**Yes—grounding an entire aircraft type can cause noticeable cancellations. Airlines have ways to reduce the disruption, but they generally cannot replace every grounded aircraft immediately.** The cancellation figures in your update are consistent with that.

Airlines plan for individual aircraft becoming unavailable through maintenance or breakdowns, using spare aircraft and flexibility in their schedules. Losing a whole type at once can exceed that allowance—and any spare aircraft of the grounded type are unusable too.

Their main options are to:

- Reassign other aircraft and use available spare capacity.
- Keep older aircraft that were due to retire or leave the fleet.
- Lease replacements, sometimes with crews supplied by another operator—a *wet lease*.
- Combine departures using larger aircraft, reduce frequencies, and rebook passengers.
- Cancel flights or postpone new routes when those measures are insufficient.

For a concrete example, **Air Canada reported protecting 96% of its planned flying** after the 2019 MAX grounding. It extended leases on six existing aircraft, accelerated the arrival of replacement aircraft, contracted other carriers, and combined some frequencies onto larger aircraft. It still suspended some routes and delayed some launches. [Air Canada’s first-quarter 2019 report](https://www.aircanada.com/content/dam/aircanada/portal/documents/PDF/en/quarterly-result/2019/2019_MDA_q1.pdf)

Replacement capacity also has limits: the aircraft needs suitable range and capacity, qualified crews, and maintenance support. When many airlines simultaneously seek replacements, they are competing for the same available aircraft.

**The important factor is the airline’s dependence on the grounded type, rather than the country’s size.** A small airline with only a few MAX aircraft might lose a large fraction of its capacity. A much larger airline could absorb the same number more readily. Southwest, for example, said its 34 MAX aircraft accounted for less than 5% of daily flights when the grounding began. It subsequently reported approximately 2,800 MAX-related cancellations through the end of March 2019. [Southwest’s grounding statement](https://investors.southwest.com/news-events/press-releases/detail/445/southwest-airlines-statement-regarding-737-max-8), [March 27 operating update](https://investors.southwest.com/sec-filings/all-sec-filings/content/0000092380-19-000044/coverpage03-27x19.htm)

For travellers, the effect is therefore uneven: many flights operate normally, while particular routes lose departures or require different connections. A flight originally scheduled on another aircraft can also be affected if that aircraft is reassigned to cover a grounded plane’s route.

Duration matters, too. A short grounding mainly requires immediate substitutions and rebooking. A prolonged grounding forces airlines to rewrite schedules, and missed deliveries can further reduce planned capacity. Southwest ultimately deferred aircraft retirements to cover part of that deficit. [Southwest’s 2019 results](https://investors.southwest.com/news-events/press-releases/detail/394/southwest-airlines-reports-47th-consecutive-year-of-profitability)