World's Leading Independent Aviation News Service
Volume 26, Number 17a
April 22, 2019
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UPDATED: AOA Sensor Malfunction Prompts Vision Jet Emergency AD
Kate O'Connor

The FAA issued an emergency airworthiness directive (AD) for the Cirrus SF50 Vision Jet on Wednesday in response to three reports of the stall warning and protection system (SWPS) or Electronic Stability & Protection (ESP) System “engaging when not appropriate.” According to the AD, “Cirrus and Aerosonic (manufacturer of the technical standard order AOA [Angle of Attack] sensor) have identified the probable root cause as an AOA sensor malfunction due to a quality escape in the assembly of the AOA sensor at Aerosonic.” The AD (PDF) requires replacing existing AOA sensors with improved AOA sensors before further flight.

The AD notes that the SWPS or ESP systems could engage even when the aircraft is operating with sufficient airspeed and at a proper AOA for normal flight, including activation of the stall warning alarm, stick shaker, stick pusher, under speed protection, and color-coded airspeed awareness ranges displaying the stall band, “regardless of actual indicated airspeed.” It warns that the potentially erroneous indications derived from a malfunctioning AOA sensor could result in “unintended automatic flight control activations; the flight crew having difficulty controlling the airplane; excessive nose-down attitude; and/or possible impact with terrain.”

"In early April of this year, one of our company pilots experienced the engagement of the Stall Warning and Protection System when not appropriate during a flight at altitude," Cirrus said in a statement. "The pilot followed the published Airplane Flight Manual (AFM) procedures and landed the aircraft safely. Out of an abundance of caution, we immediately began working with the FAA and our internal teams to determine the root cause and began our operator communication process. With the benefit of detailed feedback from our company pilot about the April event, we were able to identify service histories that pointed to a probable similar occurrence in November." The company issued Service Advisories on April 8 and 12 April 12 followed by a mandatory Service Bulletin on April 16 requiring that operators replace the AOA sensor. Cirrus emphasized that the root cause of the malfunction is an AOA sensor hardware issue, not a software problem.


Cabin Tour New Cirrus G2 Jet
Paul Bertorelli

Cirrus recently announced the second generation of its SF50 VisionJet. In this video shot at Aero in Friedrichshafen, Germany, Adam Hahn gave AVweb a tour of the new cabin improvements.

There Will Be Mud
Paul Berge

Iowa … you know, fly-over country, as in Minnesota pilots fly over us on their way to Sun ‘n Fun, and Sou’westerners cross when heading to Oshkosh. Unless you’re running for president—and who isn’t?—it’s perceived that there’s little reason to land in Iowa. But skip us at the risk of losing New Hampshire and, more importantly, missing runway mud boggin’!

Mud boggin’ is a real motor sport in, well, anywhere that NPR doesn’t reach and is the strangest event I’ve ever entered. It’s not complicated—two pits are bulldozed into the water table at the county fairgrounds. Then, at the signal from a Duane, 4x4 trucks plunge into the muddy abysses, race to the back wall, slide through a glop-floppin’ one-eighty and return to see who emerges with dignity intact. It’s second only to paintball in silliness. Aviation offers its own version for those willing to fly off the grid.

For the record, we do have paved runways in Iowa, several in fact. But I prefer grass, particularly on warm days in a 1946 Aeronca, while chanting my mantra: I fly, but not to actually get anywhere. Turf makes for good landings or at least masks the crosswind-challenged pilot’s inability to keep the nose pointed where a centerline would be. Tires never squeal under sideloads. Buckle, perhaps, but you can always blame that on mythical dust devils.

It's all about aesthetics. Rare is the pilot who swoons over the heady bouquet of asphalt on a midsummer’s noon. A grass runway, by contrast, is sweet fantasy. Green-stained tailwheels imply adventure above the ordinary. But grass does have drawbacks. It takes hours to mow an airfield, and except in drought conditions, it doesn’t stay mowed. Ground squirrels bore tunnels, coaxing badgers to root out the squinnies for brunch, leaving holes that can flip a Cub. And when the grass is damp, braking action is bupkis.

Between snow melt and verdant summer, Iowa sod turns to mud. And we’re talking Passchendaele trench warfare muck here, the kind not easily brushed off your wheel pants but, instead, sticks with malicious tenacity. Caked on landing gear—conventional or tricycle—it mocks the short-field technique I demonstrated on dry Hawaiian pavement during my private pilot checkride. Not until years later, when about to take another hard runway for my commercial ride, did I get a sense of real soft field performance when the examiner simulated a muddy runway takeoff by working the throttle himself.

Normally, I’d add full power and dutifully haul back on the yoke, without smacking the tail, to pop free of the imaginary goo and stagger into ground effect. Easy. Except with the examiner adding only partial power, the otherwise unremarkable Beech Sierra skipped along at Vmush as though impeded by a genuinely soft field. After making his point, he transferred power to me, and off we flew, so I could demonstrate how much I didn’t understand about eights on pylons. Thirty years later, I use the same soft-field technique on students about to face the checkride-versus-reality conundrum.

A checkride is a brief, albeit intense, bit of theater in which the actors (applicants) perform FAA dance steps for a critical audience of one. A good examiner takes this brief relationship to both evaluate and educate with, “Yeah, but …” As in, “Yeah, you passed, but let me lay 40 years of experience on you before you fly away to form your own misconceptions.”

In a perfect world, a checkride would involve the usual ACS kabuki, but once the show’s over, the examiner and the new pilot should fly an old, mud-boggin’ airplane to an unpaved airfield for the real stuff. In dry season, perhaps a water wagon could pre-soak the runway to stage what it’s like to plant your wheels on real earth after a thunderstorm. Frankly, there’s little that’s more beautiful.

Grass runways shimmer after a rain. They’re usually fairly short, so combining short and soft-field technique is routine. Just clear the trees and don’t land short of the threshold, or you’ll rip off the gear legs. Landing long has similar deleterious effects. (See photo.) Any hesitation while turning around after touchdown allows the spongey ground to cradle your wheels in cement shoes, necessitating local pilots to slog to the rescue with, “Got us another city mud bogger, Duane …”

But when it goes right it’s glorious … in an Iowa kinda way. Takeoff runs are long, splashing through puddles that yaw the airplane left and right. Not good with rudders? You’ll learn fast or else. If ground effect has been a vaguely understood principle, its academic benefits merely to be parroted on checkrides, then you’ll learn to embrace the magic or fail spectacularly.

Don’t be discouraged if the airplane simply doesn’t break free of the mud three-quarters of the way down the runway. If the wind is calm, turn around at the end, without stopping, and add full power to attempt a run in the opposite direction. Repeat as necessary, until your wings are thoroughly splattered with slime and no longer support lift. Find a hose.

Sure, landing on a grass runway in mud boggin’ season involves risk, but so does overflying Iowa or any rural strips that might not be in ForeFlight. By not visiting, you risk squandering the chance to slide through aviation’s primordial ooze and, with the side window open, simulate that open-cockpit thrill of wind and mud in your hair—how aviation was meant to be. Your call, but don’t blame me if you fly over Iowa and arrive clean and dry at your paved destination only to discover you’ve cheated something essential in your aviator soul.

Next time: Learn how Iowans mount paintball guns instead of ADS-B on their airplanes to repel invading Minnesotans above the prairie … maybe not a real thing, yet, but could happen in Iowa.

Lycoming 'When can an engine give you 200 extra flying hours?'
Drone NPRM Draws 899 Comments
Russ Niles

The comment period on the FAA’s Notice of Proposed Rulemaking on its rules for drone operations has ended and 899 comments were received on the highly detailed document. The agency says it’s now digesting those comments and won’t give an estimate of how long it will take to turn the NPRM and the comments into a final rule. To complicate matters, the agency also has to consider 1819 comments received in the Advanced Notice of Proposed Rulemaking (ANPRM) that preceded the NPRM. "We have to review, analyze and develop responses to the NPRM comments and include our responses in the final rule. In the case of the ANPRM, the comments may help us develop additional proposed rules,” the FAA told Avionics International.

In general, the NPRM focuses on the most common reasons drone operators now apply for waivers to conduct night flying and flights over people, and allows them without waivers as long as the pilots are trained and certified. A complex set of criteria determining the risk of injury or death to those who get in the way of wayward drones is used to determine relative risk factors of the operations of various drones and the precautions that need to be taken to minimize those sorts of misadventures. The pilot certificates will have to be renewed every two years. Flights remain restricted to visual line of sight operations and drones will have to be registered and carry identity numbers.

SpaceX Crew Dragon Has Test Mishap
Russ Niles

SpaceX suffered a setback in its manned program when one of its Crew Dragon capsules experienced “an anomaly” on a test stand at Cape Canaveral on Saturday. The nature of the incident was not immediately released but a cloud of orange smoke was reported rising over the SpaceX facilities at the Cape. There were no injuries. The incident occurred during tests of the capsule abort thrusters. “The initial tests completed successfully but the final test resulted in an anomaly on the test stand,” the company said in a statement.

SpaceX launched an unmanned Crew Dragon to the International Space Station earlier this year and the current schedule calls for astronauts Doug Hurley and Bob Behnken to ride the capsule in a test flight in July, although it's been reported the manned test will likely be pushed to the fall. It’s not clear whether Saturday’s incident will affect the manned test schedule. “NASA has been notified about the results of the SpaceX Static Fire Test and the anomaly that occurred during the final test,” its administrator Jim Bridenstine said in a tweet. “This is why we test. We will learn, make the necessary adjustments and safely move forward with our Commercial Crew Program.”

Wingtip Scuffed In Takeoff Mishap
Russ Niles

On the same day an American Airlines A321 clipped a runway distance marker with a wingtip, an AeroMexico E170 dragged its left wing for about 500 yards down a runway in Mexico. The regional jet was taking off April 10 from Chihuahua bound for Monterrey in a howling crosswind that gusted to 38 knots. On rotation, the aircraft banked 45 degrees and started grinding paint and metal from the wingtip and aileron. The crew got it airborne and immediately returned for a safe landing in that same wind.

In addition to the abrasion damage on the wing, tip strobes and markers were smashed. Authorities are investigating. The passengers got to Monterrey four hours later on another E170. Surveillance video caught the incident. Note the windsock early in the clip.

Canada May Require MAX Sim Training
Russ Niles

Canada’s Transport Minister Marc Garneau is suggesting he’ll break ranks with the FAA’s handling of the Boeing MAX 8 fix and require simulator training for MAX pilots flying in Canadian airspace. The FAA has so far said it will not require sim time for MAX pilots as it works with Boeing on a software update to address the potential safety issues associated with the Maneuvering Characteristics Augmentation System (MCAS). Garneau said last week he’s not sold on that approach. “Simulators are the very best way, from a training point of view, to go over exactly what could happen in a real way and to react properly to it,” Garneau said. “It's part of it—the software fixes ... and the training itself, which in my mind requires simulation time,” Garneau, a retired astronaut, said at an event. Canada has not issued a directive on simulator requirements yet, however.

To date, no sim time has been required for 737NG pilots transitioning to the MAX, even though the cockpit is substantially different and the MCAS was added. Last week, an FAA panel said computer and classroom instruction will be enough for current NG pilots to make the switch to the MAX. Garneau was not impressed. “From our point of view, it's not going to be a question of pulling out an iPad and spending an hour on it,” he said referring to published reports about the training some pilots have received. If other countries follow Canada’s lead, there will instantly be a shortage of full-fidelity MAX simulators. Air Canada says it owns the only one in North America besides those used by Boeing itself and there are reportedly only two airline-owned MAX simulators in Europe.

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Aviation Associations Object To FAA Drug Study
Kate O'Connor

Nine aviation associations are objecting to a proposed FAA study that would perform toxicology tests on anonymous urine samples gathered during pilot medical exams, according to a letter sent to the FAA on April 3. The letter (PDF) states that the study proposal was presented to Aircraft Owners and Pilots Association (AOPA) team members during a Feb. 27, 2018, meeting by staff from the FAA Civil Aerospace Medical Institute (CAMI).

The testing proposal stems from a 2014 NTSB recommendation (PDF) that the FAA “conduct a study to assess the prevalence of over-the-counter, prescription, and illicit drug use among flying pilots not involved in accidents, and compare those results with findings from pilots who have died from aviation accidents to assess the safety risks of using those drugs while flying.” In addition to concerns about lack of true anonymity and whether pilots would be informed prior to the use of their samples or given the opportunity to opt out of the study, the study’s methods are also being called into question. Issues being cited include how long drugs linger in urine after use, the potential for counting pilots who might have self-grounded after taking medications as being actively flying under the influence of drugs, and the accuracy of comparing urine sample data to NTSB drug use data which is collected from tissue and blood samples of accident victims.

“We believe the study does not comply with legal requirements, represents a waste of government funds and resources, and will further erode any trust left between the pilot community and the Office of Aerospace Medicine,” the groups wrote in the letter. “It is our strong belief that outreach, communication, and education are areas where the FAA should focus its resources.” Organizations that signed the letter include the Aircraft Owners and Pilots Association (AOPA), Experimental Aircraft Association (EAA), Helicopter Association International (HAI), National Business Aviation Association (NBAA) and Southwest Airline Pilots Association (SWAPA).

The FAA has not yet responded to a request for comment.

Industry Round-up, April 19, 2019
AVweb Staff

AVweb’s weekly news roundup found reports on a special award for Gulf Coast Avionics, a new training system at Pacific Sky Aviation, a drone-based aircraft inspection solution from Rizse, and a new GLIDERBOOKS Academy online ground school course. It also uncovered announcements from the U.K.’s All-Party Parliamentary Group on General Aviation (APPG-GA) regarding how aviation firms are handling issues surrounding Brexit, responses to new drone laws, and proposed changes to the country’s VFR cloud clearance minimums in Class D airspace.

Gulf Coast Avionics has been awarded Garmin's 2018 Platinum Dealer Award for the 20th consecutive year. The award is given by Garmin for outstanding sales of the company's aviation products. British Columbia-based flight school Pacific Sky Aviation has announced the implementation of the Fox Training Management System by Britannica Knowledge Systems. The system manages operational training requirements including resource allocation, scheduling, pilot training records, qualifications and learning.

U.S.-based drone robotics company Rizse has introduced its new solution for aircraft inspections, which uses autonomous drone hardware and proprietary software. Rizse’s StreamSense platform is capable of inspecting aircraft fuselages for damage such as that caused by lightning strikes, hail and bird strikes. Also with a new product, GLIDERBOOKS Academy is now offering an online ground school course in aeronautical decision making. The course is available for $25.

A delegation from the U.K.’s All-Party Parliamentary Group on General Aviation (APPG-GA) attended Aero 2019 in Friedrichshafen, Germany, where they spoke with exhibitors about concerns regarding Brexit. The delegation reported that the groups they spoke with had measures in place to address potential Brexit issues. The APPG-GA also discussed recently toughened laws on operating small unmanned aircraft around airfields which expanded restriction zones and removed the lower weight limit of models that the regulation applied to. Concerns were raised about the speed with which the regulations were enacted and their effects on model airplane fliers. Finally, the U.K.’s Civil Aviation Authority is proposing increasing cloud clearance distances in the country’s Class D airspace to align with the Standard European Rules of the Air (SERA). Under the new proposal, VFR aircraft within Class D airspace below 3,000 feet would be required to maintain 1,000 feet of vertical distance from clouds.

Top Letters And Comments, April 19, 2019

Cold Correction

Canada has had this solved for years. If you go to our AIM manual (freely available online at on page 303 you will find a simple table to correct for cold down to -50 C. No hassle and quick.


Electric Flight

I read [Paul Bertorelli’s] comments about electric flight. You are absolutely right about batteries. "Better batteries in the near future" has become the most believed rumor in recent years. And it is solely based on desire and not science. Even a slight improvement will not be enough. Consider just 2 things: EPA has established that the energy bound up in just one gallon of gas is equal to a lithium battery that would weigh 953 pounds. Plus, the fact that the best battery ever made is the nickel metal hydrate and it was invented by Tom Edison.

Batteries are chemistry and unless new elements fall from the sky - we are faced with what we have. I have been saying for the past 5 years that we need a light weight onboard charging system to extend the flight time. We have developed a small one that weighs about 40 pounds and can supply 200 amps at 120 volts. It is designed to put out 350#'s of thrust at 1/4 of the fuel that a Cessna 150 burns.

Don Lineback

737 MAX

I see in a number of articles AVweb have made on the 737 MAX there have been statements similar to this one in the latest newsletter, "to address issues with the MCAS automatic stall prevention system that is implicated in two fatal crashes." The MCAS is not a stall prevention system, it is a longitudinal stability enhancement system.

Brian Abraham

Picture of the Week, April 18, 2019
This image was taken from a DG 1000 glider over the Lac de Joux in the Swiss Jura mountains, 30 miles NE of the city of Geneva. Photo taken with a Pentax K5 camera at 1/500 sec., focal length 100 mm. Copyrighted photo by Gilbert Benzonana.

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Short Final: Be Nice!

A few years ago I was flying into my home field in my Columbia 400. Descending, I was doing a bit over 210 knots 10 miles out, number two for landing. Ahead of me was a regional jet. As I approached the field I had the following conversation:

Tower: “999TJ, reduce speed for landing traffic.”

Me: “The single‑engine piston will gladly slow down for the twin jet.”

Tower: (holding back laughter) “Now be nice!”

I threw in my speed brakes and chuckled all the way to the numbers.

Chris Watson
Charleston, SC
Brainteasers Quiz #254: Flying Is So Easy ...

... It's the other stuff that interferes with slipping surly bonds of reality while attempting to touch the face of the insanely glorious notion that humans -- and a few dogs -- can fly, provided they can ace this quiz.

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