Elevator up-travel

Ask Questions and Offer Advice Related to the Cessna 120 & 140 Type

Moderators: 6643, 6183, V529

Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
User avatar
hotrodmac
Posts: 64
Joined: Mon Aug 12, 2019 12:33 am
Location: Mint Hill, NC
Name: Lance B
Aircraft Type: C140
Occupation-Interests: Information Technology
Contact:

Re: Elevator up-travel

Post by hotrodmac »

So the saga continues...

I went out to the airport this afternoon to look things over. I've attached a couple pictures of the bellcrank hitting the upper stop, and one of the lower stop when the elevator is full-up. This gives me the 10 degrees of up I've mentioned before, and I do get the specified 20 down. Based on the drawings of the bellcrank, and some photos, it looks symmetrical to me; I've been wrong before though. Talked to an A&P friend and an IA friend, and we've decided to take the rudder off this weekend to investigate. The cable fittings have plenty of room to get through the opening in the tailpost bulkhead, so that doesn't appear to be the problem. Since I'm actually hitting the stop, it's got to be something in that area. right?

I'll let everyone know what I find.
Attachments
Down Stop with Elevator full up
Down Stop with Elevator full up
IMG_0400.jpeg (177.97 KiB) Viewed 3610 times
Hitting up stop
Hitting up stop
IMG_0401.jpeg (169.45 KiB) Viewed 3610 times
hitting up stop
hitting up stop
IMG_0403.jpeg (157.94 KiB) Viewed 3610 times
'46 C140 - Flying
Kitfox SS7 - Building
User avatar
6643
Posts: 2337
Joined: Tue May 01, 2018 7:00 am
Location: KLCI
Name: John C
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: Elevator up-travel

Post by 6643 »

Those stops don't look right. Look at some of the other photos posted. No nuts on the aft side of the spar. I think the nut plates are backwards.
User avatar
6597
Posts: 335
Joined: Tue May 01, 2018 7:00 am
Location: Vancouver WA KVUO
Name: David Sbur
Aircraft Type: '46 140 0-200A
Occupation-Interests: Agriculture
Contact:

Re: Elevator up-travel

Post by 6597 »

I think the nut plates are backwards.
I agree...
User avatar
hotrodmac
Posts: 64
Joined: Mon Aug 12, 2019 12:33 am
Location: Mint Hill, NC
Name: Lance B
Aircraft Type: C140
Occupation-Interests: Information Technology
Contact:

Re: Elevator up-travel

Post by hotrodmac »

6643 wrote: Mon Oct 21, 2019 7:27 pm Those stops don't look right. Look at some of the other photos posted. No nuts on the aft side of the spar. I think the nut plates are backwards.
That's certainly a possibility based on the other pictures. Does anyone have a drawing to confirm? I cannot find one. So silly question, if the nut plates are backwards, how in the devil am I going to get them turned around without removing the skin on the vertical stab to install new hard rivets?
'46 C140 - Flying
Kitfox SS7 - Building
2066
Posts: 600
Joined: Tue May 01, 2018 7:00 am
Location: North Carolina
Name: Mac Forbes
Aircraft Type: '46 Cessna 140
Occupation-Interests: Retired - Current 120-140 Assoc. NC Rep.
Contact:

Re: Elevator up-travel

Post by 2066 »

IMG_1356.JPG
IMG_1356.JPG (369.59 KiB) Viewed 3605 times
IMG_1357.JPG
IMG_1357.JPG (131.88 KiB) Viewed 3605 times
So, while this (pic) is a bit smaller nut plate, if the one installed was turned around (replaced) it would allow the stop bolt head significantly more clearance (?). Mac
User avatar
6597
Posts: 335
Joined: Tue May 01, 2018 7:00 am
Location: Vancouver WA KVUO
Name: David Sbur
Aircraft Type: '46 140 0-200A
Occupation-Interests: Agriculture
Contact:

Re: Elevator up-travel

Post by 6597 »

The bulkhead has a hole for the head of the nutplate, you can see it on your top two pics. Creative rivet bucking, don't know if a cherrymax would be acceptable?
User avatar
hotrodmac
Posts: 64
Joined: Mon Aug 12, 2019 12:33 am
Location: Mint Hill, NC
Name: Lance B
Aircraft Type: C140
Occupation-Interests: Information Technology
Contact:

Re: Elevator up-travel

Post by hotrodmac »

6643 wrote: Mon Oct 21, 2019 7:27 pm Those stops don't look right. Look at some of the other photos posted. No nuts on the aft side of the spar. I think the nut plates are backwards.
My first response to this was FSCK, those things are backwards! It boggles my mind to think that the previous owners didn't notice that things are screwy and need to be fixed! It's gonna rain tomorrow, so I'm headed back to the airport on Wednesday to pull the stop bolt out and see how much extra travel I get. Airport owner won't let you drive through the fence, and I might float away walking to the hangar. Lord knows I won't melt. ;)

IA says we can use Cherrymax to replace the nutplates, so I have a feeling that's in my future.
'46 C140 - Flying
Kitfox SS7 - Building
2066
Posts: 600
Joined: Tue May 01, 2018 7:00 am
Location: North Carolina
Name: Mac Forbes
Aircraft Type: '46 Cessna 140
Occupation-Interests: Retired - Current 120-140 Assoc. NC Rep.
Contact:

Re: Elevator up-travel

Post by 2066 »

Interesting. Wonder if there's any situation when utilizing a nut plate this way (with "elastic" material before the threads) would be acceptable? While the catalogue page doesn't show detail it's surprising that anyone would have installed it as it is. Mac
V529
Posts: 552
Joined: Tue May 01, 2018 7:00 am
Location: Michigan
Name: Victor G
Aircraft Type: C-120
Occupation-Interests: Work on airplanes till the cows come home..........they're still out.
Contact:

Re: Elevator up-travel

Post by V529 »

6643 wrote: Mon Oct 21, 2019 7:27 pm Those stops don't look right. Look at some of the other photos posted. No nuts on the aft side of the spar. I think the nut plates are backwards.

Great catch John, I'll bet that is exactly what it is. Just when you think you've seen it all...........
8342
Posts: 293
Joined: Sun Oct 14, 2018 11:55 pm
Location: KUSE Wauseon OH
Name: Rick F
Aircraft Type: C-140 (sold)
Occupation-Interests: Captain B-777 (Retired)
Contact:

Re: Elevator up-travel

Post by 8342 »

Just wondering how long it has been wrong like that.
Obviously since before the airplane was painted.

Rick
Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 12 guests