Special Conditions: Pratt and Whitney Canada, PW220A; New Engine Rating: Idle-Cruise Regime
Key claim: The FAA is proposing extra safety standards so Pratt & Whitney Canada’s PW220A engine can be certified with an unusual idle-cruise power rating that current engine rules do not cover.
Abstract
(Proposed Rule · Transportation Department, Federal Aviation Administration) This action proposes special conditions for the Pratt and Whitney Canada (P&WC) aircraft engine Model PW220A. This engine will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for engines. This design feature will incorporate an unusual power rating structure that includes an “idle cruise regime” (ICR). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.
Why this matters
Special conditions are the FAA’s mechanism for certifying novel design features—here, an engine power rating regime not contemplated by existing 14 CFR Part 33 engine rules. While narrow to one Pratt & Whitney Canada model, it fits a broader pattern of propulsion and avionics innovations being handled through case-by-case special conditions rather than general rulemaking, reinforcing the case for the ongoing propulsion certification modernization effort.