A few problems with the hydraulics

I wrote a blog previously about hydraulic failures. The blog was technical and hypothetical in nature. It can make for dull reading and many helicopter pilots still regard hydraulic failures as a minor problem in some aircraft. Certain helicopters will fly perfectly fine with hydraulic failures and malfunctions that can be easily isolated. This blog is about some failures that were anything but dull and in a couple of the emergencies I am fortunate to be here to tell the story.

Quite a number of years back when I flew a Bell 47 mosquito spraying, the local residents of the city had become pretty used to my early morning flights over the parks and ravines. We were spraying a mist of a mosquito adulticide that has since been banned. Spraying the material now would probably get me about 30 days in the electric chair but it was effective and  that was what mattered.

This particular morning I had blown a hydraulic line while spraying and the high pressure hydraulic leak was squirting directly onto the Bell’s red hot turbo charger with spectacular effect. I had detected the problem in a turn and radioed the control tower that I was returning to base. The tower spotted me and asked me if I was aware that I was on fire.

“Well I am not on fire yet “I responded,” but I would appreciate a straight in without delay to my base for landing” “The tower wondered if I might be inclined to declare an emergency and request crash rescue ? I told the tower that I would soon be out of hydraulic fluid and as long I kept my speed up I was pretty sure I wouldn’t start burning. I should have availed myself of the emergency services and back then as a fledgling pilot I was probably more afraid of explaining to my boss about the declared emergency than I was  about burning up.

It all worked out OK and my chief pilot commented on seeing my little air show on his way into work that morning. He had a few other comments as well but nothing that I can write here.

A few years later another hydraulic failure in an S-55,(Sikorsky) required no emergency call either.  It started and ended in about 3 seconds and this time my youth was an asset. I had just passed over the power lines on a descent into a field to finish my last pass on the headlands of a corn field. The trees of the headland were on my right and I was just about to boom on when the cyclic pulled out of my hand and slammed against my left knee. I was pulling collective, rolling in throttle, pulling on the cyclic and switching to auxiliary hydraulics at a speed that only adrenaline and youth can perform. The cyclic that I was pulling on with who knows how many pounds force snapped free and I almost snap rolled the old S-55 into the trees on my right side. Good thing for me that the S-55 rotor system is slow or I would have topped the trees on my way out of the field.

The S-55’s don’t fly around much anymore but a turbine version almost got me with a hydraulic failure a year later. I had an uncommanded series of inputs while water bucketing on a fire. Isolating the primary hydraulics got me flying back straight and level and after consultation with maintenance we decided that since neither hydraulic system was acting up currently, perhaps I could fly the hundred miles plus back to the main hangar. It was a dumbass decision and my finger hovered over the hydraulics switch all the way to the base.

Maintenance could simulate a less spectacular hydraulic spasm with the hydraulic mule hooked up to the helicopter as it sat on the hangar floor. Several parts were replaced and the helicopter was returned to service with the mandatory test flight and sign off to be performed by the same dumbass that had flown the ship back the day before.

I asked for a mechanic to accompany me on the flight and the director of maintenance cast a glance around the hangar at the rest of the mechanics who were looking intensely busy. Since I only needed someone to watch a couple of gauges the D.O.M sent our most junior and I suspect expendable apprentice.

The helicopter was rolled to the fuel pumps in front of the office and with nothing but fear and suspicion to stop us we started the helicopter.

Almost immediately I could feel a feedback in the flight controls that while not severe, was definitely not right. The mechanic, who was in addition,  a low time helicopter pilot, asked for the controls to see what I was sensing. He thought what we had was just air in the system and wanted to do a short flight. I thought that his desire to get some stick time was overriding his better judgment and told him so.

We agreed on a run up to 100% to see if the feedback would became more or less pronounced. I felt about the same level of feedback and the young mechanic, pilot, was now manipulating the cyclic  and trying to negotiate for a check flight about the time the cyclic slammed hard over to the right .

The cyclic returned to center as quickly as it had gone hard over and we shut the helicopter down a millisecond later. Had we elected to lift off we probably would have ended up in the front office of the hangar.

The helicopter was successfully returned to service a couple of days later but I never ever relaxed in the S-55T.

A few years later I had another hydraulic failure in the S-55T . Add to that,a  couple of engine failures in the same type S-55T and I finally convinced myself to stop flying the type. I have had several more hydraulic failures in Bell products and others including two in the always challenging A-Star or Squirrel but that’s stories for other blogs.

About Heligypsy

Has it really been forty three years flying helicopters all over the world? I guess its time to share some stories, I hope you enjoy my adventures.
This entry was posted in Helicopter Pilot, Random rantings, World Travel and tagged , , , . Bookmark the permalink.

2 Responses to A few problems with the hydraulics

  1. Ken Klarfeld says:

    Hi Keith,
    Remember me?
    We traded emails about yout daughters training. I have just founded a new company dedicated to video training for new helicopter pilots. Our first video, Wire Strike Prevention, will be given away free. I am looking for some still pictures of wire strikes. Can you help? I want a few for a slide show on the website. http://www.rotorsense.com

    Hope to hear from you!
    Thanks,
    Ken

    • Hi Ken, I do remember you and you might want to talk to Bob Feerst at Utilities Aviation Specialists. He has been presenting audio/visual presentations on flying in the wire environment for more than twenty years.
      Fly safe,
      Keith

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