Date: 202109
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Turbulence
Light: Night
Aircraft: MBB-BK 117 All Series
Operator: Air Taxi
Operating under: Part 135
Flight plan: None
Mission: Ambulance
Flight phase: Parked
ATC / advisory: Tower ZZZ
Second aircraft: EC135
Reporter organization: Air Taxi
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Commercial
Human factors: Time Pressure; Situational Awareness; Communication Breakdown
Anomaly: Conflict Ground Conflict; Critical
Detector: Person Flight Crew
When detected: Pre-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Ambiguous

Narrative: I was the PIC of the BK117; shutdown on top of the ZZZ helipad. I began my overnight shift at XA:00 that evening. After delivering a patient to the hospital; I was awaiting the medical crew's return from delivering the patient to the hospital. Two of the medical crew had returned to the helicopter to configure the medical equipment for the return flight to our home base of ZZZ1. As I was waiting for the crew to finish; I noticed an approaching helicopter from the southeast direction. It has been confirmed this helicopter is operated by Company X. I checked my company pilot phone to see if I had missed a call from our organic dispatch/communications (comm) center alerting me to an incoming Air Ambulance. This is common practice amongst the dispatch/communication centers of Air Ambulance companies in order to alert pilots of incoming aircraft in order to vacate the helipad and reposition to either an airborne holding area or to a ground holding area at ZZZ2. I did not have a missed call so I called [my company] comm center to inquire about the helicopter approaching and now in a downwind leg (south to north) to the helipad. [They] had no knowledge of the approaching helicopter.This is the first breakdown in the chain of events and the primary contributing factor. The Company X dispatch failed to alert [my] communications center of the inbound aircraft to the ZZZ Helipad.Additional contributing factor: a helipad camera exists at the hospital entrance doors adjacent to the helipad always focused on the helipad. Typically; ZZZ hospital Security personnel monitor the helipad camera when helicopters are inbound and/or shutdown on the helipad. Reportedly; the ZZZ Hospital Security team was not alerted to the inbound H135 Air Ambulance.During my phone call to [my company] comm center; the H135 continued it's approach from downwind to base leg and to final approach. It became quite apparent that the PIC did not see the helicopter shutdown on the pad. As the helicopter continued the approach; I began to quickly move from the helipad to the catwalk connecting the pad to the hospital and yelled at the two medical crew-members to get off the helipad. The H135 continued it's final approach for landing as the medical crew also quickly vacated the helipad. [My company] comm center phone calls are recorded; without exception for this phone call. The urgency in my voice alerting the medical crew can clearly be heard on the recording as I believed our safety was compromised.The H135 began a wave-off maneuver at approximately 300 meters north of the helipad and 50-75 above helipad elevation (100 feet AGL). As the H135 continued it's wave-off; the PIC side-stepped to the east to avoid low overflight of my shutdown helicopter on the helipad. The H135 PIC continued the wave-off over the adjacent hospital building and established an airborne holding area to the southeast.It is unknown if the H135 PIC was aided with Night Vision Goggles (NVGs) at this point in the evening. Official sunset had occurred at approximately XA:15 that evening and end of evening civil or nautical twilight had not yet occurred. I also do not know the typical procedures for this specific PIC or operator concerning NVG practices flying into/out of metropolitan areas. In my experience; I remain aided when landing to metropolitan hospital helipads as an aid to identifying hazards that I may not be able to visually acquire unaided.An additional unknown element is whether or not ZZZ2 ATC tower advised the H135 PIC of the presence of a helicopter shutdown on the ZZZ Hospital helipad. In my experience; the ZZZ2 Tower frequently advises me if a helicopter is on the helipad after my initial Tower check-in. I do know; however; that there was communication between the H135 PIC and the ZZZ2 Tower at some point during the incident. Upon powering on my avionics during my start sequence; I overheard the H135 PIC communicating with the ZZZ2 Tower of my presence on the helipad.Finally; though this appears to be a communication breakdown in normal operating procedures; I believe this incident could have been avoided even with the multiple occurrences of communication breakdown if the helipad had Pilot Controlled Lighting (PCL) available for incoming Air Ambulance Helicopters. Currently; the lighting system is only controlled by a rheostat (timing only; not intensity) from inside the hospital on the helipad floor leading to the helipad.




Synopsis: Air ambulance helicopter pilot reported that prior to engine start and while waiting to depart the hospital helipad; a critical ground conflict occurred when another helicopter attempted to land at the same location. The pilot eventually aborted the approach and entered holding. The reporter cited as contributing that dispatch had not notified the crew on the ground of the inbound helicopter