Sunday, February 1, 2015

January XP-82 Twin Mustang Restoration Update

How did 2014 go by so quickly!
And the first month of the new year is already gone.

Wings / Ailerons
The final fitting of the aileron and flap hinges on the right wing is almost completed. Having to remake most of the aluminum parts for the XP non-boosted aileron system has been a challenge, but now successful. The left-hand wing will go smoothly now that all of the “reinvention of the wheel” has been completed on the right-hand wing.

Center Section Gun and Ammo Door Covers
Three team members have been repairing the original doors and pressing new replacement hat channels for the three removable covers that close out the armament section and the left and right ammo bays in the center section. This task should be completed by the middle of February. 

Left-hand ammo bay door without the top skin

Right-hand ammo bay door

Gun bay door

One of our machine shops has completed the remaining four gun mount castings for the aft gun mount position, and they have been installed. 

Also, one of our friends has collected .50 caliber cartridges and links to be installed in our ammo bays for authenticity.  And I just received notice that the gun barrels I traded for have been shipped to us.

Two team members have now completed the set-up fitting and drilling of the dorsal fin(s) parts. All the final riveting on these dorsals should be finished by mid February.

Over the six years restoring this XP-82, we have gone to extreme lengths to keep it as original as the day it came out of North American’s Inglewood plant.  One modification we chose to do is one that absolutely will not show.  Have you ever seen any aircraft, whether a Cessna or a P-51, that didn’t have its dorsal fin bent by someone pushing on it while trying to reposition the tail of the aircraft on the ramp?  We decided to PRC glue (attach) reinforcing 7075 T-6 plates in between the ribs internal in the dorsals and then fill the voids with structural foam. This hidden mod will dramatically strengthen our dorsals from dents by ground handlers inadvertently pushing on the dorsals.

Back drilling dorsal from inside rear fuselage

When both the dorsals and gun/ammo bay door jobs are completed, the entire sheet metal team will begin the final riveting of the lower aft skins on both wings.

Many Small Jobs Have Been Completed
We are starting to see the light at the end of the tunnel. A multitude of small tasks are being completed.

1.  Most of the steel push/pull rods forward and aft of the firewalls for the prop and throttle quadrants  have been welded.

2. Two new old stock high tension ignition booster coils, used to generate additional amperage through the magnetos for starting, are now completed.

3. Two hydraulic cylinder barrels, one tail oleo strut had to be chromed and a second aluminum door up-lock cylinder had to be anodized.

4.  The two rudder pedal arms for the right-hand cockpit are now completed and they, plus the two hydraulic cylinders, are in FED EX coming to us.

We are well into the final assembly of both seats. Its amazing how many moving parts that each seat has to accomplish the up and down and fold back positions so one pilot could sleep on long missions. 

Pilot Elevator Bell Crank Control
One of the most difficult parts that had to be manufactured by one of our sub contract machine shops for our XP-82 was a T-shaped bell crank which synchronizes the pilot’s and co-pilot’s elevator stick movements together. We have two original bell cranks, one of which we could save, but the second had severe magnesium corrosion which was beyond its limits. This “T” bell crank will be delivered to us and installed in in the left-hand cockpit mid February.

Both windscreens are coming along well.  All four side glasses and both center bullet-proof panels are now fitted and edge-routed. Within another two weeks both should be completed, PRC-sealed and awaiting final installation.

Edge-routing one of the side glasses

Both windscreens, with the glass fitted and the clear plastic
protective layer still on the side glasses

Fuel Tanks & Submerged Engine-Driven Pumps
We have contracted with a fuel tank manufacturing company in Eagle River, WI, to manufacture our six required fuel tanks. This same company manufactured these same tanks for Pat Harker’s “E” Model restoration.  While at Harker’s, I looked at his tanks, and the workmanship was excellent. We expect to have these tanks completed and delivered to us by this summer.

We have sent off the six fuel pumps, four submersibles and two engine-driven fuel pumps for inspection and overhaul. All six pumps were new old stock, but they still needed to be reworked by a FAA-licensed overhaul facility for new bearings, seals, etc., to come back with overhauled serviceable tags. 

Larry Kelley, B-25 Panchito, has graciously contributed six new old stock liquidometers (fuel gauge sending units) for our project. Since the beginning of our XP-82 project, Larry has given us countless items for our XP restoration, including a pitot head.
Thank you, Larry.

Liquidometer fuel gauge sender with float

Pitot Head - airspeed probe to be mounted on the right lower
outboard wing surface

The fuel control box has now had the last of the remaining switches, lights, terminal strips, fuel-quantity gauges, etc. completed. This box will be installed in between the left-hand pilot’s two knees below the instrument panel. This is a complex electrical panel which controls the boost pumps, fuel shut-offs, cross-feed valves, and installed in it are original unique illuminated tracks which light to show the pilot the direction in which the fuel is being routed.

Coolant Exit Door Motors
Both new old stock coolant exit door motors are now installed along with their wiring harnesses and limit switches. These coolant motors, which actuate the opening and closing of the coolant exit doors, are thermostatically controlled to regulate the airflow through each radiator for engine cooling. 

The Katz
“Come on …
Give me a break. I was here first.” -- Rivet

Lt. Col. Edward Joseph Saylor
Engineer Crew #15 - Doolittle Raiders
March 15, 1920 - January 28, 2015

Lt. Col. Edward Saylor, one of the last survivors of the “Doolittle Raiders” who flew a daring WWII bombing mission over Japan just four months after the attack on Pearl Harbor, died near Seattle.  He was 94.  With Saylor’s death, only three of one of the most storied group of airmen in American history remain.  When the young men -- all volunteers -- took off from the USS Hornet on 18 April 1942, they numbered 80.

Those of you who have been following the progress of the XP-82 restoration project know that we are moving into the final stages. We are trying to meet an 18-month deadline.  As a result, we will have to change the update schedule to every six months, thus saving us 3-4 days a month (newsletter preparation time) that we can apply to our restoration. The next update will come out in June / July.  However, The Katz may say “Hi!” from time to time.”

Thank you.
Tom Reilly

Thursday, January 1, 2015

December XP-82 Twin Mustang Restoration Update

 What a year 2014 has been for progress 
that the XP Team has made on the 
XP-82 Twin Mustang Project.

Just looking back to last 
December’s photos really shows 
what has been accomplished this year.

Center Section
All the gear door castings and link rods are now installed with the exception of the two aft door hooks and hook mounts that we should have any day now.  Gear door up-lock casting mounts, hooks, bell cranks and push rods are pictured in numerical order starting on front spar.

Left-hand wheel well, forward gear door up-lock hook mounted on forward spar

Left-hand 90 degree door up-lock bell crank mounted on forward spar

Center gear door up-lock mount with one push rod coming from 
forward spar and one push rod going to the middle spar

Aft gear door up-lock mount with push rod coming from center gear door mount

Both emergency gear up-lock release mechanisms are now installed and cables run.  These up-lock releases can be operated independently by either pilot through a common cable to release the gear doors and up-locked landing gear by a pull handle mounted under each instrument panel. Both gear will then gravity fall to down-lock position.

All of the 3/32 stainless steel cables that run through the center section from each throttle quadrant are now installed and rigged. These sixteen cables, eight running from each side, synchronize the throttle and prop control levers mounted in each cockpit. 

Also, the six one-inch diameter five foot long control rods that transfer and synchronize the elevator and aileron movements between both pilots are now installed pictured below the cables.

And at last, the two remaining (out of 20) fuselage-to-center-section attach fittings are now permanently installed. Each fuselage is attached to the center section with ten huge NASA bolts bolted down through and into barrel nuts mounted in fittings attached to the forward, middle and aft center section spars.

The final installation and rigging of the opening and closing crank and cable mechanisms for each canopy are now completed.  (Two of the very few parts in the 82 that are the same as a P-51.)  Both under-canopy aft closeout skin panels and phenolic rub strips are now completed and installed.

Aft Fuselages
All of the rudder, elevator and balance trim cables are now run through numerous pulley banks, installed and up to tension. As you can see, not that easy to get to.

Both rudder lower side skins (four) and tail light receptacles are now completed.  Both lower rudder boots that were mashed beyond recognition are now back to final shape and fit, awaiting special English wheel rollers to roll out the final small dents.

Dorsal Fins
Both dorsal fins are well on their way to completion.  All of the parts are remade and fit, awaiting final riveting.

Fuel check valves, before and after. New nipple fittings are on order

Wings / Flaps / Ailerons
The remaining flap hinges, mounts, bell cranks and arms have now been completed and painted, awaiting installation. 

The aileron combination sector/arm/hinge mounts (25 in all)(23 pictured) have all been delivered to us from two of our sub-contract machine shops and are being fit.

Tail Wheel Retract/Extension Mechanisms

We have just started to get full time into sorting out what we still need in the tail wheel assemblies. The majority of the steering parts that were originally magnesium didn’t survive the sixty years of element exposure very well. We have two machine shops just starting the duplication process of all the parts that are still required.

The Katz
Tom explaining to Rivet how the rudder adjustment rails are assembled.

Saying of the Month
'When flying try to stay in the middle of the air. 
Do not go near the edges of it. 
The edges of the air can be recognized by the appearance of
 ground, buildings, sea, and trees. 
It is much more difficult to fly there."

- W.W.II Undergraduate Pilot Training Sign

The entire XP-82 team would like to wish everyone
 a very Merry Christmas and a 
Happy, Safe and Prosperous New Year.


Monday, December 1, 2014

November XP-82 Twin Mustang Restoration Update

What a Fabulous Year 2014 was for Our 
XP-82 Twin Mustang!

Aft Fuselages
Part of the team has completed riveting of the all of the little hard-to-get-to places on both aft fuselages. They are now concentrating on completing both dorsal fins. 

With the exception of the completion of the riveting work on the aft fuselages and dorsals, the remainder of the team has been working on completing the multitude of systems and small-to-complete jobs. 

Center Section Gear Door Hooks

The up-lock mechanism for activating the gear door up-lock hooks is quite complicated with the amount of moving parts that it has, but very dependable. The mechanism is controlled by one hydraulic cylinder on each side mounted on the forward spar for the forward hook, and then transitioning all the movements through a number of bellcranks, push rods and levers to actuate each aft hook mounted on the center spar. Two team members have spent the entire month locating each casting (ten) that holds the bellcranks, etc. These bellcranks and mounts are all interwoven with the hydraulic lines and wiring harnesses. Pictures of the completed systems will be in next month’s update.

Emergency Up-Lock Releases
In the XP-82, and all subsequent models, there are landing gear up-lock emergency releases controlled by a pull handle, one in each cockpit, that will unlock the main and tail gear and allow the gear to free fall without hydraulic pressure to the down position and positive lock. These back-up safety factors are in place in the event of battle damage to the hydraulic system or the normal gear down actuation system. 

There is an incredible number of pulleys in both wheel wells changing the direction of the cross-ship pull cables and releases. The NAA engineers who designed these complex gear door hook and emergency release systems deserve to take their hats off and take a bow.

Control Cables
All of the primary and secondary flight control cables, chains, pulleys, bellcranks, push rods, etc., are now installed with the exception of the final completion of the trim and balance cables, which will be completed this coming week.

Rudder Pulley Chains and Sprockets are now installed

 Elevator Pulley Chains and Sprockets are now installed

Rudder and Elevator Trim Tabs
The installation of the hinge blocks, new bearing mounts with new bearings, and three trim tabs are now completed. Finding the N.O.S. needle bearings for the bearing mounts has been a challenge, but I think we have bought every last one that was available in the world. We replaced the magnesium needle-bearing mounts and machined the new ones out of 7075-T6 aluminum, giving us a much higher safety factor due to numerous known in-flight trim tab failures. 

7075 T-6 Trim Tab Hinge Blocks with New Bearings

Both Rudder Trim Tabs are now installed

Elevator Trim Tab  is now installed

The team has completed the remaining items on the elevator, i.e., elevator control arms (two), counter weights, close-out panels and the final fitting of the elevator trim tab. We were required to add a small amount of extra counter balance weight to offset the additional weight of the trim tab 7075 fittings that we exchanged for the lighter original magnesium fittings.

 Right-hand Elevator Control Arm with Counter Weights installed

Note: All aircraft control surfaces must be precisely balanced as per the factory data so that the control surfaces, i.e., rudder(s), elevator(s) and aileron(s), does not flutter in flight like a flag on a pole in a heavy wind. A flutter in a control surface during flight is extremely dangerous. Thus our balance calculations must be perfect.

Aileron Hinge Points
The four special machined aileron hinge points that we need are nearing completion at one of our sub-contract machine shops. These are the main hinge point attaching-and-actuating fittings that attach the ailerons to the trailing edge of the wings.

We expect to receive these fittings and have them installed during December or January.

Canopies / Windshields / Aft Fairings
The final adjustments of both windshield bows to match the mating canopy bows has now been completed. Both center windshield glasses are now permanently installed, awaiting the delivery of the four windshield side glasses that were completed and shipped to us this past week. The final fitting of these side glasses will be completed by the end of December. A picture of the completed windshield assemblies will be in next month’s news release.

The aft canopy fuselage fairing located under the canopy is now completed on the left-hand fuselage and well on the way to being completed on the right-hand fuselage.

Left-hand Under Canopy Fuselage Fairing (above) is now complete.

Right-hand Under Canopy Fuselage Fairing

The P-82 series has an incredibly complicated brake system that is not fitted on any other known aircraft type. Thus replacement parts are impossible to come by. We recovered one main brake caliper out of the Fairbanks scrapyard parts that had been exposed to the weather for 50+ years. It appeared to be in terrible shape, but a couple of weeks ago, I decided to try to take it apart to expose the internal hydraulic pistons just to look at their condition. To my surprise, all three of the caliper hydraulic cylinders and bores were in perfect re-buildable condition. 

This leaves us with only one caliper to come up with. Pat Harker has machined new ones for his F-82E in Anoka, MN, and we will talk to him about him supplying us with a newly manufactured one.

Newly Machined Inboard Aileron Sector Controls

 Newly Machined Flap Push Rods (above) and Matching Threaded
Flap Push Rod Fittings (below)

The Katz

“Where are my helmet and goggles? 
Crank up the engines, I’m ready to go fly.”  
-- Allison

 Hope everyone had a Happy Thanksgiving.
Wishing you a very Merry Christmas and Happy New Year!

Tom and the XP-82 Crew