incident N32YX

[Carlos Trigo]

HI Guys,

I'm curious. Are guys failing to pin the canopy closed? Or is the locator pin through the longeron failing?

What's going on here?

Wes

Wes

Failing to put the security pin seems to be one possible reason for the canopy to open in flight.
But for your 2nd question, despite having
zero experience in Sonex flying, because I’m still building a XENOS- B, I would say, from the plans, that the locator pin doesn’t have anything to do with latching the canopy, and therefore no influence in the safety of the canopy in flight.
Am I wrong?

Carlos

[WesRagle]

HI Guys,

I've discovered my locator pin missing on two occasions. Both during pre-flight. Not sure exactly when they went on walkabout. Locktite would be our friend if it weren't for the plexi. The current one is testing the tenacity of JB Weld.

Working from memory, I believe the plans call for the locator pin to be threaded through only the bottom side of the square tubing. I tapped through the top and kept tapping through the bottom side, cleaned it up, threaded and epoxy'd a longer pin with West Systems (it's what I had).

But for your 2nd question, despite having
zero experience in Sonex flying, because I’m still building a XENOS- B, I would say, from the plans, that the locator pin doesn’t have anything to do with latching the canopy, and therefore no influence in the safety of the canopy in flight.
Am I wrong?

You're probably right. I'm just trying to imagine anything, other than failing to pin the canopy, that would cause the canopy to open in flight.

Talking about accidents can seem insensitive, and I don't want to be insensitive, but this has happened too many times causing several accidents. The tendency to forget only increases with the addition of the second "ventilation" hook.

I guess the only thing that can be said is "BE CAREFUL!".

On the pre-takeoff check list: Canopy latched AND PINNED.

On my old Sonex, the canopy pin held a red flag that dangled over the Master Switch so I would be reminded as soon as I boarded. I would have done the same on the Onex except the flag dangled over the flap handle while the canopy was pinned.



Spring loading the latch to the closed position might help in the event the pin was forgotten.



"For Want of a Nail".

Enough from me.

Wes

[GraemeSmith]

I would say, from the plans, that the locator pin doesn’t have anything to do with latching the canopy, and therefore no influence in the safety of the canopy in flight.
Am I wrong?

Carlos

Simply - Yes. The locator pin gives the latches something to work against. Without the pins - the latches can push the canopy backwards and alongside the empennage and the latches never meaningfully engage.

--

Since switching to the Peter Anson canopy lock - I've had WAY less trouble with being sure the canopy latches shut (though you still need that pin). And it's a lot easier for a passenger to understand manipulate if they need to get out and you can't help for some reason.

[Fastcapy]

You're probably right. I'm just trying to imagine anything, other than failing to pin the canopy, that would cause the canopy to open in flight.

Talking about accidents can seem insensitive, and I don't want to be insensitive, but this has happened too many times causing several accidents. The tendency to forget only increases with the addition of the second "ventilation" hook.

Enough from me.

Wes

I would like to see the in cockpit footage of the timeframe where he closed the canopy. It would maybe show if it was actually pinned or not. Like you said, I also have a feeling it was maybe forgot after closing it from the vent position. Which I can see how that can happen as my lock pin checklist item is before taxi.

[Rynoth]

In the interest of education, I'm going to re-share this post I made on the thread: viewtopic.php?f=25&t=6147

Post follows:

I have been hesitant to share this video of mine out of embarrassment, but it was definitely a learning moment and should be shared. This is the ASA swingback canopy (Model A Waiex.) When I was building it I had decided to drill additional holes for the lock-pins to allow me to secure the latches in the "open" position, for fear that the locks might move with the canopy closed and end up locking me out of the cockpit (there is no external mechanism to move the latch.) It turns out there's no reason to do this, there is enough friction that the latches just don't move on their own.

This was a pure "human factors" error. I had inserted/verified the locking pins (part of my pre-takeoff checklist) without verifying that the latches were actually locked. The solution, which I have since implemented, was to make it impossible to insert the pins with the canopy unlocked (I filled in the extra set of holes.) At some point I realized that this was a potential issue but kept putting it off, and sure enough it bit me later.

https://youtu.be/uc4EZB5KtGI

I can't speak for other canopy designs, but my swingback will (apparently) readily open when takeoff power is applied if not secured. I'm thankful for this, and also that the canopy was not damaged as a result.

[radfordc]

I decided early on in my Sonex experience that the canopy latch locking pin wouldn't be a great idea for me. Too easy to overlook, ignore, or lose the pin. I added a spring that kept the latch securely pulled forward into position. If the latch was secured properly the spring ensured that it would stay secured.

[Rynoth]

My own pre-takeoff acronym is FAT PIG.

Flaps And Trim
Pins Ignitions Gas

Flaps and Trim are self-explanatory. Flaps at takeoff setting. Trim for takeoff.

Pins are for ensuring the canopy is secure.

Ignitions are both on (In an Aerovee engine I often do not use secondary ignition during taxi to save draw on the battery, but want them both on for takeoff.)

Gas is verifying mixture and fuel cutoff on and appropriately rich for takeoff.

[XenosN42]

[/quote]
I've discovered my locator pin missing on two occasions. Both during pre-flight. Not sure exactly when they went on walkabout. Locktite would be our friend if it weren't for the plexi. The current one is testing the tenacity of JB Weld.[/quote]

When I built my first Sonex, a XENOS, I noticed that the locator pin became a bit loose after a while. Never fell out, but it wobbled a bit and I needed to screw it back in a few times.

Obviously the cause was that pin was only being held only by the relatively thin wall of the rectangular tube.

When I built my second Sonex, a OneX, I addressed this problem. After looking around my workshop I found a piece of round aluminum that snugly fit inside the square tube. I cut a piece about 5 cm long and shoved it into the square tube so that it doubled up the wall thickness in the area where the pin is tapped.

The pin is tight and hasn't wobbled in six years.

[Area 51%]

I decided early on in my Sonex experience that the canopy latch locking pin wouldn't be a great idea for me. Too easy to overlook, ignore, or lose the pin. I added a spring that kept the latch securely pulled forward into position. If the latch was secured properly the spring ensured that it would stay secured.

My plans (Waiex 212 page D-02) include a spring for just that purpose. I thought all Sonex/Waiex/Xenos had it, but I guess it was added somewhere along the evolution of the kits even though there's no mention of it in either the service bulletins or drawing revisions that I could find.

[Bryan Cotton]

My plans (Waiex 212 page D-02) include a spring for just that purpose. I thought all Sonex/Waiex/Xenos had it, but I guess it was added somewhere along the evolution of the kits even though there's no mention of it in either the service bulletins or drawing revisions that I could find.

Mine (Waiex 191) has a spring also, per the plans.