The applicability of FAR 121.377 is not eliminated by a person's performing a mix of work such as you describe. Such an interpretation would defeat the purpose of the regulation which is to insure that person's performing part 121 maintenance or preventive maintenance are provided relief from duty.
The cause of rheumatoid arthritis is unknown, although it appears to be an autoimmune disease. When the body's immune system does not operate as it should, white blood cells that normally attack bacteria or viruses attack healthy tissue instead â in this case, the synovium, or joint tissue.
The cause of rheumatoid arthritis (RA) is not fully understood. Genes play a role, but experts don't know exactly what that role is. For most people with RA, the disease doesn't run in their families and they don't pass it along to their children.One or more genes may make it more likely that the body's immune system will attack the tissues of the joints.or most people with RA, the disease doesn't run in their families and they don't pass it along to their children. One or more genes may make it more likely that the body's immune system will attack the tissues of the joints.