USAF's F-15 Eagle Recently Set Record For World's Longest Missile Shot -- Sources -- April 16, 2021

Decades ago I was assigned to the F-15D as my primary aircraft when flying with the USAF in Germany. It was the first time I heard the phrases, "Fox one," "Fox two," "Fox three," and "Fox four."

See wiki. 

The definitions of the four phrases may have changed a bit over the years or perhaps the USAF pilots I trained with simply used their own version.

For us, back in the 1980s and 1990s:

• Fox one: the USAF fighter aircraft launched / fired a medium-to-long-range missile (AIM-7 Sparrow).
• Fox two: the USAF fighter aircraft launched / fired a short-to-medium-range missile (AIM-9 Sidewinder).
• Fox three: the USAF fighter engaged the gun. Obviously this was used only in a "dog fight." If an F-15 ended up in such close range requiring the use of a gun, the pilot had obviously erred be getting too close to the enemy aircraft in the first place. Using a gun was not good form.
• Fox four: when all else failed, and perhaps having run out of ammunition, the pilot had one last option -- an intentional mid-air collision with the enemy aircraft. That was a "Fox four," greatly frowned upon, and to the best of my knowledge has never been used in modern warfare by the USAF. At least not reported. 

Apparently now, according to wiki:

• Fox one: semi-active radar guided, AIM-7 Sparrow;
• Fox two: infrared-guided, AIM-9 Sidewinder:
• Fox three: active radar-guided, AIM-120 AMRAAM and AIM-54 Phoenix; the former a replacement for the AIM-7 (one can start to see the ambiguity in terms)

That was all preface to the following. According to The Drive and Popular Mechanics, the F-15 Eagle recently scored the "longest known" air-to-air missile shot during a US Air Force test. 

The first link, the link to The Drive, I think had the better story. The actual distance that qualified for a new record is, of course, classified, but it sounds like it was around one hundred miles. 

The F-15 radar has a range of around 100 miles, according to unclassified sources. 

I've long forgotten much of this, so as usual, there may be content errors in the note above. Plenty of open source material available.