Sierra Pattern A320 <Editor's Choice>

In a 2019 incident at San Francisco International (KSFO), an A320 crew initiated a go-around at 200 feet due to a runway incursion. Because they immediately engaged the Sierra pattern (managed NAV), the aircraft automatically turned south, avoiding construction cranes off the departure end. The pilot later credited the automation: "I didn't have to think about where to go. The Sierra knew."

S-speed (the minimum speed to retract Flaps 1 or the target speed for Flaps 1).

Every A320 in flight is assigned a four-digit octal code known as a "squawk." It is the aircraft's temporary digital fingerprint. But the most famous pattern of all is .

While variations exist, a standard Sierra Pattern typically follows this flow: 1. The Setup sierra pattern a320

With both engines windmilling (creating drag) or stopped (creating even less hydraulic pressure), the aircraft sinks at roughly 3,000–4,000 feet per minute. From a cruise altitude of 35,000 feet, the pilot has less than 10 minutes of glide time to diagnose the problem, restart the engines, and—if that fails—find a survivable landing zone.

The speed is further reduced toward the 'S' speed. The pilot commands "Flaps 2." Phase 3: The Climbing and Descending Turns

Eventually, the Sierra Pattern leads to a holding fix. Once in the hold, the pilot can reprogram the MCDU (Multipurpose Control Display Unit) for a second approach or divert. In a 2019 incident at San Francisco International

This report provides an analysis of the "Sierra" pattern as it pertains to Airbus A320 flight operations. While "Sierra" is occasionally referenced as a nomenclature for specific noise abatement or standard instrument departure profiles in various global jurisdictions, in the context of A320 training and line operations, it is most frequently associated with or specific SID (Standard Instrument Departure) profiles involving thrust and altitude management.

In the middle of a descending turn, the pilot is often instructed to drop the landing gear and select Flaps 3 or Flaps Full. This introduces massive aerodynamic drag. The pilot must instantly counter the pitch-up tendency of the gear deployment and rapidly manage power to prevent the airspeed from decaying below the minimum maneuvering speed ( VLScap V sub cap L cap S end-sub Phase 5: Clean-Up and Exit

Although specifically named routines may vary slightly between operators, ⁠Sierra Pattern training typically includes: The Sierra knew

: Transition from level flight into a descent that mimics a final approach, requiring a "Gear Down" command followed by landing flap configurations while maintaining a stable glide path

An A320 is considered stabilized when it meets the following parameters: