It is particularly tragic that rotor blade (and tail rotor blade) strike mishaps, along with airmen, have included bystanders, passengers, and children among the injured persons. Rotor strike mishaps differ from other aircraft mishaps in that they usually result in fatal or serious injury. This is due to the fact that a rotor rotating under power, even at slow speed, has sufficient force to inflict serious injury. It should be remembered that a rotating rotor is extremely dangerous and should be treated with all due caution.
The rotor is difficult to see when in operation, and the nonprofessional public is often not aware of its danger. Even personnel familiar with the danger of a turning rotor are likely to forget it.
1. Some manufacturers of rotor blades use paint schemes to increase the conspicuity of the blades. Owners should give strong consideration to maintaining the conspicuity paint scheme of the original manufacturer.
2. In the event that the paint scheme does not lend itself to conspicuity, the owner should consider having the blade repainted. A customized paint scheme should not be used until an evaluation is made by a person qualified to determine that it will not interfere with the pilot's visibility, promote vertigo, or create an unbalanced blade condition.
3. In August of 1978, the FAA issued Report No. FAA-AM-78-29, Conspicuity Assessment of Selected Propeller and Tail Rotor Paint Schemes. The report summarizes the evaluation of three paint schemes for airplane propellers and two for helicopter tail rotor blades. The document is available to the public through the National Technical Information Service, Springfield, Virginia 22161.
In-Flight Crew Personnel
Persons directly involved with enplaning or deplaning passengers and aircraft servicing should be instructed as to their specific duties through proper training, with emphasis placed on the dangers of rotating rotors. Ramp attendants and passenger handling personnel should be made aware of the proper procedures and methods of directing passengers to and from parked aircraft. The following safety measures should be considered to help prevent accidents on airport ramp areas:
1. When the possibility of passengers wandering on the ramp exists, physical barriers should be provided such as rope stanchions from the aircraft to the terminal doors.
2. Airport management personnel should be on the alert to keep unauthorized persons from milling around on ramps among parked aircraft. When spectators are permitted to view and move among aircraft parked on a ramp, the airport management personnel should caution those persons to stay clear of all propellers and not touch or move them.
3. Helicopter landing and ramp areas should be marked and provided with safety barriers to restrict access by unauthorized persons.
4. Tail rotor danger areas should be clearly marked on ramp areas. Helicopters should be parked with tail rotors within the marked area.
Aircraft Service Personnel
Persons directly involved with aircraft service are most vulnerable to injuries by rotors. Working around aircraft places them in the most likely position for possible rotor strike mishaps. Aircraft service personnel should develop the following safety habits:
1. Treat all rotors as if they were turning, remain clear of the rotor arcs.
2. Remember when removing an external power source from an aircraft, keep the equipment and yourself clear of the rotor.
3. Always stand clear of rotor blade paths (rotor arc's), especially when moving the rotor. Particular caution should be practiced around warm engines.
4. Ground personnel should be given recurrent rotor safety lectures to keep them alert to dangers when working around helicopters.
5. Be sure all equipment and personnel are clear of an aircraft before giving the pilot the signal to depart.
Flight Personnel / Flight Instructors (CFI's)
Prior to starting an engine, flight personnel should make certain that all personnel are clear of the rotor.
1. The engine of a helicopter should be shut down (and rotor stopped / rotor brake engaged if equipped) before boarding or deplaning passengers. This is the simplest method of avoiding mishaps.
2. Boarding or deplaning of passengers, with an engine running, should only be allowed under close supervision. The pilot in command should have knowledge that either the company or the airport operator has ground attendants fully trained in their specific duties to board or deplane passengers from an aircraft with an engine(s) running / rotors spinning. The pilot should instruct passengers, before they exit an aircraft with an engine(s) running / rotors spinning, the path to follow to avoid the rotor blades.
3. When it is necessary to discharge a passenger from an aircraft on which the engine is running / rotors spinning, never have the aircraft with the tail rotor in the path of the passenger's route from the aircraft.
4. When flight and ground instructors are instructing their students about rotors, they should emphasize the dangers of rotating rotor blades. Safety through education is the best and most positive means available for reducing potential mishaps from blade strikes.
5. The prestart portion of the checklist should include an item to make sure the rotor blades are clear. The proper use of the aircraft checklist should be taught to all student pilots.
In reviewing rotor blade strike mishaps, the most impressive fact is that every one of them was preventable. The danger of rotor blade strikes is universally recognized.
The pilot can be most effective in ensuring that his or her passengers arrive and depart the vicinity of the helicopter safely by stopping the engine / rotor system completely at the time of loading and unloading, or by providing a definite means of keeping them clear of the rotors if they are left in motion.
Prominent warning signs, placed in the aircraft's interior near or on the inside face of the aircraft doors to alert passengers and crewmembers of rotor hazards, could be helpful in preventing a mishap.