burkey wrote:

Is there a convenient train
plus underground route? No stairs please because the passenger will
have both a suitcase and an over-night bag to carry.

The passenger could get the London Midland/Southern service from
Watford Junction (Lifts available) to Harrow Wealdstone (99% of the
time this comes into platform 6) ramp available, then cross the road
and get on the 140 bus to Heathrow? No stairs needed here!

Does the bus have proper storage for luggage? Will the driver or
conductor help with the handling of luggage? The Green Line 724 fails
on these counts and swapping one such bus for another like it is no
advantage.

--
Which of the seven heavens / Was responsible her smile /
Wouldn't be sure but attested / That, whoever it was, a god /
Worth kneeling-to for a while / Had tabernacled and rested.