Aircraft Operations

There are training and checking staff for ensuring all of the crew are trained for flights.  There are staff who help the pilots plan a flight. They monitor weathers and other such problems at various airports applicable to that airline.  They prepare flight plans to optimise the flight for the least fuel consumption for the pilots. International airlines will most likely have a navigation department which will keep tabs on the various airways and obtain over flight requirements etc. Airlines get charged for overflying countries.  The list does go on.

Most airlines will have catering staff who prepare meals and snacks for flights. Every staff member is required for the operation to work. So, just like a football team, every member is important.  They might all have different jobs to do, but they are all necessary for flights to work.

At the flight planning stage the pilots study the route and weathers and check on expected traffc. Each airline will have a fuel policy that has been approved by the country of operation. This fuel policy must meet international standards. Here is a link to give you an idea of what is involved. https://aviation.stackexchange.com/questions/3740/what-are-the-icao-fuel-reserve-requirements

Pilots will generally take extra fuel on busy long haul routes to cover the possibility of not being able to fly at the altitudes planned due to a previous flight obtaining a clearance frst.  This is a massive problem on the busy Asia to Europe sectors.  I should mention that the airways flights operate generally have specifc heights for planes to fly.  For example flights flying West may have a choice of flying at: 31,000ft, 35,000ft, 39,000ft, while flights operation East on the same airway will be able to choose from: 29,000ft, 33,000ft, 37,000ft.  There is always a height difference between opposite bound flights.  Each aircraft weight will have an optimum height to fly to conserve fuel.  There is a definite maximum height a plane can fly for each weight. Flights generally fly in a height band.  That is a flight might climb to 33,000ft which might be 1,200 feet above the optimum altitude for that weight and stay there for 2-3-4 hours until the plane weight decreases to say 2,500’ below optimum.  The pilots will then request a further climb.  Once within about an hour of destination there is little to be gained by climbing.  However, if there is a flight being held down by your plane and it has further to go, the crew will climb to help them out. Unlike car drivers there is a defnite camraderie amongst airline pilots, of most airlines.

A very heavy plane might be only able to climb to 32,000 feet so it will need 31,000 feet to fly West or 29,000 ft to fly East.  Fuel is consumed as your flight progresses and as the aircraft weight decreases to a certain level, the pilots will request a climb.  This might depend upon the wind along that route.  When encountering very strong headwinds it is not unusual to fly well below the optimum level for the weight of the plane.  If you would like to know more I suggest you look here: https://www.skybrary.aero/index.php/Pre-flight_Preparation

There are defined ICAO rules of the air which are far too numerous and complicated for me to mention here.  However, if you would really like to know more do an online search for “ICAO PANS OPS”. There is also “TERPS”, but they are basically the same thing.

So just like car drivers have road rules, pilots have air rules to obey.

Flight plan stage.  If your destination weather is such that an alternate is required then your flight must carry enough fuel to be able to divert to an alternate airport.  If the alternate requirement has a time limit, for example your destination airport is expecting fog until 9am, then you do not need to carry an alternate as long as you have suffcient fuel to hold until 9:30am (a buffer of 30 minutes).d  If there are thunderstorms forecast for an hour at destination, then that's hour's holding fuel is all that is legally require to be carried. I never found weather foecasting to be that accurate!

If enroute and the weather at your destination airport changes to now requiring an alternate your flight cannot fly past a PNR (point of no return) airport unless it has the legal amount of fuel to fly to your destination and carry enough fuel to divert to an alternate airport.  You cannot nominate an alternate airport which itself requires an alternate.  Technically you can but you must carry fuel to cover the holding time at the alternate.   If the weather at your destination airport changes after your flight has passed beyond the PNR airport, then your crew will have to do the best they can.  They will most likely divert your flight straight away to an airport with better weather.

The North American Winter can cause massive problems for flights flying into the busy airports located in the North East of the USA and Eastern Canada when blizzards occur.  Keeping the runways and taxiways clear of snow is an airport problem, and generally the airports which suffer blizzards have the equipment and staff to keep an airport open.  They do a terrifc job.

Operationally, a passenger flight operating to an airport within the USA must carry an alternate if there is weather below 2,000 ft above ground level, or the visibility is less than 3 miles forecast one hour before to one hour after a flight.  You cannot nominate an airport as an alternate that needs an alternate, unless the alternate only needs one hour’s holding fuel to cover changeable weather.

If your flight is from (say) Frankfurt to New York, and all the airports capable of handling your size plane on the East Coast and in as far as far as Chicago all require an alternate, you are most likely going to have delays, and in most cases your flight will not depart.  If your plane can operationally carry enough fuel to be able to fly to New York and then to divert from New York to St Louis ( not having weather problems) then there will only be slight problems.  It is a long way from New York to St Louis and would depend upon expected traffc that would use St Louis as alternate and if it makes economic sense to carry such a huge extra amount of fuel, before such a flight would depart.

Short haul fghts have a different problem.  Say your flight is to fly from New York to Cleveland.  You cannot depart unless you have a suitable return airport within 1-2 hours of (in this case) New York( rules vary a bit internationally).   This is to cover the case when a flight must return with an emergency.

If you were to fly from New York to Bermuda (lucky you!) and New York was suffering a blizzard as was the whole East Coast, and Bermuda weather was fne, you could depart because the flight is only about an hour long.   Bermuda does not require an alternate.  Bermuda is magic!

Another unusual problem is the case of an isolated airport as destination. For example Tahiti. Airlines will have a different isolated airport fuel policy. You can get a general idea here: https://www.theairlinepilots.com/forum/viewtopic.php?t=1158     What they call a pre determined point is a PNR

The pilots on a flight to Tahiti, say from Los Angeles, will need to check the Tahiti weather before they pass a PNR on Honolulu. The flight cannot fly beyond PNR Honolulu unless the flight has the legal amount of fluel required on Tahiti.

The alternate requirements for airports vary around the world.   The USA requirements are quite tough due to the very high density of air traffc. See youtube videos on understanding alternate airport requirements.

https://www.youtube.com/watch?v=8K0Uu1yxKFw

https://www.youtube.com/watch?v=Ecbe1ybMuwA

I hope this page has given you a bit of an insight into operational problems airlines suffer.

I will add more operational information to answer various questions when I am asked.

   May 10, 2019