After many years of flying with an elderly relative in her 90`s, with many mobility issue I would say the SA at Heathrow is quite reasonable. Do talk to someone if you think time is getting tight as we were once, many years back, forgotten at Stansted airport though they did manage to get us on the plane very last minute.

Other airports around the world vary and and you do need to leave extra time and be patient. On my recent trip home from Hamburg airport, when for once I was the one in need of SA having damaged my knee, I was sad to discover the service was barely functional. There were insufficient wheelchairs and the staff were clearly overworked. I was told a lot of people these days are using the service merely as a means to skip security queues and get an easy ride through the airport. Upon arrival back in the UK I asked the assistance help there if they had experienced the same problems and was given a vehement yes.

When having to re-arrange flights etc over the last Xmas period due to my husband having an accident I found BA to be extremely helpful, and happy to explain how they could help (book an appropriate seat, board first etc) and though the flights had to be re-arranged yet again to a time later this year when the SA should not be required, (the doctors strikes meant he could not be get a fit to fly report) BA have remained helpful and accommodating.

Whilst the airline is responsible for booking the SA the airport is responsible for delivering it.