It should just be a hole in the bottom of the aircraft for low-level bombing
Fly over the enemy and bombs away!
Oh lol, yeah thatd be a surprise
"Sir, we're outta bombs!"
"Well, what do we attack them with?"
"..Oh i know"
10 minutes later at an enemy location
"Sir, we're being attack by a Su-34, its dropping some kind of sludge bomb"
*Boss guy walks out and has a look*
"Thats not sludge, its sh*t"
"Oh, dirty rotten ba*tards"