Dear friends and followers
today I'll be answering an interesting question
which was sent in by one of my
youtube subscribers
Joe, what does block time mean?
That's a great question, so let's get started.
Okay, let's imagine you've just boarded a plane
and the captain gives an announcement
through the PA, saying that he has received start up clearance, and they are ready to go.
A minute later you can feel the aircraft being pushed back
but have you actually ever wondered what goes on below your seat.
Just before the aircraft is being pushed back
the ground crew removes the chokes
that are placed in front and behind the tyres.
But why are they there in the first place?
Now most aircrafts have a hydraulic break system
so once the pilot sets the parking break
hydraulic pressure is applied to the brake cylinders
squeezing the disk brakes together
and preventing the aircraft from moving.
The problem is that once you've shut down the engines
the hydraulic pressure drops and a pressure accumulator takes over.
Due to technical issues
the accumulator can only maintain the pressure for a minimum of 12 hours.
So once the pressure is lost
the aircraft could start rolling off
and damage ground equipment or
other parked aircraft.
To prevent that from happening
the ground crews place chokes
at the tyres of the aircraft which
lock the aircraft from moving.
So once the ground staff remove the chokes
the plane goes "off blocks"
start in the off bloke time
and then taxi's out
takes off, flies off to its destination, lands
taxi's in and when reaching the gate
and the pilot sets the parking brake
and the chokes are placed
the plane goes "on blocks".
So the time inbetween is called block-time
and is always recorded in UTC
but more about UTC in another video.
So why is block time so important
flight crews have a maximum flight duty time
that they can have per day
which is cohesive with block time
and determines how much rest the crew has to have.
Many flight crews are paid by block time
but that can vary from airline to airline.
Dispatchers schedule flights and planes
in accordance with estimated block times
because if they would only calculate with flight times
that could cause chaos regarding connecting flights
because taxi times can vary from 5 minutes to an hour
depending on the airport.
where do you see the block time?
The time you can see on your boarding card
is the "off block" time
and the time you see here is falsely mistaken as the "flight time"
which in fact it's your "block time".
Also if you book your flight on the internet
the time you see is not the flight time
which would only be from take off until landing
no it's the block time including both
taxi out and taxi in.
The only time you actually get to know the actual flight time
is during the passenger announcement by the flight attendant
after boarding is completed.
We let the flight attendance know what the estimated flight time will be
so they could co-ordinate their service scheduled for the flight
and announce it to the passengers.
So the next time you sit on a passenger jet
use a stop watch and time the block time
from push back until stand still
after landing and compare it to
the time that is written on your boarding card.
It should be fairly the same.
Other than that pilots write down their block time
after each flight
into their pilots log book to keep track
of how much they have flown over the last month or year
for example.
And if you were to have applied to another airline
they will be asking you for your total block time
to estimate your overall flight experience.
I hope you have enjoyed this video
give me a thumbs up and make sure to subscribe my channel
so you won't miss out further videos like this
and share this video with other aviation enthusiasts!
Hope to see you soon, all the best, your Captain Joe!