Thanks for the reply and information. I'm a little confused now though as the job ads on Titan's website are as follows (I'm too new here to post the URLS):
Stansted:
Applicants must be 18 years plus, drive and own a car and be within 30 minutes of Stansted airport on a standby duty.
LGW
Applicants must be 18 years plus and be within 60 minutes of Gatwick airport on a standby duty.
I was assuming that means 60 mins to report for the LGW contract.