DeltaRNOmd-80 From , joined Dec 1969, posts, RR:
Reply 2, posted (14 years 10 months 2 weeks 6 days 22 hours ago) and read 2237 times:
I was seated near the rear of a DL md-90 and saw this yellow spiral as I looked back at the engine. Probably so they can tell how fast the fan is spinning by looking at the spiral, or to scare birds away.
ExPratt From United States of America, joined Mar 2000, 311 posts, RR: 0
Reply 4, posted (14 years 10 months 2 weeks 6 days 20 hours ago) and read 2217 times:
JAL did a study with its 747s having some airplanes with engine spinners that were painted black and some airplanes with spinners painted with the spiral pattern. The different airplanes were operated on similar routes. JAL's study clearly showed that the airplanes with spiral-painted spinners had fewer birdstrikes. The irony is that despite its test results, JAL did not paint its remaining spinners.