India's first 737-based P-8I nears flight debut

[Dash]

We wanted to add an Indian touch to the product, so we added a mustache

What????....mustache.....hahahahahahahahaha

 

[Lord Of Gondor]

We wanted to add an Indian touch to the product, so we added a mustache

I think it has something to do with reflections affecting the pilots' line of sight.
These black coloured skin/fur is found on the cheetah's face(beneath it's eyes) which apparently helps it against reflections from the sun which might interfere in it's hunt for food(Courtesy-Animal Planet)

Even many spec ops soldiers wear black paint below their eyes and i assume that the reason would be the same as in the case of the cheetah.
^^^Just my assumptions so please feel free to correct my points.