LeoNYC10

I flew JetBlue from LAX to JFK yesterday. The plane was a spanking new A321 made in mid 2017. I was seating in the middle of the plane in row 14

One thing that surprised me is a relatively high level of noise, even when the plane was cruising. Considering that this is a brand new plane and should supposedly have the latest/greatest materials, including the isolation, this was quite surprising to me.

I flew to LAX on the previous leg on United's 777-200 that is one of the oldest 777s in service - over 20 years old. It was much quieter.

Any ideas why?

hi55us

LAX-JFK yesterday, guessing it was because of the extremely high winds that have been making eastbound flights reach the speed of sound. Lot of factors go into aircraft noise, not just the aircraft.

jaysona

An airplane built in 2017 is built using the exact same materials as a plane built in 1997. Newer airframes may have different/upgraded interior seating and overhead bins, but the wall paneling and insulation behind the paneling will be the same as the older airplanes.

aviators99

What???

LeoNYC10

I guess the high winds were constant across the whole country from California to New York, because it was noisy all the way through. But serious, I assume you were joking.

klanfa

Yes, aircraft were approaching speed of sounds but only in terms of ground speed. In terms of airspeed they were still at their usual ~0.8 mach.

High winds can definitely make a plane a lot more noisy. And yeah, high eastward wing across the country, pretty much. Check the news on Virgin Atlantic over the last couple of days and their ground speed.
Row 14 is over the wing, so you do get quite a lot of engine noise (though not as much as farther back).
Comparing a 321 to 777 isn't really a fair comparison, even less so without mentioning seating area.
Finally, as someone mentioned, the 2017 year of build JetBlue 321 is pretty much the same as a 2000 year of build 321 in terms of noise. Yes, aircraft have, in general, become quieter, which allows the manufacturers to make thinner insulation and cut the weight down, lowering operating costs. So noise reduction inside the cabin isn't really that big of a deal. It's still quiet where it matters most (J/F) because those cabins are in front of the engines.

cmd320

A321s are just noisy. This is nothing abnormal or special about JetBlue's newer ones. Pair that with the fact that they are relatively underpowered so on transcontinental flights with higher loads they're going to be running at a higher thrust setting.

Coming off the A380 and getting on an A321, it sounds like you're sitting outside. As noisy as they may be though, nothing is worse than the 737.

bemis

Note that the higher speeds were speed over ground; the airspeed (and presumably engine load/rpm, amount/velocity of air across the body of the airplane) was the same.

In any case; QC-35's or equivalent are a sound investment for flying these days.

aviators99

So much misinformation in this thread, I don't know where to start. I'm not even going to try on the speed-of-sound thing. Anyway, wind noise will not make a difference, relative to other noise generated by the aircraft. To the extent wind noise varies with high wind even theoretically (with a plane not making any noise), I would guess it would be headwinds; not tailwinds. Each flight's noise level is different, mostly because of the thrust setting. Harmonics can vary greatly, due to particular settings. Note that the fan blades within the engine *do* break he sound barrier, and create mini-sonic-booms. Even propeller planes have this effect.

ricktoronto

If it's exceeding Mach 1, that's relative to the ground, e.g. ground speed not airspeed, which the aircraft (any non Concorde airliner) is certainly not designed for. Its speed in the airmass in which it is flying is will be the maximum cruise speed for flying in air, whether that air is still or moving.

The ground speed is the sum of the two vectors, airspeed and the speed of the air they are in moving over the ground. A Gypsy Moth aircraft back in the 40's had a slow enough stall speed that it could fly at 45 kts into a 45 kt headwind and from the ground it had a speed of zero but on the airspeed indicator it would be going 45 kts.

Flaflyer

I knew an old pilot who decades ago flew smoke patrol for the forest service in a Cub type plane. He could get it down to just above 40 without stalling. On a day with good winds aloft, he would "park" it above the center of a small country town and stay in one spot. Totally freaked out the country folks seeing a plane "motionless" in midair.

bennos

Back rows of a DC-9?

moondog

Was this a joke post?

diburning

JetBlue's A321s are of the latest ceo (current engine option) generation, with the spaceflex galleys and thinner side walls (for more cabin width), which was achieved by having less insulation. I'd imagine they'd save some weight on the insulation as well.