While walking out home today I nearly went deaf when a fighter jet flew over head. I live near the airport and jets are always overhead. The landing(glide?) path basically runs right over my apartment. Anyway, the 747s and 727s aren’t too bad as far as the noise goes but the fighter jet nearly blew out my ear drums. The fighter looked like it was on the same path as the rest of the planes.
Does anyone know how much louder fighter jets are compared to 747s. I didn’t get a good look at the fighter but it had twin engines and twin tails so I think it was an F-15. I did try google but couldn’t find anything.
Unless you are on the coast, like in CA, the planes will be both landing and taking off on all the runways depending on the wind direction. Most aircraft are in general, louder on takeoff. (Somebody who has been to a real airport will come along and point out any errors in that statement soon.)
Now, don’t get me wrong, they can and do sometimes land and take off in different directions on the coast also but not as often as say Oklahoma City.
Anyway, as a general perception thing and with a decibel meter, they are louder, on average. Especially fighter and or combat aircraft because being quiet is way down on list after, power - speed - ability to get the job done and such are taken into account first.
Also, high by- pass engines ( which are in general quieter in and of them selves and are more often used on airliners) do not go supersonic very well and so they are less likely to be used on high speed jets. (understatement)
Now, as long as they don’t light the afterburners right over your head and scare the stuffin out of you, they are not all that bad, of course I’m about ½ deaf from wind noise in my left ear so I don’t mind it so much.
YMMV
Oh, short answer = yes, they are generally louder.
I can’t provide any numbers, but I have been on and around a military base long enough to say that yes, usually military jet fighters are louder than big passenger jets. And F-15’s (with two jets) are the loudest of all that I remember (though I never saw any F-18 visit). Even when just performing lazy standard takeoffs, the fighters are louder.
If you’re around them a lot, you can even tell airplanes apart by their engine noise: F-15’s, F-16’s, C-9/Medivacs/Nightingales, C130’s, C-5’s all sound different…
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I think ariliners have to meet tougher noise standards than military jets. I’d bet military jets’ engines during cruise are at least 25 dB louder than airliners’ engines during cruise.
I remember a few weeks ago two F-16s flew really low over the stadium during the national anthem before we routed the Baylor Teddy Bears. They were so loud! Just the noise made me take pride in our military power. Imagine being an enemy and hearing that. You’d know you’re screwed big time.
I think the FA-18 is the loudest jet ever developed, although I don’t have any data. My guess is that during design and test the builder kept saying, “Crank 'er up anohter notch. My eadrums haven’t burst yet.”
Two more fighters just flew over my place. I was inside typing another post when they went overhead. The volume difference between the passenger jets and the fighters has to be at least double. I don’t know what that means in decibles. I can barely hear the passenger jets. The fighters scared the hell out of me and my cats. They also set off car alarms. Jeez those thing are loud. (Which makes them cool in my mind. I really like big noises and shiny things)
At the same time I have no idea why they are landing at McCarren instead of the Airforce base. There was nothing on the news and in the two years I have lived hear fighters never landed at McCarren as far as I know.
As touched on by a few people, commercial jets are constrained by two factors - fuel usage and noise output - that have driven the development of high-bypass turbofans. These engines are very efficient and very quiet, but they do not meet the needs of a military fighter (transports and tankers are different - the KC-135R sports CFM-56 high-bypass engines bought basically off-the-shelf).
Fighter engines are designed for speed, durability and the ability to withstand massive throttle changes in all regimes of flight.
You can’t say a fighter is x times louder than a passenger jet, bacause there are so many different varieties. The difference between an old 727 and a 777 on takeoff is probably the same as between an F-15 and a 727.
BTW, for pure “Holy God!” amounts of noise, be anywhere close to a B-1 when it takes off with all four engines in afterburner! Car alarms will be going off all over the place from the vibrations!
One thing I have noticed is that even though they are very loud you really don’t hear the sound until they are on top of you. And of course you hear it when they are headed away. So they can still “sneak up” on you at least in terms of sound.
We were sitting on the tarmac at the Tulsa airport waiting to take off and two fighters from a nearby airbase took off right out our window. I was sitting pretty near the engines in the back of an MD-80 and for a few seconds the sound coming from our engines ceased to exist. Sitting inside the MD-80 you could still feel the roar of the fighters. Everyone in the whole plane sat open-mouthed staring out the window.
Of course I have no way to really give accurate #s but I do a bit of amateur sound and am somewhat familiar with “how loud” things are and measuring sound. I can tell you the SPL inside the MD-80 when the fighters took off had to be in excess of 100db.
I’ll have to say the loudest jets I’ve ever been near are Harriers and A-6/EA-6 Intruder/Prowlers. The nozzle system of the Harrier is incredibly loud particularly when hovering or semi-vertical takeoff/landing. The A-6 has a long tailpipe that’s in a spiral shape because of the way the engines are buried inside the fuselage. I think the pipe resonates when at military power. It was so loud I could swear I could feel my nuts vibrating.
In my google search for an answer I found a couple of sites that had the sound level of a passenger jet at about 120 db from roughly 100 feet. The sound level on the deck of an aircraft carrier was about 140 db.
** YWalker**,
Yep, you hit it on the head. The noise from the fighters hit at once and scared me and my cats. Since I wasn’t expecting it it really freaked me out. My cats are finally starting to calm down.
Slee
::No one caught my Simpsons reference. I am really suprised::
<sidetrack>
I remember a wonderful 20-minute trip in a car of a friend of mine’s. He had a big, big subwoofer in the trunk. He played one song that seemed to have a wonderful resonance with my chest cavity. I found that by taking only shallow breaths I avoided feeling very odd indeed.
Padeye, for six months I slept six inches beneath the girder supporting the Number 6 spot on the USS Saipan, LHA-2, where the Harriers tested their engines in vertical mode before takeoff. They can be loud. Yup.
I also grew up fairly near MCAS Beaufort in the F-4 Phantom days (5 miles by the crow). When they powered up at 7:30am my window rattled.
I spent a day trying to sleep in the parking lot of the GM plant in Oklahoma City waiting for a dock door. The lot is across the street from Tinker AFB. After a while, I stopped hearing the AWACs and Tankers doing touch and goes. The B-1 taking off with afterburners, on the other hand, was quite difficult to ignore.
May, 1975. I was peering through the lens of level on a tripod situated two miles from shore on the tidal flats of The Wash, by the mouth of the River Nene, on the east coast of England. I was intently studing the marks on a level rod a thousand feet away, trying to take a reading.
In an instant my entire being was consumed by the most deafening roar that a human being could hear and still have hearing. Irrationally I dove under the tripod, to protect my head and jarred the tripod. A Buccaneer on its way to drop its load several miles away on the RAF Holbeach Bomb Range no doubt deliberately set course directly towards the back of and 200 feet over that lone figure on the barren landscape hunched over a tripod.
My partner laughed into the radio, but stopped laughing when he realized that as a result of jarring my instrument that he had to walk back 2000 feet to the previous stake so that I could reestablish the elevation of my instrument. Then he had to walk another 2000 feet to get back to where he was.
I’ve been on tarmacs observing jets taking off. They are nothing compared to that Buccaneer.
I’ve had years of enjoyment listening to loud jets, and I have to agree with Padeye - the EA-6B Prowler is the loudest I’ve heard yet.
sleestak, military pilots often go out and about to experience different approaches and departures for different airfields. This experience is necessary to operate on a global scale. My guess is this is what you heard.
