Pilatus cuts down on cabin noise in the PC-12

NBAA officially starts tomorrow, but most of the important announcements are today.

“Pilatus Unveils NGX, Its Third-Generation PC-12” is interesting:

In what Pilatus is calling a first for turboprops, the new engine will be able to operate in a low-prop-speed mode, reducing the prop speed from 1,700 rpm to 1,550 rpm and lowering cabin noise.

This is potentially an enormous improvement for the PC-12. For passengers in the cabin it is about as quiet as a turboprop can get, but a similar-size true turbojet is as much as 10 dBA quieter. As noted in my Pilatus PC-12 review, the faster PC-12 NG is actually a little bit noisier than the original comparatively sluggish PC-12/45.

What else is new and exciting?

Additionally, the new engine will have a 5,000 hour time-between-overhaul period with hot section inspections only required on-condition and be able to transmit data on more than 100 engine parameters that are continuously monitored, adjusted, and recorded. “Building on the legacy of the PT6 family, the new engine is a leap forward in engine control and data management systems,” said P&WC president Maria Della Posta.

The old engine was 3,500 hours TBO and, unlike in a piston, that was a requirement for Part 91 operators. Fleet operators often got extensions to 4,500 or 5,000 hours, but this new engine will do it without the paperwork hassles and maybe without as many borescope inspections.

Too busy punching autopilot buttons to adjust the power lever? The new PC-12 will do it for you:

An option in the NGX cockpit is a fully integrated digital autothrottle.

The 15-year-old Honeywell avionics that everyone agreed were powerful, but that nobody loved, get a user interface update with a touch screen.


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Helicopter Aerodynamics Talk and Demo for Boston-area Schools

We have a new full-time instructor at East Coast Aero Club and the snow hasn’t arrived yet, so I thought I’d remind Boston-area readers that we are happy to bring a helicopter to any local school (for free) and talk to the learners about how everything works.

Full explanation: “Helicopter Demonstration for Schools”

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NTSB preliminary report on the B-17 crash

A reporter sent me the NTSB preliminary report on the recent B-17 tragedy at Bradley in Connecticut. Here’s what I wrote back…

This more or less eliminates a popular speculation that the plane was mistakenly fueled with Jet A. Two people were there at the fueling. A good FBO will sample the fuel truck every morning for water, sediment, etc. This particular truck was thoroughly checked as part of the investigation.

The NTSB found no skimping on maintenance. The plane was within its annual inspection and had received progressive inspections at 25-hour intervals. Three of the engines were more or less fresh from overhaul (0 hours in January 2019; 268 hours of operation since then). Based on a quick search, I found that gently operated big radial engines in airline service after World War II were able to go 3,000+ hours between overhauls.

The plane should have been light. Out of a total fuel capacity of 1,700 gallons for a standard B-17, only 160 had been added that morning (to whatever was held in reserve from previous flying).

The report seems to eliminate another possibility, i.e., that the No. 4 engine wouldn’t feather properly, thus creating a huge amount of drag on one wing. (see ASA 2311 and ASA 529, both of wouldn’t have occurred if a prop could have been feathered; multi-engine planes are designed with the ability to twist the prop blades until they’re more or less at a knife edge to the wind, thus minimizing drag and workload for the remaining engine(s)).

The report hints at the No. 3 engine also being feathered. That would be bad. The plane isn’t designed to fly with two engines on one side and none on the other, though it probably would still be controllable at a low power setting consistent with approach and landing, especially at the “no flap” setting that they were using (flaps are essentially for landing on a short runway because they let the plane be flown slower and descend steeply at a slow speed, but they add drag and require extra power, so the pilots were being conservative in not extending them and relying on having a long runway for rolling out from a higher airspeed).

This doesn’t resolve any of the mystery, I don’t think. The failed engine was feathered, so the multi-engine plane should have been flyable just like the book says to fly it. The fuel was good 100LL. The pilots shouldn’t have needed more than a touch of power since they wanted to descend and had no flaps out.

The most surprising part of the report: “the airplane was about 300 ft agl on a midfield right downwind leg for runway 6.” Normal pattern altitude is 1000′ above ground level (AGL). “Right downwind” means they were going in the opposite direction of Runway 6 such that they’d have to turn right and right again to land. If this 300′ AGL altitude is correct, the plane was buzzing buildings on the SE corner of the airport (diagram) and better set up to land on Runway 33.

Still just as sad and still nearly as mysterious.


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Complete glass cockpit in one retrofit instrument

Here’s something that one would have thought would have been built about 15 years ago: a complete glass cockpit that fits into a legacy instrument panel 3″ hole. The uAvionix AV-30: it can be an attitude indicator, an HSI, a G meter, angle-of-attack indicator (“AoA is calculated by comparing the aircraft’s pitch, flight path, and G-loading”), etc. It even has a built-in battery that will run for 2 hours after the aircraft’s electrical system fails. All for about $2,000 for a certified aircraft.

Thought: if the Boeing 737 MAX had used this device, which tries to determine AOA via inference, instead of the (failure-prone) mechanical AOA sensors that it did use, nobody would have been killed by the airplane.


  • the same company has a retrofit wingtip-mounted ADS-B OUT transponder and a new one that will work on the 1090 MHz frequency required for Canada
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Why don’t airplanes have parking sensors for the wingtips?

At a recent aviation gathering, the topic of the Boeing 737 MAX came up. I gave my usual spiel about how TI was able to make the Speak & Spell in 1978. Why couldn’t a B737 have had a $1 voice synthesis chip saying “trimming forward” when MCAS was running, potentially prompting pilots to hit the trim interrupt switches much earlier. And why couldn’t the rest of our aircraft have voice warnings instead of simply beeping with different tones for different kinds of problems, e.g., gear not down, approaching a stall, etc.

An airline pilot responded “We lose millions of dollars every year from minor collisions on the ramp. If I buy a car for $20,000 it will come with parking sensors. Why doesn’t a $50 million jet have sensors in the wingtips to warn of a collision?”

I would love to know the answer to this question! It does not seem as though FAA certification would be a huge hassle given that the system won’t be used in flight. The sensors are commercially available from Bosch (parking ultrasonic; rear radar).

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Boeing’s attack on the Bombardier fly-by-wire regional jet

“How Boeing Tried to Kill a Great Airplane—and Got Outplayed” (Daily Beast) has a lot of good background on the Bombardier CSeries (Airbus A220), an evolution of the Canadair Regional Jet that I used to fly. I knew that the airplane had a geared turbofan engine for fuel efficiency, but I hadn’t realized that it was fully fly-by-wire (as long as the software works, impossible to have a Boeing 737 MAX-style catastrophe).

The article shows that critical importance of political connections in the U.S. business world:

Boeing’s formidable Washington lobbying machine swung into action. Dennis Muilenburg, the Boeing CEO, had already cozied up to President Trump by agreeing to cut the costs of the future Air Force One jets. In September 2017, the Commerce Department announced a killing blow to Bombardier, imposing a 300 percent duty on every C Series sold in the U.S.

The story of how Airbus outfoxed the high-paid Boeing executives is interesting.

One thing that the article does not explain is why Boeing executives moved the HQ from Seattle to Chicago. Why would high-paid workers want to be in Illinois with a 5 percent income tax rather than in Washington State with no income tax? (the family law is radically different in the two states as well; Illinois offers plaintiffs unlimited child support profits while Washington caps revenue at about $400,000 (tax-free) for one child)

I’m not sure that I agree with the conclusion:

Boeing provides no end of a lesson in how a great company can lose its moxie because of an indecent lust for short-term gain. It used to be the classic American can-do company. Now it can’t do anything right.

How do we know that Boeing is imploding due to a decision to seek short-term profits? Since the company’s problems are primarily engineering failures, why couldn’t it be that the quality of engineers the company is able to hire is not as high as in the 1960s? Americans with excellent quantitative skills have a lot more career choices today, most of which pay better than working at Boeing.

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A factory-new airplane for $1,270

From a recent visit to the National Air and Space Museum:

Behind and above, a Piper Cub (derivative of the Taylor Cub being advertised).

Adjusted for inflation, if we assume that the advertisement was from 1931 (first year of production), the “costs no more than a medium priced car” price of $1,270 is around $21,000 in 2019 mini-dollars.

[Note that the manufacturer apparently did not expect readers of the ad to be surprised that a person identifying as a woman (based on clothing) would be the owner-pilot. This was before Americans agreed that women are the new children (quoting a Facebook post in which a woman who earned a Private certificate in 1970 was “an original feminine trailblazer”, fully 60 years after the first woman earned a certificate).]

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Boeing B-17 crash at Bradley

Yesterday was a sad one for aviation enthusiasts due to the Boeing B-17 crash near Hartford, Connecticut.

Friends and reporters have been asking me about this, but it is tough to say much. A plane of that vintage does not have the hooks necessary to feed a flight data recorder (“black box”). There wouldn’t be any reason for the plane to have had a cockpit voice recorder either, though that would be comparatively simple to install.

Currently, the only clue as to what might have gone wrong is the following exchange with Bradley Approach:

  • Pilot: Boeing 93012 We’d like to return to the field.
  • ATC: November 93012 Sorry, say again.
  • ATC: What’s the reason for coming back?
  • Pilot: The number four engine. We’d like to return and blow it out.

The italicized words are a bit tough to make out, but I think that is what one of the airplane’s pilots said. My friends who fly planes with radial engines don’t know what this means and neither do I. Certainly it doesn’t mean anything for pilots of a conventional piston-powered Cirrus or Cessna.

[Speculation: Aviation gasoline is leaded to prevent detonation. Spark plugs are subject to lead fouling and a fouled plug will cause the engine to run rough. In the event of a failed magneto check during the preflight run-up, a technique for clearing the fouled plug and restoring the engine to smooth operation is to lean the mixture (less fuel per unit of air) and run the engine up to a reasonably high power setting on the ground. I haven’t heard anyone refer to this procedure as “blow it out,” but perhaps that is what was meant.]

After this exchange, the radio exchanges were essentially ordinary until the plane landed short of Runway 06, damaging the approach lights (out of service by NOTAM issued shortly after the crash: “RWY 06 ALS U/S 1910021702-1910092000EST”), and eventually veered off into the de-ice area to the right of the runway (airport diagram). The ILS 6 procedure says that the runways has an ALSF-2 approach lighting system and this FAA document says that those lights should start about 2,400′ before the runway pavement begins.

Flying a multi-engine plane after an engine failure is challenging due to the fact that the plane wants to yaw and roll (good explanation). If the pilots do everything right, the plane will fly slightly sideways and with reduced performance. That’s assuming a working feathering mechanism for the propeller on the dead engine, though, so that the prop blades can be turned into knife edges rather than massive speed brakes. After the initial reconfiguration and getting the prop feathered, touching down is the trickiest part. A plane flying slightly sideways through the air is inefficient. A plane going sideways off the runway is crashing.

[When I was fresh from my multi-engine instructor rating, I wrote up this page on how one trains for the failure of an engine on one side. See also my post about how I was unable to pull on the correct lever during my own training and our MIT ground school class, in which this topic is covered during Lecture 19 (PPT and video linked and free to download).]

Both pilots of this airplane died in the crash (Hartford Courant) so we may never find out exactly what happened. I looked them up in the FAA Airmen Registry:

Airplanes heavier than 12,500 lbs. or powered by turbojet engines required specific training and a checkride to add a “type rating” to fly that type of aircraft. The B-17 can take off at more than 50,000 lbs. and therefore requires a type rating for the captain. I believe that it also requires a two-pilot crew at a minimum (and in World War II was flown with two additional flight crew members: a flight engineer and a navigator). Depending on the operation, the second crew member need not be typed.

Michael Sean Foster, described in the media as the “co-pilot,” had a significant amount of aviation experience. He starts out with an Airline Transport Pilot certificate, the highest level, and is typed in three Boeing airliners, the DC-10, and the Learjet. He also holds an FAA Flight Engineer certificate, which would have qualified him to serve in this position in planes such as the DC-10. He was a Navy carrier pilot veteran. Ernest Herbert McCauley, who was serving as the “pilot”, held a Commercial certificate and was typed in the B-17. The NTSB credited McCauley with 7,300 hours of B-17 time; a World War II bomber pilot might have come home with 250 hours of total time in the B-17 (from 25 missions). He also held an FAA A&P certificate to perform maintenance on certified aircraft.

Weather cannot have been a factor. Tower reported “wind calm” just before the plane returned. The plane took off at 1348Z (9:48 am local time). The METAR from three minutes later: KBDL 021351Z 00000KT 10SM FEW110 FEW140 BKN180 23/19 A2981 (“Bradley Airport, October 2, 1351Z time, wind calm, 10 statute miles of visibility, few clouds 11,000′ above the airport elevation, few clouds 14,000′ above the airport, broken layer of clouds 18,000′ above the airport, temperature 23C, dewpoint 19C, altimeter setting 29.81”).

The Collings Foundation is a great organization, based here in Massachusetts as it happens, and everything that I’ve seen them do has been done with meticulous attention to safety, detail, and historical accuracy on a spare-no-expense basis.

Not having any B-17 training or time myself, that’s all that I know. It was good weather at a great airport, an aircraft that was likely maintained as well as possible, a plane that can fly safely on three engines, and two pilots with a tremendous depth of experience. Very saddened that it didn’t work out better.


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Making America Great with a German Helicopter

Democrats will debate tonight, presumably seeing whose empty unfunded promises can come closest to what Hugo Chavez promised voters.

What do Trump supporters have? At Oshkosh, we saw the Trump Chopper: Turning Washington Upside Down. What does it take to make (keep?) America Great? A Messerschmitt-Bölkow-Blohm Bo 105!

Everything is right-side up on one side and upside down on the other. This includes the tail number(!):

Watch the videos on trumpchopper.com. The machine does aerobatics, just like the Red Bull BO-105.

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