I don't have a specific link, but an aeronautical feat would be an act of some uniqueness or difficulty, or unusual combination of features, especially one qualifying as the first successful achievement of such an act.
First controlled powered flight, Flying non-stop from NY to Paris, First 747 commercial flight, First all-female crew, First to break the sound barrier, orbit the earth etc.
In US Law "The Administrator" is the person nominated to lead the FAA, or any of his staff he has delegated authority to. The Administrator obviously has a large organization to manage, but the administrator is responsible for all of it's decisions and rules. Similar language applies to all the other offices in a legal sense i.e. "The Secretary" of Interior, "The Secretary" of Transportation, "The Attorney General" of DOJ etc, etc.