Category Archives: N332UA disassembly

The first phase of the project involved cutting the airframe into small enough pieces to fit through the basement door.

Into the house

The forward section, reassembled in the basement.
The forward section, reassembled in the basement.

Once again it’s been a long, long time since I wrote an update, but work has continued over the past year.

Over the past three years I have had unbelievable luck in a complex cat-and-mouse game with the ninnies at Manassas Regional Airport. I always planned to bring the project home, but my hand was forced one rainy day last summer when I pulled the trailer over to Skyworks for an early morning rearrangement of the disassembled pieces. I finished this task around 7:30 am, and figuring that government employees probably wouldn’t be at the office that early, I drove my pickup with the project in tow up into the semicircular driveway leading to the secure gate onto the ramp. Standing next to the terminal enjoying morning cup of joe was none other than the airport director himself! One glance at the look on his face told me that there was no way to put the project back into the hangar as planned without getting busted, so I just kept driving, and ninety minutes later the trailer was safely parked in my driveway.

In the driveway, divided
After removing the control columns, throttle quadrant and dual-control linkages, the forward section was divided along the centerline to prepare for the move to the basement.

The trailer remained there for another two months while I spent days in sweltering heat removing the control columns and yokes, throttle quadrant, and all control linkages crossing over the centerline. All of this was done in preparation for moving the pieces into my basement.

Having finished the prep work, I gave the entire project a good bath with soap and water, then divided the forward floor section along the centerline with an angle grinder and reciprocating saw. This yielded two sections that were not particularly heavy but very bulky and awkward, so I bribed three friends with promises of burgers and beer to come over and help move everything into the basement. This was made easier by temporarily removing the sliding double door.

The two halves of the forward floor just after arrival into the basement.
The two halves of the forward floor just after arrival into the basement.


Dividing the floor

Looking forward from an area abeam the forward cabin door. Throttle quadrant, control yokes and rudder pedals were all left in place to facilitate future decisions about how to configure the underside of the forward floor.

Having removed almost everything above the waterline, I’m turning my attention to the remaining floor section, which one recent visitor said “looks more like a boat than anything else.”

A very leaky ‘boat’ is all that remains after the walls came off.

The strategy with this task is to divide the floor into pieces that are small enough to get through my basement door, taking advantage of the original Boeing structure to leave matched holes that will allow for realignment later.

The floor of the lav. The floor aft of the cockpit door is covered with composite panels, easy enough to remove once the incredibly thick, incredibly sticky tape is removed. Orange area is the part underneath the sink, flimsy plastic because no one ever stands on it.

After some investigation and feasibility experiments with drilling out various rivets, I settled on a line parallel with the lateral axis of the aircraft, about ten inches forward of the cockpit door frame. Underlying this line is a heavy spar that is attached to the aft part of the floor by six lighter spars that run longitudinally. Fortunately these lighter spars were secured to the heavy one with aluminum rivets, thankfully easy to drill out given the awkward spaces in which I had to use the right angle drill. I’m still looking for a more efficient way to drill out the steel huck rivets that continue to slow me down. An online hint to use a masonry drill bit did not seem to be much faster than the standard black oxide.

After drilling out the rivets attaching the longitudinal spars to the heavy lateral spars.

The dismantling continues

It’s been way too long since I updated this blog, but I have actually been busy making progress. The cockpit is now cut down to the flight deck floor, also known as the water line. To accomplish this I divided the structure above the floor into seven major pieces, all with the goal of preserving the geometry of the windows and doors. As I discussed in a previous post, I used custom fabricated angle brackets with pre-punched holes that were put in place with cleco fasteners prior to dividing each section. These brackets were labelled according to their location as unfortunately there is some variation in the location of the pre-punched holes. After drilling all the appropriate mounting holes in the original structure, the clecos and brackets were removed and the cutting process began.

The biggest challenge in making many of the cuts in the metal was finding a tool that was small enough to fit in the available spaces. The structure designed by Boeing becomes increasingly more robust as you move forward through the cockpit, and unfortunately the space also narrows simultaneously. I used a combination of a Ridgid 4.5 inch electric angle grinder and a reciprocating saw with various blades to make the cuts. A double cut saw from Harbor Freight also came in handy for some of the thicker pieces.

After cutting the aft part of the top off, I lifted it off the structure with ropes run over the ceiling spars in the hangar.

The resulting segments were awkward to move around but not especially heavy, probably on the order of about 100 pounds each. To make things safer and easier, I took advantage of a steel girder running across the ceiling in the hangar, and used a set of ropes to lift the pieces off the structure and slowly lower them to the floor. Once on the floor, the pieces were easy to slide around.

In order to preserve the geometry of the windows, I elected to remove the top of the cockpit in one piece. Red circles indicate predrilled holes for mounting custom made alignment brackets. This will preserve the geometry of the windows and maintain the proper angle of the overhead panel.

One major decision involved the roof of the forward part of the flight deck, which is relatively heavy with many thick  spars. As I now possess a complete set of real Boeing windows, I wanted to make sure that the window geometry was maintained, especially for the sliding P2 windows. Another goal was to preserve the positions of  the mounting brackets for  the overhead panels. I determined that the best way to satisfy both requirements was to remove the top as a single piece, cutting about two thirds of the way up the window pillars, with the exception of the center, which was cut at the top. These locations were chosen both to meet design requirements as well as for convenience of cutting.

After removing the top, the next decision was how to divide the remaining portion into manageable pieces. 


Following top removal. The galley remains in one piece at the rear of the trailer.
The top of the cockpit, successfully relocated to my basement.Note sliding P2 window track visible in the P3 window opening.

The removed top fit easily in the bed of my pickup truck, and was moved into my basement with the help of my good friend Miguel. Putting it back into place will require a crew of at least four of us.

After removing the instrument panel and CDU bay, it was time to make some important decisions about how to divide the remaining structure. Note the thick structure.

The next few weeks were taken up with identifying all the places the instrument panel and CDU bay were connected to the structure. This was removed as one piece, intact but not without some minor damage from the process.

Having exposed the structure, it was time to pick some lines to cut up what remained. It initially seemed appealing to make vertical cuts just under the window pillars between the P1 and P2 windows, but when the structure was fully revealed it became apparent that this would involve cutting some of the thickest parts in the whole setup.

Practical considerations led to choosing a vertical line aligned with the outer edge of the FO's left side rudder pedal.

Selecting a different line closer to the longitudinal axis of the aircraft led to a much easier cut that preserved the structure. The hardest part of removing these outer pieces proved to be cutting the spars along the floor line, several of which were in very tight spaces.

After making all the cuts, the FO side separates with a little coercion.

Having completed all of those cuts, the sides came off relatively easily and were lowered onto the floor with ropes.

After separation, the FO side of the forward cockpit rests on the floor of the hangar.

This left the center section, which was cut away from the floor relatively easily. There were only two thick spars to cut in this section, part of the radar mount.

The center section is all that remains after removing both Captain and FO side forward side sections.


Two days of solid progress

The march towards the cutting process continues: almost down to bare metal!

As predicted, the circuit breaker panel on the captain’s side was somewhat easier to remove. I continue to be slowed by tenacious stuck fasteners, some covered with a thick layer of paint courtesy of some past United Airlines refurbishment project. Today after breaking not one but two damaged fastener remover bits, I decided to direct my efforts at something less frustrating: cleaning out the overhead area. The pictures show the results. Hopefully another two days will have the inside metal surface of the airframe completely exposed and ready for cutting into sections.

These plastic trim panels below the side windows are secured with several screws, usually very difficult to remove.
The overhead area after removing the forward and aft Dzus frames. The remaining grey plastic is a tray that is held in place by the support rails on either side. This piece will have to come out in order to find places to cut the structure. Another mystery waiting to be solved.
Large beefy beam defines the aft limit of the flight deck. I plan divide this arch into three sections during the cutting process.

Work starts back up on two fronts: the real nose section and the avionics test bed.

In late October my wife and I finally moved into our dream house: a place big enough for our menagerie of two dogs and two cats, with ample room left over for the ultimate man cave: a full size, fixed-base Boeing 737 simulator in the basement! Unfortunately all the tasks associated with moving brought progress on the sim to a grinding halt for close to six months.

The avionics test bed in my basement. Looks pretty spare right now, but in a few weeks this will be all lit up by a network of five computers to start testing avionics.

I did manage to bring home most of the gear I had acquired prior to taking the major leap of buying an entire nose section. I set this up in the basement with the idea of making an avionics test bed for the additional real Boeing parts that I continue to find on eBay and other internet sources. The dual-linked flight controls, throttle quadrant and projection screen were made by Art May-Alyea of Northern Flight Sim. I had a steel frame made at my local metal fabricator that allowed me to hang the overhead panel in the proper position on the ceiling. It’s not flying yet, but I will need to get it running soon, as I just acquired a real fire control panel and other real parts that need to be interfaced.

The lav, left, and the galley, right, flank the cockpit door.

The nose section of N332UA still sits out at the airport, where I continue to remove parts from the interior in anticipation of cutting it into sections small enough to fit through the standard residential door of my walkout basement. The galley was easy enough to remove, as it is essentially a single assembly bolted to the floor, and attached to the top of the airframe by only one large pin. Removing the plumbing and electrical connections was relatively easy, especially compared to removing the lav on the captain’s side. The walls of the lav were bolted to the floor some 24 years ago, and almost every fastener was stuck enough that removal required drilling. A side benefit was that I finally figured out how to use those damaged screw removal kits they sell at Sears.

The galley, liberated. A lot of really mediocre coffee and food passed through these cubicles, some of it still stuck to the insides.
After removing the galley, the F/O side circuit breaker module comes into view.
Extraction of the F/O side circuit breaker module required removing a section of the composite floor below the galley. The assembly was attached to the airframe in at least 15 different places, only a few of which are seen here along the bottom of the zinc chromated (green) wall. Believe me, no one ever intended these things to be removable.

The disassembly phase continued to the wall of circuit breakers behind the first officer’s seat. For better or for worse, I had seen a really cool video online showing how the interior of the 737 is installed, and it was very clear (see it at 0:25 into the video) that the structure housing the circuit breakers was an assembly that rolled in and bolted to the airframe. While it was probably made to be easy to install, it was never intended to be removed  and it took a couple of days of removing wire bundles, ducting and insulation before I found all of the fasteners holding it in place. There was also quite a bit of head-scratching and occasionally swearing. Several times I was certain I had found all the screws and bolts but a vigorous shaking only revealed that it was still attached somewhere. It finally came loose and fell backwards onto the floor, with a very satisfying thud and a genuine feeling of progress.

The circuit breakers behind the F/O's seat, early on in the removal process.
The circuit breaker assembly on the F/O side, finally liberated from its many attachments to the airframe and free to fall on its back.

The wall behind the captain’s seat consists of a much smaller circuit breaker assembly, as well as a wall and a jumpseat. If anyone ever had the idea of burrowing through the front of the first class lav to break into the cockpit in flight, let me just say that it’s never going to happen!

Captain's side circuit breaker panels and jump seat.

Now that I’m basically up to the rear of the crew seat area, the next step is to remove the rest of the interior so I can start cutting the structure into sections. To that end, I’ve had some paired brackets made that I will rivet into place on either side of the section lines. The hole in the receiving bracket is elongated, to allow for some play during the reassembly process. With continued good weather, I should be cutting sections within the next two weeks.

Pair of brackets ready for installation on the airframe.

I’ve been making quite a bit of progress on another front: making a working 737 simulator for my friend Radcliffe, a WWII veteran of the Army Air Corps who learned to fly in Stearmans and T-6’s. Before he saw combat, the war ended and his flying dream ended along with it. After discharge from the military he found himself with no money and no opportunity to keep flying, so he went to work for the US Government Printing Office. In retirement he has rekindled his dream by building increasingly complex 737 simulators. Currently he has one large one in his garage and a smaller one in what used to the living room of his house. Working on this sim has been a pleasure as Radcliffe has invested in some really nice avionics from Flight Deck Solutions, Northern Flight Sim and CP Flight. This week we managed to take off and fly for a couple of hours on the autopilot, with a fully functional overhead.

Radcliffe during flight training in 1945


Radcliffe in his latest sim, formerly the living room of his house
Radcliffe's sim, complete with overhead panels from Flight Deck Solutions


Finally back in a level attitude!

Luckily the center of gravity after cutting favored this nose up attitude, which facilitated landing on the trailer about an hour later.

The past month has been a busy one for N332UA. After it became apparent that the cockpit would not fit into the originally planned indoor destination, we had to divert to a nearby corporate hangar, which was generously offered by Pat Colgan, the owner of Capital Aviation, an excellent avionics and general maintenance shop. Not wanting to overstay my welcome,  I embarked on a plan to cut off the bottom four feet or so of the nose section. After a month of pulling wire, removing insulation, wrestling with ducts and removing pitot/static lines, the section was finally separated and I rented the telescopic forklift again.

We were concerned about picking up the entire 2000 pound section with one strap through the eyebrow windows, but this turned out to be no problem with a strap rated for 6000 pounds. We had no way of knowing where the center of gravity was prior to picking it up, but luckily it would up being slightly aft of the middle of the section, which facilitated putting it down on stack of 6×6 beams we had put in place to keep the cockpit level on the trailer I scored off of craigslist.

After securing it with tiedown straps, we climbed up on the tires holding up the aft edge, walked past the galley and the lav, and onto the flight deck for the first time. I had crawled underneath and stood up a few times in the previous weeks when we were in the process of cutting, but with the cockpit a full 90 degrees nose up, I wasn’t really able to get much past the jumpseats to touch anything. Now that I was able to really get a good look at the main instrument panel, flight controls and throttle quadrant, it became clear that this particular cockpit is in really good shape, even in spite of having sat out in the weather for few months after it was put up for sale. Whatever buyers remorse I might have had went flying right out the window.

Next steps: build a metal dolly to reduce the height, and cut off another foot from the aft end to reduce the width, all on the way to the next borrowed work space.

Click on any of the images below to see a larger image with descriptions.


The Eagle has landed!

Arriving from the boneyard.

Back in April I bought an actual aircraft cockpit from a boneyard located in Walnut Ridge, Arkansas. It took that long to coordinate the transport of the this 3000 pound behemoth, the front 12 feet (minus the radome) of a Boeing 737-322 that came off the assembly line in August 1988, just after I graduated from college. This thing has probably seen quite a bit more of the country than I have, most recently on the back of a flatbed trailer.

I bet it never had this attitude back when it was working for United!

My new baby arrived last Wednesday evening. With a rented telescopic forklift in hand, two buddies and I used web straps to lift it up in the air to set it on its back. It was fairly dramatic watching it rain water (it’s been outside for several months at the boneyard), fasteners, and various items including an Starbucks cup. There was plenty of structure inside to pick this up with the forklift. We just needed two web straps,  one through the eyebrow windows and the other through the nose gear well, to get it safely into the air.

No glass cockpit out of the box. This one is going to need some modification. Oh, and some cleaning, too.

I already have a pretty sweet setup based on gear from Northern Flight Sim, but I really wanted a full back wall, including the structures holding the circuit breaker panels and cockpit door. This cockpit seemed like a good deal when it came along, but when I later started actually talking to people who had done this before it was apparent that it probably could have been done for even cheaper.

The seller offered to include ‘cutting’ in the price, and I returned the pictures he sent with very specific lines drawn as to where I wanted my cuts. Compared to others who buy this sort of thing for home use, I wanted relatively few cuts, because I wanted to make sure that all the flight control stuff underneath the floor was properly preserved. I also had delusions that I recover some of the cost by taking the leftover aluminum to the scrap dealer.

After the first six hours of cutting. It may not look like we made much progress, but its an important first step towards shaving about four feet off the bottom. We managed to remove a large piece from the very front which allows better access to all the ribs moving aft.

Had the seller actually performed the cuts I wanted, this thing might have actually fit under the door of my hangar. Unfortunately the cockpit arrived in its original condition, with no cuts at all. Some scrambling that evening led to its storage in a secure, undisclosed location, where I am now in the process of cutting about 4 feet off the bottom. All I have to say is, Boeing sure makes a sturdy airplane!