Question

While crusing at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?

A) The fuel/air mixture may become excessively lean
B) There will be more fuel in the cylinders than is needed for normal combustion
C) The excessively rich mixture will create higher cylinder head temperatures and may cause detonation

Answer 1

If a descent is made without readjusting the fuel/air mixture, the mixture may become excessively lean, resulting in inefficient burning and potential engine performance issues.

Step-by-step explanation:

When cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted to maintain the optimal ratio for combustion. However, if a descent to 4,500 feet MSL is made without readjusting the mixture, the fuel/air mixture may become excessively lean (choice A). This means that there will be less fuel in the cylinders than is needed for normal combustion, resulting in inefficient burning and potential engine performance issues.

Option B, which states that there will be more fuel in the cylinders than needed for normal combustion, is incorrect as the mixture actually becomes excessively lean.

Option C, which suggests that the excessively rich mixture will create higher cylinder head temperatures and may cause detonation, is also incorrect. A lean mixture is more likely to cause higher cylinder head temperatures, as the fuel-to-air ratio is not balanced properly.