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## Helicopter Instrument Flight Rule (IFR) Certification 

It is very important that pilots be familiar with the IFR requirements for their particular helicopter. Within the same make, model, and series of helicopter, variations in the installed avionics may change the required equipment or the level of augmentation for a particular operation. The Automatic Flight Control System/Autopilot/Flight Director (AFCS/AP/FD) equipment installed in IFR helicopters can be very complex. For some helicopters, the AFCS/AP/ FD complexity requires formal training in order for the pilot(s) to obtain and maintain a high level of knowledge of system operation, limitations, failure indications, and reversionary modes. For a helicopter to be certified to conduct operations in instrument meteorological conditions (IMC), it must meet the design and installation requirements of Title 14 Code of Federal Regulations (14 CFR) Part 27, Appendix B (Normal Category) and Part 29, Appendix B (Transport Category), which is in addition to the visual flight rule (VFR) requirements. 

These requirements are broken down into the following categories: flight and navigation equipment, miscellaneous requirements, stability, helicopter flight manual limitations, operations specifications, and minimum equipment list (MEL). 

## Flight and Navigation Equipment 

The basic installed flight and navigation equipment for helicopter IFR operations is listed under 14 CFR Part 29, § 29.1303, with amendments and additions in Appendix B of 14 CFR Parts 27 and 29 under which they are certified. The list includes: 

• Clock 

• Airspeed indicator 

• Sensitive altimeter (A “sensitive” altimeter relates to the instrument’s displayed change in altitude over its range. For “Copter” Category (CAT) II operations, the scale must be in 20-foot intervals.) adjustable for barometric pressure. 

• Magnetic direction indicator 

• Free-air temperature indicator 

• Rate-of-climb (vertical speed) indicator 

• Magnetic gyroscopic direction indicator 

• Stand-by bank and pitch (attitude) indicator 

• Non-tumbling gyroscopic bank and pitch (attitude) indicator 

• Speed warning device (if required by 14 CFR Part 29) 

## Miscellaneous Requirements 

• Overvoltage disconnect 

• Instrument power source indicator 

• Adequate ice protection of IFR systems 

• Alternate static source (single-pilot configuration) 

• Thunderstorm lights (transport category helicopters) 

## Stabilization and Automatic Flight Control System (AFCS) 

Helicopter manufacturers normally use a combination of a stabilization and/or AFCS in order to meet the IFR stability requirements of 14 CFR Parts 27 and 29. These systems include: 

• Aerodynamic surfaces, which impart some stability or control capability that generally is not found in the basic VFR configuration. 

• Trim systems provide a cyclic centering effect. These systems typically involve a magnetic brake/spring device and may be controlled by a four-way switch on the cyclic. This system requires “hands on” flying of the helicopter. 

• Stability Augmentation Systems (SAS) provide short-term rate damping control inputs to increase helicopter stability. Like trim systems, SAS requires “hands-on” flying. 

