The   Boeing   737   Prototype   Airplane
Storage and Preservation at Moses Lake, Washington 1997-2003
by Bob Bogash

  1967            1998



Airplane  PA099, Manufacturer Serial Number 19437 is the Boeing 737 Prototype.  It is a Model 737-130 (-100 Series) built to a Lufthansa Detail Spec, and assigned the last customer variable number in the DLH PA001-PA099 block.  The airplane was assembled in Boeing Plant II at Boeing Field, during the summer of 1966.  In September 1966, it was moved out of the Plant II assembly bay, and had the vertical fin and both engines installed on the ramp in front of the factory building.  It was then moved down the field to Position 1 of the Thompson site (a purpose-built factory building at the southwest end of Boeing Field), for systems installation.

The airplane was painted in December 1966 in an olive drab, dark green and yellow color scheme, and formally rolled out in a ceremony in the Thompson site the same month.  Assigned registration was N73700.  The airplane was then moved to the Flight Center flight line for final functional tests, fueling, and engine runs.  The airplane made its first flight April 9, 1967 from Boeing Field to Paine Field.  The Captain was Brien Wygle and the co-pilot was Lew Wallick.  The airplane was the lead airplane of a six airplane (4 -100's and 2 -200's) certification fleet.  Certification was received from the FAA in a ceremony in the B-52 hangar in December 1967.  Initial production airplane deliveries and entry into revenue service occurred in January and February 1968 to Lufthansea and United.  All details here.


After First Landing at Paine Field

As a liaison engineer, flight test engineer, and later as a field service engineer, I was fortunate enough to have participated in all the above activities.

Following FAA type certification, PA099 participated in the flight testing and certification of various follow-on mods and configuration changes as an experimental airplane in the Boeing flight test fleet.  One major change was the testing and certification of the hydraulically powered target thrust reversers installed commencing line number 136 to replace the original pneumatically powered 727 clamshell door/deflector door reversers.  The new reversers were known as HPTR for High Performance Thrust Reverser, and were based on the DC-9 reverser, built by Rohr.


After several years of Boeing flight test work, PA099 was placed in storage by Boeing for several years, until sold to the U.S. Government -  National Aeronautics and Space Administration (NASA) - as a flight test airplane.  NASA had two blue and white color schemes over the life of the airplane.  Their call sign was simply NASA 515.  As a public use airplane,  PA099 became N515NA on the FAA registry.

After about 23 years in NASA service, the airplane flew its last research flight from its base at the Langley Research Center in Hampton, Virginia on June 27, 1997.  The airplane was placed with the Museum of Flight in Seattle, and was flown to Moses Lake, Washington for interim storage in September 1997, pending creation of a permanent display location at Boeing Field.  NASA stipulated that the airplane be maintained in an airworthy condition.  They also retained title to the airplane until such time as it was placed on permanent display.  They continue to hold title to the airplane as of this date.


After retirement from Boeing in 1995, having been active at the Museum since its inception in 1965, I  began volunteer work on “E1", the 727 Prototype at Paine Field.  That was an airplane I had obtained from United Air Lines in 1984.  See here.  I had worked on 737's for over 30 years - since the very beginning.  After arrival of NASA 515 in September 1997, I began helping Tom Cathcart, MOF Chief of Restorations, during his monthly visits to the airplane.  In November 1998, I took over complete responsibility for the airplane, and became Crew Chief.  I  made visits on approximately 4 week cycles thereafter.   Ultimately, I made about 160 trips to Moses Lake. Each trip entailed about 8 hours driving plus 6 - 8 hours working at the airplane - long days!  Hot in the summer and COLD in the winter.

The drive to Moses Lake was about 8 hours round-trip (when the weather was good!)

Usually, I was accompanied by a helper, many of whom were individuals associated with the airplane and its history.  Helpers were pretty essential and I had to work hard - sometimes - to get "volunteers". Two of my "helpers" were Brien Wygle and Lew Wallick, pilots of the first flight of this airplane.

  Steve Huemoeller, a United Air Lines mechanic, was a very frequent assistant and an individual without whom I could never have accomplished this task.  Steve, a 737 qualified A&P, ultimately signed off the airplane for its Ferry Flight.

Steve Huemoeller

Here's 'da Man himself - Steve was working nights at the time as a UAL Mech at Sea-Tac.  Luv 'ya, guy!!!

  Other helpers included Jim Gannett, Dale Ranz, Peter Morton, Bruce Sutherland, Grey Clark, Jack Wires, Morgan Barber,  Barry Eberhardt, Harold Isaacson, Jocko Worthington, Del Fadden, Jim VonDerLinn, Doug Roulstone, Jim Johnson, Bill Moritz, Dave Early, Jim Blue, Dick Taylor, Evan Elliott, Charlie Cawvey, Jim Devany, and my wife Dot.  Some helped multiple times.  And some braved some pretty nasty blizzards driving with me over the Pass in the dark!  Thanks to all - they now know they were participating in a piece of history.

    Jim Gannett - Boeing Test Pilot on PA099 - see more here

Dick Taylor   

Dick Taylor - Director of Engineering for 737

Jocko Worthington  

Neighbor and retired Naval Aviator Jocko Worthington


Spring time "bird cleaning" with Steve Huemoeller and his neighbor - a NWA 757 pilot

Grey Clark    Grey Clark - 757 Director of QA


Sometimes I was a little desperate for helpers......

Jeff Akridge

Jeff Akridge, owner of Columbia Pacific Aviation, the FBO at Moses Lake was also key to our success.

Alaska Airlines provided parts support and Japan Air Lines provided me with facilities and equipment at their Moses Lake hangar (since closed.)

All contributed a lot ..... and charged nothing.


Based on my experience with long-term storage of airplanes, including the Comet, 727, and B-52, it was very apparent how rapidly the condition of the structure and systems can deteriorate if not actively maintained.  Accordingly, a maintenance schedule was established that involved periodic operation of the airplane and its systems.  The results were more than validated.  The 737 condition remained superb.  Virtually all systems on the airplane  are still, today, fully functional, reliable, and in a nearly flight-worthy condition.  The objective of an airworthy airplane capable of a final ferry flight with minimal maintenance restoration was met.

   Setting up for an 8 hour work shift

Each visit involved a detailed pre- and -post operation walk-around inspection, checking of, and servicing all fluids (engine and APU oil levels, CSD oil, hydraulic reservoirs), checking and servicing all tires and shock struts, brake and thrust reverser accumulators, engine and APU fire bottles, etc.  Operation involved running the APU, operating all cockpit control systems, exercising all flight controls, trim systems, air conditioning packs, pumps, motors, fans, lights, and valves; all avionic systems, communication, fire protection, ice and rain protection systems.  The engines were operated and the airplane was taxied around the airfield checking engine operation, thrust reverser, and brakes, as well ensuring the condition of the wheel bearings and tires.  At the conclusion of each visit, all openings, inlets, exhausts and vents were closed and sealed with custom covers purpose built for this airplane by my pal and former colleague Bruce Sutherland.  Special springtime surveillance was carried out to curtail, interrupt, and remove bird nesting activities.  With JAL's help, the airplane was made ready for her final flight on all new wheels and tires.


Nice!  A new Nbr 4 brake getting installed - and new tires and wheels too!

At least one high speed taxi run down Runway 32R was normally accomplished. Speeds up to 144 kts were attained on occasion.  Ultimately, I taxied the airplane over 600 miles!  (More than enough to take I-90 to Seattle - except for the tunnels......)


Working those flight controls, flaps and reversers

Several documentary videos were made of my activities, including those made by KING-5 TV in Seattle, and Airside in New Zealand (four in-depth videos available on YouTube with the first episode starting here.

Jocko and film crew from New Zealand


In May 2002, Moses Lake held an Air Show and asked if we would participate.
Of course, we said Yes!



With the creation of the Air Park at Boeing Field, Plans were approved, and activities undertaken, to allow the airplane to be placed on permanent display at the Museum in the late spring of 2003.  After its ferry flight to Boeing Field, the airplane would join RA001 - the 747 prototype, and N874AA, an American Airlines 727-200 (that arrived at the Museum 20 Jan 2003,) on static display across the street from the Museum on the west side of East Marginal Way - a facility then known as the Air Park..

On September 21, 2003, the airplane was flown successfully to Boeing Field in Seattle, and on November 22 was moved to the west side of East Marginal Way to its static display location.  Information on the Final Flight can be found here.

    Steve Huemoeller

As a young engineer, I worked on the design, assembly, and flight testing of this airplane.  Fate has allowed us to come together again, each in our retirement.  Joined by hand and heart - as much as one can be - with what is, I guess, what some people would call "just a machine...."

It has been an honor and a privilege, to work on, and to be the custodian of, this beautiful airplane. 

                                     A Happy Man at Work!

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Copyright 2003- 2017 by Robert Bogash. All rights reserved.

Last revised

30 Dec 2004
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