In an era in which only one in three U.S. businesses survive past their 10th anniversary, according to the U.S. Small Business Administration, Airport Development Group, Inc. (ADG) will celebrate its 35th anniversary of serving airports across the country and internationally on April 30.

In the highly competitive aviation industry, tightly regulated by the federal government, ADG's success can be attributed to a compilation of several skills, but ranking close to the top of the company's priorities are customer collaboration and service.

"One of ADG's guiding fundamental core beliefs is to work so closely with our customers that they think of us as one of their staff or teammates," says Dana P. Hartshorn, P.E., an ADG principal along with co-owner Charles. L. Kellerman Jr., P.E.

"In many smaller communities, the airport manager wears many hats during the work day, so we work closely with them to lift the burden of airport compliance, capital-improvement planning and cost estimating, grant administration and project management off their shoulders," he continued.

On its website,, the company is hosting a special congratulatory webpage where friends, colleagues, former employees and patrons can post a message wishing ADG a happy 35th anniversary. Three creative messages will be selected to receive a $100 gift card to the winner's choice of Home Depot, Lowe's or Menards. Deadline for contest messages is June 30, and messages will stay online for the remainder of 2019.

ADG was founded in 1984 by Peter J. Muller and James E. Sirhall as Muller, Sirhall and Associates. The company's original market orientation continues today as dedicated solely to the aviation industry, offering planning, environmental assessment, design, engineering, project administration and marketing/public relations services to all sizes and operations of airports nationally and internationally. A few years after the company's founding, the original partnership was dissolved in 1995, and Sirhall reorganized the firm under its present name. He retired from ADG in 2014.

Over its long history in a small niche market with a singular customer-focused approach, ADG has completed more than 800 planning, engineering and construction projects at more than 250 airports around the world.