Upvote:5
In short, don't worry about it. As long as the first name and last name in the passport match, you should be good to go.
Middle names are generally ignored in flight reservations: many legacy systems can't even handle them, so they get shoehorned into the first name and often truncated in the process. You're not going to find an 'official' source for this, but here's one largish travel agent on the topic:
My ticket does not show my middle name β does it matter?
The majority of airlines simply require that the first name and surname shown on your ticket match the first name and surname shown on your passport. Middle names are not normally required.
Even the US, which is generally very picky, doesn't care about middle names on tickets, only in SFPD (their version of API). American Airlines:
Q: Is the middle name or initial required for Secure Flight documentation?
A: For SFPD data the passengerβs full name as it appears on a person's valid government-issued photo identification that will use when traveling. ...
NOTE: The middle name or middle initial is not required in the name field of the reservation for ticketing or upgrading purposes. GDS functionalities differ and may not support the middle name or middle initial.