Final answer:
A PIREP is a Pilot Report on actual weather conditions encountered during a flight. 'CYXU 010005' in a PIREP refers to the London International Airport in Ontario, Canada, and indicates the observation at 00:05 UTC time on the first day of the month.
Step-by-step explanation:
In aviation, a PIREP stands for a Pilot Report. It is a report of the actual weather conditions encountered by an aircraft during flight. The code CYXU 010005 is likely to be a part of a PIREP, where 'CYXU' refers to the identifier of the airport (in this case, London International Airport in Ontario, Canada), and '010005' indicates the time the observation was made, which could be interpreted as the first day of the month at 00:05 Zulu (UTC) time. PIREPs are useful to meteorologists and pilots for understanding and forecasting weather conditions, and they typically include information such as turbulence, icing, sky cover, visibility, and weather phenomena.