This can be done easily if you have a friend help you.
First, choose Versus, Xbox Live, Player Match, and then Custom Match.
At the screen where it is searching for active servers, hit Y to create a match. Change the game to a private match, create the server and invite your friend.
Select the hanger and select a plane that has that has Radar Guided missiles. Several planes have them, however, they may be on payload variants you haven't unlocked.
When the match starts, immediately switch to the Radar Guided missiles and fly straight at your friend while they fly straight at you. When you hit a distance mark of ~3500m, fire the missile. By the time the missile reaches them you should be below the target mark. If not, get lined up and try again.
The missile only has to hit the target, not destroy them. As soon as it makes contact, you'll receive the achievement and the TMDM challenge of the same name.
The following planes all have Radar Guided bombs in one or more of their loadouts:
A-12 Avenger II
AV-8B Harrier II
EA-6B Prowler
F-14A Tomcat
F-14D SuperTomcat
F-15C Eagle
F-15E StrikeEagle
F-16A Fighting Falcon
F-20 Tigershark
F-4G AdvancedWildWeasel
F-5A Freedom Fighter
F-5E Tiger II
JAGUAR
MIRAGE 2000 C
MIRAGE 2000-5
Mig-25 Foxbat
Mig-29 Fulcrum
Rafale C
Saab-35 Draken
Su-27 Flanker
(There are probably a couple more, but I have yet to unlock them all)