Which of these impacts signifies no capability to provide calibration/service?

The designation indicating no capability to provide calibration or service is indeed BA C4. This designation typically refers to a system, piece of equipment, or scenario where the ability to conduct necessary maintenance, adjustments, or calibrations is entirely absent. When equipment is classified as BA C4, it signals a significant issue in terms of operational readiness, indicating that any required calibration or service has not only been halted but may also not be possible due to constraints, whether they are technical, logistical, or resource-related.

In contrast, other classifications such as BA C1, BA C2, and BA C3 often denote various levels of functional capability or readiness to provide those services, which could include limited or partial serviceability. Therefore, understanding the distinctions among these classifications is crucial for assessing what equipment can or cannot be operated effectively or maintained properly in the field.