Monday, March 31, 2014

March Twin Mustang Restoration Update

Another month has come and gone.  March was no exception.   
A lot of progress was made on our XP-82!

The leading edge skin riveting on the right-hand wing is now completed and all of the internal close-out doubler plates in the left- and right-wing front spars are also finished.   The two aileron sector support boxes have been completed as well by one of our machine shops and fit into the leading edge spars at the root end. All the flat skins for the right-hand wing are now being drilled and dimpled awaiting the installation of the wing in the wing fixture for final riveting.

Aileron sector support boxes

Riveting the leading edge skins on the right-hand wing

One structural access panel installation on the top inboard leading edge of each wing had us scratching our heads for a while.  The factory drawings showed these access panels (XP all the way through the G models) right above the sector support boxes so one could gain access to the sector for adjustment.  Without these access panels installed, one would have to remove the wing for final interior cable adjustments. The problem was that we have countless pictures of other F-82s without the access panels installed.  But looking at the original top skins of our XP wings showed the panel installation, we made the decision to install them to maintain the originality of our XP.

The sub-assembly work on the left-hand wing structure has now caught up with the right-hand wing, and the team has started preliminary leading edge and surface skin drilling with the reduced size drill bits. 

Left-hand wing skins being fit

With the canopy jettison systems complete, we have now finished the sheet metal panels that cover the outside of the canopy rails.  They all had special stepped joggles rolled into them to accept the lower edges of the canopy frames.  We were able to make special shaped beading rollers to press in these joggles.  

The team has completed the glass installation in one of the two canopy frames. The second canopy frame needs a little more internal skin structure completion and the new canopy bow fit before the glass is installed. Both windshield frames and new bows are in the process of being assembled.

The final assembly and installation of the left-hand pair of rudder pedals has now been completed along with installing and connecting the balance cables.

We have also started hooking up the throttle and prop quadrant cables that synchronize the left and right quadrants together. 

Center Section
The newly completed control rods (welded and painted) that operate the forward spar uplock hook for the forward edge of the main landing gear door have been installed. 

One of our men completed the aileron trim gear box mounted on the left aft spar--a very complex little structure with all kinds of bends and angles designed in it.  A very good job.  Thank you.

The Katz
We have been trying to teach Allison how to read a tape measure.  She just about has it figured out.

Please support and donate to the Wounded Warrior Project.


Friday, February 28, 2014

February Twin Mustang Restoration Update

February was a fabulous month … lots of exciting progress made on our XP

Outboard Wings
Ayman, Tim, Paiden and Josh have completed all of the preliminary rib to stringer to spar drill-ups on the left-hand wing. All the preliminary drill-ups were done with a reduced size bit so if any final adjustments are required when the wings are in the fixture, the final size drill-up will allow a small amount of final alignments.

Paul and Randall have completed the final preliminary drill-up of the right-hand outboard wing and are now fitting the two leading edge skins.  

Wing Leading Edges
Weezie and I went to Thrust Aircraft in Albany, GA, to have the leading edges rolled on their Farnham roller, a special roller that will simultaneously roll two different leading edge curvatures on each pair of skins for each wing.  Thank you, Thrush.

Close up of the rolled skin

Aileron Controls and Fittings (Boosted / Non-boosted)
Our XP-82 prototype came with non-hydraulic boosted aileron and elevator controls, unlike all subsequent B thru H production models. The boosted controls assist with taking the control forces off of the pilot’s stick when the air speeds start getting up in the 400+ mph range. The parts that we purchased out of Alaska all had boosted aileron control fittings in the wings and ailerons.  We were able to save all four fittings (two hinge and two control) required in the four ailerons to use with the non-boosted XP system. (The two outboard ailerons do not require any individual aileron controls as they are both mechanically linked to the inboard ailerons.) The non-boosted bellcranks and associated cable sectors required in both wings are being machined and should be completed within a couple of months.

Center Section Fuel System
I have completed the fuel feed lines that run from the fuel shut-offs thru the wheel-wells to the C-4 strainers, then thru a pair of fittings on each firewall to the engine-driven fuel pumps. I chose to use the later model Stratoflex 111 hose and 300 fittings due to their fire resistant construction.  The original hose and fittings were a Mil-H 6000 non-reinforced hose and push-on nipple fittings that were not at all fire resistant.  This is a safety improvement that I chose to do, and this modification could be easily changed back to the original if desired for originality.

Machine Work
Our sub-contract machine shops are making excellent progress on the last number of items that we need for the center section and wings.

Martin Radiator is also making good progress on our two heat exchangers. 

Our phenolic / carbon fiber floorboards are being manufactured in Florida from the molds we made.

Tail Wheel Assemblies
The two tail wheel assemblies that we have passed NDI inspection. I built the eight new 4130 steel tube mounting arms as the originals were rusted due to being in the weather for years. Although two of the four mounting lugs passed NDI inspection, I chose to have them re-machined due to some deep scratches. The only other tail wheel parts we are going to have to make are the two yokes which hold the tail wheel, and the four small tail wheel gear doors as they were all severely corroded.

Push-Pull Control Rods
While in Florida having the tail wheel parts NDI’d, I had our welder extraordinaire in Titusville weld up many of our control rod ends to the new steel 4130 tubing. Thank you.

Rudder Pedal Assemblies

Flap Arm Assemblies

A group from LaGrange, GA, flew in to look at the XP-82 project. While they were here, one of the men contributed the “original” Flight Manual that had the serial number of our aircraft penciled in on the first page of the manual. He told me that he got it from a man that was stationed at NACA/Cleveland where our aircraft was based.  What a find!  Thank you, James Mackey of LaGrange, GA.

"You could have given me a bigger box you know!" -- Allison


Friday, January 31, 2014

January Newsletter

Our XP-82 Twin Mustang Prototype on her first flight in 1945

 It’s a new year already.  
It seems that I was writing the January 2013 newsletter
just a couple of months ago.

Paul and Randall have completed final back-drilling of all four top wing skins and have completed the riveting of all the ribs to the spars.  Weezie and Paiden (our new guy) are completing the riveting of the 64 doublers on the top of each hat channel assembly located in the fuel tank bays in each wing.

Ayman, Jeremy, Tim and our part-time volunteer, Josh, have predrilled all the stringers, ribs, bulkheads and spar caps, actually a mirror image of what was done on the right wing a couple of months ago. Very soon Paul and Randall will complete the final small tasks in the right wing prior to it going into the fixture, and they will switch over to the left wing.  Ayman and Tim will then complete the coolant exit doors and fuselage ducting.

Left Wing

Right Wing

Time is getting closer for both wings to come off the center section and go into the permanent wing fixture for final drilling and riveting.  At that time we will rotate the fuselages and center section on their main gear 90˚ to the right to start the attachment of both aft fuselage extensions and horizontal stabilizer.

 English Wheel Parts

Casey Hill, English Wheel parts maker extraordinaire, completed our two under canopy aft fuselage skins. A very nice job.   Thank you.

Systems (Canopies and Coolant Tubes)
Weezie and I have completed both cockpit emergency canopy jettison systems.  There must be a mile of cables and pulleys for both of those systems to work, and very precise set-up measurements to follow to assure that each canopy truck releases simultaneously. Tim has completed the final tightening and clamping of all forward coolant tubing in both cockpits.

Right-hand Throttle Quadrant
Ken Friend (volunteer), Weezie and I completed the right-hand throttle quadrant.

During the Alaska crash recovery in 2008, I stumbled over the burned remains of the right-hand quadrant.  Most of the aluminum parts were burned beyond recognition, but the key steel parts, arms, bushings and shafts survived. There are many changes between the right-hand and left-hand quadrants due to the different locations and through-firewall holes for the throttle and prop control rods. During the recovery, I looked at the throttle quadrant and made the decision that it was too damaged to load into the basket, but then had second thoughts a day later.  Thank goodness I decided to take it as some of these steel parts would have been very time consuming to duplicate.  We did Rockwell testing on the hardness of the steel parts to determine that the fire had not permanently damaged them, and they all passed.

Machine Shops
One of our four sub-contract machine shops has been making magnificent progress on all of the remaining large and small parts that we need to complete our XP-82 project. There are still quite a number to finish, but the list is getting shorter each day.  Some of the key parts that were completed last month were the heat exchanger end caps, mounting rings, seat rail mounts and flap arms (that were pictured in last month’s news release).  With these parts completed, Martin Radiator is making good progress on our two heat exchangers. 

Weezie, Tim and I have been installing the remaining countless small parts in the fuselages and center section that have been detailed and packed away for months in our storage container.

Heat Exchanger End Caps, Mounting Rings, Flap Arms
and Seat Rail Mounts

Bumps in the Road – Firewall Dishpans
The dishpan is a stainless pan similar to a small kitchen sink that mounts the oil tank into the steel firewall. 

We had the two original XP-82 dishpans, one perfect and one severely damaged and an E model one that we got from the Colorado parts find that was identical except for 2” in vertical height. After I started making a modification to add these two vertical inches, I realized that when the instrument panel cover was off, the welded modification would be obvious and not acceptable. So the decision was made to press a new one.  A very difficult job, but it can be done.

Pictured is the heavy-wood frame around our undamaged original XP dishpan to accept the extremely high strength mold epoxy prior to it being poured in to make the mold.

The finished mold

"We're not spoiled."


Tuesday, December 31, 2013

December Restoration Update

 What a fabulous year it has been working on the XP-82

Since 15 January 2013 Weezie and I have been installing systems in the center section and both fuselages at a rapid pace.  We started sub-assembling all the systems about 18 months ago, i.e., gear and retract mechanisms, electrical, quadrants, control and trim cables, trim boxes, hydraulic components and lines, stick/pedal assemblies, flap, and coolant tube systems; and then sealing them in boxes awaiting installation(s). The shelves are getting emptier and emptier every day.

Left-hand Cockpit with Systems Installed

The entire team--Paul, Randall, Ayman, Jeremy and Tim--have been steadily working on the two outboard wings attached to the center section prior to their going onto the steel fixture. The preliminary drill-up of the skins with #40 drill holes (tiny) on the right-hand wing is now completed.  All of the fuel bay hat channels and stringers in the left-hand wing are nearing completion.  By the end of January, we project that both wings will be in the steel fixture for final sweep, dihedral and wash-out alignment (see our May issue for descriptions) and final drill-up to size and final riveting.

Right-hand Wing

Left-hand Wing

Control Systems
The final fitting of all the control cables and pulleys in both fuselages and center section is now completed back to the tail assembly factory breaks in the aft fuselages. We are still waiting for three parts from the machine shop to complete the installation of the rudder pedal assemblies in the right-hand fuselage. We are now just completing the canopy opening/closing and jettison systems. As mentioned last month regarding the canopy trucks, one of the six failed NDI (non destructive inspection) due to cracks so small that one cannot see them even using a magnifying glass.  One of our contract machine shops is now machining a replacement for us.

 Canopy Trucks

Coolant Systems & Tubes
All of our multi-layer coolant tube insulation was delivered the second week of December.  A beautiful job matching the original color, texture and stitch patterns. We just completed installing all of the insulated 2” and 1.25” tubes from the firewall(s) back to just forward of where the radiators mount.

Floorboard Molds
In order to make the compound shape floorboard molds, I have epoxy-glued salvageable parts from each damaged floorboard together to make a complete pair of left- and right-hand floorboards to serve as molds to be used to make four new panels.  I should have these two molds completed some time this coming January.

As critical as we have been on matching everything back to as original on this XP-82 restoration--paint colors, 442 rivets, #1 cad plate, etc., etc., we had to make a modification to the original phenolic floorboards.  We have a number of original phenolic floorboards, and every one of them has fracture-failure repairs made when this aircraft was in service.  

Phenolic is a laminated cotton, somewhat like fiberglass, but no where near as strong. They all had failed where the pilots had to stand on the floor panels when entering and exiting the cockpits.  I have come up with a non original idea, (Pat Harker actually did this mod to his F-82E), to make the floorboards out of carbon fiber with a layer of the correct color and weave cotton laminated on the exterior top and bottom of each surface giving the appearance that each panel is still phenolic. With the carbon fiber laminated in between the two exterior cotton layers, the finished floorboards will look identical to the original, but will be many times as strong.  

Heat Exchangers (Oil Coolers)/Miscellaneous Parts
Martin Radiator has started on our two heat exchangers.  Pictured are the four end-cap brass rings that we had machined for Martin.  Also, our last needed wing jack point was delivered and is now installed.

We are awaiting the last two of five flap control arms to be delivered in January. When they arrive, we can complete the center section to outboard wing flap tube structure and install them on the aft center section spar located under each fuselage.

9" Heat Exchanger Brass Rings

New machined jack point, gear door stops and rudder pedal adjusters

Wing Jack Point Set-up and Drilled on Rib

Rudder Pedal Assembly

Completed Flap Control Arms

A special thank you to Michael O’Leary, Editor of Warbirds International magazine, for the very nice article on our XP-82 restoration. And, Larry Kelley, B-25 Panchito, contributed the special N.O.S. rubber mounts for our radio racks.  Thanks Larry and Michael.

The Katz

Merry Christmas & Happy New Year from Allison, Rivet
and the XP-82 Team