ummm
excuse me we have had the 737 in the UK since 1968 (Britannia)
why does QF need to trial using a set of steps on the back door in 2015!!
its laughable - is this really news lol
2 sets of steps works wonderfully well in obtaining quick orderly turnarounds and our charter carriers since jets were invented always nearly had 2 sets of steps - boarding by seat number - god this is 40 odd years on!!!
737 fwd airstairs and rear set manual steps
1-11 fwd and aft airstairs (self sufficient) as was many 727's too if they had fwd airstairs
DC-9 self sufficient
707 and DC-8 2 sets of steps