Headset review
Overhaul or LPIP?
Ruth Kelly’s RV-8’s constant speed propeller goes to Proptech for its six-year inspection. Will it be LPIP or complete overhaul? s Ian Fraser and I grappled with lock-wiring the six bolts that retain the propeller hub to the engine flange, Ian asked, “Do you really need a constant speed prop?” He might well ask. Lock wiring is a hard job. But I had been ruminating about the entire, rather expensive, proposition of owning a CS prop myself, as well as the slightly awkward installation task. So why? Well… my Van’s RV-8 has an ex-RAF Bulldog Lycoming IO-360, which churns out 200hp. A CS prop is arguably essential to make the most of all that power – and to be sure my aeroplane has sparkling take-off and climb performance, yet also be economical (and still fast) in the cruise. At 2,300rpm and 23in of manifold pressure you can aerobat all day without touching the throttle. And the propeller helps slow the aeroplane very effectively when the throttle is pulled back during landing. But yes, it comes at a cost. The propeller is heavier than a fixed-pitch equivalent, reducing the payload and taking the C of G further forward, which can be an issue
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Top Ruth’s prop does the business prior to going off to Proptech for its LPIP inspection
on an RV-8 if you want to fly solo. Mine is well within limits (the battery is mounted aft which helps balance it out), but you really do notice heavier stick loads in the flare when you’re on your own. And then there’s the cost of overhaul. This wasn’t any kind of surprise for me, I accepted it as part of the deal when I bought the aeroplane. My prop is a Hartzell two-blade type which (the manual says) must be overhauled every 2,400 hours or six years, whichever comes first. Let’s face it, you don’t want your prop to fail in flight any more than you want an engine failure – and those heavy metal blades whirling round at up to 2,750rpm are absolutely lethal. A safe and smoothly working propeller is an absolute must. I had two years’ grace when I bought the aeroplane – but 2,400 hours was nowhere in sight! Now, a full overhaul is a fairly massive undertaking. The prop is completely dismantled. All the paint is stripped off to allow a thorough visual inspection and non-destructive testing designed to reveal the presence of cracks and any other latent defects that might result in failure. Nicks and scratches are dressed out and the
46 | LIGHT AVIATION | June 2020
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21/05/2020 16:02
