Tuesday, January 3, 2012

Hazards to Helicopters

Recently on TV, their was a news item that showed a helicopter making a perfectly normal landing, when suddenly just before the helicopter touched down, it started to thrash about and come apart as if it were in slow motion.  The main rotor came into contact with a wire or cable in the landing area.  This resulted in a chain reaction of the helicopter self destructing.  Once the rotor system becomes unbalanced, the results of all that uncontrolled energy then separates all the other helicopter components.

Every once in a while, when I have been in a conversation amongst some of my non flying friends,  I'll be asked about the dangers of flying helicopters or you might say hazards.  I never felt that what I did on an every day basis,  flying helicopters, was the very least bit dangerous.  Certainly several things come to mind, but wires are probably one of the most likely problems, coupled with low visibility and low ceilings.  Or the combination of all three can ruin your day.  You may have noticed when driving on major freeways where power lines cross the highway or in mountain passes, large brightly colored balls are attached to the wires to mark them for low flying helicopters or even airplanes in some cases.  In the days before modern electronic navigation devices like GPS.  Pilots often followed highways, railroad tracks or any other surface landmarks that would enable them to reach their destination.  Even today, this is a common practice, but when you get down that low, sometimes you just can't see the wires soon enough.  Once the helicopter has made contact, the wires will come in contact with the main rotor mast and usually down the helicopter by pulling the complete mast and main rotor out of the helicopter.  Has this ever happened to me?  No, but I sure have come close a couple times.

One cold winter morning, I was getting ready to depart Joplin, MO and then follow a local highway to Jefferson City, MO.  This would have taken approximately 3.0 hours to cover the 200 plus miles.  I was flying a Hughes 269A helicopter that was equipped with an aux fuel tank, so I had more than enough fuel to make the flight non-stop.  I called and received a weather report, and was assured that the low stratus and fog near the surface would be non existent once I got a few miles outside of Joplin.  I took off from the local airport and headed out of town to the Northeast.  I located the highway that would take me to Jefferson City and leveled off a few hundred feet above the ground.  Visibility was very poor and I was able to just duck under the low ceiling.  I had reduced my airspeed to around 50 MPH and continued this way for about an hour hoping that the conditions would improve as I had been told by the weatherman.  Conditions didn't get any better and I found my self dropping down lower as the ceiling and visibility got much worse. Common sense would tell you to turn around and return via the route you started from.  I did attempt to do this a couple times, but the weather had closed in and I had no place to go.  Out of the corner of my eye, I spotted what looked to be an open field near the highway and I elected to land.  The landing was uneventful and I shut down the helicopter to wait out the fog and low ceiling.  It was early in the morning and I had know idea of where I was at.
It was very quite and I guess no one heard the helicopter when I landed.
I sat there for what seemed like a long time and then I could hear the laughter of children walking nearby.  I would guess out to the highway to catch the school bus.  The time was near sunrise and usually when the temperature/dew point are this close, conditions will get much worse.  So after an hour or so, the sun finally began to burn the fog away and I could start seeing a little of where I was at and what was around me.  I had landed in the middle of this field that was surrounded by power lines.  I was sitting in a box of wires on every edge of the field.  This was my lucky day.

On one other occasion, I was making a flight from Long Beach, CA to the airport in Ventura, CA.  I was flying a Hughes 369 helicopter (or to some, it was called a Hughes 500).  A five place turbine powered helicopter.  We departed after sunset and it was getting very dark outside.  Flying around Los Angeles at night is like one giant Christmas tree with all the lights. So no problem with navigation or seeing the ground.  I had four people on board and there was a lot of conversation back and forth between the passengers.  This can be distracting, but I was trying  not to let this bother me.  As I passed over the West boundary of the San Fernando Valley I headed West towards the Ventura area.  The terrain is mostly low rolling hills with very little ground illumination.  I elected to stay high until it was time to begin my approach to the airport.  Off in the distance I could start seeing the lights of the city.  So it was time to check in for a landing clearance and start losing some altitude.  For some reason I misread the altimeter, when I thought I was passing through 1000 feet above the ground, actually I was lower than I thought and I was close to 100 feet above the ground.  The Ventura area is right at sea level, so no problem until I reached down and flicked on the landing light.  Looming just ahead of the helicopter was a set of high tension power lines streached across several steel towers at about the same height as the helicopter. It was too late to make any corrections and I just cleared the wires by just a few feet.  A near fatal mistake on my part, but again a certain amount of luck was again in my favor.

Believe it or not, many helicopters are equipped with wire cutters.  A very sharp blade is located a the top of the canopy and another blade on the lower side of the nose.  These blades can cut a steel cable one inch in diameter at a forward speed of 25 MPH like it was butter.  It doesn't always work, but one more method of making helicopters safer.

Wire Cutter location on a Bell 206 Jet Ranger

Unicorn like Wire Cutters

Several mountain passes near Los Angeles have claimed the lives of some of my friends that were not so fortunate when trying to make their way to higher ground by attempting to follow the highway with low visibility and ceilings, and then flying into high tension power lines.  While flying around the greater Los Angeles area, I made a point of knowing where these power line hazards were located.
When you make good decisions, the outcome can make for a great day flying helicopters................more on this later..............

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