witches are selected ON and APU BLEED AIR is selected ON (isolation valve opens automatically). or: • Any two of the three available bleed sources (L ENG, R ENG and/or PRODUCTION AIRCRAFT SYSTEMS 2A-36-00 Page 7 Janaary 31.07 Keyision 6 EFTA_R1_02095983 EFTA02705531 CUINIFC:IM IV OPERATING MA