Photo  by Jim Koepnick

July 30, 2009 - Oshkosh, Wisconsin  - In 1962 Grimes Manufacturing Company, a leading manufacturer of aircraft lighting products, purchased four Beechcraft Model 18 twins. Three of the airplanes went into service as executive transports, but the company used the fourth as a flying laboratory for testing and certifying the company’s lighting products.

The Twin Beech replaced a T-28 serving the same mission.

Grimes flew the lab craft until 1986 when the plane suffered damage to the right wing after striking a utility pole during a fly-by. The Beech was grounded and ultimately sold—still in its laboratory configuration— a year later.

Plans to repair and use the plane to lift sky divers fell through after the owners learned that all of the test fixtures and test modifications would have to be removed to return the airplane to a standard airworthiness certificate from its experimental airworthiness designation.

The experimental designation precluded commercial use like sky diving—and removing all the fixtures was not economical.

So the well-known ambassador for the Grimes Company was abandoned to disintegrate in a field.

After 13 years serving as a home for more than one animal species, the Twin Beech caught the attention of a former company executive who saw the plane and convinced Honeywell, by then the parent corporation of Grimes, to rescue the old bird.

Over the Christmas and New Year’s holidays in 1999, a team of Honeywell employees traveled to Waynesville, Ohio, removed the plane’s wings, loaded everything on a truck, and returned it to its original home in Urbana, Ohio.

The Grimes Flying Lab lights up the night sky over Oshkosh just after sunset.

Getting company support for a restoration, however, proved to be more difficult than finding resources to purchase the craft. So a group of enthusiastic folks, some still Honeywell employees, formed a not-for-profit foundation and convinced Honeywell to turn over ownership of the plane.

After a lengthy and thorough restoration, the Beech 18 Grimes Flying Lab flew again January 8, 2008. Restoration of the lighting was still underway, however, and the date recognized as the true rebirth of the plane fell on May 31, 2008—when it was unveiled to foundation volunteers and to the public, at night, in all of its sparkling glory.

“All the lighting on here, with the exception of five LED lights, is original,” explained Chris McConnell, a member of the Honeywell Engineering department and part of the restoration team. “We were able to rebuild all of the original units.”

McConnell had a big part in the very extensive rewiring required by the project.

“The whole ship was completely rewired,” he said. “Dave Youtz, also in the engineering department, designed the circuitry, and I ran most of the wiring.”

“Dave designed in delay relays for the different strobe systems so they don’t all flash together. It really twinkles in the sky,” he added.

The ship sports dual 100-amp alternators— more than enough for most aircraft but insufficient to power all of the lights on this Beech. To meet the power requirements the Beech sports a separate battery installed in the cabin; that battery also powers an AC inverter necessary for some of the brightest strobe lights.

Typical light aircraft strobes are rated at 18 to 20 joules, a measure used for strobe brightness. One single strobe light on the lab ship is rated at 100 joules.

Overall 115 light fixtures are installed on the airplane—in addition to those delivered by the Beech factory. Fifty-five of those fixtures are on the outside.

Back in 1973 a European tour for the plane combined with the upcoming U.S. bicentennial prompted Grimes to replace the original black-, white-, and red-striped paint scheme with the patriotic red, white, and blue livery in which the bird was restored.

The Grimes Flying Laboratory Foundation (www.GrimesFlyingLab.org) is funded entirely from donations and is one of the 14 partner organizations that compose the National Aviation Heritage Area (www.AviationHeritageArea.org) in and around Dayton, Ohio. NAHA is one of 49 National Heritage Areas created by Congress.

The flying lab is on display at the NAHA exhibit, just south of Exhibit Hangar A.