In a message dated 7/15/2003 6:45:03 PM Pacific Daylight Time, RWM@xxxxxxxxxx writes: << 'm thinking bleed air starter noise, like on the DC8-70 series where interaction with the compressor cascade often set up 'sawtooth' waves, but you could be right about the chainsaw pitched into the inlet.. >> So, why not on 737s. I have flown plenty of 737s and they don't make the noise that the CFM powered A320 family do