turbine engine noise

[bones]

Is it just my imagination but after spending a week at an airport, where a AT802 or is it AT820, anyway one of those big kick ass spray planes fly from.

 

My question is why do those engines sound soo much louder when the plane is empty coming back in, on full song taking off they not too bad, but as they land to reload, the just sqreams????

 

 

[Guest basscheffers]

When idling you mainly hear the high-pitched jet noise, but when on high power, the lower pitch prop noise masks the jet whine?

 

 

[Tomo]

They often apply reverse thrust to help with braking once on the ground also, that usually makes a fair noise.

 

 

[bones]

No i was talking on the approach before they landed, they just seem soo much louder empty, i know they throw reverse in once they touch ect, and yes you can really hear that, but it was surprising how loud too me anyway the noise empty.

 

 

[bones]

yeah good one Cam didnt think of that :)

 

 

[facthunter]

Engine noise Plane Empty/full.

 

Think it is more likely to be the different power settings. With a Turboprop there is usually more noise at the intake as most of the energy has been extracted to drive the prop at the other end. Most of these engines are "free spool" with the compressor section driven by a different spool to the power turbine. You see this on start-up when the engine is running well before the propeller comes out of feather and starts to rotate. The high frequency noise does the most damage to your ears. Nev

 

 

[jetjr]

I reckon noise from turbines in Air Tractor etc is VERY directional, much more noisy from behind aircraft

 

They can feather off and come in from behind you nearly silently, you see it just as the noise hits. At 20ft over your head nearly makes you load up........ .

 

They know it and love doing it.

 

I agree with Bass though, its prop noise hiding turbine noise.

 

 

[Guest davidh10]

Cool Handling

 

We've had Ag planes operating out of Yarrawonga for weeks now and yes we've all noticed the noise, but in our case I hadn't noticed noise on final to be greater or more annoying than on takeoff.

 

What is cool is watching how they handle the aircraft, both when spraying (from above)... weave between trees, under power lines (mad bas...ds, but very skilful);

 

.. and when ground handling... Lands.. apply reverse pitch to slow down... turns into taxiway and then spins aircraft through 180 degrees before reaching the spray tanker... now engages reverse pitch and backs the aircraft up to the tanker.

 

 

[facthunter]

prop noise.

 

The biggest potential for prop noise is tip speed. When the tips go supersonic you get lots of noise. I would think that in Beta range, the airflow through the prop would be anything but smooth so potential for noise there also..

 

Think most of the noise that we are talking of here would originate from the prop of the PT6? rather that the turbines. The noisiest place re the RR Dart (F27 and Viscount, Argosy etc) was just in front and it definately was from the intakes but the compressors were centrifugal rather than axial. Nev

 

 

[pudestcon]

this would be a good ringtonehttp://www.alexisparkinn.com/photogallery/Videos/henry1_start_up.mp3

Where would I go to get a nice throaty roar of a Merlin in a low pass for a ring tone?

 

Pud

 

 

[Guest davidh10]

Where would I go to get a nice throaty roar of a Merlin in a low pass for a ring tone?Pud

 

Enjoy

 

Here's a site with just mp3 files

 

 

[pudestcon]

 

Mate, thanks for that. The hair is still standing up on the back of my neck.

 

Now how do I get the sound from there to my phone? :big_grin:

 

Pud

 

 

[Guest davidh10]

...Now how do I get the sound from there to my phone? :big_grin:

Pud

Good question. I don't even have sound turned on on most of the systems I use, so I can only hazard a guess.

 

• Maybe you can use the output of the audio mixer to record the data using an audio recording application on the PC.
   
   
  
• As a last resort plug a recorder into the headphone jack on the PC and record the sound. Then play it back into the Line-in and record it with an audio recording application on the PC.
   
   
  

 

 

Either way, the resulting audio file would beed to be either saved or converted into the audio format supported by your phone. This seems to vary by phone; could be wav or mp3. wav would be a large file so one of the compressed formats like mp3 would be better if the phone supports it. Check your phone manual.

 

Getting the audio file onto the phone. If you can mount the memory card in the phone on your PC, either by connecting the phone to the PC or removing the card from the phone and plugging into a card reader on the PC, you can probably just copy it to the card. The directory to use is phone / phone operating system specific. If your phone does not have a memory card, just a SIM, then it is going to be much harder and may not be possible. For an Android based phone, you copy the file into "[sdcard]/Ringtones" directory and then select it using the standard ringtone selection method.

 

That's me tapped out :). If you indicate your make / model of phone, maybe someone else can offer some thoughts.

 

 

[Guest basscheffers]

You can use keepvid.com to save the video file from YouTube. Then there is plenty of software that allows you to "demux" the file to get just the audio. This one should do the trick on Windows: mp4UI - MP4 file tool (never used it, I am on Mac.)

 

How to get that into your phone depends on the model...

 

 

[bernardc]

remember , the exhaust is on one side of the plane on take off and on the other side when landing, a fair ammount of db comes out those massive holes

 

 

[dazza 38]

Off thread a bit, but the Harvards/Texans are very noisey on Take off, because there Propellor Tips are breaking the speed of sound.

 

 

[Spin]

Off thread a bit, but the Harvards/Texans are very noisey on Take off, because there Propellor Tips are breaking the speed of sound.

C206 has a habit of doing that too - I eventually had to have stern words with a survey pilot who persisted in buzzing my house at low level at 4.30am every morning, waking the baby in the process; became a wee bit tiresome.

 

 

[pudestcon]

How to get that into your phone depends on the model...

I have a HTC HD2 Touch Phone Bass.

 

Pud

 

 

[Spin]

Normally that supersonic buzz is something that attracts a smile from me, however not virtually every morning at 4.30am, especially as I lived around 30 deg off centreline and about 8km from the threshold! A bit of detective work at the time revealed the ID of pilot and aircraft rego, turned out the ex wife lived on the ridge behind my place. Anyhow I prepped atc and the following morning phoned them as he passed over, they were a little more co-operative than expected and passed my threat of where said 206 was going to be stuffed more or less verbatim:big_grin:. It didn't happen again.

 

 

[facthunter]

Fast turboprops.

 

Years ago the common propulsion unit for large Russian planes was a turboprop with the blades DESIGNED to RUN supersonic. High speed props have to have some very clever auto-coarsening and pitch locking features. When a prop fails it tends to go to fine pitch and then you have massive drag and an overspeeding problem. REALLY dangerous. Nev