They can seem draconian, petty and even pointless: the numerous safety rules that apply to airline passengers.
Contrary to general opinion, however, the various procedures and laws that govern behaviour onboard are applied with good reason, says Australian aviation expert, Trevor Bock.
Bock (through his company Bock Consulting) is a training and safety auditor who regularly works with international airlines and IATA (International Air Transport Association) to ensure compliance and verify safety ratings as well as set safety policy.
In other words, he's one of the guys who recommended you turn off your phone inflight. That makes him ideally placed to answer the questions every harried air traveller would love to ask and to explain once and for all why your tray table needs to be up during landing.
If I can turn my phone on after landing, why do I need to have my phone off when crossing the tarmac?
"The main reason we identified when looking at Qantas's phone policy was safety. It's a rainy day, you've got your umbrella up, you've got your carry-on, you're talking on the mobile phone, you hit the bottom step before you realise it's there – and you're flat on your face.
Also, airports are very busy places and tarmacs are even busier, and dangerous. People do get injured. If you're walking across talking on your phone, the chance of you wandering too near equipment or being hit by something or someone increases. It's about paying attention.
There's also the issue of fuel and the possibility of mobile phones igniting it. Research hasn't proved this will happen. But the point is nobody wants to take the risk and say it's fine and then have someone blow themselves up.
We live in a world run by lawyers and insurance companies, so everyone errs on the side of safety to avoid litigation."
Why can't I have my phone on during flight?
"Some airlines do allow it now. They have a mobile cell in the aircraft and charge you an arm and a leg for the call.
There was a lot of discussion about whether or not phones would interfere with the navigation equipment. No one has been able to prove that they do and nobody has been able to prove that they don't. Again at the moment, they are erring on the side of safety.
But there have been a number of instances where the autopilot has had a glitch, just lost the plot and the aircraft has done a dirty dive or a big pitch-up and there's a whole lot of speculation about what's causing that. Airbus and Boeing have both now experienced it and they don't have an answer.
It could be a mobile phone being used. It could be the long-range wave frequency of US submarine communications. There's one of these transmitters in northwestern Australia and that is where a couple of these incidents have occurred.
Having said all this, a lot of people still don't turn off their phone. The airlines say put it into flight mode and switch it off. I suspect most don't turn it off."
Why can't I use my iPod or other non-transmitting electrical device all the way to the gate?
They do have a microprocessor in them and they do emit some radio energy. However, the real thing is they are distractions. If the flight crew is suddenly asking you to get out and you've got headphones in, you won't hear the emergency immediately and you won't realise something's going on, possibly until everyone's climbing over you. Every second counts, not only for you, but for those around you. If you're not paying attention you may block someone else's way.
Is that also why the movie goes off during landing, even when it's only got five minutes to go?
"Yes. The statistics say if there's a crash, and you're out in the first 90 seconds you'll survive. You don't have a lot of time. Being attentive is crucial. That's a safety requirement of all new aircraft. They have to be able to prove they can get everyone, including children and old people, off within 90 seconds. Even off the A380 (which can carry up to 538 passengers, depending on which airline you travel with)."
Why is the position of my tray table, seat back and window shade such a big deal during takeoff and landing?
"That's for emergency evacuation. It's important that the person sitting by the window can get out. It's also important that the cabin crew can see outside. If there's a fire, they need to make sure no one gets out that side, for instance. Tray tables and reclined seats can add extra hindrance to evacuation."
Why can't I stand up and get my bags during taxi?
"I see people doing this all the time – especially in Sydney.
But consider the fact that the aircraft is doing 80 knots (after landing) on a high speed taxi way. If the pilot has to brake, you and your bags are going to end up all over everybody else. There will be injuries.
Some of the aircraft are pretty big. It's deceptive. They don't seem to be going very fast. But you've got 300 tonnes travelling at 60 kilometres an hour. If a vehicle pulls out or there's a piece of equipment in the way, the pilot will touch the brakes and the brakes are very powerful. The aircraft will stop almost immediately. Everything else, including you if you're not strapped in, will keep going."
Why the seatbelt even if I'm asleep?
"It comes back to insurance. A couple of years ago Qantas hit some unexpected turbulence, people were injured and the airline was sued for millions. After that Qantas changed the wording on their announcement from "recommend you keep your seatbelt fastened" to making it a requirement.
A number have changed their wording like that.
It does protect you though. No doubt. If the aircraft hits medium to heavy turbulence and you are not wearing a seatbelt, you will hit the ceiling and come down on the seat back and break your hip or leg on the way down. The injuries are normally broken bones.
It's not uncommon for flight crew to be injured. Over any three-month period, somewhere in the world, a crew member will be injured. That's why when you hear the captain say "Flight crew be seated immediately," they make for the nearest empty seat and strap in. They don't wait to get to the jump seat."
What is up with plastic cutlery in and out of Australia and not other countries?
"It changes. At one point Hong Kong didn't allow it either. It's usually a response to them having found something or hearing some kind of intelligence. If security measures increase, it's never without reason."
Why do flight crew still not find my terrorism jokes funny? Haven't we moved on?
"The threat of terrorism is still very real. You just have to watch the news. There are people out there who want to do harm to other people. It's just the world we live in. Planes are still seen as easier to blow up than buildings."