How loud is the F-35?

All about the Pratt & Whitney F135 and the (cancelled) General Electric/Rolls-Royce F136
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zerion

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Unread post31 Oct 2014, 18:09

Spaz your link doesnt work. Not sure why it's not linking the whole address. Tried posting one and same thing happens.

http://www.airforcemag.com/DRArchive/Pa ... -35-Noise-“Good-to-Go”.aspx
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smsgtmac

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Unread post31 Oct 2014, 18:31

It's because the Air Force Association, in their infinite(ly infinitesimal) 'wisdom' recently decided to put their content behind a paywall for members only. For you see, the AIr Force Association Mission:
"...to promote a dominant United States Air Force and a strong national defense, and to honor Airmen and our Air Force Heritage. To accomplish this, we:
EDUCATE the public on the critical need for unmatched aerospace power and a technically superior workforce to ensure U.S. national security.
ADVOCATE for aerospace power and STEM education.
SUPPORT the total Air Force family, and promote aerospace education."

... is somehow better implemented by hiding all of your 'message' away from the prying eyes of the general public?

P.S. Try looking at the 'cached' view in MSIE if you can. They haven't figured out how to hide that away....yet.
--The ultimate weapon is the mind of man.
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spazsinbad

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Unread post31 Oct 2014, 20:43

Hmmmm.... agree about the 'association' being inscrutable - their bad - but anyway when the link worked I saw all of it; so ALL of it is excerpted on previous page. And a graphic just to be safe....

ttp://www.airforcemag.com/DRArchive/Pag ... -35-Noise-“Good-to-Go”.aspx

TIN Y URL of above (leadin' aich missing): http://tinyurl.com/ksa28h5
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F-35 Noise GOOD TO GO AFA Magn.gif
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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Unread post01 Nov 2014, 02:03

Thanks
I archive as much as I can for quick access in arguments.
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spazsinbad

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Unread post02 Nov 2014, 08:24

Noise testing on the F-35A and F-35B
31 Oct 2014 JPO/AFRL

"The F-35 Joint Program Office, in partnership with the Air Force Research Laboratory, conducted noise testing on the F-35A and F-35B in 2013, using production...

...Summary:
o All F-35 US Services and Partners are using the same noise data. However, the F-35 community noise contours will be different at many US and overseas installations due to differing regulations determining the calculation method, local takeoff and arrival profiles, terrain, and local environments.

o The community noise contours computed using the Sep 2013 production representative F-35A and F-35B noise data are essentially equal to or slightly smaller than the contours in recent F-35 Environmental Impact Statements developed using the 2008 F-35AA1 noise data.

o F-35C noise data is expected to be essentially equal to F-35A noise data except for low power approach conditions and high speed (>450 knots) conditions, where it is estimated to be slightly louder.

o The F-35 Joint Program Office is releasing noise data to our US Services, International Partners, and Foreign Military Sales customers to perform their Environmental Impact Assessments.

Source: http://www.jsf.mil/news/docs/20141031_F ... ummary.pdf (324Kb) Attached anyway....

"...The F-35A and F-35C engines are only different in that the F-35C has special salt corrosion prevention materials for aircraft carrier operations. The F-35B engine includes a swivel nozzle and lift fan for short takeoffs and vertical landings. All three variant engines have a maximum thrust of 43,000 lbs...."
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20141031_F-35_Noise_Executive_Summary.pdf
(311.61 KiB) Downloaded 424 times
F-35groundNoiseComparisonFig1.gif
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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Unread post02 Nov 2014, 18:26

I can't describe how much I love this. The imaginary 'Noise' issue has been a central pillar in the Anti-F-35 crowd's strategy to kill off the F-35 because it is an 'issue' they thought they could really get the average citizen behind. It has been beaten to death in Vermont, where the 'Antis' (Socialists to NIMBYS) have tried every legal angle possible, and distorted data and truth beyond recognition in their arguments, trying to stop the Green Mountain Boys from getting their next airplane.
--The ultimate weapon is the mind of man.
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spazsinbad

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Unread post04 Nov 2014, 22:00

Clarification on F-35 Noise
04 Nov 2014 AFA Mag'n

"F-35 Program Executive Officer Lt. Gen. Christopher Bogdan said an engine with the same decibel level of noise as another may be perceived as louder if the character of the noise has a higher or deeper pitched tone. During a press briefing on Oct. 30, Bogdan made an analogy to the F-4 Phantom (see F-35 Noise Good to Go). However, the F-35 engine noise study to which he referred did not compare the F-35’s sound to that of the F-4."

Source: http://www.airforcemag.com/DRArchive/Pa ... Noise.aspx
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NoiseClarifcationAFAnov2014.gif
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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Unread post05 Nov 2014, 01:14

The science should settle the noise non-issue. Won't be surprised if it does‘t for many.
"When a fifth-generation fighter meets a fourth-generation fighter—the [latter] dies,”
CSAF Gen. Mark Welsh
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Unread post11 Dec 2014, 20:23

Possible development?
Keeping the noise down
Jeff Peters AEROSPACE AMERICA/DECEMBER 2014

"The Aeroacoustics Technical Committee addresses the noise produced by the motion of fluids and bodies in the atmosphere and the responses of humans and structures to this noise.

Aeroacoustics is a critical area in the development of aerospace products, as the demand for low noise remains important in both military and commercial applications. Controlling acoustic emissions at the source requires engineers to design for low noise from the start. Aeroacoustics research conducted in 2014 responded to this challenge, highlighted by progress made in understanding complex features in the jet plumes of tactical military aircraft and launch vehicles. Also noteworthy are recent improvements to aeroacoustic measurement systems and test facilities that provide more insight into noise source characterization of aerospace products.

An important area of research for military applications is noise reduction in supersonic exhaust. The objective is to mitigate noise-induced hearing loss and improve the safety of people operating near tactical aircraft. A team of engineers from Lockheed Martin, BAE Systems and the U.S. government continued the investigation of noise generated by all three variants of the F-35 fighter aircraft. Noise data was recorded in the near and far fields for static engine tests, conventional flight and short-takeoff/vertical-landing operations to characterize the external sound generated by the aircraft.

Researchers at Penn State University developed a novel jet noise reduction system for high-performance aircraft. The patented method injects “fluidic inserts” in the diverging section of a supersonic exhaust nozzle. The inserts generate streamwise vorticity in the plume, which enhances jet mixing and reduces broadband shock-associated noise. Early experiments resulted in a 4-decibel overall sound pressure level reduction in the peak noise radiation direction using moderate amounts of bypass air to generate the inserts Recent experiments demonstrated that the device also worked in the presence of forward flight. Larger-scale experiments are being planned at a General Electric facility, while small-scale tests and simulations continue at Penn State...."

Source: AEROSPACE AMERICA/DECEMBER 2014 Magazine
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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