PW-5 Canopy jettison adjustment

Greetings,

While doing some minor maintenance, the canopy of the PW-5 that I was working on auto jettisoned it's canopy on the ground. Others around said this was a somewhat known issue and this had happened before after a firm landing.

I noticed there are 3 contact points between the support structure and the canopy and wondered if a slight adjustment to the supports might tighten up the interface.

Any other PW owners have any experience/suggestions?

Thanks,

Mark

My first flight in a PW-5 was a pleasurable 3 hours. It was a bit noisy at 90 kt - one of those days when it was hard to get down.

After landing I opened the canopy and it came all the way off.

It turned out that the canopy eject had been operated. The canopy is secured by a long rod with a notch for the eject mechanism. Once the notch is disengaged you have to push up the canopy a considerable distance to get it off.

It takes a careful preflight to ensure the canopy is secure. Fortunately it stays on unless you give it a good push.

On Sunday, November 8, 2020 at 9:35:35 AM UTC-5, wrote:
Greetings,

While doing some minor maintenance, the canopy of the PW-5 that I was working on auto jettisoned it's canopy on the ground. Others around said this was a somewhat known issue and this had happened before after a firm landing.

I noticed there are 3 contact points between the support structure and the canopy and wondered if a slight adjustment to the supports might tighten up the interface.

Any other PW owners have any experience/suggestions?

Thanks,

Mark
My understanding of the three points of contact is that they determine the fit between canopy and fuselage. I don't think 'messing' with them will achieve what you are attempting to achieve. When locking the canopy in place, if there is a good tight over-center feeling when the lever arm is locked, that should do it. There is a barrel nut that can be adjusted for tightness of the over-center lock, perhaps that needs a turn or two? There is a plastic tube over the release cable and the end nearest the panel can become worn and/or slip out of position on the 'fork' where it terminates. I'd look at those two spots for any issues first. The absolute last thing to do would be to mess with any of the three positioning-adjustment screws. As I recall, they are paint-marked at the factory. That usually means "don't mess" unless you know what you are doing.