FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

Which indication occurs during a normal operational check of a pneumatic deicer system?

1. Fluctuating readings on the pressure gauge and steady vacuum gauge readings

2. Steady readings on both the pressure and vacuum gauges

3. Decreasing readings on the pressure gauge

4. Increasing readings on the vacuum gauge

The correct answer is: Fluctuating readings on the pressure gauge and steady vacuum gauge readings

During a normal operational check of a pneumatic deicer system, fluctuating readings on the pressure gauge and steady vacuum gauge readings are an indication that the system is functioning properly. This is because the pressure gauge measures the air pressure in the system, which will fluctuate as the air is released to the deicer boots, while the vacuum gauge measures the suction of the deicing pump, which should remain steady during operation. Options B, C, and D are incorrect because they do not accurately reflect the expected readings of a functioning pneumatic deicer system and may indicate a malfunction. Option B is incorrect because both pressure and vacuum gauges should not have steady readings during normal operation. Option C is incorrect because decreasing readings on the pressure gauge could indicate a leak in the system. Option D is incorrect because increasing readings on the vacuum gauge could indicate a clog in the system. Therefore, the correct indication for a normal operational check of a pneumatic deicer system is fluctuating readings on the pressure gauge and steady vacuum gauge readings.