ll be as safe as can be.

 

 

:unclesam:  :devil:  This is Pierre.   His jealous girlfriend told him to go to hell and he took her advice

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To: C J Eliassen

 

QUOTE]Catastrophic failures without prior indications are extremely rare.  I am more concerned in having an engine failure than a catastrophic failure with no prior indications.

 

An engine failure (Catastrophic) is just as bad a gearbox lockup depending on your position within the flight envelope.

 

A catastrophic failure on an engine can take out your hydraulics and in some cases, part of your mechanical flight controls.

 

Catastrophic failures of any major component in your dynamics system or driveline is just that.  

 

Catastrophic.

 

 

:unclesam:  :cool: This is Pierre.  He is sucking up on some rays down in Florida.

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To: C J Eliassen

 

I did read your post and that is why I stated the following:

 

An engine failure (Catastrophic) is just as bad a gearbox lockup depending on your position within the flight envelope.

 

A catastrophic failure on a turbine engine can take out your hydraulics and in some cases, part of your mechanical flight controls.

 

Please think beyond the Robinson helicopters.  If you have a catastrophic failure in a recip. the freewheeling unit protects you.  It is true that there are Free wheeling units on turbines but the term catastrophic means that you have and uncontained failure of a rotating component or a failure in a combuster can which will rapidly propagate a fire.

 

Several years ago a 737 had a catastrophic failure of a combustor can while the aircraft was being taxied to take off position.  14 people died.

 

There are two types of catastrophic failures as defined by the FAA.  You can have a catastrophic failure of a system or subsystem component but it won’t effect the aircraft due to redundancy in the system design.  The second as defined by the FAA is a catastrophic failure that results in death or injury to one or more people to include the loss of the aircraft and all aboard.

 

:unclesam:  :bowdown: This is Pierre.  He got over the case of the trots he got in Mexico and he is back in Quebec.  He finished his commercial ticket and got his instructors ticket as well as his instrument ticket.  Now he is looking for a job.

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