Pilatus PC-12 NG test flight and cabin noise measurements

I had the opportunity to test-fly a PC-12 NG. I was interested to see how this would compare to the “legacy” PC-12 that I flew back in 2006 (review of that plane). The new plane has a more powerful engine and is therefore a few knots faster. Friends who are pilot at PlaneSense, the largest U.S. operator of the PC-12, said “the extra speed might save you an hour per year.”

What does the new engine do to cabin noise, a traditional weakness of turboprops compared to jets? Here are some data from January 17, 2014 in N47NG, a 2010 PC-12 NG, serial number 1103, in a flight from KBED.

  • idling on the ramp: 76 dBA center cabin
  • taxi: 76 dBA center cabin
  • takeoff: 85-90 dBA center cabin
  • climb: 86-88 dBA center cabin
  • level 6000′, 217 knots: 90 dBA pilot ear level; 87-88 dBA center cabin; 84-87 dBA rear of the cabin (but 89 dBA next to the cargo door)
  • level 10,000′, 200 knots: 90-91 dBA pilot ear level; 85-87 dBA center cabin; 84-88 rear of the cabin
  • level 15,000′, 200 knots: 89-90 dBA pilot ear level; 83-87 dBA center cabin; 83-86 rear of the cabin
  • descent: 80-83 dBA center cabin
  • pattern: 80 dBA center cabin

I didn’t record the numbers as carefully back in 2006 but it seems that these are roughly 4 dB louder than the older slightly slower airplane. In fact, the PC-12 NG has roughly the same measured interior noise level as a friend’s G36 piston-powered Bonanza and is louder than a Diamond Star DA40 (previous posting). From a pilot’s point of view, the 90 dBA in the front exceeds OSHA limits (85 dBA) for exposure at work without hearing protection (and so do most of the cabin readings). This is 9 dBA louder than an early 1980s Twin Commander turboprop that I measured (posting). It is also much louder than a King Air (previous posting), though no worse than a TBM 850 (previous posting). For reference, interior noise levels in light jets are usually below 80 dBA in the cockpit and below 82 dBA in the passenger cabin, closer to the engines.

How about the fancy Honeywell avionics in the front that are part of the NG experience? The PlaneSense pilots all have hundreds or thousands of hours of experience with this system but they prefer the legacy avionics, updated with the latest Garmin touch-screen GPSes.

Being an owner of a Honeywell glass flight deck is pretty expensive, with annual extended warranty coverage costing about $15,000 per year. In other words, every four years you pay Honeywell enough to have bought all of the stuff in a brand-new Garmin G1000 system. I’m not in love with the user interface philosophy of Garmin, but I think it would have saved everyone a lot of time and money if Pilatus had used a Garmin system, which nearly all pilots know how to use. Certainly if the Garmin systems are capable of supporting faster and more complex aircraft, such as the Embraer Phenom 300, they would be capable of performing in a PC-12. ┬áIt might be simpler for a piston pilot to transition to a Phenom 100 or Cessna Mustang twin-engine turbojet because (1) the piston pilot already knows how to use a Garmin glass panel, and (2) the latest turbojets include FADEC for the engines.

If you need 10 seats and must visit airports with short runways, the PC-12 remains a strong candidate. But the high cabin noise level, apparently made worse in the NG model, means that passenger and pilot comfort will not be comparable to a jet. Everyone in the plane should be wearing some sort of hearing protection.

(A friend who traded in his Twin Commander turboprop on a Phenom 100 jet a few years ago said that “Now we usually have to stop for fuel when we go to Florida, which we didn’t have to do in the Commander, but the family arrives much more refreshed.”)

Related: measurements from a 2000 Series 9 PC-12/45.

1 Comment

  1. Dg

    March 14, 2014 @ 1:24 am

    1

    For $60K a nickel-edged 5-blade carbon MT prop will lower the cabin noise 6-7dB, and it looks wicked. Not sure why all PC12s don’t have them.

    http://www.mt-propeller.com/en/entw/stcs/pilatus_2.htm

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