What happens
Found it flat in Hillingdon? Leave it where it is.
Heathrow has its own flat-tyre hazards: a screw picked up on the M4 spur that empties the tyre over a week in an airport car park, a valve that gives up at the drop-off, a slow leak found at the pick-up on the Bath Road. Every part of the airport, terminals, drop-off zones and car parks, is private and patrolled, so nobody can work on a tyre there. The nearest public streets are in Harlington, Sipson and Harmondsworth.
If the tyre holds some air, drive it gently out to a residential street in Harlington or Sipson and call with the road name and the size; if it is fully flat, put the spare on or use an inflator kit, or ask airport recovery to bring the car out to that street. Once there, the fitter strips the tyre, traces the leak and says whether it is a BS AU 159 repair, a valve or bead fault, or a replacement, each priced on the phone.
On run-flat tyres? They behave differently once deflated, so check the handbook's limits and read our page on run-flat tyres; we fit replacement run-flat tyres at the car in Hillingdon as well.
The same Brent Cross team also handles broken tyre replacement and 24 hour tyre repair in Hillingdon, booked on the same call.