Bobo2196 From , joined Dec 1969, posts, RR:
Reply 1, posted (13 years 11 months 3 weeks 6 days 4 hours ago) and read 1080 times:
There was an article in AIRLINERS magazine (in the ask airliners? section.)
"When jet fan blades rotate, they generate a supersonic flow at their tips, which creates and audible shock wave. Because each blade is slightly different (there is a small variation from tip to tip), several different frequencies are created, resulting in the distinct "combination noise." This is the "buzz saw" sound that we hear, especially in the foreward cabin, when the engines are at high power settings such as takeoff roll and initial climb. Some high-bypass engines do not exibit this effect. According to the acoustic engineers at Pratt & Whitney, a possible reason for this is differences in engine inlet and fan blade sizes."
It also says that this happens on alot of aircraft, 747, L-1011, DC-10, 757, 767, etc.
UNDpilot From United States of America, joined Dec 1999, 76 posts, RR: 0
Reply 2, posted (13 years 11 months 3 weeks 6 days 4 hours ago) and read 1061 times:
You took this topic write out of my mouth! I just got back from Hawaii on a Hawaiian DC-10 to Seattle, and I was wondering what that buzzing was as well. I never really noticed the sound before, but this really got my attention. I was sitting right next to the right engine and I first heard it while we were taxing at HNL, then we taxiied on to the runway and accelerated. During the long takeoff role and accent my friend and I really heard the buzz and then it died down once we got to cruising altitude. Really interesting though...it sounds sort of like a chainsaw. Ive also heard it on a US Airways 757.
Airman99o From Canada, joined Aug 1999, 975 posts, RR: 1
Reply 6, posted (13 years 11 months 3 weeks 6 days 2 hours ago) and read 1020 times:
I know that Air Canada's A-320's and Canadian's 320's do this as well. I have flown numours times on Air Canada's and the first time that I flew on them it was a totally different sound for me. I was used to flying on the older jets and just hearing that roar!! then I get on this and look out to see if it actually a Jet engine. only joking!!
AA777 From United States of America, joined May 1999, 2544 posts, RR: 28
Reply 7, posted (13 years 11 months 3 weeks 5 days 23 hours ago) and read 992 times:
I have noticed it on MEA's A320's. It was quite loud, and at first I was quite alarmed by this noise... I havent Heard it on the 757, On the 757 All I hear is the loud sound of the engines at high trust levels on take-off. In the 757, when sitting in the last row, you feel it too...woa.
Adam84 From United States of America, joined Jul 1999, 1400 posts, RR: 2
Reply 8, posted (13 years 11 months 3 weeks 5 days 13 hours ago) and read 978 times:
I think it depends on how much power they use. I was on a CO 757 which has the RB211, I was right next to the engine and it didnt buzz, but also I was on a CO 737-300 that did buzz but its not as pronounced as DC-10s. Also I noticed that the JT9D's on NW DC-10-40's have a more pronounced buzz than the GE's. (my personal observation)
Ex NWA From United States of America, joined Apr 2000, 118 posts, RR: 0
Reply 10, posted (13 years 11 months 3 weeks 5 days 9 hours ago) and read 947 times:
I totally forgot about that "buzzing" noise I've heard on USAirways 757's until now. I was flying with a companion on a US 757 flight from PIT-DCA a few years ago and she heard that noise and got really nervous and asked me what is was, because she knew I fly all the time. I had absolutely NO idea what it was, but I played it off and said it was just the engines on this this type of plane.