Why can't a plane land?

Short answer

A plane can't land when safety conditions aren't met: visibility below the procedure's minimums, crosswind or tailwind beyond the aircraft's limit, an occupied or contaminated runway, a destabilized approach, or a technical failure. In those cases the pilot goes around and either tries again or diverts to an alternate.

Published: September 21, 2026 · Updated: September 21, 2026 · Edited by Above Ten Thousand · Editorial policy

De Havilland Canada DHC-1A Chipmunk, Pennzoil Special

Weather minimums

Every approach has minimums, a height and a visibility below which the pilot cannot continue unless the runway or its lights are in sight. On a Category I precision ILS approach, the decision height is about 200 ft (60 m); on Category III, with autoland and a qualified crew, it can drop to just a few meters or even dispense with a decision height altogether. If the runway isn't visible at that point, the landing cannot be completed. The same applies to fog, low clouds, or heavy rain that push visibility below what's published for that runway.

Wind and runway condition

Every aircraft type has a maximum demonstrated crosswind component and a tailwind limit, typically 10 kt (18 km/h) and in some cases 15 kt. Gusts and wind shear, sudden wind changes near the ground, can prevent a landing even with perfect visibility. The runway also has to be operational: contaminated by snow, ice, or standing water beyond the limits, occupied by another aircraft or vehicle, or with reduced usable length due to works, and the approach is discontinued. A runway incident can close it for hours and force dozens of flights to divert.

Destabilized approach and technical failures

Airlines require the approach to be stabilized by a set height, typically 1,000 ft (300 m) in instrument conditions: on the correct path, with speed, configuration, and rate of descent within tolerances. If it isn't, the rule is to go around without debate, because unstable approaches are a recurring factor in runway excursions. A technical failure can also prevent landing at the intended spot: landing gear that won't extend or lock, a brake or flap problem that lengthens the landing distance beyond what the runway allows, or a malfunction that calls for burning off or dumping fuel before touching down.

A go-around is not an emergency

Discontinuing a landing is a trained procedure, planned into every approach. The pilot applies takeoff power, retracts flaps and gear, climbs to the published altitude, and decides whether to try again, hold, or divert to the alternate airport, for which reserve fuel is always carried. For the passenger it's a scare; for the crew it's applying a safety margin planned well in advance.