Airline information systems — this topic has gotten complicated with all the buzzwords flying around. I worked with a regional carrier’s IT team for a stretch a few years back, and honestly, even people inside the industry sometimes can’t explain how all the pieces fit together. Let me walk through the main systems airlines depend on, because there’s more going on behind that booking confirmation email than you’d think.
Passenger Service Systems (PSS) — The Big One
If you’ve ever booked a flight, changed a seat, or checked in online, you’ve interacted with a PSS. It’s the core system that handles reservations, ticketing, and inventory management. The three major PSS providers — Amadeus, Sabre, and Travelport — power the vast majority of airlines worldwide. Some of the bigger carriers have built proprietary systems, but even they tend to integrate with these platforms at some level.
The reservation component tracks every booking, every itinerary, every fare class. Ticketing handles the financial side — issuing tickets, processing refunds, managing fare rules that are absurdly complicated (seriously, airline fare structures could be their own college course). Inventory management controls how many seats are available at each price point, which shifts constantly based on demand.
Probably should have led with this: the PSS isn’t just one application. It’s a suite of interconnected modules that talk to each other and to external systems like travel agencies and online booking platforms. When your travel agent pulls up flight options, they’re querying the PSS in real time.
Departure Control Systems (DCS)
Once you move from “I have a reservation” to “I’m actually at the airport trying to board,” the Departure Control System takes over. DCS handles check-in (whether you do it at the counter, a kiosk, or on your phone), boarding pass generation, seat assignment, and — this is the part most people don’t see — weight and balance calculations for the aircraft.
That last bit matters more than you’d think. The system has to know how many passengers are on board, where they’re sitting, how much baggage is in the hold, and how much fuel is loaded, then calculate whether the aircraft’s center of gravity is within safe limits. Pilots get a load sheet before departure that comes straight from the DCS. I remember being surprised by how much math goes into just getting a plane pushed back from the gate.
Flight Operations Systems
This is the behind-the-scenes stuff that passengers never see but pilots and dispatchers live in. Flight operations systems handle flight planning, crew scheduling, fuel management, weather integration, and maintenance tracking. The flight planning piece alone is surprisingly involved — it has to account for winds at different altitudes, airspace restrictions, fuel costs at different airports, and alternate routing in case of weather or closures.
Crew scheduling is its own beast. Airlines have to comply with regulations about duty time limits, rest requirements, and certification (not every pilot is rated for every aircraft type). The system has to juggle all of that while keeping costs down and making sure the right crews are in the right cities at the right times. When things go sideways — say, a snowstorm cancels a bunch of flights — the crew scheduling system is working overtime to piece together a recovery plan. Or trying to, anyway. Sometimes it feels like it’s held together with duct tape. Actually no, that’s unfair — it’s more like controlled chaos managed by some pretty impressive software.
Customer Relationship Management (CRM)
Airlines have gotten really sophisticated about tracking passenger preferences and behavior. CRM systems store your frequent flyer data, travel history, preferences, complaint records, and spending patterns. This feeds into marketing — those targeted emails you get about fare sales to cities you’ve visited before aren’t random. The CRM flagged you.
It also drives service recovery. When things go wrong (delayed flight, lost bag), the CRM can tell the agent whether you’re a first-time flyer or a top-tier loyalty member, which — for better or worse — influences how aggressively they try to make it right. I’ve seen both sides of this and it’s a little uncomfortable, but it’s how the industry operates.
Cargo Management Systems
Most people forget that commercial airlines carry a ton of cargo in the belly of passenger aircraft. Cargo management systems handle booking, tracking, customs documentation, and capacity management for freight. It’s practically a parallel business running underneath the passenger operation.
These systems have to integrate with the DCS (because cargo weight affects that load sheet I mentioned), with customs and border agencies, and with freight forwarders who are booking space. During the pandemic, when passenger flights dropped off, some airlines pivoted hard to cargo-only operations, and their cargo systems had to scale up fast. That was a real stress test for a lot of these platforms.
Enterprise Resource Planning (ERP)
On the corporate side, airlines run ERP systems for finance, procurement, human resources, and supply chain management — pretty standard stuff that any large company needs. What makes airline ERP a little different is the scale and the regulatory environment. You’re managing a fleet worth billions, a workforce spread across dozens or hundreds of cities, and procurement that ranges from jet fuel to in-flight snack boxes.
The financial reporting alone is complex because airlines deal with multiple currencies, interline agreements with other carriers, and revenue recognition rules that are specific to the industry. SAP and Oracle are the big players here, usually with heavy customization for airline-specific needs.
How It All Connects
That’s what makes airline IT endearing, in a weird way — none of these systems exist in isolation. The PSS feeds the DCS, which feeds flight operations, which feeds back into the PSS when schedules change. CRM pulls from all of them. Cargo talks to DCS and flight ops. ERP sits over the top tracking the money. It’s a web of integrations, APIs, data feeds, and sometimes legacy connections that haven’t been updated in years.
When it works, you book a ticket, check in on your phone, walk onto the plane, and your bag shows up at the other end. When it doesn’t — well, we’ve all seen those viral meltdown stories. Usually it’s one of these system links breaking down and causing a cascade. The technology is impressive, genuinely. But it’s also fragile in ways that are hard to appreciate until you see the wiring behind the walls.
