I have never seen it on any other aircraft and it seems curious on this one. The only thing I could think of why its there is that that it would prevent water ingestion into the engines, but the location of the engines on these aircraft would seem to make it irrelavent.
Dl757md From United States of America, joined May 2004, 1560 posts, RR: 18 Reply 1, posted (7 years 2 months 2 weeks 2 days 4 hours ago) and read 3638 times:
It is to prevent water ingestion by the engines. Without it the spray would go up over the wing and directly into the intakes. The 727 and many other tailmounted engine aircraft have chines molded into the nose tires to deflect spray away from the engines.