On modern passenger jets shortening flying time is not a question of “going faster” - or hitting the throttle and turning on the afterburners. Unless you’re on the Concorde there is no boost button on a commercial jet engine, which has a fairly fixed cruising speed.
“Aircraft are designed to cruise within a fairly small speed bracket,” UK-based captain Nick Anderson told Condé Nast Traveler.
“We almost always fly at the fastest economical speed.”
Flying at higher speeds not only has the effect of increasing fuel consumption, the biggest cost to airlines, but also increasing wear on aircraft. Both these things mean the accounts department (and engineering) of a carrier are loath to allow their aircraft to increase their maximum cruising speed.
There are rare occasions where it is deemed appropriate for a pilot to approach top speed, such as if they are carrying many passengers with connecting flights or the aircraft is needed elsewhere on the network.
If you really want to avoid delays to travel, passengers are advised to fly earlier in the day and off-peak, midweek.
“Summer holidays bring increased demand for flights and with that comes inevitable problems,” Boeing 787 pilot Charlie Page told The Points Guy.
Statistically a plane at the beginning of the day is less likely to be delayed or cancelled, having not yet been used on other routes and avoiding the “domino effect” of other late-running services.
In the worst case scenario, there is also a much better chance of getting a replacement flight that day, preventing an unexpected overnight layover.