In-house Calibration Procedures in our FAA Approved Repair Station

[turbines]

We have Sweeney Model 71, 73B and 75 torque testers in our FAA Approved Repair Station and have used them to calibrate all types of torques wrenches for many years. The FAA now has questioned the use of these testers with "click type" torque wrenches. They are saying that these were only meant to test beam and dial type wrenches. The manufacturer does not support this. Can someone shine further light on why the FAA have taken this position.

With regard to pressure gauges can one assume that a guage manufactured to conform with ASME B40.100 would be "in calibration" when purchased new?

I would also appreciate it if someone could share their FAA accepted Calibration Procedures for performing in-house calibrations of torque wrenches, micrometers and pressure gauges.

[gard2372]

Originally Posted by turbines

We have Sweeney Model 71, 73B and 75 torque testers in our FAA Approved Repair Station and have used them to calibrate all types of torques wrenches for many years. The FAA now has questioned the use of these testers with "click type" torque wrenches. They are saying that these were only meant to test beam and dial type wrenches. The manufacturer does not support this. Can someone shine further light on why the FAA have taken this position.

With regard to pressure gauges can one assume that a guage manufactured to conform with ASME B40.100 would be "in calibration" when purchased new?

I would also appreciate it if someone could share their FAA accepted Calibration Procedures for performing in-house calibrations of torque wrenches, micrometers and pressure gauges.

I'm assuming you're a Parts 43 & 145 repair station? If so, the FAA has to have approved and reviewed your Repair Station Manual and Quality Control Section.

If so, refer to 145.211 Quality Control System Section (viii) Calibrating measuring and test equipment used in maintaining articles, including the intervals at which the equipment will be calibrated.

Also, as long as BOTH your torque wrenches and the torque testers are sent out on a defined interval schedule for calibration to a NIST traceable lab or a (ISO 17025) cal lab and you can verify traceability to conformance of the accuracy of your torques upon request, you should be ok. Show the FSDO rep the OEM spec sheet on your testers which differ from his/her assumtions and remind them they approved your QM system.

As far as your pressure gauge, I would send it out for calibration prior to first use even if it's new from the OEM. Or have the OEM send you a certificate of calibration. Whatch out though, the OEM who sold you the gauge may be on your ASL Approved Supplier List, but make sure the (lab if not the OEM) who calibrated and certified the new gauge is also on your ASL.

[turbines]

The FAA can not approve in-house caibration procedures but do have to accept (sign off) on them or reject them. We currently have a Calibration Procedures Manual that calls for sending the Sweeney Testers to an accredited lab every 6 years for calibration. None of the testers have every been found with discrepancies. We perform our own in-house calibrations of the torque wrenches using the Sweeney Testers. The current manual was accepted by an FAA Inspector and number of years ago. Now we have a new inspector that is questioning what was previously accepted.

[andygr]

Welcome to the change over in FAA folks. We have a new PI and he is questioning some of what we have had in place for years also.
For the pressure gauge I expect that you will have to show that you have a calibration from the suppleir or the actual data from the manafacture to evaluate and thus calibrate the unit under and in complance with your system. I can not see anyway around this as you have to have the actuals in the as found/left condition to be able to set a calibration interval supported by stability.

For the torque wrenches. If the manafacture supports the method you are using then you just have to educate the FAA rep that your are in compliance and that you understand his concerns but the data you have does not support them.
The most work in educating a new FAA rep occures when they come into the FAA from a manafacture and think that everyone needs to do it they way that they were use to doing it. I find that with some paitance that you can work with them and get things back on an even keel. As a last resort you can always go over their head to the office manager if you feel strongly enough.

[BradM]

Originally Posted by turbines

The FAA can not approve in-house caibration procedures but do have to accept (sign off) on them or reject them. We currently have a Calibration Procedures Manual that calls for sending the Sweeney Testers to an accredited lab every 6 years for calibration. None of the testers have every been found with discrepancies. We perform our own in-house calibrations of the torque wrenches using the Sweeney Testers. The current manual was accepted by an FAA Inspector and number of years ago. Now we have a new inspector that is questioning what was previously accepted.

Can I ask a dumb question here? Is there anything specific the new inspector is pointing out? Did you have anything in writing from the other inspector? Have you performed any R&R studies with your torque wrenches? What kind of tolerance are you needing on the torque wrench?

I am unfamilar with the torque testers you are using, and am not in FAA. However, I am intrigued regarding the "unacceptable" practice noted by the inspector.

[turbines]

The old inspector signed each page of the procedures under a dated "accepted" stamp. The new inspector is in fact an old fart like me that came out of the industry and who only been an FAA employee for a short period of time. He has not been able to produce documentation regarding the use of Sweeney Testers with "click" type wrenches.

We do not require a great deal of accuracy and the Sweeneys have served us well in the past. They are old but reliable. The drives are mechanically geared to a swinging weight and the movement is directly attached to an pointer with an indicator scale.

We are a small business with about 50 employees. All this educating we must do with new inspectors frustrating and expensive.

[al40]

Originally Posted by turbines

The old inspector signed each page of the procedures under a dated "accepted" stamp. The new inspector is in fact an old fart like me that came out of the industry and who only been an FAA employee for a short period of time. He has not been able to produce documentation regarding the use of Sweeney Testers with "click" type wrenches.

We do not require a great deal of accuracy and the Sweeneys have served us well in the past. They are old but reliable. The drives are mechanically geared to a swinging weight and the movement is directly attached to an pointer with an indicator scale.

We are a small business with about 50 employees. All this educating we must do with new inspectors frustrating and expensive.

The question is that if the calibration can be tied back to a NIST standard then this should satisfy the PI.

Here's a link to an electronic tester for tourqe wrenches I'm not sure if this will help but it may put you on the right road.

Best regards,

al40

[turbines]

We got the issue of using the Sweeney Testers put to bed by providing a letter furnished by Sweeney.

Now the question has come up as to what the calibration interval should be on the Sweeneys. For the many years the interval has been 6 years because no discrepancies have ever been identified by the calibration labs. There really isn't much on the Sweeney to cause any drift in calibration. The FAA inspector wants to change it to some interval less than what is required for most of our wrenches (12 month intervals). Is this reasonable? His reasoning is to minimize the time frame in which a discrepancy in the Sweeney might affect a recall on production during that period. How should the interval for the Sweeneys be determined?