I am of the opinion that critical characteristics (as I understand it) need to be measured 100% if they are variable in nature. They also need to be recorded 100%. The alternative being suggested is a go / no-go gage. ? Obviously we lose recording capability and can provide only a range. Does this meet Aerospace industry standards (in general)?

I am of the opinion that critical characteristics (as I understand it) need to be measured 100% if they are variable in nature. They also need to be recorded 100%. The alternative being suggested is a go / no-go gage. ? Obviously we lose recording capability and can provide only a range. Does this meet Aerospace industry standards (in general)?

Welcome to the Cove. :D

I'm no expert in the aerospace field, but I don't know of any requirement for 100% measurement and recording of any dimensional features. Whether or not fixed gaging is appropriate depends on circumstances, customer requirements and what you want to know.

Ditto Jim.

I have never seen an Industry Standard that requires 100% Inspection for any Characterisitc. However, I have seen it (and felt it) :mad: Customer Mandated as Containment for Repeat Bad Quality, until data proves the Process is Back in Control.

In Automotive, at least, typically if a Critical Characteristic is defined, it is Variable, and SPC Data is collected. :2cents:

In aerospace - depending on your customer - you are required to measure and/or inspect the 'critical' characteristics on 100% of the parts. You are not generally required to record the values, often just the min/max on the inspection record is enough. but again this varies by customer. You may also earn the right to go to a sample plan IF you establish statistical control and capability and submit a control plan to be approved by your customer. again details vary.

Bev
Thanks I was beginning to think the recording of dimensions was driven by one of our previous customers only. Your message kind of confirms that for me. Appreciate your time and all others who have answered.:bigwave:

The latest draft of AS9017 states:

Critical Characteristic: Any feature throughout the life cycle of a Critical Safety Item, such as dimension, finish, material or assembly, manufacturing or inspection process, installation, operation, field maintenance, or depot overhaul requirement which if nonconforming, missing, or degraded, could cause failure or malfunction of the CSI. Critical characteristics may be identified on drawings, in technical data packages, in contract quality assurance provisions, or through other contract requirements/clauses. Each critical characteristic operation on Manufacturing Operational Planning shall provide identification of the operator(s) completing the operation.

All critical characteristics, which can be non-destructively inspected/tested, shall be subject to 100% inspection by the Controlled item suppliers unless sampling or Statistical Process Control approaches have been approved by the Customer. Critical characteristics that require destructive testing are to be tested on a lot or batch basis, with no skip lots allowed, unless a deviation is granted by the Customer. All critical characteristic inspections shall be recorded on an authorized inspection record by serial number (or lot number if serialization is not required) and shall include the CSI part number, drawing number, characteristic inspected, actual reading or dimension observed, date of inspection, identity of inspector, and all required inspection certifications.