David Heymsfeld — the House Transportation and Infrastructure Committee’s majority staff director — is a tough deal maker with a conciliatory spirit, the man behind the negotiations on the $500 billion reauthorization of the nation’s surface transportation programs and the $70 billion Federal Aviation Administration reauthorization.

Both massive pieces of legislation are sponsored by Heymsfeld’s boss, committee Chairman James Oberstar (D-Minn.). But they have worked together for so long that it’s hard to know where one man ends and the other begins — and Heymsfeld is a well-respected surrogate for the chairman.

“He’s so well thought of, you know [Members and staff] are going to consult with him throughout … down to the final constructs” of the bills, said Pete Ruane, president and chief executive officer of the American Road and Transportation Builders Association. “When you have David on your side, you’re in good shape.”

Regarded as Oberstar’s most trusted aide, Heymsfeld said that in the 34 years that he has been with the committee, he has come to see the Congressman as his mentor. Oberstar also served a stint as a chief staff assistant for the committee, and both Oberstar and Heymsfeld are known as aviation experts who share a love for cycling.

Their history began in 1975, during Oberstar’s first term in the House, when Heymsfeld joined the House Transportation and Infrastructure Committee — then called the Public Works and Transportation Committee — as counsel for the Subcommittee on Aviation. In 1989, Oberstar took over the helm of the Aviation Subcommittee and Heymsfeld continued to serve as counsel for the subcommittee.

In 1995, while the Democrats were in the minority, Oberstar — who had ascended to the committee’s ranking member post — named Heymsfeld as the Democratic staff director for the full committee. Heymsfeld has served in that capacity since — through the party’s difficult years in the minority and now in the restoration of its majority status after the 2006 elections.

“They fit well together,” one senior Democratic House Transportation aide said of Oberstar and Heymsfeld’s working relationship.

Heymsfeld brought 13 years of aviation law experience to the committee, having worked as an attorney for the Civil Aeronautics Board — a predecessor of the FAA charged with safety rulemaking, accident investigation and economic regulation of the airlines. After losing much of its regulatory authority through changes to the Federal Aviation Act of 1958, the CAB was phased out in 1984.

“He’s written aviation history,” said Sharon Pinkerton, vice president of government affairs for the Air Transport Association. “There’s not much in aviation he hasn’t seen.”

Three years into Heymsfeld’s service as counsel on the Aviation Subcommittee, Congress passed the Airline Deregulation Act of 1978, a dramatic shift away from the regulation of old and toward an air transportation system that relied on competitive market forces to determine the quality, variety and price of air services.

“Aviation is an exciting industry and has a national focus … and regulatory challenges,” he said.

Heymfeld’s Capitol Hill colleagues say it’s his attention to detail, zest for aviation and transportation policy, respect of and concern for other people’s opinions and an ability to work across the aisle that make him such a valuable legislative draftsman.

Although he spends much of his time poring over legislation, Heymsfeld is often called on to update the experts on the state of play in transportation debates, appearing regularly at roundtable events and forums. His immersion in aviation law earned him the Lawyer of the Year award from the Federal Bar Association’s Transportation Section in 1995, and Heymsfeld was chairman of that section in 2000.

Oberstar presented Heymsfeld with the award, which recognized that his “exquisite legislative craftsmanship has defined and given direction to an entire generation of aviation law.”

But Heymsfeld is modest.

“I like my work,” he said.