The lateral "S" turn kept them from overflying the runway where emergency vehicles were rushing. If they had simply climbed straight, they would have flown directly into the fire trucks. The Sierra Pattern saved lives.
Do it right, and your track over the ground will be a perfect S. Do it wrong, and you’ll be going around—which, in the A320, is just another opportunity to learn.
The Sierra Pattern A320 is a specific application of the Sierra Pattern approach procedure, tailored to the performance characteristics of the A320 aircraft. This procedure involves a series of waypoints, altitudes, and headings that guide the aircraft through the mountainous terrain. The Sierra Pattern A320 is designed to be flown during IMC, when visibility is limited, and pilots must rely on their instruments to navigate. sierra pattern a320
: Lower the landing gear and extend Flaps 1 or 2 as you approach the "abeam" position of the runway threshold. The Base Turn and Final Approach
Pilots operating in the Sierra Nevada region are strongly advised to: The lateral "S" turn kept them from overflying
This turn is tighter and more dangerous. You are now heavy (low speed, high drag) and need to roll onto the final approach course at 1,000 ft AGL.
The final leg of the Sierra Pattern leads the aircraft to a or a holding fix. At this point, the crew decides: Do it right, and your track over the
1,800-2,000 ft AGL, 170-180 knots, clean configuration.
The Sierra Pattern is a predetermined lateral and vertical flight path designed to transition an Airbus A320 from a descending approach configuration (landing gear down, flaps extended) to a climbing, clean configuration while avoiding terrain and maintaining a safe distance from the runway.
Consider the famous 2016 incident at Chicago O'Hare where an A320 crossed an active runway as another A320 was landing. The landing crew saw the crossing aircraft at 200 feet. Their "Sierra Pattern" go-around was executed in 1.5 seconds. Because they followed the procedure—TOGA, pitch up, positive rate, gear up—they cleared the obstructing aircraft by just 50 feet.