What is climb and descent rate? ​

Climb and descent rate is how fast an aircraft gains or loses altitude, measured in feet per minute (fpm). A Boeing 737 climbing at 2,500 fpm gains 2,500 feet every minute. Simple enough, but the numbers vary a lot depending on aircraft type, weight, and altitude.

Typical climb rates ​

Aircraft climb fastest when they're light and low. As they get higher, the thinner air reduces engine performance and wing efficiency.

Heavy aircraft climb slower than light ones. A full B777 at max takeoff weight might manage 1,500 fpm through FL250, while an empty A320 could do 3,000+ fpm at the same altitude. This matters when you're sequencing climbers - a regional jet will outclimb a heavy widebody.

Typical descent rates ​

Descents are more controlled. Pilots prefer a smooth, idle-power descent rather than steep dives. Passenger comfort matters.

• Comfortable descent: 1,000 - 2,000 fpm
• Normal descent: 1,500 - 2,500 fpm
• Expedited (ATC request): 2,500 - 3,500 fpm
• Emergency descent: 4,000+ fpm

Controllers sometimes need aircraft down quickly: "expedite descent." This tells the pilot to increase the rate, but there are limits. Descending too fast can be uncomfortable for passengers and hard on the engines.

The 3-to-1 rule ​

This is the simplest tool for planning descents. To lose 1,000 feet of altitude, you need about 3 nautical miles of distance. So:

• Need to drop 10,000 feet? Start 30nm out.
• Going from FL350 to 10,000 feet? That's 25,000 feet to lose, so start about 75nm out.
• Descending from FL380 to sea level? About 114nm.

The math assumes a roughly 3-degree descent path at normal speeds. It's a rule of thumb, not exact. Headwinds, tailwinds, and speed changes shift the numbers. But for a quick mental check, 3-to-1 works.

Top of descent ​

The top of descent (TOD) is where the aircraft begins descending from cruise altitude. Flight management computers calculate it precisely based on the arrival procedure, winds, weight, and speed restrictions.

For controllers, knowing when aircraft need to start down is critical. If you leave someone at FL350 too long, they won't be able to make their crossing restrictions on the STAR. They'll either have to fly a longer path, descend uncomfortably fast, or miss their altitude constraints.

Busy arrivals to major airports have STARs with specific altitudes at specific fixes. The aircraft needs to plan its descent to hit each one. The earlier a controller starts the descent, the more comfortable it is.

Why this matters for ATC ​

Climb and descent rates affect spacing. If you clear two aircraft to the same altitude and one climbs at 3,000 fpm while the other does 1,500 fpm, the fast climber gets there first. You need to think about who reaches the assigned altitude when.

On descent, if you need an aircraft at 10,000 feet in 20 miles but they're at FL350, that's 25,000 feet to lose. At 2,000 fpm and 250 knots groundspeed, they need about 12.5 minutes and roughly 50nm. Twenty miles isn't enough. You needed to start them down earlier.

In radarcontrol.io ​

Aircraft in the sim have realistic climb and descent rates based on their type and weight. Heavies climb noticeably slower than light jets, especially at high altitude. You'll see this when trying to get a B747 up to FL370 - it takes a while.

The vsFpm property in the aircraft data shows current vertical speed. This updates in real time as aircraft climb and descend.

For STAR procedures, the sim calculates top of descent automatically. Aircraft will begin descending to meet altitude restrictions on their assigned STAR. If you assign a lower altitude manually, the aircraft starts down immediately at a realistic rate.

Command reference | Play Atlanta TRACON

Related: What is a flight level? | What is a SID and STAR? | How arrivals are sequenced

Play Chicago Center - practice managing climbs and descents across a busy center.