Fifty laps around the sun and here I am — still in this business going full gas and still driven to perform to the best of my abilities. Yet in the last couple of years that ‘best’ has varied depending on the month. My knees hurt more, as does my back. Reading glasses have become my shadow. All told, things out of my control are creating a little more lag in the overall picture.
On a more recent Bell medium project, an extensive work scope was planned, which included avionics upgrades, utility system installations, and some modifications to existing systems. I knew going in that it would mean working all over the airframe. Kneeling, laying down, squatting, and close-quarters work would be the order of the day. For the most part, the work itself would be routine — but as with any new project, a visual inspection and assessment of the aircraft was needed.
I often like to start with the ‘harder’ work first. For example, when I evaluate the work scope, I look for the systems that may tie into existing ones. On this project, the added radios and the governor control switches on the collective meant interfacing new with old and existing. Those things that ultimately impact labor hours are where I like to spend most of my time while reviewing the job onsite.
The audio system was quite extreme. Having been a retired air medical helicopter, it had a lot of systems tied to it. The hope was that the shared network of audio wires connecting all the various audio controllers would be intact, and I would just have to remove some of the existing radios and replace them with the new ones. Then, I could wire their interface into what I will simplify here as a ‘hub’ (terminal blocks).
It’s not uncommon for older aircraft to be sold with technical records that don’t contain the wiring diagrams. But these diagrams are vital to future installations, as they take a lot of the guesswork out of the integration phase. But in the same breath, they may not reflect the current status of the aircraft wiring.
As I compared the drawings to what I saw in the aircraft, I was confident I caught an anomaly in the wiring. It seemed the terminal block layout was actually mislabelled when compared to the drawings. The latter indicated that the radio source inputs would go to a ceiling mounted terminal strip — the furthest physically from the radio sources themselves. This made no sense. I expected to find the terminal strip contact locations void and empty — and they were. The wire codes were so faint I could barely read them and most were not legible. I left convinced I had it right.
It wasn’t until I returned to start the work and actually get into the existing wiring, cutting open looms and taking stock of what was and what wasn’t jiving with the original drawings, that I caught my oversight. It turned out the terminal strips indeed matched the drawing designators and the radio source inputs were located at the furthest away overhead terminal strip. However, aftermarket systems — not documented in the drawings — had been installed and their wire codes did not appear on any of the existing drawings.
All told, it took the better part of a couple of hours to truly take stock of the audio system’s actual configuration. My mind was battling conventional wisdom (how I thought it should be) versus the reality in front of me. Add to that poor near sightedness and the inability to kneel in the same position for too long, and the dwell time I would normally have had to process my real time situation would have been greater. There is a chance I would’ve spent that extra minute or two processing thought and maybe, just maybe I would’ve saved myself another slice of humble pie.
