How can air traffic controllers determine when it's clear for takeoff and landing?

The pilot of the aircraft with the compressor stalls was calling "mayday mayday mayday" then explaining his problem. The response was the tower acknowledging the mayday call and telling the pilot that he's cleared for any runway that he needs.

It is very common for small airports not to have a control tower, radar, or communications equipment. There are very well developed procedures for "uncontrolled airports". There is a standard traffic pattern that aircraft fly at almost all airports (consisting of a downwind, base, final, and upwind leg) and there are specific radio calls that are supposed to be made at certain points in the pattern. Most airports have a fixed base operator to supply fuel and services. They often monitor the common traffic frequency and supply some info to pilots about wind direction and runway in use. There's also a specific way to enter the pattern - usually at a 45 degree of the downwind leg, Yes it's possible for aircraft to collide and it happens several times a year - usually when a low wing airplane is above a high wing airplane in the pattern. Neither can see the other so occasionally that can happen.

Technically is you are flying domestic you are not flying over foreign airspace. If flying IFR you must file one. Needless to say when filing a flight plan you must decalre if you are domestic of international flight.

From a pilot perspective, the pilot is ultimately responsible for all operation of the aircraft. This includes following all the instructions of an air traffic controller who often gives their radio commands so fast a stenographer couldn't keep up with it. Often an unbelievable amount of stress, but we can always ask them to repeat slower - though they frequently get a little sarcastic when you ask. Controllers, on the other hand, are responsible for sometimes dozens of aircraft in their sectors and many of them are not talking to the controller. I can imagine an equally huge stress trying to keep the planes that are talking to a controller away from the ones who aren't talking to the controller. So I'd call it fairly even.

it is the relative direction around the aircraft using a clock face. 12 oclock is in front of the pilot, 6 oclock behind. 3 oclock to the right etc. it is also used with high, level or low. for example, a contact off to the right and above the flight level of the pilots aircraft would be 2 oclock high.

As long as the plane is equipped for icing, which all airlines are, there is not really any added danger to flying in snow. Braking on landing may be affected if there's any accumulation but they keep close track on braking ability as each plane lands at the airport. Snow won't affect the way the plane flies as long as the wings are clear of snow on takeoff.

How much fuel would that be in pounds? Remember that the plane will need to get into the air, if it is too heavy it wont be able to takeoff. Also what if something happens that requires the plane to come back and land?

Departure controllers have blocks of airspace with altitude limits. Chances are that there was other traffic that they needed to have out of the way so they held him at 5000 before clearing him to the next controller's airspace.

James,

There are navigation and softwares inside the cockpit so pilot can find easily as well as air traffic controllers will guide them so they can easily land there....
with regards,
jaijith

Aircraft too heavy. Weight is extremely valuable/expensive and the weight of a parachute system would be too heavy and costly, sacrificing room for paying passengers.