I’ve started to compile a range of facts, descriptions, and opinions pertinent to programming and systems design for airline operations
Airline operations? Yeah, airline operations. This page is the start of an attempt to explain it, especially as it is relevant to systems design and application programming.
DISCLAIMER: These are entirely my own observations and have nothing to do with my employer.
What do I mean by “airline operations”? In short, these are the activities involved in making the aircraft fly on the day of operation. So this doesn’t include scheduling, the booking and payment systems, or the loyalty program, for example. Although, aspects of these systems depend on the operational systems for data, of course. It does include the sorts of things you interact with at the airport and on the plane, for example: check-in; bag drop and baggage handling; loading the aircraft with cargo, bags, fuel and catering; embarking and disembarking the aircraft; and, of course, the flying itself.
At my airline, the three main operational departments are flight, ground, and network. There are multiple other departments for example, engineering and scheduling, and also marketing, all the sales and customer-facing stuff like apps and so on, but, apart from the engineering department, none of these are my focus at work. I’ll outline in brief what these departments do. I’m leaving off engineering (maintenance) for now. But when you’re told your flight is late, or cancelled, in your app, or from a website, that data came from one of my systems, probably (if the flight is one of my airline’s of course). Sorry about that.
Flight operations is one of the most obvious. This department includes the tech crew, flight crew, or what you’d call the pilots, and the cabin crew. The latter people may be those who you think are there to serve you food and drink, but whose real job is to manage this sometimes uneasy and motley collection of family, friends, and total strangers, so that they may hurtle through the air at 900km/h most importantly keeping themselves, i.e. the airplane and everyone in it, safe and sound for a few hours.
Obviously pilot stuff is hugely covered on many websites, forums, podcasts, and youtube channels (Mentour Pilot and Captain Joe are particularly recommended, although there a lot of channels). I’m not really going to go into that. I can’t fly a Cessna, let alone a Boeing 73H. I’m concerned with how, why, and when the information they need to do their job, and the data that they generate in doing their job, is processed and delivered.
This is the other part of the airline you will have contact with. Well, that in fact depends on the airline and the airport. My airline has employees at all 4 of its major hubs. At other airports they are contractors. For other airlines they may be all contractors, or a mix like mine. I can’t and won’t say. But contractor or employee, they are responsible for not only helping you with checkin, printing your bag tags at the kiosk, navigating automatic bag drop, and scanning your boarding pass as you enter the gate. The guys who assist the airplane at the gate. Engineers on call. Tug drivers, teams that handle and process your baggage, freight, pets and all the rest. Refuellers who work for the fuel company.
All this is the surface of the iceberg. What you don’t see the endless gate planning, ramp co-ordination, baggage services, labour planning and task assignment, and myriad other ground services required. At a lot of places this stuff (especially gate planning) is done entirely by the airport. At our airline, we spend a lot of effort co-ordinating activities with the stuff the airport does provide. The airline-airport relationship can be adversarial at times. Especially at privatised airports collecting rents via transiting people.
Network operations is the part of the airline that travellers really don’t see, and most don’t even know exists. It’s the one that can have the biggest impact on your travel. Network operations runs the operational control centre (OCC). This has many different components which allow it to control the operations of the entire flight network for the airline. The crew scheduling and control function, responsible for making sure that there are the correct numbers of flight and cabin crew, with the appropriate qualifications, in the right aircraft at the right time, is part of this back office department. The aforementioned OCC is responsible for making sure all the equipment (the aircraft) are in the right place at the right time, closely liaising with numerous internal departments like the meteorologists, flight planning (they create flight plans), flight dispatch (they perform a function called load control), slot controllers, a special flight disrupt team (who re-accomodate passengers onto new flights if there is a disruption, like cancellation, or a missed connection), of course, key people in the ground and flight operations departments as well as the guest services people, and, critically, the air navigation service providers (ANSPs) that manage the airspace we will fly through, which is a function you may otherwise refer to as ‘air traffic control’.
Flight planning is a process by which the flight planners take in data from the ANSPs, the weather, the expected passenger and cargo load and produce a flight plan. This contains the planned fuel amounts (e.g. block, taxi, take off, minimum take off, and trip fuel amounts, among others) for the flight and the expected route the flight will take taking all conditions into account. This plan is filed to the relevant ANSPs, and the flight crew of course, as well as handed off to the load control department.
Load control is responsible for maintaining the aircraft’s trim, that is to say, its weight, and the balance around the centre of gravity. Load control parameters can determine why you get a limited seat selection when you check in (as well as, naturally, the type of fare that you bought): it can also result in you being asked to move seats as you board. Obviously the effect of too much weight on an aircraft should be manifestly obvious. However, trim is just as vital for the aircraft’s safe operation: if the weight distribution is uneven, the aircraft may not fly stably, or even at all. They also have to pay attention to things like connecting bags and priority bags (belonging to first and business class passengers) so these bags are not only distributed in the aircraft’s cargo holds properly for the purposes of trim, but are also able to be retrieved from the aircraft quickly, so they can connect to the onward flight, or prevent our high value guests from waiting too long at the baggage carousel. From all these inputs they produce a load plan (which includes the revised fuel figures) which is sent to the pilots, and the ground crews loading and unloading the plane.
The pilots have final say over the acceptance of the load plan and the flight plan.
There are myriad other functions in all these departments which I’ve only just touched on, or not touched on at all. Hopefully you’ve gotten the gist of just how complex the logistics and planning of even a single plane full of people can be!
There are so many interdependencies between all these factors, and the external companies that we deal with (catering has remained unmentioned here for example!), and the external factors like the weather. The really interesting thing about airlines, is this complex dance on the tarmac and in the skies of hundreds of aircraft and other ancillary equipment and literally thousands of people has to be repeated over and over each and every day, even on Christmas, to a level of regulated precision and exacting standards of safety.
All this makes for a really fascinating and interesting computer systems environment. Something I will touch on in my next article in this series.