At EGKK, ( and probably lots of other airports as well ) there are certain Stands where you should not use the APU between 23.00 and 0700 Hrs.
So, to comply you have to run a conditioner truck to keep the cabin cool during boarding and then have two dirty great big air start trucks screaming away just to start the engines....if its a really bad day and the fixed ground power is U/S , you will have to have a GPU as well....... all instead of an efficient APU !
OK, the APU on the 747 makes quite a lot of noise but its still less than the lot above ! and most other types now have extremely quiet running APUs
Never liked using Ground start trucks........not when you've seen a hose burst......... of course ground equipment is always kept in A1 condition ..........NOT !
