Sunday, January 27, 2008

Common problems with loaned general aviation headsets

Ever since I joined the Redcliffe Aero Club in March last year, I’ve been borrowing a headset each time I went flying. The club has a number of basic headsets that students can use for free during lessons, most of them of the Altronics brand. They are regularly maintained and even replaced, and they usually do the job.

I grew a bit frustrated with those headsets over the last few months though. The most common problem I experienced was with the mike boom not staying in place correctly. The mike book is the part of the headset that connects the microphone to one of the ear cups. It is usually either a hinged wire frame assembly or a flexible metal tube that can be bent so that the microphone sits just a few millimetres from the lips (the so-called “flex boom assembly”). What happens over time is that screws on the wire frame get loose, the flex tube develops a tendency to move back to its original position, or the linkage between the mike boom and the ear cup comes apart and pops out, leaving the mike boom dangling.

As a result, the mike invariably ends up moving away from my lips, which means that people on the receiving side of my radio communications experience a fainter voice and a lot more noise, i.e. a very badly degraded signal-to-noise ratio. So that’s all not very optimal.

Typically, with such a faulty headset, I would need to use my left hand to push the mike closer to my lips when making a radio call. This is not ideal in the circuit since the best practice is to make calls during turns and not after or before. This is to maximize the chance of other aircrafts sighting us. Other pilots will look for us when they hear the call (“turning base”, “turning final”, etc.), and they’re most likely to see us if we maximize the cross-section of the plane that they can see, i.e. if we are banked.

Therefore, with one hand holding the mike near my lips, that leaves only one hand for the yoke, throttle, trim and flaps. In most cases this works fine since flaps, throttle and trim are set before or after the turn. But you get the idea. It seems wrong to have my left hand busy with the “communicate” thing while both hands could be used for the “aviate” thing. In addition, it is quite disruptive when trying to have a conversation with the instructor. Try that when adjusting power in a turn and you’ll realise you need to grow a third hand. Or get your own headset.

There are a few other problems I’ve found with headsets that have seen too many hours, too many students and too many planes. On one occasion, I had one of the two jack plugs slightly come out of the socket. That was the thick one, the one connected to the speakers in my headset. I think it was helped by my right knee nudging against it, but I also suspect it was caused by wear and tear of the plug. As a result, the instructor could hear me, but I couldn’t hear him. It happened during the roll on a touch-and-go, and I realised something was wrong when Mal reached for the carby heat and firmly pushed it in.

The story was that we were practicing crosswind circuits and I had forgotten to remove carby heat on final, most likely because I was busy with all those things that keep you busy in a crosswind final. After I applied full power for take-off, Mal shouted “carby heat, carby heat” at me but I couldn’t hear him, and I can understand he got a bit cranky on this one as the end of the runway was approaching. On the climb-out we sorted out what the problem was and realized the plug was a few millimetres out.

Another thing that happened to me during training lessons was that the headband came lose and changed position in flight. Before each lesson I took time as part of the pre-flight routine to adjust the headband and make sure it felt comfortable with my sunglasses on. Still, one ear cup would drop at some point, which would force me to hand over the controls to the instructor while I was putting the headset and my sunglasses back in place. Not the kind of thing you want to be bothered with when you’re trying to make the most of a training flight.

Comfort is another problem with “best value” headsets. Last September I went on a one-week air safari from Redcliffe to Ayers Rock, for which we spent about 30 hours in the plane. I’ll talk more about this trip in future posts. For the time being, let’s just say that after 4 to 5 hours in the plane each day I had the impression that the headset had grown spikes that were slowly making their way through my skull. Granted, I do not have much hair to offer as a cushion between the headset band and my skull. But still, a nice cushion around the headband would have been nice.

So, little by little, I made up my mind about buying my own headset sooner rather than later. I had in mind to buy one after I got my GFPT as a gift to myself, so why not now rather than in two months? According to what I heard and read, proper GA headsets can last decades if properly taken care of, so delaying that purchase did not make sense. I ended up buying a pair of David Clark H10-60 which I find absolutely awesome. This post is getting a bit long now, I’ll go through the details of the selection and purchasing process in the next post.

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