The B-24 bombers were produced there by Ford Motor company from roughly mid-1942 until mid-1945 — when this picture was taken.

Taken by Ford Motor Company and property of Yankee Air Museum

The update to the trust’s strategy comes after stakeholder forums in December and February that forced the trust to re-evaluate the way it was marketing the property, said Bruce Rasher, redevelopment manager for RACER.

“In combination with the unsatisfactory results that our marketing has produced … it caused the trust to reevaluate whether we could market the site without the building,” Rasher said. “We were told unequivocally by the market that the real opportunity at this site relies on capitalizing on the amenities the site has to offer and not on the building … The building is an impediment to redevelopment on the site.”

The building was assessed at $16,284,900, making its market value more than $32 million, according to the property's marketing brochure.

Part of the former GM Powertrain plant contains the Willow Run Bomber Plant which turned out B-24 Liberator bombers during World War II. It’s adjacent to the runway at the Willow Run Airport.

The Yankee Air Museum has launched a $6 million campaign to buy the bomber plant — a 175,000-square-foot piece of the overall Powertrain property. Its operations now are in a 47,000-square-foot facility on the east side of Willow Run Airport.

The B-24 bombers were produced by Ford Motor Company between mid-1942 until mid-1945.

Taken by Ford Motor Company and property of Yankee Air Museum

Should the museum raise the money, its purchase agreement would be for a total of 840,000 square feet of property at the site from RACER that would include a 700-space parking lot.

Dennis Norton, founder and first president of the museum, told AnnArbor.com Tuesday if the campaign is not able to raise the money by Aug. 1, the bomber plant portion of the facility also could be at risk for demolition.

“Once it’s gone, it’s gone, and no one will get to see it or hear the stories from it again,” Norton said Tuesday.

RACER Trust, or the Revitalizing Auto Communities Environmental Response Trust, is the authority formed in the wake of GM’s bankruptcy in 2010 to market 89 GM holdings across the country - including those in Ypsilanti Township.

RACER has been marketing parts of the property separately as:

• The Company Vehicle Operations facility, now under contract with International Turbine Industries
• The Engineering Center: An office building attached to the main plant
• The Powertrain Plant: 5 million square feet of manufacturing space

“We have approached the marketing up to this point as seeking a user of the existing building,” Rasher said. “The building was an important capital asset for the region. … We were seeking users to occupy the space.”

The former Powertrain Plant location has “significant economic development opportunities,” Rasher said, including its proximity to rail and highway routes, airports, the U.S.-Canada border crossing and the University of Michigan.

However, Rasher said Tuesday evening RACER Trust has not received one offer from a user that would use the entire 5 million square feet in the Powertrain facility.

The message to offer the development land up to the market and not the 5-million-square-foot building from key players at the December and February forums “wasn’t just a subtle message to the trust; it was very loud and clear,” Rasher said.

Among representatives at the forums were elected officials from Ypsilanti Township and Washtenaw County. Personal property tax revenue from the GM Powertrain Plant declined after RACER Trust sold the machines from inside the building, and the property's value as a whole has sagged.

Ypsilanti Township saw a 2.53 percent decrease in taxable value from 2012 to 2013, according to Washtenaw County's 2013 Equalization Report. The county as a whole saw an increase in taxable value.

The B-24 bombers between mid-1942 until mid-1945.

Taken by Ford Motor Company and property of Yankee Air Museum

Rasher said he knows the township would like to see development on the GM Powertrain site. RACER Trust is in “active discussions” with one developer for the property, Rasher said Tuesday -- an update from the "several companies" RACER Trust reported being in active discussions with at the end of March.

“They’re showing a lot of promise,” Rasher said of the prospective developer. “But we feel it’s the responsibility of the trust and to the community that we’re seeking out as many proposals that will come our way. … We will likely go out to the market and seek more proposals in the current future.”

There’s a concern that a company would demolish the GM Powertrain Plant, sell the materials for scrap and then leave the property undeveloped and abandoned, Rasher said.

Developers must meet a list of six criteria in order for RACER Trust to make a sale. The trust is committed to funding the cost of environmental cleanup of the site, even after it transfers out of their ownership.

Rasher said RACER Trust is committed to vetting developers to make sure they have the financial capital to market and fully redevelop the property to create jobs.

“Because our mission is to create jobs at these facilities, if we were to sell to a buyer that did not have the capability to do that, that would be a significant cost to the community,” Rasher said. “We need a qualified buyer.”

Amy Biolchini covers Washtenaw County, health and environmental issues for AnnArbor.com. Reach her at (734) 623-2552, amybiolchini@annarbor.com or on Twitter.