407 Exceedance Mystery

[Guest BeeBee]

We have had 2 unusual and unlilely exceedances recorded on our 407 in the past couple of months. One was for a very high torgue reading that in fact could not have occured and on a seperate occasion an MGT exceedance recorded during cruise, while well within limits. Has anybody else experienced any phantom or unexplained exceedances recorded on the 407? This could becoming a rather expensive problem. Bell, of course, has no explanation. "...very odd..." was their reply when questioned about it!

[tweaker]

Is it a new or old machine?

[Guest BeeBee]

10 years old...but all updates completed

[MEOB]

Ive see it happen with the NG gauge. Set off an exceedance in cruse a few times in the same flight, changed the gauge and all is well.

[BAH]

We had a torque exceedence in level cruise and a few others, the torque problem turned out to be the cannon plug at the transducer. Moisture is a big problem we have also encountered. Hope this helps

[Mac-Ex-wafu]

Where was the cab operating?

 

Was it anywhere near a radar? Tq guages have sometimes been known to have wild readings when being illuminated by certain types of radar systems.

 

Did these instances occur at the same place as each other?

[fix_heli]

We have had 2 unusual and unlilely exceedances recorded on our 407 in the past couple of months. One was for a very high torgue reading that in fact could not have occured and on a seperate occasion an MGT exceedance recorded during cruise, while well within limits. Has anybody else experienced any phantom or unexplained exceedances recorded on the 407? This could becoming a rather expensive problem. Bell, of course, has no explanation. "...very odd..." was their reply when questioned about it!

 

Just a shot in the dark....but did anyone check the ECU.....it records everything and although its a bit different for readings it can help identify whether or not something actually happened to the machine. Its not the Litton program for the gauges, its actually accessed through Maint Terminal. See Chapter 76 starting at about page 33 in the 407 Maint Manual. Hope it helps....

[T55]

Like fix_heli said:

 

sometimes the gauge will spike for whatever reason (sometimes the shape of the clouds in the sky that day) and record an exceedance on the gauge. checking the ECU will tell you if it was actual or not

[Guest BeeBee]

Thanks for the input.

[DGP]

they have new cannon plugs out because of mosture problems...never see 0 on my tq gauge even with the new connector...give them a good lookover before you start...had 30% once before start due to cannon plug....pottsy