The International Cessna^® 170 Association

Right... It appeared the thread had morphed into something more. Maybe not...

I will check and see if I still have the old door post striker plates in my "giblet box". I am pretty sure we saved all that stuff after we did the rotary-clutch door latch conversion.

Matt

punkin170b wrote:Right... It appeared the thread had morphed into something more. Maybe not...

I will check and see if I still have the old door post striker plates in my "giblet box". I am pretty sure we saved all that stuff after we did the rotary-clutch door latch conversion.

Matt

Matt,
Do you have any pearls of wisdom you learned while doing the conversion to Rotery latches?

The newer latch mechanisms in the door are too "phat" to fit in the existing door. A section of the inner door panel will have to be cut out to accept the new mechanism. Be ready to fabricate new linkages between the door handle and the mechanism.. At least ours required "push/pull rods" of different (shorter) length. The rotary clutch housing required a little modification and we ended up welding a "side wall" onto the inboard side of each clutch housing to give it a bit more strength. The 170B door post bulkead is a little different in that area than the 172L, and the clutch assembly had to mount to the door post in a different fashion than it was originally designed to do. However, the clutch assembly is stronger than original with the modified configuration. I have a few pics that I took during the mod, but I can't remember if I took any of the clutch assembly... If anybody's interested in the pics, email me.
Matt

Matt thanks for the information. It sounds like the hardest part is the installing the rotery striker.
I bought the latch assemblies (I think from a late 150) from JohnD some time ago and have not gotten around to installing them. JohnD provides STC paperwork so I do not have to get a field approval, thats a good thing.

Personally I never had enough trouble with the stock door latches to want to spend the time & money necesary to "upgrade" them to the rotary latch. A broken return spring on the phenolic latch-piece itself once in a while, easily remedied. You can form your own spring out of music wire, check out the 120/140 site for a drawing of a jig.

Eric

zero.one.victor wrote:Personally I never had enough trouble with the stock door latches to want to spend the time & money necesary to "upgrade" them to the rotary latch. A broken return spring on the phenolic latch-piece itself once in a while, easily remedied. You can form your own spring out of music wire, check out the 120/140 site for a drawing of a jig.

Eric

Eric,
With the expanding girth of myself and friends the doors open in flight. That is why I want to change to the Rotery latch.

I thought the original post was about the skewer that holds the door open too, and I'm glad I followed it to the bottom. That thing that Matt installed is really cool. One of my pet peeves is people 1) throwing the doors open, and 2) slamming them unnecessarily hard. In either case, this looks like it would also help keep them from being bashed around. Matt, post some more pics of your gas-shock door and latch too.

Zane

Here ya go, Zane:

I put the pics in my gallery on the BCP website... we'll see if the links work from here:

Door with old latch removed prior to any modification...

Door with hole cut for new latch:

Door Latch rigging template used to fabricate new linkages and test operation:

After fit and functional test, doors were stripped, etched, allodyned and epoxy primed prior to permanent installation:

Door jamb rotary clutch installation: We had to widen out the hole where the spring-catch mechanism used to be, but it looks okay in the end. Note stainless striker plate installation to reinforce the fuselage skin. Hoping to avoid damage from inadvertent closing of the door with the latch-bolt extended:



M

Oh yeah, the Door Steward:



The flush patch where the old underwing striker post was (c'mon, gimme another .02 knot!):




M

Matt,

Thanks for posting those. Looks like it turned out pretty slick.

Z

Matt,
Thanks for posting the pictures, they help alot.

In the picture of the finished door what is the slot in the rear door rail just above the reinforcing plate you added?

Did you create something for the wedge shaped bolt to ramp against and draw the door in?

The slot in the door jamb is for the lock "tab". When you lock the pilot-side door with the key, the tab rotates 90 degrees into that slot. It was there when I bought the airplane... I guess I figured they were all like that!

The rotary clutch in the door jamb only rotates one direction; ie. inboard relative to the latch bolt. When the bolt engages the clutch, all you have to do to snug the door tight is tug inward on it a little bit .

M

tripslip38 wrote:...............my pet peeves is people 1) throwing the doors open, and 2) slamming them unnecessarily hard. ....................
Zane

Don't havw trouble with anyone (except the wind) throwing the doors open, but everybody seems to do the "cessna slam" that lotsa them require. Not needed on mine, a simple "click" will do. I try to handle the door opening and closing myself when possible.
Matt, your installation looks great, but seems like a whole lotta work. Think I'll stick to the stock latches on mine, at least until I gain (even more) weight!
Regarding the "skewer", I put a Hatchlatch kit on mine several years ago- works really well and was cheap to boot. I think maybe Johnny Williams in Texas sells them now.

Eric

It was a fair amount of work; more than I thought it would be (but isn't every project?). I wanted to make sure doors wouldn't pop open inadvertently anymore. I lost my golden retriever out the pax side door once while taxiing. He was in the back seat and somehow leaned on the door handle just the right way to open it... and then he was gone and I was panicked! All I could do was pull the mixture and stop. Luckily the tail didn't hit him and he was just sitting there in the taxiway behind me looking around with this "what the hell?!!" expression on his face! Thankfully it was an uncontrolled field with nobody around...

Eric,

Do you have a pic of that "hatchlatch?" I found the other topic about it in this forum, but no pic there either. I'm interested to see what it looks like.

Z