This thread is depressing. So much misinformation and selfishness. And the UK government is definitely failing us by pretending it's a cold.
Long covid is affecting hundreds of thousands to the point that the Bank of England is concerned. Actuaries are crunching the numbers. Health insurance in future will likely want to know your past COVID infection status because this will determine your likelihood of serious health problems.
Of course you can catch covid in the plane. They have HEPA filters but these are not generally on when the plane is at the gate or taxi-ing. Therefore try to board last and definitely wear a mask throughout. And if no one else is wearing a mask then the risk to you will definitely be higher. One-way masking can only do so much. Masking in any public transport/planes makes 100% sense.
The most effective form of mask is an N95. These can be reworn multiple times. They don't touch your mouth so are much more hygienic. I recommend the 3M Aura.
Washing your hands/hand sanitizer will help against many diseases, but COVID is airborne, so not much help here. Hence the need for masks.
Also hence the importance of ventilation (bringing in fresh air, not recirculating old air) to dilute the viral load. In absence of ventilation, HEPA filters can do the job but they need to be powerful enough for the space they are in, and filters need replacing.
And importantly, investing in good air quality benefits everyone, not just regarding COVID but RSV and all airborne pathogens, and it keeps CO2 levels low which is vital for cognitive ability. Are your children feeling sleepy in school? CO2 is probably too high. Better ventilation will help!