Date: 201707
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B747 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Aircraft component: Pneumatic Ducting
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying; Relief Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Ground Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Returned To Gate; General Physical Injury / Incapacitation; General Maintenance Action
Contributing factors: Human Factors; Aircraft; Procedure
Primary problem: Ambiguous

Narrative: We arrived at the gate and were informed that Maintenance is working on APU. Aircraft was towed in from the hard stand; and APU failed during towing onto the gate. Upon entering a flight deck Maintenance was still in the cockpit; informing us that APU will most likely be placed on MEL as they were unable to start it. QRH did not provided an exact guidance of which engine to start first; we elected to start 4; then conduct Crossbleed by starting 1;2;3. After completion of boarding procedures; we started our before push preparation; coordinated with ground crew the Ground Pneumatic Start per QRH. We received permission to start an engine at the gate. Engine #4; started normally without problems. Upon completion of an engine start using an external pneumatics and electric sources per QRH; we accomplished the rest of the checklist and called for pushback. We received a pushback delay. After receiving a pushback clearance; we have pushed back into the alley; and received a clearance to start the rest of the engines using Crossbleed procedure. We followed the QRH Crossbleed Start procedure to conduct all remaining engines start; electing to start Eng#1; first. The bleed source was showing about 73 PSI; a First Officer (FO) waited for 25 N2 but engine rotation was showing stable at 24 N2 (a max motoring in this case); he placed RUN on fuel control. ENG #1 showed a slight EGT rise but experienced a Hung start. We consulted QRH Aborted Engine Start and elected another attempt per QRH; however achieving the same result.We were contemplating the systems of pneumatics on B747 and relationships of distance and pressure; however; since QRH has no guidance to do any other procedures we were reluctant to try any other methods like starting Eng#3 etc. We have informed the apron controllers and company that we are experiencing problems with engine start and will need to return to the gate. We were informed that we need to go to a remote hard stand area to troubleshoot since our original gate is no longer available; and they need access to the alley. We have informed them that we are unable to move on a single engine; due to the Aircraft weight. Outside temperature was around 30C and we were under single engine with single Pack unable to move; and receiving no help form Apron controllers. In the meantime; a Flight Attendant called flight deck and informed me that one of the passengers has passed out; is on the floor; and receiving an oxygen; other passengers are complaining about excessive temperature in the cabin. We asked for medical assistance immediately to attend the customer in need. After medical team took care of the passengers in need; we were towed back to the gate; deplaned all passengers to main building so they can received more assistance in air-conditioned environment.Shortly after deplaning; Maintenance personal showed up and explained that B747 especially old ones; x-bleed start should be accomplished by starting an adjacent engine to an engine already running; since the distance between 4 and 1 is to long and there are always losses in pneumatic pressure due to some leakage in the system. We informed the Maintenance gentlemen that we appreciate his input and it makes a total sense and logic; however; our QRH does not provide engine start sequence in x-bleed procedures. Furthermore; no one from Maintenance has informed us as to what is the recommended start sequence in x-bleed procedure.


Second narrative: Hot day with inop APU. Pneumatic ground start with engine 4 prior to pushback. After push unsuccessfully cross bleed start. Advised by flight attendant that a passenger was unconscious and requested medical assistance.


Synopsis: B747 flight crew reported being dispatched with an inoperative APU causing the number one engine being unable to be started via crossbleed; leading ATC issues and overheated passengers on a hot day.