get_aircraft_url: Put together the url of aircraft data files
Description
Put together the url of aircraft data files
Usage
get_aircraft_url(date = parent.frame()$date)
Value
A url string.
Arguments
date
Numeric. Either a 6-digit date in the format yyyymm or a 4-digit
date input yyyy. Defaults to NULL, in which case the function
retrieves information for all years available.