By Cara Giaimo / Atlas Obscura
October 30, 2015
livestock sheep in field
Credit: Tim Graham

Earlier this week, a Singapore Airlines cargo plane en route from Sydney to Kuala Lumpur made an emergency landing in Bali, AirLive reports. The unscheduled stop was made because the pilot feared for the cargo in question: 2,186 sheep.

The crew landed the plane after smoke was detected in the cabin. A thorough inspection in Bali revealed no trace of "fire, heat, or smoke," and determined the culprit to be "exhaust gasses and manure produced by the sheep," according to The Aviation Herald. The plane made its smelly way onward within a couple of hours, and the cargo was delivered successfully.

The sheepish plane was not an isolated incident—over the past decade, over 1.2 million goats, cows, sheep, and (yes!) pigs have been transported by air, over the course of about 2,000 flights. This means there is a slight but distinct possibility that the last plane you watched zoom overhead was a veritable air barnyard, full of flying livestock.

Though many of these trips are soft and cuddly, some aren't—last October, Singapore Airlines came under scrutiny after 174 sheep died in midair between Perth and Singapore, due to a ventilation failure. Boeing's guidelines for safely flying with live animals hint at other scary possibilities, reminding those in charge that if the transport pallets are faulty, "feet and hooves of heavy animals, such as horses and cattle, can puncture the airplane floor."

More from Atlas Obscura: Found: a Comet Stocked with Booze

In this light, it is easy to understand the pilot's decision to land, even though it turned out to show an excess of caution. Under such circumstances, ewe would have done the same.