Application information:

The EZ-Rotary canopy latch is designed as a retrofit or new build product for VariEZ, Long EZ, Cozy, and Cozy MKIV aircraft. The fuselage wall thickness and shape varies on these aircraft so there is some differences in the installation instructions for the individual aircraft.

General product description:

The plans type canopy latch and variations of it require an access door to be opened and the pilot must reach through the door to unlatch and raise the canopy. The access door is a source of air and water leakage and requires construction time on new build aircraft. The EZ-Rotary latch uses the original latch handle, is retrofit able, eliminates the door, allows access from inside or outside of the aircraft, provides an excellent seal, and improves the appearance by allowing access by only one small 3/16”dia opening in the fuselage side which is sealed from the inside of the airplane.  The rotary type canopy latch basic principal has been around for a number of years and plans for it have been published in newsletters and other sources. However, the plans published did not address the considerable problems associated with mounting and installation of the device and the device required considerable custom machine work to mount it and make it work properly. Also the placement and alignment of the device was critical to proper operation. Also, the latch could not put pressure on the canopy frame to compress the sealing gaskets as needed without requiring considerable torque from the key used on the outside. The EZ-Rotary latch solves all these problems. A fore and aft adjustable mounting bracket is provided that mounts with two screws to the under side of the longeron.

An adjustable bearing block is provided that allows the mechanism to be adjusted vertically.

All the adjustments are made and the operation is verified before the external key hole is drilled and the removable seal and guide tube installed. In addition a secondary cam is provided to allow the pilot to increase the clamping pressure on the canopy frame after the latch is closed.

One final safety feature of the rotary canopy latch is that when the latch is not in the latched position the rotary arm extends down and interferes with the control stick, this is a strong reminder to latch the canopy before takeoff.

Installation VariEZ, LongEZ, Cozy and Cozy MKIV aircraft:

Before beginning the EZ-Rotary latch installation the access door hinges and latch should be removed and the door epoxied in place with one layer of bid on the inside. Peel ply the inside bid layer.

Refer to the above exploded parts picture for identification of the parts of the EZ-rotary latch that are used in the following installation instructions.

1. Remove the 3/8” dia. extension shaft/tube by loosening the set screw holding it. Remove the E ring on the EZ-Rotary assembly and disassemble the rotary latch assembly from the bracket assembly. Loosen and remove the inner most set screw in the rotary shaft and then remove the large set screw from inside the shaft.

2. Remove the C9 knob from the C1-L latch arm. Save the CS-13 bushing for future use.

3. Loosen the three screws on the rotary latch bracket that hold the round bearing block. Adjust the screw (one screw is enough) tightness so that the bearing block is held in place but can be forced to move by hand. Then assemble the rotary latch bracket with the rotary latch assembly but do not replace the E ring.

4. Place masking tape on the top and inside of the longeron. As shown in picture #1. Close the Canopy and hold the C1-L forward with moderate pressure. Tighten the AN3 nut holding the C1-l arm to hold it in place.

Picture #1

5. Locate the rotary latch assembly behind C1-L by placing an AN3 bolt through the hole in C1-L and also into the hole in the center of the rotary arm assembly. Relocate the bearing block vertically and slide the bracket for and aft to get alignment of the drill in the two holes. Push the bracket back against the fuselage wall (this will not be possible on Cozy type aircraft. Align the edge of the bracket with the inside of the longeron) and hold it in place against the under side of the longeron. With a fine point pen mark on the side of the longeron where the bracket edges are located (as shown in picture #2). Loosen the nut on C1-L and raise the canopy. Extend the mark to the top of the longeron by using a level to get the line vertical. (as shown in picture #3).

Picture #2

Picture #3

6. Remove the rotary latch bracket from the rotary latch assembly and place the bracket with its outside edge even with the outside edge of the longeron and its aft edge even with the mark. The bracket’s slotted holes are symmetrical with the fore and aft edges.

Mark the slotted holes as shown in picture #4and picture #5.

Picture #4

Picture #5

7. Drill the holes vertically through the longeron using a .125 drill as shown in picture #7. Make sure the drill is held vertical in both directions during the drilling. Check the hole positions under the longeron by inserting two .125 drills or pins in the drilled holes and placing the bracket under the longeron. The holes are critical fore and aft because the slotted holes allow adjustment but the left and right dimension should be accurate. They can be adjusted by using a slightly larger bit and correcting the direction of the drill slightly. Drill and countersink the holes for two MS24694-10R23 screws.

Picture #7

8. The CS-13 spacer must fit inside the C1-L arm. The hole in the CS-L arm will need to be reamed to fit the CS-13 spacer. Install the white Delron cam and lock knob on the CI-L arm using the CS-13 spacer using the 10-32 socket head cap screw provided and the #10 thin flat washer. The washer should be against the Delron cam. Tighten the cap screw securely. The cam and knob should rotate freely. Reassemble the rotary latch assembly with the bracket and install the assembly temporarily using two standard nuts (not lock nuts).

9. Check the action of the latch by rotating the latch fully CCW until it hits the stop, lowering the canopy, and then rotating the latch CW until it again hits the C1-L arm. If the latch cam hits the Delron knob cam (in any position of the knob cam as it rotates). The latch cam should be lowered by moving the bearing block downward until it just misses the Delron knob cam when it is in any position. When this adjustment is complete the screws holding the bearing block to the bracket can be fully tightened by removing the rotary latch assembly and tightening the screws by holding the nuts from behind with a small wrench. Recheck the vertical position after tightening the screws. Do not try to adjust the clamping force of the latch by adjusting the latch vertically the clamping force is adjusted by moving the bracket horizontally. For ease of operation from outside the aircraft when locking and unlocking, the latch should rotate freely through its total 135 degrees of clockwise rotation. For maximum clamping pressure, the knob cam should be rotated so that it is at minimum clamping pressure position, then rotate the latch fully CW. Loosen the nuts holding the bracket so that the bracket can moved forward in the slots. Move the bracket forward so that it is close but not touching the knob cam. Tighten the bracket nuts. When the cam knob is then rotated maximum pressure will be exerted on the C1-L arm. Some installations will require more clamping pressure movement of the C1-L arm than others. The adjustment horizontally and the knob cam interference with the latch cam can be varied to accomplish this.

10. At this point in the installation the operation of the latch should be satisfactory from the inside of the airplane. A #12 drill can now be inserted in the center of the rotary latch assembly shaft and drilled through the outside wall of the airplane. The hole can re enlarged to .375 dia. This will fit the extension shaft tube dia. The shaft tube is made longer than needed to fit other applications and variations in aircraft. It should be shortened to the needed length by measuring the distance from the outside fuselage wall to the bottom of the .375 dia. Hole in the rotary latch shaft and cutting the tube to that length. This length is not critical and can be adjusted by moving the tube in and out (+/- .06) and then tightening the set screw that holds it in place.

11. Remove the rotary latch assembly from the longeron, replace the E ring, the 3/8”-16 set screw and the ¼”-20 lock set screw that holds the 3/8” set screw in place. Make sure the flat on the set screw is visible through the set screw hole before adding the lock set screw. Replace the rotary canopy latch assembly on the longeron. The nuts on the bracket bolts should be replaced with locknuts. Check the operation of the latch from outside the airplane using a 3/16” hex. key.

This completes the installation. On retrofit installations where the door area was glassed over. The inside wall can be filled with foam that is shaped to fit the back of the latch bracket and then finished to match the inside of the aircraft.