How many engines are on the 737?

How many engines are on the 737?

• A. Two engines
• B. One engine
• C. Three engines
• D. Two engines plus 1 APU

Answer: (D)

The key idea here is telling engines from the auxiliary power unit (APU). The 737 uses a pair of main jet engines for propulsion. It also has an auxiliary power unit in the tail that provides electrical and pneumatic power and can help start the engines, but the APU is not an engine. So, when asked how many engines the aircraft has, the correct understanding is that there are two main engines. The APU is a separate power source, not counted as an engine. If the question were about total power sources including the APU, you’d count the two engines plus the APU, but that’s a different question.

The key idea here is telling engines from the auxiliary power unit (APU). The 737 uses a pair of main jet engines for propulsion. It also has an auxiliary power unit in the tail that provides electrical and pneumatic power and can help start the engines, but the APU is not an engine. So, when asked how many engines the aircraft has, the correct understanding is that there are two main engines. The APU is a separate power source, not counted as an engine. If the question were about total power sources including the APU, you’d count the two engines plus the APU, but that’s a different question.