But because passengers are this time being given up to five weeks' notice of the cancellation, they will not receive any extra compensation under European Union passenger rules.
There was no immediate indication of how costly to Ryanair the latest cancellations would be.
In a statement to customers, pilots and shareholders, Ryanair said the move would minimise flight delays and would mean an earlier threat to force pilots to reschedule holidays would not be carried out.
The Irish no-frills airline plans to fly 25 fewer aircraft during its winter schedule, hitting less than one percent of its customers but more than doubling the amount of passengers originally affected by a cancellations crisis plaguing Ryanair since mid-September.
The latest wave of cancelations will affect 400,000 passengers, suspending 34 routes during the winter season.
Ryanair has also emailed each of the 315,000 customers whose flights were previously cancelled over a 6 week period in Sept and Oct. (Ryanair carries 15m customers every 6 weeks) It has offered each of these customers a Euro 40 travel voucher (EUR 80 return), again for travel between October and March 2018.
Ryanair said passengers affected by the cancellations up to the end of next month have been sent emails advising them of the flight changes.
Yellen makes case for gradual tightening
Weekly data on USA petroleum supplies will be released by Energy Information Administration late Tuesday and arly Wednesday. Traders had no details on the plan, but speculated it might raise the federal deficit and increase government borrowing.
The Gender of Kylie Jenner's Baby Has Officially Been Revealed
Blac Chyna and Rob Kardashian only recently came to an agreement on custody of their daughter, Dream Kardashian . Those of you with eyes, ears, and access to the internet will be aware of the Kylie Jenner pregnancy reports .
Intel 8th-gen Core for Desktops Unveiled: What Gamers Need to Know
Intel's newest processor has been built fit for content creators, gamers and over clockers that need the most premium performance. Prices for the new lineup start at $120 for the 3.6GHz Core i3-8100 and go up to $359 for the 3.8GHz Core i7-8700K.
According to Ryanair, fewer than 100 of over 2,000 captains left Ryanair this year, with fewer than 160 co-pilots leaving, many due to retirement or for longer-haul routes.
It said this will "eliminate all risk of further flight cancellations, because slower growth creates lots of spare aircraft and crews across Ryanair's 86 bases this winter".
In addition today, they are receiving a travel voucher (€40 one way/€80 return) which they may use to book any Ryanair flight of their choice during October for travel between October and March 2018.
Average fares are also expected to be slightly lower over the next two months as it promotes seat sales, it added.
The letter concludes: "Rest assured there will be no repeat of last week's roster related flight cancellations".
Ryanair said: "We have notified the Alitalia bankruptcy Commissioners that we will not be pursuing our interest in Alitalia or submitting any further offers for the airline".