From a passenger’s perspective, the descent and approach to landing feels like a single continuous event. The seatbelt sign comes on, the engines get quieter, the aircraft descends, and eventually the wheels touch the runway. From the cockpit, the same sequence involves a structured series of calculations, briefings, configuration changes, and ATC interactions that begin at 120–150 nautical miles (222-278 km) from the airport and take 20–30 minutes to complete. Each step has a defined sequence, specific speed and altitude targets, and standardized callouts between the pilot flying and the pilot monitoring.
The process starts with the FMS calculating a top of descent point based on the assigned Standard Terminal Arrival Route and ends with the main gear touching the pavement at approximately 130–150 knots. Between those two points, the crew programs the arrival and approach into the FMS, briefs the approach procedure and the missed approach, decelerates from cruise speed to landing speed while extending flaps and gear in a defined sequence, transitions from the arrival route to the instrument approach, and either lands or goes around based on what they see at decision altitude.
The Top Of Descent Calculation And The STAR
The descent from cruise altitude to the airport does not begin when the crew feels like going down. The flight management system calculates a top of descent point based on the aircraft’s current altitude, the distance remaining to the destination, the altitude and speed restrictions published on the assigned Standard Terminal Arrival Route, and the wind data loaded into the FMS from the airline’s dispatch system or updated in flight from pilot reports.
The FMS works backward from the runway threshold, accounting for every altitude constraint and speed restriction along the arrival route, and places a marker on the navigation display showing exactly where the descent should begin. On a typical domestic flight cruising at 35,000 feet (10,668 meters), the top of descent might be 120–150 nautical miles (222-278 km) from the airport.
A Standard Terminal Arrival Route is a published transition from the en route airway structure to the terminal area around the airport. STARs are designed to sequence arriving traffic from multiple directions into an orderly flow toward the active runway. Each STAR includes a series of named waypoints with associated altitude and speed restrictions. ATC assigns the STAR based on the direction the aircraft is arriving from, the active runway configuration, and the traffic volume. The crew programs the assigned STAR into the FMS, which builds the lateral and vertical path from the current position through every waypoint down to the initial approach fix.
The descent itself follows the vertical path the FMS has computed, which balances altitude loss against distance remaining and the speed and altitude restrictions at each waypoint. The FMS commands thrust and drag adjustments to keep the aircraft on the computed profile. In practice, the descent involves periods of reduced thrust, periods of level flight at intermediate altitudes assigned by ATC, and periods where the crew adds thrust or deploys speed brakes to manage the aircraft’s energy state relative to the path.
Pilots refer to being “on the profile” when the aircraft’s altitude and speed match what the FMS expects at each point along the arrival. An aircraft that is high on the profile has excess energy and may need speed brakes to get back down. An aircraft that is low needs to level off and add thrust to regain the correct altitude, which burns more fuel.
ATC frequently disrupts the computed profile by assigning intermediate altitudes, speed changes, or vectors off the published arrival route to maintain spacing between aircraft. When that happens, the crew adjusts manually or reprograms the FMS to accommodate the new clearance while keeping the aircraft within the energy window needed to meet the next restriction on the arrival.
The Approach Briefing
The approach briefing typically happens during the descent, after ATC has confirmed the expected approach and runway but before the aircraft reaches the terminal area. The pilot flying gives the briefing. On most airlines, the format follows a structured template that covers the same items in the same order on every approach, regardless of complexity. The standardization ensures that nothing is skipped and that the pilot monitoring knows exactly what to expect during the final phase of the flight.
The briefing covers the type of approach assigned, whether ILS, RNAV, visual, LOC, or LDA. It states the runway in use, the final approach course, the glideslope angle if applicable, and the decision altitude or minimum descent altitude for the approach. The decision altitude is the height at which the pilot must either see the runway environment and continue to land or initiate the missed approach.
For a Category I ILS, that figure is typically 200 feet (61 meters) above the touchdown zone. For a non-precision approach like an RNAV with LNAV minimums, the MDA may be 400–600 feet (122–183 meters) or higher. The briefing also covers the missed approach procedure, which specifies the heading to fly, the altitude to climb to, and the fix to navigate toward if the approach is abandoned.
Weather is briefed using the most current ATIS, the Automatic Terminal Information Service broadcast that the crew monitors on a dedicated frequency as they descend into the terminal area. The ATIS includes the ceiling, visibility, wind direction and speed, altimeter setting, active runways, and any NOTAMs affecting the approach. The briefing compares the reported weather against the published approach minimums.
If the ceiling is 800 feet (244 meters) and the decision altitude requires 200 feet (61 meters), the weather is well above minimums and the approach is expected to be straightforward. If the ceiling is 300 feet (91 meters) and the decision altitude is 200 feet (61 meters), the crew briefs the approach with the understanding that the runway may not become visible until seconds before the decision point. The briefing also covers the alternate airport, the fuel remaining, and the landing performance data.
Speed And Configuration Management On The Way Down
At cruise altitude, a Boeing 787 or Airbus A350 flies at approximately Mach 0.85, which translates to roughly 490 knots (907 km/h) true airspeed depending on altitude and temperature. By the time the aircraft reaches the final approach fix, it needs to be at approximately 130–160 knots indicated airspeed depending on aircraft type and landing weight, with flaps and slats extended to landing configuration and the landing gear down. Bleeding off 300+ knots of speed while descending 30,000+ feet (9,144+ meters) and arriving at a specific fix at a specific altitude at a specific speed is the energy management problem the crew solves between top of descent and the final approach.
The deceleration happens in stages. Most STARs include speed restrictions at specific waypoints that force the aircraft to slow progressively as it descends into the terminal area. FAA regulations require all aircraft to be at or below 250 knots below 10,000 feet (3,048 meters) MSL unless ATC specifically authorizes a higher speed. The crew begins extending the flaps and slats as the aircraft slows through the speeds published in the aircraft’s operating manual for each configuration step.
On a 737, the initial flap setting of 1 degree is typically selected around 210–220 knots. Flaps 5 follows around 200 knots. Flaps 15 around 180 knots. The landing gear extends at approximately 170–180 knots on most narrowbodies, adding significant drag that further decelerates the aircraft. Full flaps are selected last, bringing the aircraft to its final approach speed, which is calculated by the FMS based on landing weight and is designated Vref plus any additive for wind gusts.
Late changes from ATC complicate this sequence. A runway change inside 20 miles from the airport forces the crew to reprogram the FMS with the new approach, re-brief the critical items, and reconfigure the aircraft for a different approach course and possibly a different glideslope angle, all while decelerating and descending in the terminal area.
Flying The Final Approach
The transition from the STAR to the instrument approach procedure happens at or near the initial approach fix. On a standard ILS approach, ATC vectors the aircraft onto the localizer course, typically from a 30-degree intercept angle at a distance of 8–15 nautical miles (15–28 km) from the runway. The crew arms the approach mode on the autopilot or flight director, and the localizer captures automatically when the aircraft intercepts the course. The glideslope captures as the aircraft reaches the point where the 3-degree descent path from the runway intersects the aircraft’s altitude, typically between 1,500 and 3,000 feet (457–914 meters) above the airport depending on how far out the intercept occurs.
Once established on both the localizer and glideslope, the pilot monitoring begins making callouts at predetermined altitude gates. The specific callouts vary by airline, but a typical sequence includes 1,000 feet (305 meters) above airport elevation, 500 feet (152 meters), and 100 feet (30 meters) above decision altitude. At 1,000 feet, the monitoring pilot calls the aircraft’s position relative to the glideslope and localizer, the speed relative to Vref, and whether the approach meets the airline’s stabilized approach criteria.
Those criteria typically require the aircraft to be on the correct lateral and vertical path, within 10 knots of the target approach speed, in landing configuration with gear down and flaps set, and with a sink rate not exceeding 1,000 feet per minute (305 meters per minute). If any of those parameters are not met at 1,000 feet on an instrument approach, airline standard operating procedures require a go-around.
From Decision Altitude To Touchdown
At decision altitude on a Category I ILS, typically 200 feet (61 meters) above the touchdown zone, the pilot flying looks up from the instruments and searches for the runway environment. The visual references required by regulation include the approach lighting system, the runway threshold, the threshold markings or lights, the touchdown zone or its markings and lights, or the runway itself.
If the pilot sees any of these references and determines that a safe landing can be completed, the approach continues. If the references are not visible at decision altitude, the pilot calls “go around,” advances the thrust levers, and initiates the missed approach procedure. The decision happens in approximately two to three seconds.
Once visual, the pilot transitions from tracking the flight director to looking outside and flying the aircraft to the runway. The autopilot, if still engaged on a coupled approach, is disconnected at or just below decision altitude on a Category I approach. The pilot reduces the rate of descent as the aircraft crosses the runway threshold at approximately 50 feet (15 meters), begins the flare by gradually raising the nose to reduce the descent rate to near zero, and closes the thrust levers to idle just before the main gear contacts the pavement.
At main gear touchdown, the ground spoilers deploy automatically, dumping lift from the wings and transferring the aircraft’s weight onto the wheels. Reverse thrust is selected immediately after spoiler deployment by pulling the thrust levers into the reverse detent. On most modern aircraft, the crew selects full reverse and then reduces to idle reverse as the aircraft decelerates through approximately 60–80 knots to minimize noise and FOD ingestion.
Inside the Landing Sequence
Autobrakes, if armed, apply a pre-selected deceleration rate ranging from low settings used on long runways in dry conditions to maximum settings used on short or contaminated runways. The crew can override the autobrakes by applying manual braking through the rudder pedals at any time. The aircraft decelerates from approximately 130–150 knots at touchdown to taxi speed of 15–20 knots over a distance that depends on the landing weight, the braking setting, the runway surface condition, and whether the crew uses maximum or idle reverse. Once at taxi speed, the crew stows the reverse thrust, contacts ground control, and follows taxi instructions to the gate.
