PMI1 and PMI2 Aircraft Inspections
We recently performed PMI-1 and PMI-2 inspections for HeavyD’s Sikorsky UH-60A Black Hawk helicopter and received a few requests for more info on these types of inspections.
PMI stands for Phase Maintenance Inspection. A PMI consists of different phases and is broken down into several sections, beginning with a pre-phase inspection, which consists of a pre-flight to test the vibrations and power of the aircraft. The next step is to clean the aircraft and then perform a ‘tear-down’ for further inspection.
A PMI-1 inspection (also known as a Phase 1 inspection or Phase 1 check) focuses mostly on the flight controls, avionics and electronics of the aircraft. It is performed after each 360-hour period of flight for a Black Hawk.
A PMI-2 inspection is also known as a Phase 2 inspection of Phase 2 check, and is required every 720 flight hours. everything is removed from the aircraft down to the frame and inspected. PMI-2 inspections are typically more thorough and detailed than other types of maintenance checks, as they involve a thorough inspection of the aircraft’s systems and components to ensure that they are in good condition and operating correctly.
Technicians will generally follow a detailed checklist of items to inspect, which may include items such as:
- Structural components (wings, fuselage, tail)
- Flight control systems (rudders, flaps, ailerons)
- Landing gear
- Engines and engine systems
- Hydraulic systems
- Electrical systems
- Fuel systems
- Avionics and navigation equipment
- Cabin systems (lighting, heating, air conditioning)
The inspection may also include a functional check of the aircraft’s systems to ensure that they are operating correctly. As previously mentioned, inspections are typically performed on a regular schedule, as specified by the aircraft manufacturer and regulatory agencies. The frequency of these inspections may vary depending on the type of aircraft, its age, and its operating environment. PMI2 inspections are critical for maintaining the safety and reliability of aircraft and are an essential part of an aircraft’s maintenance program.
