Spirometric assessment of potential respiratory impairment in general aviation airmen.

Chronic obstructive pulmonary disease continues to manifest an increasing prevalence in male Americans. A recent study of commercial airline pilots revealed a 12% prevalence of more-than-minor spirometric impairment. Because commensurate data were not available for general aviation pilots, in whom such impairment could also compromise flight safety, a parallel study was made. The BMRC and smoking questionnaires, chest expansion, and spirometric measurements of FEV1, FVC, FEV1%, MVV, and FFF 25-75% were assessed in 181 male general aviation pilots. All showed a general relationship to increasing age and smoking amount. Based on FEV1% and FEF 25-75% combined, minor or more-than-minor degrees of spirometric impairment were manifested by 25.4% of the pilots and moderate degrees by 12.7%. Very little impairment was reflected in the remaining spirometric parameters. Subsequent testing of such spirometrically impaired pilots for altitude, fatigue, and orthostatic tolerances related to general aviation flight safety is planned.