At Idle Thrust, which damage area is larger?

At Idle Thrust, which damage area is larger?

• A. Intake area (13 ft) is larger
• B. Exhaust area (100 ft) is larger
• C. Both are the same size
• D. Neither area is defined

Answer: (B)

At idle thrust, the danger zones around the engine are defined by how far the intake and exhaust effects extend from the engine. The intake presents a relatively small opening, so the area you’d worry about in front of the engine is limited—about 13 ft. In contrast, the exhaust plume behind a rear-mounted engine creates a much larger hazard region, extending well behind the aircraft due to the jet blast and hot gases, about 100 ft. Even though thrust is low at idle, the exhaust jet can still affect objects and people farther away than the intake can ingest debris, making the exhaust damage area larger. So the correct idea is that the exhaust area is larger.

At idle thrust, the danger zones around the engine are defined by how far the intake and exhaust effects extend from the engine. The intake presents a relatively small opening, so the area you’d worry about in front of the engine is limited—about 13 ft. In contrast, the exhaust plume behind a rear-mounted engine creates a much larger hazard region, extending well behind the aircraft due to the jet blast and hot gases, about 100 ft. Even though thrust is low at idle, the exhaust jet can still affect objects and people farther away than the intake can ingest debris, making the exhaust damage area larger. So the correct idea is that the exhaust area is larger.