How fast do commercial airplanes descend?

Idle descent in many jets is around 3,000 feet per minute until reaching 10,000 feet. There is a speed restriction of 250 knots below 10,000 feet, therefore the flight management computer will slow the aircraft to 250 knots and continue the descent at approximately 1,500 feet per minute.

What is the 3 1 rule in aviation?

A general rule of thumb for initial IFR descent planning in jets is the 3 to 1 formula. This means that it takes 3 NM to descend 1,000 feet. If an airplane is at FL 310 and the approach gate or initial approach fix is at 6,000 feet, the initial descent requirement equals 25,000 feet (31,000–6,000).

How is aircraft descent rate calculated?

If you multiply your descent angle (1 degree) by your miles-per-minute, then add two zeros to the end (x 100), you’ll have your FPM descent rate. So in this example, if you’re flying at 120 knots, you’re traveling 2 miles-per-minute (MPM) (120/60=2).

What should my descent rate be?

The faster you go the faster you need to descent to maintain this descent path. So, a jet going 250 knots over the ground will need to descent at 1250 feet per minute to maintain a steady 3-degree path (250 x 5 = 1250 fpm). But a small aircraft going 90 knots only needs to descend at 450 fpm to maintain this path.

What’s the normal rate of descent for an airplane?

Reasons for higher rate of descent at the initial part of descent, could be anything from a late handoff from a previous center sector, to restricted/military areas being active, or having to wait til late to start a descent. Normal decent rate varies… but I’d say an average of around 2000-2500 feet per minute.

How is the descent rate related to passenger comfort?

Many descents are “at pilot discretion”, and thus we’ll typically stay high as long as we can until we can descend at (or near) idle to meet our crossing restrictions. Passenger comfort isn’t directly correlated to descent rate.

Is there a limit on the descent rate?

In many jurisdictions there’s a 250kias limit, so the descent rate should reduce a lot 11500 and 10000 to slow down from around 280kias to 250kias, since the true airspeed reduced, so will the descent rate.

What’s the descent rate for the VSI at 120 knots?

So once you cross PYYPP, pitch down 3 degrees, and again, you’re on your way to the runway. If you’re looking for your backup on the VSI, do the extra math step, and you find that at 120 knots, you’ll need a descent rate of 600 FPM (3 degrees X 2 MPM X 100 = 600).