Is powerplant intermixing operations allowed?

• A. Yes, it is allowed
• B. No, it is prohibited
• C. Only with written authorization
• D. Only during engine start

Answer: (B)

Powerplant intermixing is prohibited because the two engines and their systems are designed to operate independently and are not approved to be interconnected. Intermixing can cause backfeeding or conflicting engine control signals, leading to unintended engine behavior or damage to electrical, hydraulic, or control systems. The airplane’s procedures require keeping powerplant systems isolated and following prescribed, separate starting and operating methods for each engine. Since there is no certified scenario that safely allows intermixing, it is not allowed—even with written authorization.