Tip-up canopy locking

[Paul Eastham]

Hi,
With regards to the center canopy handle -- the one that mounts at the top center of the canopy frame:

Is it intended to be a primary locking mechanism for the canopy in flight? The way I have it set up right now, it spins freely when the canopy is closed. It doesn't press against the roll bar like the manual implies it should. I wouldn't trust it to stay in the "locked" position on it's own -- I assumed the two side latch fingers would be sufficient to keep the canopy closed.

Do you guys use that center handle for locking anyway, or do you trust the side latches?

[n5lp]

Originally Posted by Paul Eastham

Hi,
With regards to the center canopy handle -- the one that mounts at the top center of the canopy frame:

Is it intended to be a primary locking mechanism for the canopy in flight? The way I have it set up right now, it spins freely when the canopy is closed. It doesn't press against the roll bar like the manual implies it should. ...

I consider it a backup latch. I had the primary latch malfunction once, under high g loads, and the center latch worked to keep the canopy near closed (mine doesn't contact the rollbar either).

I wouldn't want to not have it functional and would suggest drilling a new mounting block a bit smaller.

[Paul Eastham]

Originally Posted by n5lp

I consider it a backup latch. I had the primary latch malfunction once, under high g loads, and the center latch worked to keep the canopy near closed (mine doesn't contact the rollbar either).

I wouldn't want to not have it functional and would suggest drilling a new mounting block a bit smaller.

It sounds like we have similar installations then -- it's functional to lock the canopy, but it spins very freely since it doesn't contact the rollbar -- so I wouldn't be shocked if it unlocked itself due to in-flight vibration or whatever.

I guess you are saying that if the hole for the handle were smaller it wouldn't rotate so freely. That's an interesting idea, though I think the bushing block came predrilled...

[dan]

Mine spins "freely" (the friction against the bottom of the roll bar is reduced) once the canopy is pulled down tightly by the MAIN LATCHES. If your main latches release under G, then imho they haven't been adjusted properly to go "over center."

Personally, I don't even see that center handle as a backup. Imho its only purpose is to provide something to grab when opening the canopy from inside, and to provide something to let the canopy rest on the roll bar in the ajar position.

[tx_jayhawk]

Paul,

Excellent question...I am at the exact same point. My thought was to trim the bottom of the umhw block to "move up" the handle so that it offers some catchs on the roll frame. Mine looks like it will spin freely as well.

Scott
7A Finishing

[kellyp]

I use the handle only to hold the canopy open & keep cool during taxi. Also to open & close the canopy. Works well to pull the canopy closed when you take off with it unlatched

BTW - I recommend you attempt flying with the tip-up canopy unlatched and let it open. It will take away any fear you may have if this happens during flight. When it opens it will come up about 4 inches. FLY THE PLANE. Get to altitude and trim for flight. Simply slow to about 100 MPH then pull it down with your right hand and latch with the left. Done, no big deal.

[ClayR_9A]

I used some UHMW tape on the latch where it touches the bottom of the rollbar to add some friction. It will also keep the paint from rubbing (as bad) as without the tape.

[fodrv7]

I added a piece of UHMW like Clay, but I also added a second piece on the underside of the latch so it doesn't scratch the top of the roll bar if you use it to hold the canopy ajar.

However, I no longer use th e latch to hold the canopy ajar. Instead I carry a high density foam sanding block about 2" x 2" x 6" and put it on the canopy rail and lower the canopy on to it. For wt fanatics it weights about 2oz.
Pete.

[db1yg]

I did not like the design of the safety latch either -- so I changed it. I was concerned that it could actually spin to a partial latch with me on the outside!!!! So I did the following:
1. I trashed the original attach block
2. I made a new attach block from white UHMW plastic which is wide and short vs tall and narrow like the original part.
3. I drilled it for the safety handle shaft and mounted a small compression spring (your friendly Lowe's Aircraft supply) to the top of the shaft above the attach block.

Now you must pull down on the handle and turn to latch and the spring keeps tension against the bottom surface of the roll bar. It is also impossible for the handle to spin or accidently latch when not in use since it is actually above the bottom surface due to the spring action. At this point even experienced RV builders do not notice it as looking any different.

I will post a pic if anyone is interested---100 hrs on the plane now and no spin or movement in flight.

Cheers,

db

[RudiGreyling]

I can add here, just finished this work last week.

Mine catches and locks perfectly. I put some UHMW tape on top and bottom, to protect paint in both locked and 'taxi' configuration. Mine does not spin through 360 degrees, since the cotter pin heads prevents it from a full rotation.

Looking at the assemble close up I think you can move the handle up slightly.
- The handle shaft base has welding around it preventing to sit flush on the plastic block. Remove a little material around the bottom of the plastic block base, almost like countersinking it to fit the welding.
- Then shimming the top with another washer under the existing cotter pin and washer, will move the handle a fraction higher.

I hope it works for you. Better try it before going through all the trouble of making a new block and assembly.

Regards, Rudi