Tip up canopy jettison handle

Mounz · Jan 10, 2012

I like the idea of being able to jettison the tip up canopy in case of an emergency but the standard T-handle location is both unsightly and impractical. I have noticed that most tip up builders have done away with the jettison handle on the panel and moved it to the sub panel where it is used mainly for canopy removal for maintenance.

Are there any bright ideas out there for relocating the jettison handle to a more convenient location whilst retaining the jettison function? Is there perhaps an aftermarket retrofit?

robertahegy · Jan 10, 2012

When I put mine in, I turned it 90 deg. so the handle was horizontal instead of vertical. That made it a little less obtrusive. Trying to relocate the handle might require a lot of linkage and could be less reliable.

Roberta

noelf · Jan 10, 2012

I kept the original pin retraction feature, but implemented it with a long vertical rod on the front side of the sub-panel. This new rod extends below the sub-panel and a lever arm is attached at this point that allows the original function to be retained. The new jettison handle is out of sight and accessible by the pilot underneath the instrument panel.

jmjula · Jan 10, 2012

I am tossing the handle from Van's and will install one of these and paint it red or add yellow stripes (the handle is made from aluminum): http://www.aircraftspruce.com/catalog/appages/a1870.php

It allows you to put it almost where ever you want on the panel too.

caryr · Jan 10, 2012

What do you intend to do with the gas struts?

I doubt the jettison feature would work unless you didn't install the struts.

jbagley · Jan 10, 2012

removable?

I would like to have a removable handle. Maybe a grab loop of some kind. Would be horrible ugly and annoying, but I think perfectly acceptable for the few times that I would fly with a parachute. A receptacle of some sort would take less panel space than a T-handle.

I am tossing the handle from Van's and will install one of these and paint it red or add yellow stripes (the handle is made from aluminum): http://www.aircraftspruce.com/catalog/appages/a1870.php

I can't tell from the description what the lock release button does. Does it keep the handle from moving or does it release the handle from the mechanism entirely?

jmjula · Jan 10, 2012

caryr said:
What do you intend to do with the gas struts?

I doubt the jettison feature would work unless you didn't install the struts.

My plan for when I wear a parachute, is to disconnect the struts on the ground. I will likely add 'wing' nuts to the strut attachment points to make that easier to accomplish. No one has yet to eject from an RV in flight while wearing a parachute (that I know of), but people do often enough in other aerobatic aircraft. Know your exit procedures well, practice them on the ground regularly.

jmjula · Jan 10, 2012

jbagley said:
I would like to have a removable handle. Maybe a grab loop of some kind. Would be horrible ugly and annoying, but I think perfectly acceptable for the few times that I would fly with a parachute. A receptacle of some sort would take less panel space than a T-handle.

I can't tell from the description what the lock release button does. Does it keep the handle from moving or does it release the handle from the mechanism entirely?

The lock button assures it won't open accidentally in flight, it just prevents the handle from moving. Van's handle uses a spring to assure that won't happen, but a spring isn't practical with the 1780 style handle. That handle will also work good for a parking brake.

Mounz · Jan 10, 2012

Thanks for the quick response! Turning the handle 90 degrees is one of the options I have been considering but am not thrilled about. I'm not concerned about the gas struts as I don't believe they have a chance to withstand the aerodynamic forces unless you're in a flat spin. I was however hoping that some ingenious RV builder out there has come up with some snazzy aftermarket device.

Up to now the horizontal handle seems to be the best option but it still is somewhat in the way.

Mounz · Jan 10, 2012

Noel do you have some photographs of the mechanism you built? It sounds interesting. Are you satisfied with the way it functions?

Sam Buchanan · Jan 10, 2012

This is the way the handle is "handled" in my 1999 RV-6:

This method is not original with me and many tip-ups have this arrangement. The handle is out-of-sight and uses standard kit pieces, but is reachable for service (I've had the canopy off the plane once in 13 years...). I don't worry about reaching it in flight because I don't think the canopy would leave the plane....and I don't wear a chute.

caryr · Jan 10, 2012

I install the mechanism, like Sam did, and shortened the arm to only protrude thru the sub panel.

I have removed the canopy once since 2004 for maintenance issues.

LifeofReiley · Jan 10, 2012

I would just take the Jettison out of the picture... like most have for obvious reasons.

Snowflake · Jan 11, 2012

robertahegy said:
When I put mine in, I turned it 90 deg. so the handle was horizontal instead of vertical.

Interesting. The -6 I bought was originally fitted with a jettison handle, but one of the previous owners removed the handle and just bolted the actuating arm to an adjacent flange. I wanted the handle back in, so I bought one from Vans and then fit it to my aircraft.

The interesting thing is that the drawings that came with the handle were ambiguous. One picture showed the handle oriented vertical, but then the drawing showing where to cut the slot and drill the hole in the handle was oriented so that the handle would sit horizontal on the panel.

I still think this is the intended orientation for the handle: If you look at where the actuating arm of the quick release sits when the canopy pins are in place, it is at a slight angle to the instrument panel (in the default location). The handle on the end of the rod is welded at an angle ot the rod to compensate for this offset, and to let the handle sit parallel to the panel.

If you rotate the handle vertically, it won't sit parallel to the panel unless you reweld it or change something from the default setup. At least, that's how I read it after multiple reads and re-reads of the plans.

Snowflake · Jan 11, 2012

caryr said:
What do you intend to do with the gas struts?

The stock gas struts are "press-fit" onto one of the ends. On mine, when I removed the canopy to re-paint the frame, the struts were easy to remove with a sharp tug. In the event of needing jettisoning, I suspect any aerodynamic load that got under the canopy would easily overpower the connector.

Flying Scotsman · Jan 11, 2012

Sam Buchanan said:
This is the way the handle is "handled" in my 1999 RV-6:

This method is not original with me and many tip-ups have this arrangement. The handle is out-of-sight and uses standard kit pieces, but is reachable for service (I've had the canopy off the plane once in 13 years...). I don't worry about reaching it in flight because I don't think the canopy would leave the plane....and I don't wear a chute.

I did something very similar to this, and then ended up having to pull the whole thing with all its monkey motion out because the radios had to pass right through that area. Damned annoying, actually.

I'm just going to use bolts in the hinges...

Mounz · Jan 11, 2012

The actuation arm behind the sub panel as depicted on the photograph will not work for me as my radio and transponder need to penetrate the sub panel at this location. The U-channel on the RV-7 is shorter than on the 6.

I hear what some of you are saying about never needing the release mechanism. I can argue that I've never needed the seat belts in my car but nonetheless I am glad to have them and always buckle up before driving. I also find the airbags a wonderful invention and I hope I never have to tell anyone how well they worked on my vehicle.

The bottom line is I want a readily reachable canopy jettison handle. I am confident that it will work as Van's designed it in spite of the gas struts. I know that it has never been tried and tested and I hope to enjoy countless happy hours in my RV-7 without ever needing it. I have also opted for two expensive 5 point safety harnesses with quick release buckles that I hope I will never need. I feel this is all part of a necessary package if you want an escape option in an aerobatic aircraft.

I'm not interested in the sliding canopy so I guess it's going to be the horizontal T-handle.

Thanks for your inputs. If there's somebody out there with a clever solution that he's seen or implemented, I'll be more than grateful to hear from you

noelf · Jan 11, 2012

Mounz...my solution is very similar to Sam's, except that instead of the "T" handle below the sub-panel, I have a link attached that allows the pilot to pull. I have been flying for two years and have decided it was a waisted effort to implement. If I ever need to remove the canopy for maintenance reasons, that will be the only time I will use it.

Sam Buchanan · Jan 11, 2012

Flying Scotsman said:
I did something very similar to this, and then ended up having to pull the whole thing with all its monkey motion out because the radios had to pass right through that area. Damned annoying, actually.

I'm just going to use bolts in the hinges...

That is precisely what I would do if doing it again, for the same reasons....and I have recommended omission of the mechanism to several builders.

OneCharlieKilo · Jan 11, 2012

different approach

I did something a little different; harder to remove for maintenance than setup in Sam's picture but easier to remove than bolts in place of pins. I've had the canopy off once since I started flying and that was after about 2 years of flying when I took my RV apart for painting. Canopy was very easy to remove and reinstall with this setup. As you'll see in the pictures, this method obviously does not allow for in flight jettison.

I used pins per the original design but attached them to aluminum angle that can be easily unbolted from below and then used as handles to pull the pins out. Very little structure needed on the sub-panel and didn't interfere with my avionics installation. The connection of the pins to the angle is with bolt and castellated nut with cotter pin so the angle easily rotates at the attachment point to the pin when the bolt is removed from the nutplate on the other end of the angle. This makes the angle easy to use as a handle when manipulating the pins in or out up close to the skin where there isn't much clearance for wrenches, etc after that top skin is riveted in place.