This stock commenced full service on the route on 14th May 1984 replacing 4-Veg EMUs (4 Veps modified with some seats removed to accommodate luggage racks) which, being basically suburban units, did not provide the level of comfort expected by passengers accustomed to air services.

In the true Southern make-do tradition new stock was not procured and existing handed-down BR stock was modified. Surplus class 73 EDLs were assigned to provide the majority of the traction power. Passenger accommodation was provided by refurbished and modified (revised seating plan, increased luggage rack space, plus handbrakes added to some coaches) MkII air-conditioned coaches available after the introduction of HST 125s on the Midland main line. Baggage/guards accommodation was provided by "Gatwick Luggage Vans" (GLVs) converted from 2 Hap driving motor coaches, re-designated class 489.

With each train consisting of trailer coaches sandwiched between an EDL normally at the south end and a GLV at normally the north end it was originally conceived that the trailer coaches would be formed into 4 car sets each consisting of 1 first class open and 3 standard class opens. However they were introduced into service in 2 and 3 car sets, class 488/2 formed TFOH - TSOH (H = handbrake) and class 488/3 formed TSOH - TSO - TSOH. In the summer they ran as 8 car formations with the 488/2 set in the middle so that the first class accommodation would stop adjacent to the escalators at Gatwick Airport station. In winter they ran as 5 car formations with one 488/2 and one 488/3. Towards the end of their service on the route 5 car formations became the norm with the 1st class coach - by now termed "Club" - situated next to the GLV.