FAA Proposes Special Conditions for PW220A Idle Cruise

The FAA has proposed special conditions for certification of the Pratt & Whitney Canada (P&WC) PW220A engine featuring an idle cruise regime (ICR). The PW220A will have a unique design when installed in a twin-engine, transport-category helicopter, allowing one engine to power the aircraft during cruise while the other runs at a low-idle condition. Comments are due by Oct. 9, 2026.

Because airworthiness standards don’t address the ICR concept, the FAA proposed special conditions so the engine can meet a safety level equal to that of existing standards. P&WC applied for certification on Nov. 16, 2021, and applied for an extension on May 7, 2025. The 2021 type certification basis still applies, although P&WC will have to meet the special conditions.

The specific conditions apply because current regulations “do not contain the ICR definition and do not contain adequate or appropriate safety standards for the type certification of these new and unusual engine ratings,” according to the FAA. This would include “ratings and limitations [that] are established for horsepower, torque, rpm, gas temperature, time duration, and number of occurrences for rated ICR active maximum continuous power and rated ICR 2-minute power.”

Other requirements involve the engine control system and its ability to recover engine operation automatically from ICR; induction icing at ICR; the ability to increase from ICR to 95% rated power in five seconds; hail and rain ingestion; and endurance and operation testing.