Hot or cold

June 29, 2010 by Tim McAdams

Helicopter pilots refer to certain operations as hot or cold. A hot operation is one where the engines are kept running during the procedure and cold is with everything shut down. The arguments for and against hot operations center around safety vs. time savings.

For EMS operators, one of the more common hot operations is loading the helicopter. Many times at an accident scene the pilot will keep the helicopter running while the medical crew gets out to retrieve the patient. Since the idea of helicopter EMS, especially with trauma patients, is to save time, the hot loading of patients is performed routinely. However, there have been studies that have shown very little time difference between hot loading, shutting down the helicopter, and then restarting it to depart. The argument for shutting down is that maneuvering around a running helicopter can be hazardous. For example, people have walked into tail rotors and objects have come in contact with the main rotor system. On the other hand, helicopters are mechanical machines and there have been cases where the helicopter failed to start. On an accident scene, this could shut down a highway for a much longer period of time and delay getting the patient to a trauma center.

Another hot operation that is performed is refueling. Pilots trying to save time or an engine start (turbine engines have start cycle TBOs) will ask to be hot refueled. For trained personnel this can be preformed safely on most helicopters especially when the fueling point is low and below the engine. A fueling port high up on the fuselage and above the engine increases the possibility of a fire if fuel spills. Also, climbing on a ladder or other object to reach the fuel port can place personnel dangerously close to a spinning rotor system.

The case for proper training was apparent several years ago when I was watching a Bell JetRanger giving rides at an air show. When the pilot needed fuel, I watched someone drive a pickup truck, with a fuel tank in the bed, up close to the helicopter. The driver climbed out, ran around to the back, and jumped up into the bed. He stood completely up and then quickly ducked. He obviously felted how close his head came to the spinning rotor system. I turned away because I thought he was going to get hit. I remember thinking, wow, he was lucky!


  • Avi Weiss

    Operate helicopters professionally long enough, and one is almost guaranteed to see at least one “near miss” on human-to-spinning-blade contact. Thankfully all my observations have been misses.

    I always felt that the Fenestron and NOTAR were great simply from the reduction of inadvertent rotor contact, with both human and inanimate objects.

    But I concur, so long as those operating around the aircraft are properly trained, and the area around the aircraft is properly controlled and absent of encroachment, “hot ops” can be a time and money saver…

  • Dale Long

    An ER nurse told me the other night about a security guard who back himself into a tail rotor and split his head open. He was just being curious, of course and had no need to be that close to the HOT op. His family picked up a lot of money from a legal action.

    A pilot has no control over a crowd and sits in the aircraft having to trust others to be careful. For my part, I don’t trust others to be careful. If John Q Public is standing around, beware running HOT.

  • rangerb3

    Agreed with both posters….especially about John Q Public!

    I owned and operated a helicopter sightseeing business for a few years and we routinely, “hot” fueled our bird to save on downtime. My employees were very good at, “knowing” where they were and, “controlling” who was around during those critical times….even with highly trained people “in” control, things can happen unexpectedly! Thanks to GOD, I never had anything happen during those times!

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