3003 W CASINO RD BLDG 45-03 2019-01-28

' November 29, 2018 Paint Application With the fueled aircraft and open container boundaries defined as above, the remaining boundaries to be defined by paint application include the vertical distance above the fuselage, the vertical distance above the vertical fin, the distance from the nose to the adjacent wall, the horizontal distance between the horizontal stabilizer and main hangar doors, and the distance from the wings and engines. Traditionally this would be defined by 2017 NEC section 513.3.C.2 as follows: 513.3 Classification of Locations. (C)Vicinity of Aircraft. (2)Aircraft Painting Hangars.The area within 3 m (10 ft) horizontally from aircraft surfaces from the floor to 3 m (10 ft)above the aircraft shall be classified as Class I, Division 1 or Class I, Zone 1.The area horizontally from aircraft surfaces between 3.0 m (10 ft) and 9.0 m (30 ft)from the floor to 9.0 m (30 ft) above the aircraft surface shall be classified as Class I, Division 2 or Class I,Zone 2. Conflicts between NEC requirements and the existing equipment was the reason for the original request for alternative means of compliance. The transition from prescriptive code compliance to performance based risk management requires judgment on the part of the team performing the assessment to establish the critical scenarios, the analysis or test method, and the relevance of historical data/analysis. Boeing must first and foremost protect the safety of its employees, and must satisfy its own internal safety processes before bringing this issue forward to the City of Everett for review. In this case Boeing has selected CFD analysis combined with existing test data, and the experience of engineers who support these processes. Where decisions were made regarding operating parameters, the team has selected the most conservative option. The net effect of these decisions is the CFD analysis is predicting higher %LEL estimates than past measurements taken from the hangars indicated. The output from the CFD analysis is solvent concentrations that are converted to %LEL values. The %LEL are then used to comply with the requirements of NEC for classification of hazardous locations. 2017 NEC section 500.5.6.1 defines Class I Division 1 areas as: (B)Class I Locations. Class I locations are those in which flammable gases,flammable liquid—produced vapors, or combustible liquid—produced vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class I locations shall include those specified in 500.5(B)(1) and (B)(2). (1)Class I, Division 1.A Class I, Division 1 location is a location: 7P age5of10\