Situational Awareness; Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure; Human Factors
Before performing an airstart; everything was setup correctly. We had the larger airstart machine located on the co-pilot's side of the aircraft. We also had both hoses already staged in the airstart ports under the aircraft. The airstart machine was already idling and waiting for the go ahead for full power to start the aircraft. Once everyone was positioned in place and the beacon was flashing we were ready to start the aircraft. I was located under the plane near the engine on the co-pilot's side of the airplane. I was positioned well into the ingestion area; focusing on both the opposite engine (waiting for the visible waves) that indicated that the there was exhaust coming from the engine. From what I remember; this is the engine that is always started during the airstart process; with the co-pilot's side usually the one that is started for [the] aircraft.While focusing on the other engine and waiting for the exhaust to become apparent; keeping in mind we had the airstart machine going as well as my ear protection; I started to hear a rumble that was getting louder and louder.  I then turned to my side and the co-pilots side engine was going at almost full throttle. I had to step away quickly to prevent getting sucked into the engine. To make matters worse; the lead indicated that we were ready to disconnect the hoses being used for the airstart. We told him that there was no way that we could safely disconnect any of the hoses associated with the airstart. We couldn't even cut the power to the hoses because once these hoses became limp from lack of pressurized air they would have surely gotten sucked into the engine; let alone me as I was the person that needed to disconnect the hoses. This act could have had some fatal results for me; considering I was the one that was literally standing in front of the engine.Once I had stepped away from the engine it was indicated to the pilot that the other engine was; per SOP; was the engine that needed to be started. The wrong engine was shut down and the correct engine was restarted.We asked the lead why the pilot elected to start this engine as opposed to the engine that is usually started during an airstart. He indicated that this was the engine that was the easiest to start.I understand that these things happen sometimes. Communication with the ground crew could have easily prevented loss of life; or severe bodily harm.  Carelessness of this nature will almost always result in someone getting severely injured. An incident like this should have never happened.
Ground employee reported standing well into ingestion area of an engine that was NOT started per SOP during ground air start.