Optional Angle-of-Attack Sensors on the Boeing 737 MAX

“Doomed Boeing Jets Lacked 2 Safety Features That Company Sold Only as Extras” (nytimes):

Boeing’s optional safety features, in part, could have helped the pilots detect any erroneous readings. One of the optional upgrades, the angle of attack indicator, displays the readings of the two [angle of attack] sensors. The other, called a disagree light, is activated if those sensors are at odds with one another.

Boeing declined to disclose the full menu of safety features it offers as options on the 737 Max, or how much they cost.

When it was rolled out, MCAS took readings from only one sensor on any given flight, leaving the system vulnerable to a single point of failure. One theory in the Lion Air crash is that MCAS was receiving faulty data from one of the sensors, prompting an unrecoverable nose dive.

As I noted in a previous posting, the Pilatus PC-12, a much cheaper and simpler airplane (1 engine and 9 passenger seats), doesn’t do any nose-down pushing unless two separate angle-of-attack sensors, and their respective computers, agree. Boeing’s ideas of

  • a system that works silently (so pilots don’t realize it is operating)
  • a system that works if just one sensor suggests a high angle of attack
  • a system that has the authority to drive the airplane into a full nose-down trim situation
  • a Band-Aid on the above in the form of a “disagree” warning light

are all terrible ones, as far as I can tell, and unconventional within the industry.

Does that mean we need much more stringent oversight by regulators? (as noted in this other previous posting, the “regulators” in the case of the above system were mostly Boeing employees) Maybe.

The prices of these optional items that would have made Boeing’s unsafe design a little less unsafe were too shocking for Boeing to admit or the NY Times to publish. But reasonably high-quality systems for homebuilt 2-seat and 4-seat airplanes are less than $2,000, including both the sensor and indicator. Examples:

So it is tough to know whether regulation should have been relaxed so that Boeing’s costs of putting reasonably modern avionics into the airplane were reduced or toughened so that the crazy bad ideas were squashed. (Or, as my previous posting suggests, shifted so that an independent private engineering service would do the steps that Boeing’s employees were doing while nominally wearing FAA hats.)

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Other than Elizabeth Warren, who would be eligible for reparations?

“2020 Democrats Embrace Race-Conscious Policies, Including Reparations” (nytimes):

Last week, on the popular radio show “The Breakfast Club,” Senator Kamala Harris of California agreed with a host’s suggestion that government reparations for black Americans were necessary to address the legacies of slavery and discrimination.

Ms. Warren also said she supported reparations for black Americans impacted by slavery — a policy that experts say could cost several trillion dollars,

The U.S. has no authoritative genealogy service. If the government is handing out $trillions and eligibility is based on being a descendant of a slave, how will people be sorted into “gets paid” and “does not get paid” buckets?

America’s greatest intellectuals don’t seem to have come up with any practical ideas in this area. See “The Case for Reparations” (Atlantic) by Ta-Nehisi Coates, for example. There is nothing about what to do when Elizabeth Warren shows up with a family legend about an enslaved black ancestor and asks for her check.

More than 40 years ago, the Malone brothers availed themselves of jobs reserved for Americans identifying as “black”. See “Boston Case Raises Questions on Misuse of Affirmative Action” (nytimes):

Philip and Paul Malone are fair-haired, fair-complexioned identical twins who worked for the Boston Fire Department for 10 years. Last month both were dismissed when a state agency ruled that they had lied on their job applications: They had contended they were black.

In 1975, the Malone twins, now 33 years old, took the Civil Service test for firefighters and failed. But in 1976, according to their lawyer, Nicholas Foundas, their mother found a sepia-tinted photograph of their great-grandmother, who, she told them, was black. In 1977, they reapplied to take the test, contending they were black.

Philip Malone scored 69 percent and Paul Malone 57 percent, below the 82 percent standard minimum for white applicants, according to the Massachusetts Department of Personnel Administration, which monitors Civil Service tests and hiring.

The twins won appointments in 1978. They were questioned about their race last February, when their names appeared on a list of black firefighters applying for promotion, said Capt. Matthew J. Corbett, a spokesman for the Fire Department. ‘They’re Devastated’

The system under which the Malone brothers prospered for 10 years was a lot simpler than what Kamala Harris and other politicians are proposing. The Boston Fire Department was allocating jobs based on skin color, which can be observed and measured today, not ancestry, for which there is no official source.

Readers: How would it work? If people are lining up for their $trillions and all say that they are descended from slaves, who will decide whether to write a check or not?

Also, how do we decide who pays the reparations? It can’t come out of general tax revenues, can it? Why should an asylum-seeker who arrived via caravan in 2018 have to pay reparations for something that happened 200+ years prior to the caravan’s arrival? How about Native Americans? Should Sachem Elizabeth Warren have to pay for what white people did to black people?


  • “Cure for Racial Dishonesty” by Walter E. Williams: “We can learn from South Africa. During its apartheid era, it, too, had a racial spoils system. The government combated racial fakery by enacting the Population Registration Act of 1950, which racially classified the country’s entire population.”
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College bribery scandal is evidence of social mobility?

Frequent U.S. media theme: social mobility in the U.S. is low. If your parents aren’t rich and/or famous, you’re never going to get anywhere (unless you vote for Elizabeth Warren and AOC so that they can grab what is rightfully yours!). If, on the other hand, your parents were rich, you can coast into an elite adult slot. (Exhibit A: Donald Trump!)

Recent U.S. media theme: rich and famous people bribing college officials to get their children into selective universities.

Apparent contradiction: If social mobility is, in fact, low, why are rich and famous people bothering to bribe college officials?


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The aviator with songs stuck in his head

Participants at a local gathering of pilots were required to tell a joke. Here’s what I said…

I don’t want to tell a joke because so many people in this world are suffering with serious problems, like [FAA non-essential air traffic control employee, previous speaker] who talked about his personal struggles in Arizona and Europe during the paid 35-day shutdown.

I’m teaching computer programming this month at Harvard Medical School. One of the residents talked about a recent case that he observed.

A pilot came into the hospital and said “When I’m on final at 6B6 I can’t get the song ‘The green green grass of home’ out of my head. If I see a Grumman Cheetah on the tie-downs then it’s ‘What’s new, pussy cat?’. It’s distracting me from my approaches and preflights.

The attending physician said, “I’m pretty sure that you’re in the early stages of Tom Jones syndrome. Unfortunately, 72.3 percent of the time the disease is progressive and incurable.”

“72.3 percent?!? How have you seen enough cases to give a precise number like that? I’ve never heard of Tom Jones syndrome so I assume it is quite rare.”

The doctor thought for a moment. “Well, it’s not unusual.”

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Could the Boeing 737 MAX be flown safely with a robot dome light third pilot?

Unfortunately, we now know that a two-pilot crew cannot safely handle the silent gradual pusher system of the Boeing 737 MAX.

“Pilot Who Hitched a Ride Saved Lion Air 737 Day Before Deadly Crash” (Bloomberg) says that a three-pilot crew was able to handle the design deficiencies in Boeing’s silent gradual pusher system. (The third pilot was in one of the comfy jump seats; I enjoyed a ride once in a B757 jump seat and it is remarkably luxurious.)

One of the ideas that I’ve been in love with for years is a robot copilot up in the dome light that can see everything the pilots see and, without anyone having to certify modifications to the legacy systems, help out with suggestions in the intercom. In the case of the 737 MAX, for example, the dome light copilot could notice when the runaway-trim-by-design system is operating and suggest “hit the trim interrupt switches!”

(Alternatively, of course, the Boeings could be returned to service with the requirement that they be flown by three pilots in the cockpit at all times, like a World War II bomber or Boeing 727. (In the not-so-good old days, a heavy airplane would have two pilots to manage the flight controls, a flight engineer (i.e., a third pilot) to manage the systems, and a navigator to watch the position over relative to the ground.))


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New York Times highlights academic achievement-skin color correlation

“Only 7 Black Students Got Into N.Y.’s Most Selective High School, Out of 895 Spots” (nytimes):

Students gain entry into the specialized schools by acing a single high-stakes exam that tests their mastery of math and English. Some students spend months or even years preparing for the exam. Stuyvesant, the most selective of the schools, has the highest cutoff score for admission, and now has the lowest percentage of black and Hispanic students of any of New York City’s roughly 600 public high schools.

My comment on the piece:

What if you heard about a reporter and some editors who hung around outside an academic testing center and noted the skin color of every person who failed a test? And then published the observation that people with a particular skin color were very likely to fail?

If that isn’t racist, what would be?

Readers: What does this story even mean? If Elizabeth Warren had gotten into Stuyvesant, would the NYT have included her in their Native American participation statistics? Who is the arbiter of race or skin color in the NYC public schools? Also, how does it help a group of people when there is a front page story underlining for employers the correlation between membership in this group and low academic achievement?

Thought Experiment: Suppose that Fox News had run a story revealing the same statistics and then Donald Trump had referenced that story in a Tweet. What would the NYT Editorial Board have said?


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Robot kamikaze submarines shaped like blue whales render navy ships useless?

One lesson from World War II at Sea: A Global History by Craig Symonds is that a huge expensive ship might be destroyed in a few minutes by a submarine or airplane:

Displacing 71,890 tons when fully loaded, the Shinano was the largest aircraft carrier ever built, a distinction she retained until 1961 when the U.S. Navy commissioned the nuclear-powered Enterprise. … Abe dutifully took the Shinano out of Tokyo harbor one hour after sunset on November 28[, 1944] with a four-destroyer escort. Two and a half hours later, the [U.S. submarine] Archerfish picked her up on radar.

At 3:00 a.m. on November 29, Abe ordered the Shinano and her escorts to turn west, toward the coast. It was the opportunity Enright had been waiting for, and at 3:17 he fired six torpedoes. For an attack on a carrier torpedoes would ordinarily be set to run at a depth of twenty-five to thirty feet, but Enright thought if he hit the big carrier higher up on her hull, it could make her top-heavy and more likely to capsize. He ordered the torpedoes set to run at only ten feet. That decision doomed the Shinano, because the torpedoes struck just above her armored blisters. As the Archerfish submerged, Enright thought he heard six explosions, though in fact only four of his torpedoes hit. It was enough. Tons of seawater rushed into the Shinano’s hull, and almost at once she took on a fifteen-degree list to starboard. With many of the watertight doors not yet installed, the flooding spread quickly. The ship’s list increased to twenty-five degrees, then thirty. Too late, Abe steered for the coast, hoping to run the Shinano aground in shallow water, where she might be recovered and repaired. He didn’t make it, and the Shinano sank just past ten-thirty the next morning. She had been in commission only ten days, and at sea for only sixteen and a half hours.

We have lost some expensive warships to submarines, e.g., the USS Wasp aircraft carrier and the USS Indianapolis cruiser.

After nearly 75 years since we last faced a serious naval adversary, the U.S. has spent $trillions building up and running a Navy full of large and costly warships. These do seem to intimidate Somali pirates (though not so much that they abandon their career?), but might they be vulnerable to an enemy spending only 1/100th of our budget?

What if an enemy were to built a fleet of robot kamikaze submarines? They’d pick up power from the sun when near the surface, be clad in rubber to have a SONAR signature like a whale’s, and have the same size and shape as a whale.

Our advanced systems would pick up these fake whales due to their spinning propellers? It is possible to build a machine that swims like a fish: RoboTuna. Would that make it tougher for SONAR systems to distinguish between an electric fish and a real fish?

Readers: Does it make sense to spend $billions on these Navy ships that could be attacked by robots?

World War II at Sea: A Global History on a guy who was able to predict the future fairly successfully:

Yamamoto was an outlier in other ways. He had spent two tours in the United States and had been profoundly impressed by its industrial strength, reflected by Henry Ford’s automobile assembly plant in Detroit, and the fecundity of the Texas oil fields. War against such an opponent, he concluded, was foolish. Fleet Faction admirals such as Katō did not entirely discount America’s material and economic superiority, but they insisted that the spirit of yamato-damashii could overcome mere wealth and numbers. Like Confederates after Fort Sumter who boasted that one Reb could lick five Yanks, they valued a martial culture over material superiority.

Another area in which Yamamoto defied the reigning philosophy of the Fleet Faction was his skepticism about the preeminence of battleships.

Like every other Japanese naval officer of his generation, Yamamoto had read Mahan’s book at Etajima, and he had initially embraced its tenets. By 1930, however, his natural skepticism led him to reconsider. Prior to his participation in the conference at London, he had been captain of the large aircraft carrier Akagi, and afterward he commanded the First Carrier Division, composed of the smaller carriers Ryūjō and Hōshō. Based in part on that experience, he became convinced that aircraft were poised to make battleships secondary, if not quite irrelevant. In 1934, he told a class of air cadets that battleships were like the expensive artwork that wealthy Japanese families put on display in their living rooms to impress visitors: beautiful, perhaps, but of no practical utility.


  • “China’s Navy Could Soon Have a New Weapon to Kill Navy Submarines” (National Interest, August 2018)
  • “Pentagon To Retire USS Truman Early, Shrinking Carrier Fleet To 10” (Breaking Defense): “Amidst rising anxiety over whether the US Navy’s thousand-foot-long flagships could evade Chinese missiles in a future war, the Pentagon has decided to cut the aircraft carrier fleet from 11 today to 10. By retiring the Nimitz-class supercarrier USS Truman at least two decades early, rather than refueling its nuclear reactor core in 2024 as planned, the military would save tens of billions on overhaul and operations costs that it could invest in other priorities.” (the ship cost $4.5 billion when launched in 1996 (took two more years to commission))
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Fly upside down in a helicopter

“Chuck Aaron opens helicopter aerobatics flight school” (Vertical) is interesting news! The school is just NE of Charlotte, North Carolina. Perfect spring time activity!

(Separately, East Coast Aero Club is currently looking to hire a helicopter instructor. We don’t do aerobatics in the Robinson R44s, however. Email me if interested in the job.)


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Immigration is the Reverse Black Death?

Let’s consider the political goals of righteous Americans today:

  • higher wages for the average person
  • an improved environment with less human impact on the land
  • less concentration of wealth in the hands of real property owners
  • more affordable housing for the working class

While listening to An Economic History of the World since 1400 by Professor Donald J. Harreld, I learned that all of the above goals were achieved in the 14th century via the Black Death, which reduced the European population by approximately one third.

  • wages for workers, including unskilled agricultural workers, increased as much as 40-50 percent
  • food prices fell
  • land and housing prices fell
  • the least productive farmland was allowed to return to natural forest (contrast to conditions before, from the course notes: “By about 1300, Europeans had just about all arable land under cultivation, including marginal and poorly producing lands, to sustain the growing population”)

Is it fair to think of immigration as the reverse of the Black Death? We’re dramatically growing our population via immigrants and children of immigrants (see “Modern Immigration Wave Brings 59 Million to U.S., Driving Population Growth and Change Through 2065” (Pew)).

What seems surprising, then, is that the people who say that they want to see all of the economic results of the Black Death simultaneously say that they want to adjust U.S. demographics in precisely the opposite direction of the Black Death.

Is the apparent inconsistency resolved because only about 2 percent of U.S. workers are directly employed in agriculture?

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Certification process for the 737 MAX silent gradual pusher system

A reader was kind enough to send me “Flawed analysis, failed oversight: How Boeing and FAA certified the suspect 737 MAX flight control system” (Seattle Times), which gives some more detail on how the world’s first “silent gradual pusher” system was unleashed on airline passengers and crew. (See https://philip.greenspun.com/blog/2018/11/11/boeing-737-crash-is-first-mass-killing-by-software/ for my description of how the conventional stick pusher works; it requires two sensors to agree before it will activate and the pushing is readily apparent to the pilots; disabling the pusher in a simple turboprop aircraft is as simple as pushing a button on the yoke).

The Seattle Times article describes the delegation process by which an employee of Boeing can actually do a lot of the work that members of the public imagine FAA employees would be doing. Boeing is an “Organization Designation Authorization” holder (“ODA”). A Boeing employee puts on an FAA hat periodically and checks work done by fellow Boeing employees.

Putting government workers in the critical path for engineering improvements slows things down so much that safety ends up being compromised. And having people pay designated or delegated authorities cuts the cost to taxpayers. But I wonder if it is time to say that certification scrutiny should be done by an independent private engineering team, not by engineers employed by the manufacturer.

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