OnFingers12345

There’s no such thing as a quiet turboprop lol

rickair7777

Rear mounted props would help... airplanes tend to leave the noise behind them.

Active noise reduction in the cabin would help too, they use that in some helos.

OnFingers12345

Good luck, maybe you can design the next most quietest turboprop.

ZeroTT

You need moment and arm to rotate a body around an axis, vertical axis in this case.

The rudder generates a left or right force to take advantage of its long arm from the vertical axis. An engine failure will have a very short arm for its forward asymmetric force to work

Ziggy

This has the potential to be huge. Consider the Q400, I believe has a takeoff RPM of 1200, and 800 in cruise. Combine that with being tail mounted should reduce noise levels within the cabin considerably. Couple this with today’s FADEC to constantly keeping the props in sync should also add to the comfort.

I’d also like see them to go more towards an electrical operated methodology like the 787. Use air compressors and vapor cycle for pressurization and cooling. Maybe electrical heated elements for anti icing equipment. By using this, you could keep the aircraft cool on the ground just by using ground power.

Also there are a few who are mistaken this to be the 80’s Unducted Fan experiment, this is not that.

But, I feel the potential is there.

DarkSideMoon

Yep. This isn’t 1985, the tech is there. Noise can be mitigated- if it couldn’t, the 1%’rs wouldn’t be flitting around in Pilatii and King Airs all day. I doubt someone on a current 50 seat route is pickier than your C-Suite level people that currently fly turboprops.

and before anyone points it out, yes, economics and convenience are a factor. They’re cheaper and can get into more places- that would still factor in to airline ops. People will buy the tickets if they’re cheap and if the airframe allows frequent service to their home.

hydrostream

1020 for takeoff, 900 for climb out, and 850 in cruise on the Q400. It has active noise reduction which is pretty good when it's working, but most of the time it's a nuisance. The system acts up and makes all sorts of drums and bangs and warbles that alarm passengers.

Depending on where you sit determines how quiet the ride will be. In the rear rows at cruise it's pretty good, quieter than many of the jets I've ridden on. The rest of the cabin is about as loud as a 737, with the exception of the 4-5 rows next to/just in front of the props. Those are loud as hell and ANVS doesn't do anything to quiet them down.

While the dBs in the cabin might be lower, the frequency and vibrations still make it seem louder than a jet. Especially at 1020 RPM on takeoff when every panel and bag in the airplane starts rattling and vibrating away.

If you could offer the same cabin amenities as a jet a lot of the complaints we get in the Q would go away. The biggest two that come to mind are unrelated to propellers: no first class seats, and no running water in the lav.

Ziggy

I would think that with today’s technology and re-engineering the power plant placement that this could reduce the vibration. But yes, vibration could still be present.

As far as amenities offered, since scope still limits seating (and weight, but I don’t think that would be a factor). That would leave plenty of room for upgraded classes of seating and addition baggage space. This is based on the assumption that this is a 50 seat replacement and not for the E-jets or 700/900’s.

Still, mission placement would dictate that turbo-props are best on short legs or thin routes that want to maintain marketing presence.

Ziggy

Although digital engine control has been around for a while, it’s only recently that electronic prop control has been applied to current production turbo-props (see the PC-12NGX). Before, one had to balance 3 settings (torque, temp, and RPM) for each phase of flight. Now this can be done automatically and within tighter tolerances. Not even the newest ATR 600 series has this technology. So yea, this isn’t 1985, but this technology hasn’t been applied to this until recently.

hydrostream

PC-12 NGX sounds like it’s similar to the Q400. There’s a button to switch between RPM settings. That’s exactly what the “condition lever” on the Q does. There’s no fine adjustments, it just rests in detents and tells FADEC which setting you want: 1020 (NTOP/MTOP), 900 (MCL) or 850 (MCR), start/feather, or fuel off. They could have eliminated it entirely and just used buttons and it would have functioned the same, in fact there are buttons to do just that. One setting allows us to maintain 850rpm for landing even after the condition levers are moved back to 1020 (reduced NP setting). Power levers sit in a detent to command max power in the selected setting until you pull them out to adjust power.

I assumed the ATR was similar, is it not?