Warbird Information Exchange

Hello to all the Wix members out there who have a passion for the other "Round" engine. I thought I would start this thread to update what it takes to keep our Sabre going throughout the flying season. The annual was intensive, but with all old airplanes things will break on ocassion. I'll try to post some photos of our routine maint if I can get good pictures to show what we encountered and how we fixed it.
Since the annual inspection and about 24 hours of flight time here's a short list of the maint items that have popped up.
1) Horizontal stab trim motor inop, R&R trim motor
2) Main inverter failed, R&R inverter
3) Hydraulic leak L/H wheel well, Installed nickel seals
4) Normal system transfer valve bypassing internally, R&R valve and manufacture 2 new hydraulic lines due to leaking after maint.
5) Normal system hydraulic pump failure, R&R hyd pump, flush hydraulic system and install new filters. This was an especially fun job as the pump is mounted on the front of the engine under the accessory case covers which can be a real bear to get back on, not to mention working down the inlet with minimal space, Thank goodness for Tom as he's smaller than I and could manuever better in the intake. I did spare him the pleasure of re-installing the accessory covers as there is a trick to it.
6) Turn & Bank indicator inop, R&R indicator

Here's a couple of pictures of inside the hyd pump. A bearing failed and you can see a couple of pices of the inner race in the middle of the first picture


This picture shows the other half of the bearing race on the small shaft and a few of the ball bearings found in the housing


David
WHF Maint

I thoroughly enjoyed the thread on the annual inspection! I'm looking forward to more of this kind of thing (not wishing you any problems ). I work on airliners for a living, so this is all very interesting.

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Rod Schneider
Ball Ground, Ga

It's been a busy year so far for our Sabre and another problem popped up last week. On take off roll at takeoff power we had a blue haze in the cockpit and it would go away when you pulled the power back. Also oil consumption increased dramatically.
Today I was able to locate the cause and am glad that I don't have to pull the engine as I was mentally preparing myself to do. I cleaned the oil out of the intake and off of the accessories then did a dry motor. I was then able to track where the oil was coming from after about 5 minutes of waiting. I'll do my best to explain it and follow up with pictures tomorrow. There is a shaft that comes out of the front of the compressor that drives a little gearbox that the 2 hydraulic pumps mount on. This shaft has an access cover right between the 2 hydraulic pumps and has an o-ring behind it. This is where the leak is. I've found this one and will put a new o-ring in tomorrow and motor it again to check and make sure it is the only leak.
This old bird keeps teaching me new things almost daily. I still have to laugh when I read in the old books how maint friendly the F86 was. I guess it may have been in the 50's !
David
WHF Maint

Nice job dave!
Great to see you found the leak! Especially sooner vs. later!
Great to see you again last friday as always!

henning

_________________
"The best way to control the future is to create it".

Henning,
I wish I didn't have to rush off on Friday. Always seems to end up that way. As I promised, here are a few photos of my oil leak. The first picture shows the plug installed right in between the hydraulic pumps down the intake.

The second photo shows the plug removed and the bad o-ring. Its amazing how much oil can be lost past this o-ring with the low oil pressure this engine runs.


David
WHF Maint

Please allow me to second that. I really enjoy the more “technical” subjects here.

David, post away!

_________________

Commemorative Air Force
Experimental Aircraft Association
Warbirds of America

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Best way to contact me- email my last name @gmail.com

Update to the oil leak problem. We did an engine run at power last Thursday to check out my confidence that I had found and fixed the problem. Boy was I in for a suprise when I climbed off the wing. There was oil on the ground in front of the left wheel. I stared at the fitting in disbelief as I knew hydraulic fluid comes out of this drain, but not engine oil. And I also had oil in the intake again! I took the weekend off and came back at the airplane on Monday. I found oil leaking at the same plug that I had just sealed. OK, maybe I screwed up the o-ring putting it in. The oil coming out of the drain by the left wheel really had me scratching. It wasn't until Tuesday that I was able to track those lines and find that the accessory gearbox hydraulic case drains "T" into this line where I couldn't see it. Now this had me going as to why all the oil coming out of this line. I studied the books for quite a while and was almost certain that the oil scavenge pump for this gearbox had failed and the gearbox was filling up with oil and no where to go but out.
Today I put my thoughts to the test and started to disassemble the front of the engine. After a few hours of climbing in and out of the intake I have my answer. The oil scavenge pump is fine, but the gearbox is bad. The oil outlet fitting to the scavenge pump was clogged with large metal pieces. I guess I was only right that the oil was not getting to the scavenge pump. The downside to this is that we have to pull the engine to clean all the filters and screens to check for any other metal that may have made it into the rest of the system. If OK we'll flush the oil system and start to put our Sabre back together.
I'll post some pictures after we get the engine out and the old gearbox off.
David
WHF Maint

There is never anything "easy" about maintaining these old bird. Just ask me how I know

_________________
"They can teach MONKEYS to fly better than that"

http://www.heritageflight.org
http://www.bravo369.org

Hal, your absolutely right. There isn't anything easy, but there's nothing we can't fix or attempt to fix! So now I have to ask how you know?

Its an absolute pleasure to watch these beauties take to the air after you've torn them apart and put them back together better than they were before. It's also fun to figure out these little problems. I knew I had some kind of problem with the oil scavenge, but it didn't cross my mind at what I'd find.
Here's what I expected was the problem, the oil scavenge pump for the accessory gearbox.



Here's what I ended up finding that was clogging the return line to the pump.



Here's the gearbox with the hydraulic pumps and fuel filter removed. I stopped at this point when the decision was made to pull the engine to check the other oil filters and screens.



I'll post pictures of the gearbox once we get the engine removed and we'll open it up to determine what failed.

David
WHF Maint

Stuff like changing 60+ cylinders on a 3350, just to get 18 "good" rebuilt ones...

Or hours spent up behind the panel on a O-1 replacing wiring with 3 splices within 4" of wire...

Or helping the engine builder replace leaky head-to-bank water transfer spools on a Mustang...

I could go on Some is fun and some not so fun. Still the best job I've ever had.

Hal
mech./flunky
Heritage Flight Museum

_________________
"They can teach MONKEYS to fly better than that"

http://www.heritageflight.org
http://www.bravo369.org

Hal,
It's kind of funny in that I was talking with our other mechanic today and we both crack up when we read how maint friendly these were considered in their day. I figure I'll have plenty of stories to pass on some day, at least I hope so as that means I had some fun!
David

We have found what has been causing our problem and I was a little suprised. I pulled the gearbox and split the haves to find a bearing on the normal hydraulic pump driveshaft bad.





Now that we know what was causing our problem, I pulled the engine oil filters, screen and chip detector and found metal in just about every one of them. After consulting with the J-47 shop the decision was made to change the engine as the oil jets to the main bearings could be clogged.
Next problem is that we have 3 engines and none of them are serviceable. We're hoping to have one by the first week of December, so in the meantime we have decided to start the annual and finish the paint work we had planned to do last summer.
Winter maint has begun for Warbird Heritage Foundation.
David
WHF Maint

wow...

the good news (for us) is that we'll have lots more pics to drool over.

B

I'm currently not planning on doing an annual thread as I think I'd be showing alot of the same stuff from last year. I will post to this thread if we find anything unusual or new that I think will be of interest. Feel free to request pictures or post questions as I'll do my best to answer them and post pictures.
David
WHF Maint

I saw in your previous wonderful annual on the Sabre that the ejection seat had the safety pins for the explosives installed... Is that seat active or were they just there to prevent something from inadvertently coming apart... In other words... Does the museum's Sabre have a functioning ejection seat?

BTW... Thanks for the pictures.... My father worked on the Sabre when he was in his 20's and he loved it... I've got a ton of slides from Europe when he was with the RCAF in the 50's that are nothing but Sabres and the people who worked on them...

Mark