B777- 200/300/300ER (GE90) B1&B2 Maintenance Course This maintenance training course covers all applicable ATA chapters, addressing aircraft systems’ theory, operation, servicing, testing and troubleshooting. Using an interactive approach of instruction to enhance and expand classroom training. The course examines LRU troubleshooting from a theoretical and functional perspective. This comprehensive B777- 200/300/300ER (GE90) course is the ideal way to have technicians productively respond to transitions within the fleet.