Aircraft Passengers Wearing Analogue Watches
Nov 20th 2023, 9:14 pm
#16
Started off with nothing
Joined: Feb 2009
Posts: 4,946
Re: Aircraft Passengers Wearing Analogue Watches
Me too. If pulling winder out equalised the pressure inside the watch to cabin pressure. That would reduce i.e. eliminate any pressure pushing the watch face outward. I would suggest the watch repairer was talking rubbish.
Nov 21st 2023, 8:56 am
#18
BE Forum Addict
Joined: Jul 2014
Posts: 1,109
Re: Aircraft Passengers Wearing Analogue Watches
Cabin pressure does actually vary from takeoff to cruise altitude.
On the ground it is 1 BAR (1 atmosphere), however this also varies slightly according to the altitude of the airport/airstrip.
As the aircraft climbs past the threshold of 10000 ft (which is where the oxygen level drops off) it is increased slightly because all aircraft constantly leak air pressure during flight at high altitudes.
This would be somewhere between 1.1 and 1.5 bar max. (Please note that this also differs according to a/c type and age).
This air comes from the engines and goes through a series of valves/filters before entering the pressurisation system.
There are also 'dump' valves located at the front and rear of the aircraft which compensate this pressure constantly during the flight.
In general these operations are automated and you notice nothing apart from when your ears pop at altitude or landing.
The pressurisation is supposed to be monitored by the flight engineer.
On older aircraft there were incidents where people had eardrum damage due to poor pressure compensation or defective valves or an inattentive engineer.
A glass popping off a watch is always possibility but depends on the situation.
On the ground it is 1 BAR (1 atmosphere), however this also varies slightly according to the altitude of the airport/airstrip.
As the aircraft climbs past the threshold of 10000 ft (which is where the oxygen level drops off) it is increased slightly because all aircraft constantly leak air pressure during flight at high altitudes.
This would be somewhere between 1.1 and 1.5 bar max. (Please note that this also differs according to a/c type and age).
This air comes from the engines and goes through a series of valves/filters before entering the pressurisation system.
There are also 'dump' valves located at the front and rear of the aircraft which compensate this pressure constantly during the flight.
In general these operations are automated and you notice nothing apart from when your ears pop at altitude or landing.
The pressurisation is supposed to be monitored by the flight engineer.
On older aircraft there were incidents where people had eardrum damage due to poor pressure compensation or defective valves or an inattentive engineer.
A glass popping off a watch is always possibility but depends on the situation.
Last edited by calman014; Nov 21st 2023 at 9:05 am.
Nov 21st 2023, 9:09 am
#19
Lost in BE Cyberspace
Joined: Feb 2008
Posts: 5,625
Re: Aircraft Passengers Wearing Analogue Watches
The Rotary watch I have is the only one I have ever had where the glass popped off and it only ever happened when flying . It isn't a divers watch it's a dress watch. So there is definitely a link to flying air pressure. I can't say if it happened when adjusting time with the crown or not but it certainly doesn't have a screw down/sealed crown .
Nov 23rd 2023, 6:01 am
#24
Forum Regular
Joined: Jun 2020
Location: Keszthely
Posts: 116
Re: Aircraft Passengers Wearing Analogue Watches
The other possibility is the ambient air pressure at the destination is different from the departure location, you notice this when you open a sealed bottle like shampoo (a bit squirts out), especially if you have gone from a summer to a winter location. so with the watch, the air inside adjusts slowly to the ambient air pressure where you are, when the plane is approaching the destination and they quickly adjust the air pressure to the lower value at the destination, it is enough to pop the watch open. Normally the ambient air pressure changes so slowly that the watch leaks another air to not cause the problem.
