Suspended aviation

 - August 11, 2008, 7:20 AM

“Five hundred years from now, you’ll want to be able to pop open something on the aircraft and see how it worked,” noted David Hahn, acting collections manager for the Science Education Center in Richmond, Va. For the past 13 years Hahn has cared for N802L, the Model 23 Continental that was the first production aircraft from Lear Jet. Now N802L has come home, as a wave of artifacts arrive each day for reassembly at the Steven F. Udvar-Hazy Center, the annex to the National Air and Space Museum (NASM) at Washington Dulles Airport that will open December 15. The annex, more informally known simply as “Hazy,” will house 81 aircraft before opening ceremonies; and the roster will continue to grow.

NASM curator Dorothy Cochrane stood by to accept N802L, and while waiting she thumbed through the July issue of AIN. “I think the next Smithsonian artifact should be a Beechcraft Starship,” referring to the page one story detailing Raytheon’s decommissioning of the twin turboprop. Cochrane also hopes the airplanes at the annex will still be here in 500 years but, realistically, “we think more of a 100-year time frame. There’s not as much of a problem with corrosion of airframes as with things like spacesuits that have rubber parts.”

Restoration specialist Karl Heinzel wheeled up on one of the museum’s fleet of lemon-yellow tricycles. Heinzel agreed that with humidity control, no sunlight and no temperature extremes, 500 years is attainable. “The sun is the worst thing for an aircraft’s paint,” he said. Meanwhile, Heinzel mopped his forehead–the environmental systems won’t be turned on until next month since the museum’s doors will open scores of times during move-in and to extend warranty coverage on the system.

In addition to retrieving aircraft on loan, Hazy will contain the rich, mostly unseen collection warehoused at the NASM restoration facility in Suitland, Md. The Hazy Center forms one of the largest interior spaces in the world, with a visitor catwalk four stories high for level views of suspended aircraft overlooking huge aircraft on the floor that include the oldest Air France Concorde, Boeing B-29 Enola Gay and the SR-71 Blackbird, along with an IMAX theater and a mockup control tower. The Hazy floor is awash in crates, cranes, floodlights and blueprints. A box fills with “miscellaneous” nuts and bolts left over after assembly.

Though called an annex, the collection will eventually surpass that of the original Air and Space Museum, which will continue to operate on the National Mall in Washington. The NASM is confident in its choice of Dulles Airport for expansion, but is gambling that mainstream tourists will make the 28-mile diversion from the “monumental core” of Washington. Though museum entrance remains free, the lease with Dulles mandates that parking fees be collected; a shuttle service will be privately run both from downtown and from Dulles; and food concessions will be open for bid.

‘Business Wings’ on Steroids

Until opening day, artifacts are covered with disposable, lightweight painting plastic sheets to prevent them from collecting dust. Artifacts up to 10,000 pounds are suspended while others are floor-bound. The Lear Jet 23 will rest beneath a suspended Beech King Air and Bonanza as part of a business aviation exhibit that also includes a Grumman Goose, Dassault Falcon 20 in FedEx livery and a North American Rockwell Shrike Commander 500S. Most artifacts are trucked in by NASM riggers, though the Shrike is planned to be flown to Dulles by legendary pilot Bob Hoover.

The business aviation exhibit is flanked with a glass case of scale models and a fully scripted history as guided by NBAA, via its donation to NASM of at least $1 million plus research help. The “script” consists of text panels and historic photographs presenting business aviation to the general public.

The parade of aircraft to Hazy was launched years ago using plastic templates on a blueprint to visualize the requirements for assembly, flatbeds, forklifts and the ballet of movement in space that narrows with each delivery, requiring a rigid sequence for move-in. Dimensions of every artifact were input to an autocad program and the layout continuously evolved with each firm move date or restoration, in parallel with construction of the immense facility. Though each move is unique, N802L captures the science and art.

William Lear Sr.’s number 1L had been destroyed in flight tests, so in March 1964 Lear number 2L was rushed from raw parts to its first flight in 135 days. Lear Jet N802L made 864 flights through June 1966, when an experimental modification shook its airframe beyond repair. NASA then used it for full-scale wind-tunnel tests until it was retired for restoration and display.

Cochrane chose the Lear Jet Model 23 Continental as a pioneer in the new field of business and personal jet aviation, inspiring derivative models with increased airspeed, range and capacity. The Model 23 was based on the Swiss AFA P-16 fighter. With a thrust-to-weight ratio of 1:2.2, the P-16 could outclimb an F-100 Super Sabre to 10,000 feet.

Moving a Lear 23

At Richmond, though, N802L was suspended 20 feet over a mezzanine in the concourse of a 1919-era train station. “In 1988, when it was installed, it was tight,
all right,” said Hahn. The Lear Jet was suspended from trusses on cross beams added
to the original train-station roof.

John Shatz is the technical specialist from the NASM collections processing unit, which tackles each move. “It was mostly chainfalls and stops,” he said, taking three days. The fuselage traveled solo, as did the wings, while the wingtip tanks and assorted parts made their own jaunt. The convoy moved by day, though “super loads” went by night and required a highway escort.

“We began by loosening the current wires and lowering the Lear to scaffolding to remove the keel beam,” noted Shatz. “The keel beam is a strengthening structure between the forward and aft wheelwells. We ‘trapezed’ a bit to clear the mezzanine, then the aircraft was lowered to furniture dollies that were topped with mattresses. Then we removed the wing and fuselage fairings to give access to the four mounting bolts on each side of the fuselage.” The fuselage was then lifted up off the wings and returned to the ceiling so work could continue beneath it in the tight space. Before the first day ended, the tip tanks were removed via the forward and aft bolts.

“On day two we set out to lower the fuselage, so we precut some beams to mount the aircraft on a stand,” Shatz continued. “First thing that day we removed the engine nacelles and attached chainfalls to the engine mount [the two GE CJ610-1 turbojets have been missing for decades]. A sling was put in place to replace the forward holding point, where the Lear was attached by a hook over its windscreen to the ceiling beams.” At this point the fuselage was hanging from the sling and the chainfalls.

The NASM has studied the effects of suspending artifacts on the museum itself, checking the stress on the ceiling beams, but has done little research on the artifacts themselves. For example, what is the stress of suspension on the Lear’s laminated, acrylic plastic windows beneath the hanging point? “Ultrasonics might tell you what stress, if any, came from it hanging for 13 years, but the stresses are probably less than they are during flight,” said Shatz. “Suspension is done in a way that the airplane does not know the difference between suspension and sitting on the ramp; in some cases the attachment points are to a sling beneath the axles. In N802L, the suspension points were just about at the normal center of gravity.”

Floor displays require custom stands, and NASM staff have crafted some from satellite trailers donated by Motorola Iridium, with its precision casters alone costing $1,000 each. Including its stand, the Lear is returned to its basic empty weight of 6,150 pounds, but in suspended displays weight and balance are more critical. Besides precision records of aircraft dimension, loading and structure, moves cannot be accomplished without calculating the new center of gravity as the aircraft will be displayed–sometimes in a simulated roll or pitch.

The c.g. normally falls about one-third back in the chord of the wing while the center of lift is slightly forward of the center of gravity (a design that leads the nose to drop and aid recovery in a stall). “We need to find the new c.g. moment, so we walk back the correct arm to compensate for the removal of fixtures and aircraft parts,” explained Shatz, who combines computer analysis with dead reckoning and a bit of artistry.

With the landing gear folded into the fuselage, the loop attachment points were placed 18 inches from the wing root at either side of the fuselage. To leverage “area rule” during high-speed flight, the Lear fuselage narrows markedly at each side where the wing and engine nacelles extend. During the move, the keel beam remained in place. “It’s critical to the structure when the wings are removed; it prevents flexing,” said Shatz.

While Hazy is one of the world’s largest indoor spaces, the Lear’s former home in Richmond was claustrophobic. When the Lear Jet was first displayed, technicians carved notches on either side of the entrance to allow the wings through the eight-foot wide door. “To get it out, we worked up a rig to mount the wing on a dolly at a 45-degree slant to roll through on a diagonal. We lowered the gear, placed a two-by-six beam between the tires to arrest the brakes, and a two-by-four to prevent the gear from collapsing. We tied down the struts to the end of the wing platform to prevent shifting.”

Chainfalls were attached to the Lear fuselage to raise it and release tension on the original cables, before cutting them to lower the fuselage to furniture dollies covered with movers’ blankets. For the transfer by truck to Dulles, the truckbed was lined with Serta twin-size mattresses. The museum prefers mattresses with horsehair stuffing, but few are now available.

At 35 feet 7 inches, the wingspan of the Lear easily fit the flatbed and was cushioned by six mattresses, but Shatz noted, “Generally, wings with internal fuel tanks can take more rough handling.”

On the Road Again

Though this transit was contracted to Riggers Inc., most moves use the NASM’s own fleet, which includes a 48-foot trailer with a capacity of 31,000 pounds. Its oak base allows mountings to be screwed directly to the bed.

NASM driver Lars McLamore described moving airplanes by highway: “You can go 12 feet wide by yourself in most states, non-rush hour and preferably in daylight.” The trip from Garber, where most NASM artifacts are held, to Dulles Airport is 38 miles, sometimes passing through three jurisdictions of Maryland, the District of Columbia and Virginia, each with different rules. “Empty, the trailer is 25 inches off the ground; loaded with serious weight it’s about 23 inches,” McLamore noted.

The process often comes to the fraction of an inch to clear underpasses or ancient doorways. Plain horse sense often does the trick– for example, raising a nose with a forklift to lower the tail enough to clear an obstruction.

After draining all fluids from a display aircraft, the NASM crew “pickles” a propeller with microcrystalline wax or grease to prevent turning, but after a decade of storage the prop can still windmill once at highway speed. The crew routinely discusses the merits of keeping props in the vertical position versus horizontal in their museum displays, having mixed results with both orientations in terms of bruised visitors.

Hahn said that while the Lear Jet was in Richmond, it generated fairly mundane questions from the public, such as “how fast does it go,” or “how many people does it take to fly?” Hahn would answer, “This was a businessperson’s way of flying without being tied to the airlines.” Hahn said Richmond’s task was to explain the science of flight, mainly the difference between props and jets in propulsion, and did not tackle the economic questions.

At the Hazy Center, the new “business aviation exhibit station” will continuously play a DVD explaining business aviation, courtesy of NBAA. A directory of airports suitable for business aircraft will appear on a touch screen, courtesy of Jeppesen.

“The needs of a business and what it can afford determine the type of aircraft it uses,” begins the narration of the DVD. “Roomy and expensive, the classic 1932 Beech Staggerwing defied all odds by becoming a successful corporate aircraft during the Depression.” The script describes the Travel Air Model 6000-B as the “private air office” of H.L. Ogg, president of the Automatic Washer Machine Co. of Newton, Iowa. “By removing the seats, three washing machines could be carried in the cabin and connected to an auxiliary power unit for demonstrations.”

A museum case includes the 1951 Directory of Executive Aircraft, published by NBAA’s forerunner, the Corporation Aircraft Owners Association. The narrative with photos traces the roots of business aviation from the corporate logos on the sides of World War I biplanes through 80 years of economic cycles and technical advance, citing leaps in speed, utility, efficiency and forms of ownership.

The DVD narration continues, “Why do companies use corporate aircraft? The two most important benefits are time savings and flexibility. Other benefits include reliability and safety of aircraft, market access, efficiency, security and privacy. As a result, companies that use aircraft are more successful where it counts–their annual income or assets or sales.”

In no small part, the exhibit station will rely on scale-model airplanes in a fine wood and glass exhibit case at floor level. Bombardier donated a 1:35 scale rendition of the Learjet 45 while EADS North America crafted a 1:35 scale Eurocopter EC 155. At last count, some 32 meticulously crafted business aircraft models had been given to the NASM by corporate and private collectors, ranging from a Howard DGA-15 to a Fairchild 91 Baby Clipper to an MBB Hansa Jet to a Beechcraft D-17 Staggerwing.

NASM curators are taking advantage of the move-in to photograph the artifacts from every angle using the latest imaging technology. While the aircraft temporarily offer unobstructed access, photographers Dennis Biela and David Palermo of LightSpeed Media are shooting 360-degree up-and-down views. The technology they use is QuickTime VR, a format developed, and the project sponsored, by Apple Computer.

Each aircraft is placed in a circle to form the needle in a compass rose, with the circumference marked in 10-degree increments. A turntable is custom built for each aircraft, combining three dollies as a triangle to support the nosewheel and main landing gear. The airplane is rotated, not the camera. For each camera position, 36 photos are snapped, which are later melded by software to fill in gaps. The process takes an average of one day for each aircraft. In addition to the raw photographs, precise color measurements are recorded so that researchers a century from now could duplicate every detail.

By December, Internet users will be able to use their mouse to zoom in 3-D through the cockpit window, into the bomb bay, beneath the gear or even close enough and with enough photographic detail to read tiny serial numbers on a metal plate in a cockpit. Comments from virtual viewers will be posted online at www.nasm.si.edu when the Hazy Center opens.