CHRONOLOGY-Pentagon nears new contract in air tanker saga

This is the U.S. Air Force's third attempt since 2001 to begin replacing its existing fleet of KC-135 refueling planes, which are now about 50 years old on average. Two earlier efforts failed amid ethics violations and technical mistakes.

The following is a chronology of events in what Boeing's commercial airplane chief Jim Albaugh has described as "the longest-running soap opera since 'Days of Our Lives'":

Sept. 25, 2001 - Darleen Druyun, then the Air Force's No. 2 acquisition official, meets with Boeing officials to map out a strategy to lease 100 Boeing 767s.

January, 2002 - Congress passes a law appropriating defense funds for fiscal year 2002 that gives the Air Force permission to lease up to 100 Boeing 767s.

October, 2002 - While still negotiating with Boeing about the tanker lease, Druyun meets with then-Boeing Chief Financial Officer Michael Sears to discuss a job offer. Sears tells her: "This meeting really didn't take place." A month later Druyun retires and accepts a $250,000-a-year job with Boeing.

January, 2003 - Boeing announces Druyun's hiring. Watchdog group Project on Government Oversight describes it as "one of the most egregious examples in recent memory of the revolving door between the federal government and defense contractors."

May, 2003 - Four days before his retirement, then-Pentagon chief arms buyer Edward Aldridge approves $23.5 billion Air Force plan to lease, then buy, Boeing 767 tankers.

November, 2003 - Boeing fires Druyun and Sears for unethical conduct in Druyun's hiring. Boeing Chief Executive Phil Condit resigns a week later.

March, 2004 - Pentagon inspector general says the Air Force's tanker procurement strategy was inappropriate and recommends a halt until the Pentagon resolves several issues.

April, 2004 - Druyun pleads guilty to a conflict of interest violation and later sentenced to nine months in prison.

November, 2004 - Sears pleads guilty to conflict of interest violation and is sentenced to four months in prison.

September, 2005 - Northrop Grumman Corp (NOC.N) says it will team with EADS to compete for an Air Force tanker contract, offering a variant of the A330 airliner.

January, 2007 - The Air Force releases final rules for a new tanker competition after agreeing to exempt a World Trade Organization dispute between the European Union and the United States that could have knocked Northrop out of the contest.

February, 2008 - The Air Force awards a projected $35 billion contract for up to 179 refueling planes to Northrop and EADS.

March, 2008 - Boeing protests the award, citing "serious flaws" in the acquisition process.

June, 2008 - The GAO upholds the Boeing protest after finding "significant errors" in the acquisition process.

September, 2008 - Defense Secretary Robert Gates cancels the Northrop contract. He says the process is too politicized to resolve before the Bush administration leaves office.

September, 2009 - The Air Force releases draft rules for a new tanker competition. Northrop says the terms favor Boeing's smaller 767 tanker and in December informs the Pentagon that it will not bid unless significant changes are made.

Feb. 24, 2010 - The Pentagon and Air Force release a revised final request for proposals, but lawmakers say the changes are slight and might not satisfy Northrop.

March 8, 2010 - Northrop says it will not submit a bid.

April 20, 2010 - EADS North America announces that it will compete directly with Boeing for the contract, with Chairman Ralph Crosby calling it "a hell of an opportunity."

Nov. 19, 2010 - Air Force discloses that it inadvertently sent rival bidders some data about each other's offer.

Feb. 11, 2011 - Deadline for EADS and Boeing to submit final bids.

Feb. 18, 2011 - The Pentagon's inspector general finds the data mix-up was inadvertent and the Air Force responded in accordance with federal law once it was discovered.

Feb. 24, 2011 - U.S. Air Force expected to announce winner. (Reporting by Andrea Shalal-Esa; Editing by Tim Dobbyn)