War Supplied

Achieve obtained by being the first to loot [object=290129] or [npc=135238].
Not just receive the loot, but you have to be the first to open the crate.

It is possible to get this Achievement during Darkshore
So far seen 3 different spawn points for these in Darkshore

/way 56.19 17.20 Crate can drop here but the Flying Machine spawns close to this point up in the air.
/way 53.45 29.7
/way 48.78 49.36

Respawn timer is 20min, so 20min after the crate was opened to reveal the faction chest the timer starts after 20min. A flying machine spawns, you get a sound que when it spawns. After spawning it flies in a straight line for a bit then a crate spawns on either of the coordinates above with a parachute floating to the ground.slowly

Only one player can get the Achievement for opening the big Crate after that it's unlocked for that faction and unlimited amounts of how many ppl can loot the actual Chest which has the actual loot which is ilvl 210+ appears to only drop the items from the World Quest
it despawns after a short while

Camped this in Stormsong Valley and just got the achievement. I read reports that the Flying Machines were supposed to fly by every 20 minutes, but for me, they were 45 minutes apart in Stormsong. I waited on top of a mountain to the left of Sagehold on the map and eventually I saw a Zeppelin in the distance approaching from the southeast area of the map (by the Champions of Azeroth WQ in the snowy area). The Zeppelin flew diagonally across the map towards Fort Daelin before disappearing. I did not see a crate drop. I ran around the possible drop locations and never found a crate. Probably poofed (zone was not active with players at the time).

45 minutes later, another Zeppelin showed up. Same path, didn't see a crate drop from my vantage point, followed it with a glider with no luck.

I wondered if it actually was dropping a crate sooner and I was just too far to see it. I moved to the hills by Briarback Kraul (to be closer to where the Zeppelin spawned) and had a better view of Brennadam. 45 minutes later, right on time, the Zeppelin flew by and I could see a crate parachuting down. It landed right outside of Brennadam. Got the achievement.

Came back again 45 minutes later just to see if it showed up. Saw it again so confirming four different Zeppelins in a row, all 45 minutes apart.

A few things, just because I've seen these questions elsewhere:

1. Can be done outside of an assault -- there was no active invasion going on (it was in Zuldazar earlier in the day).
2. Both Flying Machine and Zeppelins drop the crates. I saw four Zeppelins in a row for Stormsong. I've seen Flying Machines in youtube videos so YMMV.
3. I did not have the sound on while watching for this. I did enter the ID for the war supply crate (135238) and the Flying Machine (135181) in my NPC Scan mod. The crate did trigger the NPC Scan when I was in detection range. I only had the Flying Machine ID entered so it didn't go off when the Zeppelin appeared (I didn't know they both dropped it). The Zeppelin ID should be 138694.