American Airlines and US Airways, the fourth and fifth biggest domestic airlines that took another step towards merger Friday, are also high fliers when it comes to political influence.

Any marriage of the two carriers would require government approval, and both airlines have been active lobbying Congress — which controls the budgets of the federal agencies that would review the merger's impact on the market, the Justice Department and the Federal Trade Commission.

American Airlines has spent $3.8 million on lobbying in the first three quarters of 2011 and has hired 10 lobbying firms during that period.

Although US Airways has not had as big a lobbying portfolio as American Airlines during the same period (it spent $1.1 million), there are signs that US Airways is starting to ramp up its lobbying efforts.

On March 1, the Arizona-based airline hired another lobbying firm, Ogilvy Government Relations. Ogilvy has represented high-powered clients such as, Chevron, Deutsche Telekom, the American Petroleum Institute and Visa.

Both airlines and their employees are also active political givers, according to data that Sunlight's Influence Explorer has compiled for both American Airlines and US Airways. In addition, Influence Explorer shows the lobbying and giving of the three airline unions that today gave their blessing to a potential merger. Or the three unions — the Allied Pilots Association, the Association of Professional Flight Attendants and the Transport Workers Union. Of those unions, the Transportaion Worker's Union has he largest lobbying operation with $668,000 in the first three quarters of 2011 while the Piolits union and the Flight Attendent union spent $203,000 and $60,000 respectively, during the same period. 

In the fourth quarter of last year, US Airways revenue hit a record $3.2 billion, according to USA Today. Fuel costs remain high but the results exceeded expectations. American's parent company, AMR is still in bankruptcy court protection under Chapter 11.