Dec 05 2016

Trouble with autos.... Seriously? Posted 7 years 142 days ago ago by Admin

Trouble with autos. Seriously?

When I flew for the Royal Oman Police, the British, Scottish, and Australian pilots I had the pleasure to fly with had a lovely saying. Whenever they wanted to convey an idea, but wanted you to know that you may already know it, they would preface their statement by saying, “Now, I don’t want to teach Granny to suck eggs but….”

Similarly, I certainly don’t want to tell you something you may already know, but to my great amazement it seems there is ‘some problem’ with how pilots execute autorotations, which to me is an easy but fundamental maneuver. So, at the risk of “teaching Granny to suck eggs,” please indulge me while I offer my 2 cents’ worth on the subject that has served me well over the years. At the same time, I apologize if you already practice autorotations in the way I will describe.

I want to preface what I am about to say by pointing out that upon my return to America after flying abroad for three decades, I was literally gobsmacked (another British term, it means too stunned to speak) to learn that autorotations were a problem back home. I was shocked because in my early Army training at Fort Wolters, Texas, in 1968, they were not. Our instructors had a paranoid attitude toward engine failures, so we practiced them during every training session. It was every instructor’s belief that it wasn’t if you would have an engine failure, but when. So in training we would practice autorotations to the ground on every flight, and we were given practice engine failures several times a session—normally when we’d least expect it.

One incident that became flight school lore occurred when a student flew directly over the middle of Possum Kingdom Lake, which offered no forced landing area if the engine quit … except a sure descent into the water. The instructor did what instructors do when given such an opportunity to drive home a point: He rolled off the throttle and asked, “Now what are you going to do?” To which the student reached up, turned off both magnetos, and countered, “Now, what are you going to do?” (They didn’t get hurt, but the student did go on to enjoy a very successful career in motor pool maintenance.)

I estimate I have done well over 1,000 autorotations to the ground in my career, first as a student in Army flight school, then as an Army flight instructor after Vietnam, and later as a senior instructor pilot for Bell Helicopter in Esfahan, Iran, where we operated at an elevation of 6,600 feet, often with extremely high density altitudes.   

I’ve experienced two real engine failures in single engine helicopters in my career. The first one occurred in Vietnam in a Bell 205 during my aircraft commander checkride. The engine quit on climb-out when we were passing through 270 feet and 70 knots with no hydraulics. The instructor’s glove accidentally caught the fuel valve switch, which sat directly behind the hydraulic switch that he turned off to give me a hydraulics-off emergency. Neither he nor I caught his mistake until I noticed the N2 rolling back.

The second engine failure occurred in a Bell 206 when I was a methods of instruction pilot. In both instances I managed to get the machine down safely with no damage done. Had I not been suitably trained to do autorotations throughout my career, I am sure the outcome would have been quite different—perhaps fatal.

In 2008 the FAA produced an eight-page pamphlet entitled, “Planning Autorotations,” which begins: “Currently, statistics for helicopter accidents/incidents indicate the greatest exposure for an accident or incident occurs during practice autorotations.” I concur with the FAA’s philosophy on the subject, as it has also been my philosophy over the years. I also agree with the FAA on this recommendation: “If you or your student is not completely comfortable with what is happening at the exact moment, you need to ABORT the maneuver and GO AROUND. It’s recommended that you establish some limits, parameters, or gates to reference.”

The first advice I would offer Granny is to tell her not to try to “salvage” the practice autorotation, because doing so immediately puts everyone at risk. It’s better to increase the throttle, go around, and try it again.

All instructors are familiar with the building block method of instruction, which is going from easy to more complex maneuvers as you build up to the final maneuver. What I used to do (and please forgive me if I am teaching Granny to suck eggs here) was to first get the student comfortable with hovering autos.

Then, if your company allows it, I’d hover forward at a slow speed and perform a hovering auto while cushioning the aircraft on the tarmac or the grass, which of course is like the last part of an autorotation after you’ve leveled the aircraft. Then all you have to work on is the autorotation entry, management of airspeed, rotor RPM, then the gentle flare (holding it until you feel the aircraft begin to settle), initial pitch-pull, level, and cushion. Easy.  

When I’m teaching a 180-degree autorotation, I personally stress getting the first 90 degrees of turn done quickly, then “play” the last 90 degrees of turn to make your spot.  Passing through the 300-foot “gate,” (my personal minimum) I go around and try not to salvage the maneuver if I don’t have:

    •    At least 60 knots of airspeed. 

    •    Rotor in the green. 


    •    A position to safely make my spot.


Also: Never relax, no matter how much experience the person has sitting next to you.  I have had very experienced pilots do some pretty crazy, unexpected things while on a checkride. Stay close to the controls and always leave yourself an “out” by maintaining your options. Have a personal minimum standard to work the maneuver and accept nothing less. Doing so should keep Granny happy.

Safe flying!