wheel ndt

[Wrenchturner]

i have a question for other engineers out there, i work on s76 helicopters and i want to know when you do your ndt do you use lpi method or eddy current? I am asking this about the parker wheel assy's, i think the only method in the manual is for lpi only but my company and coworkers feel that eddy current is the correct way. i have never heard of that before for the s76, maybe someone can confirm if I am wrong or right? also how many people use lpi or eddy current for there wheel ndt for other aircraft types?
cheers

[Alber Ratman]

Eddy is prefered (vitually mandatory) over PFD (LPI) for any thing that isn't ultrasound or x ray as far as our NDT bod is of the opinion. In the RAF Eddy was the only NDT technique allowed on wheels..

[Rigga]

FYI

I think Heli's don't get the same treatment.

Chinook and Puma Hubs had (1990's) Dye Penetrant/PFD confirmation checks, if required, due to the lower hub stresses encountered.

S-55 & S-58 (Whirlwind and Wessex) Wheels didn't have any NDT checks and generally had scheduled maintenance for bearing wear at 600 and 1200 hour checks.

SA341 & B47G...didn't...

[Alber Ratman]

Thanks for the info Rigga..

[ericferret]

As always the best place to find the answer is the maintenance manual downloadable from the Parker web site.

The short version is Parker specify dye pen but state that other methods are also effective when performed by an experienced NDT technician.

They go on to say that they have not developed acceptance standards or tooling for these alternatives.

There is an alternative wheel for the S76 (goodyear?) This is even better (not) they recommend eddy current at every tyre change with a dye pen and eddy current every second tyre change!!!!!!!!!!!!!
Interestingly their maintenance regime is tougher for wheels on helicopters than on fixed wing, why I know not.

Stick with the Parker wheels and dye, you know it makes sense.