Abstract: A fencing assembly (66) for prohibiting circulation of primary and/or fan airflows (52), (54) into a bounded low pressure region of a jet engine installation. The fencing assembly includes one or more flow control fences. In an exemplary application, the fencing assembly includes a number of fences positioned around the sides of a batcave (48) bounded low pressure region that is located between a primary exhaust nozzle (20) and strut fairings (30). The fencing assembly includes five fences, each fence being connected to either the primary exhaust nozzle or the strut fairings. The five fences include single fences (70), (72) positioned along each lateral side of the batcave; two rear fences (74), (74') positioned circumferentially about rear regions of the batcave; and an arcuate fence (76) positioned near the two rear fences to form a half circle. The fences include a foot portion (78) and an upright portion (80).