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Thursday, August 29, 2013

August Newsletter


After five years of hard work by all of the
 XP-82 team members, the major parts have started to come together to the point where 
our XP-82 finally looks like an airplane!!

Right-hand fuselage installed 27 August 2013


It is amazing how after only one month it appears that we have accomplished years of work on our XP-82.  What explains all the visual progress is that we have been working for years completing all the “small” and “large”parts and systems that are now being installed.


Left-hand fuselage installed 24 July 2013


Fuselages/Center Section
At the end of July we removed the center section from the fixture, rotated it from vertical to horizontal, positioned it in the hangar and installed the left-hand fuselage on it. Both fuselages are now fit in place on the center section and temporarily bolted in place awaiting the final factory fuselage-to-center section shimming to align each side exactly with each matching tail section. When we took the fuselages off the center sections from the Colorado parts, it was amazing how many small shims the factory had in place for final alignment. 

Fuel Tank Bays and Top Aft Skins
Ayman and Jeremy spent about a week on each side completing all the riveting of the top aft skins and all the final work that had to be done in each of the two inboard fuel tank bays. 


Completing the top skin riveting on the right-hand aft fuel tank bay

Flap Bay & Trailing Edge
In the first three weeks of August, Ayman and Jeremy have fit and riveted the flap trailing edge ribs and assembled the access doors to the aft two gun bays.




They have also completed the heavy trailing edge support structure to support the center flap rollers. This structure carries the huge air load exerted during landing against the large center flap panel mounted between the two fuselages. Fortunately, almost all of the parts from the Colorado parts supply were airworthy so that we could reuse them after NDI (non-destructive inspection), glass beading, cad plating and painting. 





Center flap roller support



Center Section/Wing Attach Angles/Wings
All of the outboard wing attach angles have been permanently fit on the matching center section attach angles using underside drills and reamers to preliminary drill all the attach holes. They will be brought out to final size when the completed wings are fit. This procedure guarantees a perfect bolt fit for the wing attach angle(s). Each wing is held on by 60 top attach angle bolts, 50 lower, all internal-wrenching, and 30 bolts through the forward, middle (main) and aft spar attachments.

We had to use special tooling to do the draw back spot facing on the wing attach angles on the center section. When I had the new sections of wing attach angles manufactured to match some of the airworthy originals I was able to save from the Soplata and Colorado parts, I chose not to have the attach holes machined in them, fearing that some might not match. It turned out that was a good decision as two out of the 200+ were both the wrong size and in the wrong location. We were able to back drill and ream to undersize and then spot face the bolt head and nut/washer surfaces so all the attachments were parallel to each other. 



Upper wing attach angle with spot faces

Paul and Randall have fit the sub-assembled right-hand wing using its temporary wood fixture prior to the permanent steel-assembly fixture to check dihedral (6°) sweep (3°) and washout 1°, 30’ and 03”. They have also completed the coolant air exit door trunks on both fuselages and did the preliminary fit and drill of all the exit door fairings. 



Exit door fairing on left-hand fuselage

Bumps in the Road - Wing Washout (Downward twist of the tip of each wing)

We have two different figures on the washout degrees in the plans that differ by almost one degree in the XP-82/B model wings. We have decided that before we lock ourselves into a washout degree number that might be in error, we must go and accurately digital-degree measure an existing XP/B model wing to be sure which figure is correct. 




Preliminary fitting right-hand wing showing the forward fuel tank bay


Right-hand wing aft view showing the size of the outboard wing aft fuel tank.
It holds 300 US gallons internal on each side -- tons of range.

Gear Well Panels
Weezie and I completed the attachment of the two lower gear well panels. Each one of these took at least 500 screws, bolts and hi-shears to complete. This was a tough job working upside down under the center section with extreme difficulty reaching most of the hardware. Thank goodness that none of this will ever need to come down again! 

Electrical / Cockpit
We also installed the electrical and switch panels in both fuselages along with the electrical power supply breaker panel in the left-hand fuselage. None of the wires are permanently hooked up yet to their matching wires on the terminal strips mounted in each fuselage’s electrical panel. I will do all these hook-up connections over the next few weekends. 


Pilot's switch panel and electrical shelf


Also, the pilot’s trim box that houses all the trim functions, and the gear and flap handles, plus the quaddle throdrant (throttle quadrant) are now installed. (We have been jokingly calling it a quaddle throdrant for years.) 



Pilot's trim/gear retract box and throttle quadrant


Right-hand fuselage switch panel and electrical shelf are installed


Factory cutaway drawing of our XP-82


The Katz - “I’m hot ... it’s over 100 degrees.
The tag says that this thing I am sleeping on is a cooler. It doesn’t seem to be working. Go find Tom and see if he can get it fixed so that I can cool off.”
-Rivet 






"We make a living by what we get, 
but we make a life by what we give."
-Winston Churchill

Thankx.
Tom



3 comments:

  1. Hi Tom,
    I am a Director and AME with the Bomber Command Museum of Canada in Nanton, Alberta (www.bombercommandmuseum.ca). We are currently restoring a North American Yale to airworthy condition and I need some assistance with the wing attach angles. The Yale wings attach just like the XP-82, where does one obtain such parts? Any help you could provide would be super! You and are your crew are doing an awesome job on the XP-82!!!
    Thanks,
    Greg Morrison

    ReplyDelete
    Replies
    1. The wing attach angles on the NA64 Yale are very similar to the AT-6 (Harvard). I am not sure about the bolt pattern or the dihedral built into the angle. If they are the same as a Harvard, it would be best to buy them from Lance Aircraft in Dallas, TX. I have made many new angles milled together as a left and a right, a little bit wider on the bolt flange to accommodate the width of the band saw blade and enough to make a mill pass or two for cleanup. Make the angles out of 2024 T3511. Only after the milling is done, press bend both angles while they are still attached. Press bend to the correct airfoil shape, then cut them apart, do your final milling and then drill the holes with undersized drills and reamers to exact match the wing or center section angle, depending on which one you need.

      Peres Pattern, an extremely competent machine shop in Erie, PA, just finished last year milling two upper Harvard angles for me. Excellent job and reasonable on the dollars. To mill and bend only one angle, will cost you more than to make two matching ones back-to-back. Peres Pattern's phone number: 814-456-2084 (Vic Peres). Hard to reach him on the phone, but you will eventually catch him. He also made all of our XP-82 spar caps and all of the wing attach angles.

      (I owned thirteen NA64 Yales from the Simmons Auction. I restored five of them to flying condition and ended up with about 400 hours of Yale time. They are very tricky on landing and have violent stall characteristics. Be careful and have a thoroughly experienced Yale pilot do your test flying.)
      Thankx.
      Tom Reilly

      Delete
  2. Hello Tom,

    Thank you for the info!! I do have one more question for you (and to anyone who reads this) where can I obtain copies, originals, CD or PDF of the Yale Maintenance Manual and Illustrated Parts Catalog?

    Thank You,
    Greg

    ReplyDelete