THIS PERIOD AT A GLANCE
IST is now Europe's busiest airport by daily movements, operating triple independent runway procedures since April 2024 — a fourth runway is scheduled for Summer 2026
SAW is officially at capacity — DHMI prohibits additional foreign airline scheduled flight permits and will not accept technical landings or diversions
Turkish operators departing from both airports face fundamentally different slot environments and different ATFM exposure profiles
ISTANBUL AIRPORT (IST) — THE CAPACITY STORY
Istanbul Airport is now the busiest airport in Europe by daily flight operations. Passenger traffic from January to November 2025 reached 77.5 million, a 4% increase year on year, and the airport is targeting approximately 90 million passengers in 2026. RestProperty
The infrastructure to handle that growth has been moving fast. In April 2024 DHMI and iGA inaugurated triple runway operations — the first airport in Europe capable of simultaneous independent triple runway operations — increasing hourly capacity from 120 to 148 movements. EUROCONTROL That additional 28 movements per hour is significant. It provides meaningful buffer against the ground-stop cascades that previously hit IST during peak morning and evening banks.
A fourth runway oriented east-west is scheduled to enter service in 2026 Daily Sabah, which will further increase capacity and provide geometric flexibility for traffic management under crosswind conditions. For flight ops teams, this means IST's ground constraint profile is improving — the bottleneck for IST-origin flights in Summer 2026 is not the airport itself but the European airspace receiving those flights.
The practical implications for departure planning from IST:
The 0500–0900 UTC window remains the most congested departure bank. THY, AJet, and Pegasus combined generate an enormous volume of westbound departures in this window — all competing for the same ATFM slots into congested European ACCs. CTOTs issued in this window can stack. A crew that pushes back on time, taxis efficiently, and is ready at the threshold with margin does not lose their CTOT window. A crew that is two minutes late to the runway threshold on a 10-minute CTOT window has given away their slot.
SABIHA GÖKÇEN (SAW) — THE CONSTRAINT PICTURE
SAW operates in a fundamentally different environment. Due to insufficient capacity at Istanbul Sabiha Gökçen Airport, additional flight permits except those established under bilateral agreements are not granted for foreign airlines operating scheduled flights. Technical landings and diversions to Sabiha Gökçen Airport are not accepted. Flight plans shall not be accepted, no flight permissions shall be granted and no slot shall be allocated outside of existing rights. Turkish Ministry of Health
This is not a temporary measure — it is the standing operational policy reflecting the airport's structural slot saturation. SAW is primarily the base for Pegasus Airlines and AJet, both of which hold historical slot rights. For those carriers the constraint is about protecting schedule integrity, not obtaining access.
SAW's second runway became operational in December 2023, increasing hourly capacity from 40 to 80 aircraft movements. Wikipedia That doubling of theoretical movement capacity has absorbed near-term demand growth, but the airport's single terminal design and ground infrastructure constrain practical throughput. Turnaround times at SAW are tight. Schedule padding is minimal for LCC operations. When a rotation runs late at SAW it cascades quickly through the fleet.
AJet is increasing its SAW–Sharm El Sheikh frequency to 14 weekly flights from June 15, 2026 AeroHaber — one example of the continued capacity pressure being applied to SAW's summer schedule. Every additional rotation on a slot-constrained airport reduces the margin available to absorb ATFM delays on European-bound services.
THE TWO-AIRPORT ATFM PROFILE
IST and SAW generate different ATFM exposure patterns that flight ops teams should understand distinctly.
IST — High volume, well-managed ground infrastructure, improving runway capacity. ATFM exposure is primarily en-route, concentrated in French and UK airspace. CTOTs on IST departures tend to be longer in duration but more predictable — they come from known structural constraints in European ACCs, not from ground-side chaos at the origin.
SAW — Tighter scheduling, LCC operations with minimal padding, single terminal. ATFM exposure at SAW is compounded by reactionary delay risk. A 20-minute CTOT on a SAW departure into CDG or LGW is manageable. A 20-minute CTOT on top of a 15-minute late arrival from the previous rotation — on a 35-minute turnaround — is a missed slot. The reactionary delay problem at SAW is operationally more serious than the ATFM delay itself.
RISK WINDOWS — ISTANBUL SPECIFIC
Eid al-Adha — June 2026: Turkish domestic and regional traffic peaks sharply. Both IST and SAW departure banks become heavily congested simultaneously. European-bound flights compete with a volume surge on domestic and MENA routes. Brief for extended taxi times and potential departure sequencing delays.
July 4–6 weekend: Peak leisure departure weekend from both Istanbul airports. European airports simultaneously at or near peak capacity. The combination of maximum IST/SAW departure volume and maximum European arrival constraint is the highest ATFM risk window of the year.
Mid-August: Return traffic from Europe peaks. Inbound slots into IST and SAW from LHR, CDG, FRA, AMS come under pressure. Arrival ATFM regulations are less common than departure CTOTs but they do occur — and an arrival ATFM regulation means holding fuel, missed connections, and crew duty time pressure.
AIRPORT DEEP DIVE — THE IST DEPARTURE SEQUENCE
Something every crew flying out of IST in the summer peak should brief but few formally do: the departure sequencing environment at a 148-movement-per-hour airport is not the same as a 120-movement airport.
Triple runway operations mean three simultaneous departure streams. The sequencing logic at IST now assigns runway based on departure route — roughly, westbound traffic uses different runway assignments than southbound or eastbound. This affects taxi routing. A crew assigned to the western runway complex for a CDG flight will taxi a different route than a crew going to DXB. The taxi time difference can be 8–12 minutes. That margin matters when you have a 10-minute CTOT window.
Brief the taxi routing. Know which runway the ATIS is advertising for your departure direction before push. Don't assume the taxi time from your last IST turnaround applies to today's routing.
FROM THE FLIGHT DECK
IST is now genuinely one of the most complex departure environments in Europe to operate out of at peak times. Three simultaneous runway streams, a huge volume of traffic, and an ATFM overlay from European ACCs all intersect in the same departure sequence. The crews who manage this well are not the ones who rely on ATC to sort it out — they're the ones who brief specifically, communicate early, and treat the CTOT window as a precision instrument rather than a rough guide.
NEXT ISSUE
The Balkan Corridor — how the Ukraine airspace closure permanently rerouted IST–Western Europe traffic through Budapest, Zagreb, and Belgrade FIRs, what it costs in fuel and block time, and which ACCs to watch this summer.
Clearance is published twice monthly. Written by Cengehan Vefali, First Officer B737, Istanbul. Data sourced from Eurocontrol Network Manager, CODA delay statistics, and NOP rolling plan publications.