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Very nice looking piece of equipment; it's even got "VIP skids" for ground taxying! :ok:
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They might need to rebrand the company since they're not going to be only making buses anymore ! http://www.airbushelicopters.com.my/...2/10/logo3.png Oh wait, they just did ... |
Instead, the size of the landing gear doesn't impress me so much.. :hmm: |
It takes more than good looks to "kill the139", let's call the H-160 (sounds like a Renault product, just like the vent registers on its dashboard) a medium light twin with decent (paper) performance.:cool:
Oh, and probably a "smooth ride and an airy interior".:rolleyes: |
Question - is 3dB really worth what those blades are going to cost on ship?
I can't imagine the potential fatigue issues they might end up facing in long term operation. |
Learn your dB scales.
It's a reduction of half. |
Learn what a decibel is.
3dB does not equate to a subjective "halving" of noise. 3 dB increase is, by definition, a doubling of power in watts 3 dB = twice the power (calculated) 6 dB = twice the amplitude (Voltage respective sound pressure - mostly measured) 10 dB = twice the perceived volume (psychoacoustics) Nobody in their right mind would characterize a doubling of power as a doubling of volume. |
Unless mistaken, logarithmic dB scale can be applied to any physical quantity. If talking about noise, it is about sound pressure levels in Pa.
Arrakis |
Correct, and doubling of dB(SPL) does not equate to a doubling of psychoacoustic volume.
If you have a decently high end audio receiver at home, let me know if going from -25dB to -22dB on the volume makes you jump out of your sofa for being "twice as loud"! Axiom AudioFile Newsletter Now for the really amazing part: although it seems that doubling the amplifier power in watts would also double the loudness, disappointingly it only increases loudness by 3 dB, a change in volume most of us perceive as “slightly louder.” That’s why going from an amplifier of 75 watts output to one of 150 watts output only increases the actual acoustic output a bit—again by 3 dB. To make sounds subjectively “twice as loud”—an increase of 10 dB—requires ten times as much power from the amplifier. |
Purely academic, but:
based on press data: - 3 dB noise, which means - 3 dB SPL. In an audio system a 3 dB SPL change would require about 6 dB accoustic power change (x4) and would give about 50% volume change (subjective). As we are not talking about music (20 Hz - 20 kHz spectrum) but about noise of limited spectrum and our hearing subjective reaction will depend on that noise spectrum, time duration of peaks, etc... the final answer is I don't know. Probably around 50% volume reduction (but see remark above). Arrakis |
In an audio system a 3 dB SPL change would require about 6 dB accoustic power change (x4) and would give about 50% volume change (subjective). 3dB SPL =/= 50% subjective volume increases loudness by 3 dB, a change in volume most of us perceive as “slightly louder.” To make sounds subjectively “twice as loud”—an increase of 10 dB—requires ten times as much power To achieve the subjective "50% volume change", it's universally agreed in industry that the average noise (not necessarily music frequency range) dB reduction would need to be 10dB SPL. The blue edge blade design claims a reduction of 3dB SPL. The blue edge blade does not reduce perceived blade noise volume by 50%. Q.E.D. |
Lets see now -
What the EC155 really should have been instead of cobbled 365 parts? Similar concept with a new brush? Should be fast and quiet if improved in those respects as the 155 certainly is. When will you see it certified? I would guess about 3-4 years at best. Clean sheet? |
Q.E.D A 10 dB of accoustic power change gives effectively x2 volume change but also a little bit over 3x SPL change (noise level, we are talking about). Please try to make the difference between accoustic power, SPL (nosie level) and loudness (volume). From AH press release Airbus Helicopters we are talking about which reduce exterior noise levels by 50 percent (3 dB) I also made a mistake. It should be approx. 23% volume. The value of 50% volume change would be for 6 dB of noise reduction. Not enough sleep I presume :zzz: Arrakis |
on a new aircraft why is the 30second oei (blue line on fli) so much less than mcp? The pic shows the radalt and bar alt to be below 2000ft and only +9c. Acceptable risk in an old aircraft, but for me in a new twin I want to be able to cruise at close to mcp and not have to immediately be lowering collective to save rpm if a power unit quits.
Also why is the TOP range quite small with an almost equal transient range? |
It is a static display model... ;-)
I know nothing about this aircraft but think the demo display is showing the OEI mode of the FLI. If previous aircraft are anything to go by the 30s OEI rating would be the solid red line on top of the amber band and not the blue line. By definition MCP OEI must be less than the 30s OEI rating. Also I would expect the aircraft in case of an engine failure to automatically manage the power for you (even if this wasn't the case I think an engine failure in the cruise is a bit of a non event) so I don't really see much risk there. But then again I could be completely wrong! ;-) |
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A rather unfortunate combination of letters on that registration...
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Erm, has anybody else noticed the differences between the mock-ups and the actual aircraft (particularly around the cowlings)?
http://www.modeltek.com/X4-1.jpg http://i57.photobucket.com/albums/g2...psupk1zfla.jpg ...and... https://scontent-lga1-1.xx.fbcdn.net...37&oe=55F8D22D Sleek and aerodynamic seems to have turned into bulky and awkward. |
And top heavy to taxy with the narrow track
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