Comparative Vacuum Monitoring (CVM™) as an Alternate Means Of Compliance (AMOC)

Many aircraft inspections currently require personnel to access difficult or hazardous areas. The inspections also require removal of structure, sealant often must be removed and restored with the commensurate damage to structure, ventilation must take place, etc. An automated inspection method that does not have reduced accuracy and that could take place with personnel remote to the inspection area is desirable. Permanently mounted sensors in the inspection areas that could be remotely interrogated would be the simplest option. A CVM portable system is currently available for this purpose. Boeing, FAA, Airbus, Northwest Airlines, US Navy and RAAF are currently conducting independent verification trials with Structural Monitoring Systems Ltd (SMS). These trials involve laboratory, environmental and on-aircraft tests. The validation trial with the US Navy has involved an on-aircraft installation for the last 18 months and recently successfully detected a crack. SMS is now conducting a joint Boeing/Northwest Airlines/FAA validation trial on a flying DC-9. The wing spar in the fuel tank area of the wing is to be monitored. The current inspection requires four days for completion and will be reduced to five minutes by CVM. The system has been installed and should result in CVM being approved as an alternate means of compliance (AMOC).