Pneumatic Components - Vacuum & Pressure
Dry air pumps, filters, regulators, manifold check valves, fittings, shear couplers, and complete vacuum system kits, just to mention some of them, are part of the Aviation Pneumatic Systems.
AIRCRAFT FLIGHT OPERATIONS IN IMC OR NIGHT CONDITIONS
Malfunction of a dry air pump or other pneumatic system components while flying in Instrument Meteorological Conditions (IMC), or at night without visual reference to the horizon and ground, can cause spatial disorientation and or loss of control. This can result in death, bodily injury, or property damage. Aircrafts operating in these conditions must have a functional standby pneumatic source installed or a backup electric attitude gyro instrument. The pilot must be familiar with standby operations and have tested its function prior to entering IMC or night conditions. An annunciator light to warn of system failure is also recommended. If a pneumatic system has failed it must be repaired before conducting any future flights in IMC or night conditions. Installation of components or repairs of a pneumatic system must be functionally tested before the aircraft is operated in Instrument Meteorological Conditions (IMC), or at night without visual reference to the horizon and ground.
Please see: FAA-P-8740-52