146 engine start-up question
When in Maun/Botswana 3 weeks ago, I noticed an Air Botswana 146 obviously having some difficulties in running up the 4 engines. No. 1 had started, it took another 10 minutes, than the door opened, an engineer (? - not one of the two pilots anyway) came out, went to the right side of the aircraft, pulled a hose out from near the main undercarriage, connected it to somewhere at the right wing, No. 4 got started, hose was stored back, doors closed, 2 and 3 started after quite a while, and off they went to Gaborone.
Now - as you can clearly see from my post, I have not the slightest idea of how to get a 146 off the ground, but could anybody please give me a rough outline of what the Air Botwana crew was doing??? Any info greatly appreciated, thanks!
Hopper