What is a CTOT? - The aviation way of telling you to hurry up and wait

What is a CTOT? ‘Calculated Time of Take Off.

In aviation, we love an abbreviation, but here is one you should take particular attention to: CTOT.

CTOT or Calculated Time of Take Off in layman's terms refers to the actual time the aircraft is scheduled for departure, irrespective of the estimated or requested time of departure.

CTOT’s are applied when things generally get busy and the airspace is starting to become congested, so during peak times if ATC cannot safely accommodate a flight a restriction/delay may be added to the flight plan.

This can be anywhere from 5 minutes to 180+ minutes, depending on the congestion and forecasted future air traffic.

There are many factors which can result in CTOTs being applied (weather, industrial action, military movements, airway restrictions, to name a few), and it's applicable to all commercial and private air traffic.

So, if your flight is faced with a CTOT, are there ways to work around this?

Suppose on your next flight, Air Traffic Control needs to contain the airspace volume and a CTOT is applied to the flight plan, say 30 Minutes for instance. This 30-minute delay may, in certain circumstances, be circumvented by sending a ‘ready message’ to ATC stating the aircraft is ready for departure. Any aircraft is able to request this, but it should only be made once all luggage is stowed and passengers are ready for departure. To give some context, If, for example, another commercial flight is running behind schedule, the waiting aircraft, ready to depart, may be able to take that position and essentially depart without any delay incurred.

This is easier to do on a private charter flight than a scheduled service because it takes generally less time to prepare the aircraft for readiness than waiting for 180+ passengers to take their seats.

If you have been advised of a CTOT on your flight, what is the best general action to take as a passenger?

As a general rule any airline will ask passengers to arrive at the airport lounge/gate as per the original schedule, the aim here as mentioned above is to be ready but it can openly mean waiting in the aircraft but be assured that the airline and flight crew will be diligently making efforts to get the flight going.

Are CTOT’s Delays Common?

Generally speaking, during the busier times of the year (holiday seasons), it's not that uncommon to receive a CTOT. In instances where the CTOT is less than 15 minutes, you may not even notice any delay and still arrive at your planned arrival time.

What tips can we give?

·       Consider that CTOT can accumulate ongoing delays throughout the day if you're flying on a scheduled service; those flying at the end of the day may be facing bigger waits than if you're flying in the morning. That's why im always personally fearful of taking the last flight of the day.

·       If you can avoid the peak days of travel, the beginning of the school holidays, when air traffic will be at its busiest.

·       In certain circumstances, using smaller, more regional airports may also work in your favour. Chartering a private aircraft from London airports such as Farnborough and Biggin Hill is far more adaptable to accommodate schedule changes and delays than major airports such as Heathrow.

Overall, ask anyone in airline operations about CTOT’s and you may hear a groan or two. Much as it can be an annoyance to everybody’s schedule, it is enforced to ensure that airspace doesn’t get too congested and unmanageable it should be respected to ensure a safe separation of aircraft, and something we all can appreciate.