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Volume 26, Number 14f
April 6, 2019
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Report At Odds With Claim That Ethiopian Pilots Followed Boeing Guidance
Paul Bertorelli

According to a preliminary accident report, the pilots of an Ethiopian Airlines Boeing 737 MAX that crashed on March 10 were unable to manually counter significant nose-down trim before losing control of the airplane in a dive that reached 500 knots. The report, released by the Ethiopian government Thursday, confirms that the MAX 8’s MCAS subsystem, a stall-protection add-on, rolled in nearly maximum nose-down trim in response to a faulty angle-of-attack sensor.

But the report, which draws no final conclusions, is silent on whether the crew simply didn’t know how to use mechanical manual trim or if trim input was inhibited because the airplane was flying at such high speed. The pilots retained takeoff/climb power throughout the accident sequence. Ethiopian Airlines said that following the crash of a Lion Air MAX 8 last October in Indonesia, the crew was briefed on Boeing-provided information on how to disable MCAS. And although some mainstream news organizations have reported that the Ethiopian pilots followed Boeing’s checklist, the report suggests they departed from it in one key detail: After initially disabling electric trim to isolate MCAS, they reengaged it later, allowing the malfunctioning system to trim the airplane nearly full nose-down.

MCAS—Maneuvering Characteristic Augmentation System—was added to the MAX series because the engines are heavier and mounted farther forward than on previous 737 models. As a result, in flight test, the airplane demonstrated a pitch-up tendency at high angles of attack and/or high load factors. To counter this, MCAS automatically adds nose-down trim at high angles of attack when the airplane is hand flown with the flaps up. Boeing has described it as a stall-protection system, but it also increases perceived pitch force before stall angle of attack is reached.

MCAS is fed by a single AoA sensor and in both crashes, the sensor furnished inaccurate information to the flight computer. The Ethiopian report said that the left-side AoA indicated 74.5 degrees less than a minute after takeoff, while the right side indicated 15.3 degrees. This activated the left-side stick shaker and MCAS eventually responded by rolling in nose-down trim. It also gave the crew airspeed and altitude disagree alerts between the left and right side displays.

Following Lion Air, Boeing’s guidance for this situation—published in the Ethiopian preliminary report--called for several steps that combine its existing standard runaway trim with the MCAS’s peculiarities. Specifically, the checklist calls for disengaging the autopilot and autothrottles and, if the runaway continues, setting electric trim to the cutout position, disabling electric trim. Boeing said it should remain off for the remainder of the flight. The checklist advises to trim manually with the mechanical wheel and to “anticipate trim requirements.” Following Lion Air, Boeing also said that a significant out-of-trim condition caused by a runaway could first be corrected with electric trim before the cutouts are used. Flight data appears to show that the Ethiopian crew didn’t do this.

At 5:38:58, the captain, who was flying, called for the first officer to engage the autopilot, opposite of Boeing’s guidance. At that point, the crew had a left side stick shaker, some of the fault warnings and a master caution light Boeing listed, including airspeed and altitude disagree. It’s unclear if this had any bearing on the accident scenario, since MCAS is disabled when the autopilot is engaged. (The autopilot disengaged 33 seconds later.)

Shortly after the autopilot disengaged, the FDR showed that automatic nose-down trim activated for nine seconds, confirming that MCAS was reacting to and trying to resolve the erroneous AoA indication. The captain countered this with electric trim with his yoke thumb switch and later asked the first officer to “trim up with him.” The aircraft began a series of pitch and altitude excursions, but the power was never reduced below 94% N1, an unusually high power setting.

After struggling against the automatic pitch trim and excursions for several seconds, at 5:40:35—about two and half minutes after takeoff—the first officer called “stab trim cutout” twice. The captain concurred and the report indicates the cutouts were used. The 737’s trim system is operated by an electric motor/jackscrew arrangement that trims by moving the entire horizontal stabilizer. In the event of a trim runaway, the cutout switches on the lower pedestal disable the electric motor. But the 737 still has manual mechanical trim wheels on either side of the pedestal that are accessible to both pilots.

Six seconds later, the FDR showed that more automatic nose-down trim was commanded, indicating that MCAS was still sensing high AoA. However, the data showed the stabilizer didn’t respond to this command, confirming that the cutout switches were engaged. MCAS can only move the stabilizer if electric trim is active.

The report indicates that shortly after the cutouts were used, the trim gradually moved nose-down from 2.3 to 2.1 units. It’s unclear why this happened, since electric trim was disabled. At this point, according to the report, both pilots were exerting pitch-up force on the control columns, after the captain asked the FO to assist him.

At 5:41:46—a little over four and a half minutes after takeoff—the captain asks the FO “if the trim is functional.” The FO replied that it wasn’t and asked the captain if he could trim manually. What’s unclear is if the FO meant trim manually with his yoke-mounted electric trim switch or the 737’s mechanical wheel. The training manual for the 737 MAX includes a warning that excessive airloads on the stabilizer could require the effort of both pilots to correct a mistrim condition. "In extreme cases, it may be necessary to aerodynamically relieve airloads to allow manual trimming. Accellerate or decelrate towards the in-trim speed while attempting to trim manually," the training guidance says.

The data indicates the stabilizer was never moved manually mechanically. However, 32 seconds before the crash, the FDR trace revealed two momentary manual electric trim inputs commanding nose-up from 2.1 to 2.3 units.

This indicates that counter to Boeing’s guidance, the crew reengaged electric trim, allowing MCAS to once again regain control of the stabilizer. In five seconds, it moved the trim nose down from 2.3 to 1.0 unit, a value that’s nearly maximum nose-down in the 737, according to sources AVweb contacted for this story. The aircraft reached 40 degrees pitch down before impacting at 500 knots, according to the FO’s data. According to the report, power was never reduced from the takeoff/climb value.

Ethiopian Airlines said that its pilots did follow the Boeing guidance and in a press statement, the airline said, ”We are very proud of our pilots' compliances to follow the emergency procedures and high level of professional performances in such extremely difficult situations."

For its part, Boeing continues work on a new software package for the 737 MAX, but it’s not known when it will be available. For the time being, more than 370 MAX series 737s remain grounded throughout the world.

In a press statement, Boeing said, “The preliminary report contains flight data recorder information indicating the airplane had an erroneous angle-of-attack sensor input that activated the Maneuvering Characteristics Augmentation System (MCAS) function during the flight, as it had during the Lion Air 610 flight.

"To ensure unintended MCAS activation will not occur again, Boeing has developed and is planning to release a software update to MCAS and an associated comprehensive pilot training and supplementary education program for the 737 MAX.

"As previously announced, the update adds additional layers of protection and will prevent erroneous data from causing MCAS activation. Flight crews will always have the ability to override MCAS and manually control the airplane."

Video: Cool Stuff At Sun 'n Fun 2019
Larry Anglisano

Always on the prowl for exceptionally cool stuff at airshows, with cameras rolling KITPLANES Magazine Editor Paul Dye and Larry Anglisano set out to find three cool things on display at Sun 'n Fun 2019 in Lakeland, Florida, and prepared this video report.

Lycoming 'When can an engine give you 200 extra flying hours?'
10,000 Hours In A Mustang
Russ Niles

Legendary P-51 guru Lee Lauderback hit the remarkable milestone of 10,000 hours in the Mustang during Sun ’n Fun and is being inducted into the Florida Aviation Hall of Fame. Lauderback hit the big number while performing his solo P-51 demo routine in Crazy Horse, his mint Mustang, at the opening day airshow on Tuesday. He is believed to be the highest time Mustang pilot in the world and the only one to hit 10,000 hours. Lauderback is the CEO of Stallion 51, a Kissimmee-based flight school and aircraft management company.

The company also gave away an orientation flight in the dual-control Mustang when Lauderback flies it back to Kissimmee after Saturday’s airshow. The flight was part of the auction at the Thursday night fundraising dinner benefiting the Aerospace Center of Excellence.

Video: Levil Astro Link
Marc Cook

At Sun 'n Fun this week, Levil Avionics debuted a new ADS-B In receiver to drive various tablet-based systems with no-cost weather and traffic. In addition to the dual-band receiver, the Astro Link has a built-in WAAS GPS receiver and full AHRS module for attitude information. This allows the Astro Link to provide valuable backup attitude data to connected tablets.

Auto GCAS Team Wins 2018 Collier Trophy
Kate O'Connor

The National Aeronautic Association (NAA) has announced that the Automatic Ground Collision Avoidance System (Auto GCAS) team has been named the recipient of the 2018 Robert J. Collier Trophy for "successfully completing a rapid design, integration, and flight test of critical, lifesaving technology for the worldwide F-35 fleet." Auto GCAS was developed by Lockheed Martin, the U.S. Air Force, the F-35 Joint Program Office, NASA and the Defense Safety Oversight Council. According to Lockheed Martin, the Auto GCAS system uses a set of complex collision avoidance and autonomous decision-making algorithms to determine if a ground collision is imminent. As shown in the video below, if an imminent collision is detected, the system will roll the aircraft wings-level and pull up with no pilot input.

In addition to Auto GCAS, this year’s Collier nominees were the Bell V-280 Valor, Boeing T-X, Draken International Contracted Close Air Support & Adversary Air Services in Support of Combat Readiness Training, Embraer E190-E2, F-35 Integrated Test Force, General Atomics Aeronautical Systems Inc. Integration of Large UAS into Civil and International Airspace, NASA/JPL Mars Cube One (MarCO) Project Team, Perlan Project, Responsive Environmental Assessment Commercially Hosted (REACH) Project and Virgin Galactic SpaceShip Two Program. As previously reported by AVweb, last year’s winner was the Cirrus Aircraft Vision Jet.

The Robert J. Collier Trophy is awarded annually by the NAA "for the greatest achievement in aeronautics or astronautics in America, with respect to improving the performance, efficiency, and safety of air or space vehicles, the value of which has been thoroughly demonstrated by actual use during the preceding year." It will be officially presented to the Auto GCAS team at the Annual Robert J. Collier Trophy Dinner in Washington, D.C., on June 13, 2019.

Podcast: Alsim Talks New U.S. Facility, More Automated Sims
Kate O'Connor

In addition to experiencing the best year in its 25-year history in 2018, simulator manufacturer Alsim is moving toward opening a new production facility in the U.S. and developing more automated simulators. Global Business Development Director Mike Tonkin sat down with AVweb at Sun ‘n Fun 2019 to share the details.

Lancair Showcases First Barracuda Build
Kate O'Connor

Kitplane manufacturer Lancair is displaying the first of its Barracuda two-seaters to be built at Sun ‘n Fun 2019. The aircraft was constructed by first-time Lancair builder Wade Marcantonio. Marcantonio, who holds a BA in Mechanical Engineering from Texas A&M and is a Certified Solidworks Professional, built the aircraft with the help of Lancair’s Builder Assist Program.

Lancair introduced the composite Barracuda at AirVenture 2018. According to the company, the design was developed from the Lancair Legacy. Based on installation of the standard 210-HP Lycoming IO-390 engine, the aircraft typically has a maximum cruise speed of over 200 MPH (174 KTS) and an estimated fuel consumption between 10 and 12 gallons per hour. Useful load generally ranges from 750 to 825 pounds and usable fuel from 65 to 75 gallons depending on options selected by the builder.

Available options for the aircraft include the 310-HP Continental IO-550-N engine, electronic fuel injection and ignition, air conditioning and full de-ice protection. Cost for the Barracuda starts at about $175,000 for a complete kit, which includes the airframe, engine, propeller and avionics (typically the Garmin G3X Touch and GTN-750). Lancair's basic two-week Builder Assistance program comes free with the kit purchase.

Video: Vashon Ranger LSA Update
Russ Niles

Last year Vashon Aircraft set out to revolutionize the Light Sport market with an under-$100K, all-metal, Continental-powered glass cockpit-equipped airplane that was both easy and fun to fly. To see how that's been working, AVweb's Russ Niles caught up with company founder John Torode at Sun 'n Fun 2019 in Lakeland, Florida.

D-Day Squadron Finalizes Plans
Russ Niles

Possibly the largest flotilla of C-47s and other DC-3 variants since the Second World War will cross the Atlantic in late May to take part in a reenactment of the first stage of the D-Day invasion. A total of 18 “Daks” will follow the historic Blue Spruce Route through Canada, Greenland, Iceland and Scotland for the 75th anniversary of the most pivotal battle of the war. The 18 U.S.-based aircraft will be joined by 17 European aircraft for the flypast, which will include parachute jumps by reenactors using round canopies. Many of the aircraft took part in the original raid, including That’s All Brother, the plane that led the assault and was the first one over the beaches. The aircraft, which flew at Sun ’n Fun, was rescued from a scrap heap and refurbished by the Commemorative Air Force over the past three years.

There will be plenty of opportunity for the public to get close to the historic aircraft, which have led varied and sometimes colorful lives since they were built more than 70 years ago. The U.S. contingent will gather in Oxford, Connecticut, May 13-17 for final preparations, which will include a formation flight around the Statue of Liberty. May 18 the plan, subject to the fickle North Atlantic weather, is to head to Goose Bay in Newfoundland and Labrador, using the original airfield that was the main North American staging base for Europe-bound aircraft during the war. Some will go to Greenland while longer-range models will go to Iceland the next day before heading to Prestwick, Scotland, and finally Duxford, England, where the D-Day event is being staged. After Normandy, many of the aircraft will take part in anniversary events marking the Berlin Airlift, and other European side trips are planned. It’s expected most of the DC-3s will be back in the U.S. in time for AirVenture 2019 in Oshkosh.

Podcast: High School Flying Club Starts Aircraft And Engine Builds
Kate O'Connor

The high school students at the Lakeland Aero Club started several new projects at Sun ‘n Fun this year. Club President Mike Zidziunas talked with AVweb about the club’s history and the students’ work on aircraft and engine building, restoration and repairs.

New Course, Instructor At King Schools
Kate O'Connor

John and Martha King announced the launch of a completely redone version of the King Schools online instrument rating test prep course at Sun ‘n Fun 2019. According to the Kings, the newest version of the course adds “extensive discussions of risk management interwoven throughout the course in accordance with the new Instrument Rating Airmen Certification Standards (ACS).” In addition, the course contains more material on GPS procedures and use.

“The new video lessons benefit from King Schools’ 45 years of developing techniques to help pilots deeply understand aviation concepts, along with ways to absorb and recall facts when rote memorization is required,” said King Schools CEO Barry Knuttila. “As we do with all our test prep courses, we guarantee that our customers will pass their exams and that their online courses will always be up to date.”

The Kings also announced that Knuttila will be adding on-camera instructing in King Schools’ online video courses to his role with the company. Knuttila holds an ATP certificate with a Falcon 10 type rating and flight and ground instructor certificates with “all available airplane ratings.”

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