Defrosting aircraft on the ground - why, how, when

We are in full winter, with snow and temperatures below 0 degrees. I always informed you about the status of flights to / from airports in Romania, about cancellations due to adverse weather conditions, but also about delays in taking off, which are determined by the need to defrost the aircraft.

Defrosting of airplanes

Why is the defrosting process necessary? Before talking about defrosting, I bring up the phenomenon of frosting. Under conditions of low temperatures and high humidity, an ice layer may appear on the metal parts of the aircraft. Ice on airplanes is very dangerous. It can influence the aerodynamics, it can lead to the decrease of the lift, all culminating with the collapse of the flight apparatus. So deicing is necessary for flight safety.

When is the defrosting process applied? This process applies especially in the cold season, when temperatures are below zero, when there is snow and high humidity, all of which contribute to the appearance of ice on the fuselage of the aircraft.

According to aviation regulations, defrosting may also be required in good weather conditions, with sun and a few degrees above 0, but each time at the request of the commander.

How is defrosting done?

A special solution is applied with pressure to the metal surfaces of the aircraft. It has the role of detaching and melting the ice sheet from the entire fuselage, while also preventing the formation of a new ice layer for a period of up to 20 minutes. During this time, the aircraft must take off.

For defrosting, a machine (or more) specially designed for this process is used. Some are more modern, with a platform equipped with a special spray system. Others are a bit older and require 2 people for handling / moving, having an older system of applying degreasing solutions.

Why are delays resulting from the defrost process? This process can take between 15 and 40 minutes, depending on the weather conditions outside, the dimensions of the aircraft and the concentration of the solution used in the defrost process.

Considering that this process is necessary in the winter season, it is not taken during the standard time required to prepare an aircraft for the next flight. Thus, the defrost time accumulates to the standard ground operating time.

The next time you fly by plane, do not get angry because of delays caused by the defrost process. It's for your safety, your flight and your entire crew.

PS It is worth mentioning that the defrosting process is done after boarding the passengers, so the aircraft can be quickly prepared for take-off. Defrosting is done on the platform or at the boarding gate.

We thank the Bucharest Airports Communication Directorate for the photos and videos provided!