Date: 202104
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: APU
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness; Troubleshooting; Workload
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Flight Deck / Cabin / Aircraft Event Illness / Injury; Ground Event / Encounter Ground Equipment Issue
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Release Refused / Aircraft Not Accepted
Contributing factors: Equipment / Tooling; Company Policy; Aircraft; Human Factors; Weather
Primary problem: Human Factors

Narrative: Some really troubling events unfolded on our flight; ZZZ-ZZZ1. After ground power failed and the high pressure air carts were removed to be repositioned for a gate start (APU is on MEL) the cabin environment was no longer safe or acceptable to have nearly XXX passengers onboard. I had the FO call ZZZ Operations on the radio to have them send an agent to open the cabin door and deplane the passengers. The jetway was still attached to the aircraft but nothing was being done to get the passengers safely off the jet.  I turned on my cell phone and called the ZZZ ramp manager's phone number and requested immediate assistance. After further needless delays several flight attendants came to the flight deck to tell me they could see the agents standing in the jetway but there were doing nothing; my request to begin the deplaning was being ignored. I next called the flight office and requested a Chief Pilot and a manager to come ASAP to gate XX to assist. I have attached several photos to include the air synoptic of the excessively hot cabin temperatures after the air start units were removed and the jetway power failed! It gets much worse; and I will provide the whole narrative as it unfolded.When I arrived at the gate 50 minutes or so before departure I was informed that only the first officer had arrived and was onboard. The gate agent had just received a call that the cabin was very warm and ZZZ Operations wanted us to start the APU (why did Operations not know the APU was placarded). I assured them that the FO was most likely already addressing the matter. When I arrived at the flight deck I saw the FO had the air synoptic pulled up and I noted the aft cabin temp showed 102F. The FO pointed out that the APU was placarded inoperative. Air start units were being connected at this time to power the air conditioning pacs. During the FO's walk around he had taken a picture of the way the ground crew had connected the PCA hoses. How long had the PCA even been hooked up is unknown; the jet arrived at this gate at XA:00 in the morning; but regardless; it was all to evident the PCA air was not making it into the cabin do to the improper connection. The FO joined me and we returned to the terminal; I spoke with the gate agents and told them it would be a fairly long delay waiting for the cabin to cool.  I asked them to keep the flight attendants from boarding the hot jet when they began arriving at the gate area.  After the ground crew had finished hooking up the air start carts; the FO and I went to the flight deck to check that the air conditioning was functioning. Nearing the schedule departure time we were finally getting the cabin temp to where boarding could begin. After boarding was complete and the cabin door closed the ground crew checked in and cleared us to start the right engine. I informed them that on this aircraft; per the manual; the left engine is started first with ground air start. The ground crew had positioned the air start units incorrectly to start the left engine. I told them to let me know when the left engine was clear for starting. The crew then shutdown the air start; even though they did not have a tug hooked up to reposition the equipment!  We no longer had ANY cooling airflow into the cabin. A couple of minutes later the electrical power from the jetway fails. The ground crew begins fiddling around but can't get the power restored and there are no portable power units near this gate. I later learned; after speaking with a facilities manager; that this jetway power supply had a service tag hanging from the power panel and should not have been used do to erratic 400HZ service. So with only battery power on the airplane; recirculating fans have shutdown; there is no cool air being provided; you can see [on] our air synoptic the cabin temps quickly were above 95-98 F.  In the interest of safety for the passengers it should be obvious why I requested an immediate de-planning of the passengers.  Unsatisfactory that ZZZ station was delaying opening the cabin door and safely removing the passengers.  I even resorted to threatening a ground evacuation after a repeated request for help to draw their attention to the seriousness of the issue at hand.  Passengers are wearing face coverings in a cabin approaching 100 F with all the cabin and cargo doors closed.  Still the gate agents would not open up the cabin to begin deplaning the passengers until some passenger service manager gave the go ahead; why?After the passengers had begun deplaning the ground crew finally located a portable electric unit and began reconnecting the air start carts so we could operate the air conditioning. The ramp supervisor was now on the flight deck with us with along with some other manager in tow. They were questioning why I had their ground crew shutoff the air start units and have them moved. I said that is not what I told them to do. I only stated that per this aircraft manual the left engine is to be started and to let me know when the area was clear to start the left engine. While discussing the horrible failings and going over the situation I looked up and noticed the ground power had only been restored to the PRIMARY GRD source. This aircraft requires two ground power feeds or one from the ground and the APU; our APU was still placarded INOP! There is a risk of overheating the eclectic connection the way they had provide power (see PIC). I pointed this out to the manager. I also asked him that when they provide the correct ground power and air conditioning and we can get around to re-boarding the passengers are we going to have a ground crew available so we can start and pushback as quickly as possible. The manager assured me they would have a crew there for us. He lied!  After we had closed the cabin door with our original passengers minus 20 or so that chose to not fly with us; I called the ground crew to get the go ahead to start. No ground crew at our gate!  The FO called ramp to ask where our ground crew had gone? Twenty seven minutes later a crew arrives at the nose but does not check in on the headset. I have the nose camera on so I can see them as they fiddle around with connecting a tow bar and what not. I had flashed the nose taxi light to get their attention and made many interphone GND crew alert chimes; all of these signals were ignored. When they did finally get on the headset I expressed some frustration that we could have been starting the engine while they prepared for the pushback. They were quick with the excuse that they had just arrived and were unaware of the situation. When we were cleared to start the left engine the air start units were not running in the high flow position and the duct pressure has only 16 PSI; 25 PSI is minimum to start. I asked them to check the start units were set correctly. This ground crew had no idea how to operate their equipment. The AutoStart of the left engine failed on the first start attempt. The second start attempt reached idle and stable barely.Almost three hours late and somewhere about half way to ZZZ1 from ZZZ I noticed that ZZZ1 had us arriving to gate XX; even though the APU was on placard. ZZZ1 gate XX is a tow in only gate with engines shutdown per the ZZZ1 airport pages. FO wants to send a message to dispatch right away. I say lets just give them a little more time to do the right thing and see if they get it sorted out. Sure enough about an hour from arrival we send for the changeover info for ZZZ1 and they still have us arriving gate XX! I sent dispatch a message to ask if ZZZ1 is really planning for us to use gate XX with an INOP APU? Dispatch calls ZZZ1 Operations and they finally get around to changing our arrival gate.Ground crew not following procedures and failing to correct errors.  Station management not supporting a safety culture to support flight operations in the interest of passenger safety.Attention to details in preparation for supporting an operation with a aircraft that has an MEL placard affecting normal ops; in this case the APU inoperative.  When the PIC Captain of the flight; after all the doors closed and ready for flight; calls and radios the station that the passengers need to be immediately de-planned due to safety concerns; then this decision needs to be supported and executed without delay!




Synopsis: Air Carrier Captain reported while at the gate with an excessive cabin temperature and no air conditioning; the Captain deplaned all passengers.