Indeed. Back in the mid-90's, over the Easter period, my parents and I were unable to get back home on staff tickets from DEL-LHR on BA for 4 days in a row as the flights were absolutely rammed. We tried getting the ticket endorsed on other airlines too, but same story. Eventually we had to purchase one-way tickets on AF in J as even Y was maxed out (apparently) across all the usual airlines for a further 6 days. That was the first & last time we flew anywhere standby in peak season!