@Paladin_HGWTIf he's going to start with contractions, finish with contractions. While Ernest is correct that if he's using the proper numbers for it (which, by the way, is the MQ-9 Predator) he'd probably use the phonetic alphabet, in my experience, he's going to call it by the nickname.
Sergeant Jones said, "We shouldn't be risking our only Reaper unless it's urgent."
About the only time anyone DIDN'T use the nickname is for the Flying Crane, which officially is the CH-54 Tarhe. You had Apache, Cobra, Chinook, even the Huey. And then there's the Tarhe. No one knows that it's an Indian name meaning Crane.
Also, nobody calls their rifle a Mike Four or that they're carrying a Sierra Alpha Whiskey. I've got an M4 and a SAW. For damn sure if you're actually in something vaguely resembling an actual combat situation, you're going to use the common language of either Predator or Reaper, instead of RQ1 or MQ9. (Note that when I'm writing military nomenclature, I simply use M113 APC, or T72 MBT, even in conversation. I run into this discussion frequently. If you're writing conversation, people do NOT talk grammatically correct.)