Pelforthb From United States of America, joined Jan 2000, 8 posts, RR: 0 Posted (13 years 7 months 3 weeks 4 days 14 hours ago) and read 5528 times:
I've done a quick search but can't find the answer to the following question:
Why is the engine noise from an A320/1/9 sooooooo completely different from that of a 737/9/8/7/6 even when they are both CFM engines?
Both on takeoff and landing, the A320 (even with IAE engines) noise is 50-100% more of a high-pitched whine. I'm RIGHT over all 3 north approach paths to SEA, a 737-dominated airport, and I can EASILY tell if the approaching airline is an A320/9/1 because of it's whine.
p.s. I did a 1-yr search on 'whine' and there was only 1 topic but it didn't answer that above question...
Cdfmxtech From United States of America, joined Jul 2000, 1341 posts, RR: 25
Reply 1, posted (13 years 7 months 3 weeks 4 days 13 hours ago) and read 5472 times:
I don't think the fact that the engines are both CFM has anything to do with it. They are different engines.
The CF6 family used on the DC10 has a totally different sound than the ones used on the B767. Yes, they are different dash numbers...but so are the CFms used on the B737NG (CFM56-7), and those used on the A319/2/21 (CFM56-5) series.
Anyhow, I believe the sounds have to do with the blades.
Buzz From United States of America, joined Nov 1999, 697 posts, RR: 20
Reply 3, posted (13 years 7 months 3 weeks 4 days 8 hours ago) and read 5428 times:
Hi Pelforthb, Buzz here down in sunny Portland Oregon. About half the time we have airliners flying over when on aproach to PDX, about 2000 feet up. And i work on everything UAL flies into PDX so i'm familiar with the "Renton Rejects" and "Toluse Trash Haulers".
The different sounds are resonance: the fan blades are different lengths, the inlet airflow is different, the nacelle sound absorbtion is different. And then you have the A320's with CFM engines and those with V2500 engines.... idle at different speed.
Here at PDX Northwest has CFM's on their Airbuses, and we have V2500's, my abused eardrums can hear a bit of difference.
I remember the JT8D engines had a huge whine from the airflow coming through the Inlet Guide Vanes, which set up a real vibration on the first couple stages of fan blades. I don't miss trying to work through IGV's to repair fan blade damage
Buzz Fuselsausage, Line Mechanic by night, DC-3 Crew Chief by choice.
Americanmd80 From United States of America, joined Apr 2000, 491 posts, RR: 5
Reply 4, posted (13 years 7 months 3 weeks 3 days 22 hours ago) and read 5389 times:
Pelforthb- I was definately wondering the same thing!
This summer when I was flying my last leg of my trip, I flew on a USAirways A320-200, and the engines definately sounded strange (The high pitched whine) and I certainly noticed this after riding on 3 USAirways 737-300 that day, and 2 weeks before!
Gotta say...I love the A320 though
do what you like . like what you do . life is good
Cfalk From , joined Dec 1969, posts, RR:
Reply 6, posted (13 years 7 months 3 weeks 3 days 1 hour ago) and read 5329 times:
You want whine? Listen to a Tu-134! When one of them is taxiing by, you just have to hold your ears - it is a high-pitched screech. And you don't even want to hear about when they power up for takeoff and stand on the brakes.