Category: Uncategorized

George W. Bush graduated from Yale in 1968 with a C+ average (source: CBS News). How might he have done today?

The July/August 2013 Yale Alumni Magazine points out that “Sixty-two percent of all grades awarded by Yale College in the spring of 2012 were As or A-minuses. Comparing that with 50 years ago, when only ten percent were in the A range, some faculty believe Yale has a grade-inflation problem.”

Perhaps Yale students today are simply better prepared due to the increased competitiveness of getting into an elite school (larger and more mobile world population; women now eligible for admission; roughly same number of slots). Or maybe Yale students spend more time studying than did their counterparts in the 1960s, contrary to the conclusions reached by Babcock and Marks in http://www.nber.org/papers/w15954.pdf (“Using multiple datasets from different time periods, we document declines in academic time investment by full-time college students in the United States between 1961 and 2003. Full-time students allocated 40 hours per week toward class and studying in 1961, whereas by 2003 they were investing about 27 hours per week. Declines were extremely broad-based, and are not easily accounted for by framing effects, work or major choices, or compositional changes in students or schools. We conclude that there have been substantial changes over time in the quantity or manner of human capital production on college campuses.”)

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Consumer Reports has rated the Tesla sedan the best car that they’ve ever tested (list). Tesla has a market capitalization of about $14 billion (July 22, 2013). According to Wikipedia, Tesla seems to have required about $1 billion in debt and equity funding.

The GM/Chrysler bailout required roughly $85 billion in taxpayer funds (Wikipedia). Instead of preserving these relics we could have instead have had nearly 85 startup automobile manufacturers on the same scale as Tesla. Wouldn’t that have been a lot more interesting and more likely to push forward the automotive state of the art?

Let’s consider the suspension. GM and Chrysler sell vehicles with springs and shock absorbers, more or less the same system that carried Henri Fournier to victory in the 1901 Paris-to-Berlin race in an automobile made by Mors (source). What would nimbler upstart car vendors, forced to compete with each other and unable to tap into the federal river of cash, be likely to do with suspension? One hint is provided by Levant Power. They make an active shock absorber that can push against the spring if necessary to preserve vehicle composure. The shock can also generate electricity from the pounding action of the road on the wheels. See this video for a demonstration of ride over bumps (the company says that more videos are coming soon). I’m not sure how much funding went into Levant, but I am betting that it was less than $85 billion and they are the only company that seems to be doing anything practical to address my main complaint with my 6-year-old sedan (review). Note that Bose has a Web page devoted to its 33-year-old effort to build active suspensions but for whatever reason (maybe because they don’t have to compete too hard!) car makers never bought it (and it does seem a lot more complex than Levant’s idea).

Whenever a company or a government finishes spending a ridiculous amount of money on something the PR folks say “Look at this great thing you got for your money!” Somehow hardly anyone ever asks “What could we have gotten if we’d spent the money on something else instead?”

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If you want to feel better and stop complaining about your own life, Frozen in Time: An Epic Story of Survival and a Modern Quest for Lost Heroes of World War II is a great book to read. The story concerns a crazy American who bankrupts himself, the author, and the U.S. taxpayer in an attempt to dig a Coast Guard airplane (Grumman Duck) out of a glacier in Greenland. The plane crashed during World War II while rescuing the crew of a B-17 bomber. They in turn had crashed while trying to rescue the crew of a military version of the DC-3 cargo plane.

As someone who has flown piston-powered aircraft in the Arctic (e.g., from Boston to the Arctic Ocean at Kugluktuk in a Cirrus SR-20 and then south to Alaska!) I found the descriptions of similar activities during World War II fascinating. These guys took crazy risks due to their inferior-by-modern-standards navigation equipment and avionics.

If you’re suffering from the maladies of modern life, e.g., being stuck in traffic while commuting and/or handing over 50 percent of your wages to local, state, and federal governments, this book will show you how much worse things could be. The lucky guys in this book were stuck on the ice for months; the unlucky ones died.

The U.S. Air Force comes out looking good in this account. They truly spared no expense and effort in supporting these guys on the ice, e.g., with B-17 flights and supply drops every day with flyable weather.

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I just finished listening to No Easy Day: The Firsthand Account of the Mission That Killed Osama Bin Laden as an audiobook. For those curious about the Osama bin Laden raid about one quarter of the book will be interesting and the rest may be skimmed. The author, Matt Bissonnette (the pseudonym “Mark Owen” appears on the cover), was a passenger on the Blackhawk that crashed in bin Laden’s front yard. The crash has been previously attributed to vortex ring state (see previous post) and Bissonnette’s account seems to confirm this. He describes the helicopter as rocking and then yawing sharply to the right, as though suffering from loss of tail rotor effectiveness (Wikipedia).

Much of the rest of the book concerns Navy SEAL training and missions in Iraq and Afghanistan. As a American citizen you’ll be simultaneously awed that some of us are willing to endure so much physical discomfort and risk and dismayed that so many tax dollars are spent to fight against a handful of barely literate guys with a few hundred dollars worth of Chinese-made weapons. Owen describes how SEAL tactics have evolved from “flying to the X” (dropping in on a house by fast-roping down from a helicopter) to “patrolling to the X” (landing a few miles away and walking quietly in the dark). Much of the tactical advantage of the SEALs seems to come from their use of infrared lasers and night-vision googles. They light up the house with a bunch of bright IR beams, quietly enter, and shoot people in their beds. When they are lucky, people in adjacent bedrooms don’t even wake up from the sound of the silenced rifles that the SEALs typically use. What is difficult to understand why a market has not developed for an automated system that uses a CMOS sensor and a bit of software to sound an alarm when swept by an IR laser. One would think that Afghans and Iraqis would be willing to pay a reasonable price for a machine that they could place in a window and that would wake them up when U.S. forces come to visit.

[Wikipedia says that the U.S. military was upset about the book’s publication on the grounds that it revealed secret SEAL tactics. To the extent that the guys we are constantly at war with did not previously appreciate the importance of infrared lasers I would have to agree with the Pentagon.]

Finally the book has a few stories from Bissonnette’s childhood in a remote Alaskan village.

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I haven’t been following the immigration “reform” debate too closely. But I know a lot of immigrants. One guy has been here for about 10 years. He spent his first two as an MBA student. He has split his time for the remaining 8 years working for Goldman Sachs and for a health care technology company. His two employers have probably paid close to $50,000 in legal fees to keep him on the green card track, but he has not yet received a green card and is thus nowhere close to citizenship. Let’s assume the government has paid public employees $25,000 to look at the paperwork that his employers have filed, scrutinize his paperwork every time he comes and goes, etc. “The quotas were set up in the 1960s,” he explained. “And Iceland would be given the same quota as India, despite the disparity in population. So the waiting time for a green card is much longer if you come from India or China compared to other countries.”

Right now we’re getting a great deal from having this guy here. He is paying staggering amounts of tax every year, much of it to support obligations incurred prior to his arrival, e.g., pensions for public employees who retired in the 1980s. He is paying into Medicare and Social Security but if we deport him before he reaches 65 he won’t be able to collect any benefits from these programs (which may, in any case, be restricted to folks with lower incomes than his by the time he reaches 65).

On the other hand, if he were a citizen he might add a bit to the property bubble that America’s successful cities are enjoying. “I have the money to buy a condo or house,” noted the immigrant, “but if I were to lose my job I would have to leave the country within 10 days. So I keep renting.” (probably he is happier as a result!) If he goes into the property market that might inflate the prices available to existing owners of residential property (but maybe not; his demand for rental should also work).

I’m wondering what happens if immigration reform goes through. My friend’s immigration should consume at least $100,000 in private and public paperwork and bureaucracy costs by the time he becomes a citizen. Supposedly if the laws are tweaked there will be 10 million new citizens. If each of these new citizens consumes the same $100,000 that’s $1 trillion that will be added to the officially calculated GDP.

[Whether or not this kind of paper-shuffling should be calculated separately from, say, maintenance of machine tools in factories and other more obviously productive activities, is a separate issue.]

Maybe this is the answer to Detroit’s woes. Everyone there can become an immigration lawyer or a federal government worker reading paperwork filed by immigration lawyers…

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Detroit has now filed for bankruptcy protection. The estimated cost of funding its pension obligations fully would be somewhere between $3.5 billion and $9.2 billion (Guardian article) though in fact the actual cost is not knowable (future interest rates and life expectancy for currently fairly young retirees being impossible to know for certain). The cost works out to an estimated maximum of $13,143 for every man, woman, and child currently living in Detroit. There are only about 225,000 people in Detroit who work (source) so the $9.2 billion estimate (from public employee unions) works out to about $41,000 per worker.

Unless you have a printing press for money and/or a direct connection to God who will tell you how long people are going to live and what return on investment can be expected 30 years from now, why would you promise to pay someone, e.g., $150,000 in today’s dollars starting 20 years from now and continuing until that person dies? Politicians seemingly cannot resist making these promises, however, so perhaps it is time to restrict their ability to do so. They are not, after all, actuarial experts. If insurance companies stuffed full of such experts are now having trouble meeting their annuity obligations (WSJ; nytimes) why would we expect politicians, motivated by a desire to get reelected, to do better?

Back in 2009 I wrote a review of a book covering the history of public employee unions and consequent pension commitments. Here we are four years later and one of America’s largest cities needs bankruptcy protection. Many of the rest (notably those whose populations are not growing) will follow into bankrtupcy if only their retirees can contrive to live a bit longer than expected and/or if interest rates remain low. Why would we want politicians to place those kinds of bets on our behalf?

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I was talking with a friend who is in her early 30s. She expressed ambivalence about having children. “I love my nieces when I go to visit them but it seems like a huge amount of work and I’m happy to turn them back over to their parents.”

I told her that it was a mistake to make decisions about having children based on observing other people take care of their own children and/or one’s own experience taking care of others’ children.

Speaking for myself, I spent about 25 adult years watching friends and relatives taking care of kids and periodically babysitting others’ children. (Typical babysitting experience: taking care of three children at my Cambridge apartment for three hours and needing to take a 10-minute business phone call during that time. The 7-year-old picked those 10 minutes to break away from her siblings, come into my home office, and say “I’m bored.”)

From the outside the life of a parent has many unappealing aspects. These people appear to have hardly any time to concentrate on reading a book, watching a movie, or engaging in an adult conversation with a friend.

But when I finally moved into the parent role myself the things that I would have expected to be bothersome were not. It doesn’t bother me to interrupt an adult dinner table conversation and cut up food for Greta, for example. Perhaps it is because I did a lot of traveling when younger but I don’t feel trapped because I can’t run off to New Zealand for two months. Generally I like to do things efficiently and quickly. This is simply impossible with a 3-year-old in tow. She is not interested in point-to-point walking time. She is interested in having her hand held while she balances on a curb or line of bricks. She wants to ask about the function of a metal strip that separates a brick sidewalk from mulch. She wants to know why there is a green railing alongside a wheelchair ramp in front of Harvard’s Sackler Museum. So a 10-minute walk to meet friends for dinner turns into a 25-minute exploration of the urban environment. If you’d asked me ten years ago “Would it get on your nerves to spend 25 minutes on a 10-minute walk?” I would have said “Absolutely.” But in fact I enjoy answering her questions and helping her explore.

This is not to say that parenthood is for everyone. My point is only that you can’t expect to learn much about how you’ll feel as a parent by watching other people, even close relatives, engage in parenting. Nor can you learn that much by taking care of others’ children.

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If you have a Canon Rebel or APS-C sensor Nikon body, check out DxOMark’s review of the Sigma 18-35/1.8 zoom lens. Nikon and Canon haven’t put too much effort into designing lenses for the bodies that they are actually selling, i.e., the small sensor bodies. Sigma now shows up with a 29-56mm equivalent lens with a constant f/1.8 aperture that outperforms prime (fixed focal length) lenses.

This is a surprising result to me because I’d always thought that a lens designed for the full 24x36mm frame would do an awesome job on an APS-C camera since the sensor is underneath the sharpest center portion of the image circle. Apparently a lens specifically designed for the job does a lot better, even when it has to zoom. (In retrospect this makes sense; in the film days we didn’t see a lot of folks using Zeiss and Schneider medium format lenses, designed to cover a 6x6cm frame, being used on 35mm film bodies.)

(Amazon sells the lens, but right now the only stocking retailers they show are in Japan.)

[Separate question: What is it about a lens that makes it suitable or unsuitable for use with contrast-detection autofocus, as opposed to the phase-detection autofocus that has been conventional on SLRs? A variety of lenses, including this one, are available only for conventional SLRs and not the APS-C-sized mirrorless systems, such as Sony NEX. A quick Web search reveals people asserting that it is because the lens design is not compatible with contrast-detecting autofocus, but I would think any f/1.8 lens would be a fine feed to a contrast evaluation system (shallow depth of field causes images to snap in and out of focus).]

 

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Based on preliminary reports, the Asiana 214 crash may end up being partially attributed to confusion regarding to what extent the autopilot was managing the airplane and what the human crew still had responsibility for (notably in the management of the thrust levers).

As flight instructors one thing that we stress, starting with the very first lesson, is a positive exchange of flight controls. This is particularly important in helicopters due to their lack of stability. There shouldn’t be any confusion about who is responsible for the aircraft attitude.

Here’s how it works with humans:

1. instructor or pilot1: you have the controls
2. student or pilot2: I have the controls (puts hands on yoke, stick, or cyclic)
3. instructor or pilot1: you have the controls (after seeing student’s hands on controls, removes his or her hands)

When sharing responsibility, here’s an example exchange:

1. instructor or pilot1: you have the pedals and collective
2. student or pilot2: I have the pedals and collective
3. instructor or pilot1: you have the pedals and collective; I have the cyclic

When an autopilot trips off due to a failure of some kind or simply due to disconnection via a switch there is typically a fairly loud alarm that the pilot(s) would have a hard time missing. But when changing modes there is nothing like the positive control exchange described above. The autopilot may switch from flying a heading, for example, to tracking a course over the ground and the only indication is some text changing at the top of the “primary flight display” (PFD). A pilot whose attention is focused on some other task may very likely miss the change.

The popular conception of the autopilot is that it does everything or it does nothing. Push the autopilot button and the airplane will land itself at the destination. Disconnect the autopilot and you’re hand-flying like a 1920s barnstormer. In fact the autopilot has a dozen or more modes, even on a simple four-seat airplane. The autopilot could be set, for example, in any of the following ways:

• hold altitude, letting speed and heading vary (the autopilot will adjust pitch (airspeed) to hold altitude, regardless of throttle setting, and the result may be slowing down all the way to an aerodynamic stall)
• descend at 500 feet-per-minute, letting speed be determined by the pilot’s throttle setting, until the airplane hits the ground (or the autopilot is given new instructions)
• climb at 200 knots until the airplane reaches 31,000′ (climb rate will be determined by the throttle/thrust setting)
• track a multi-leg course over the ground that has been programmed into the GPS, getting the aircraft almost all the way to the destination
• track a radial off a VOR (radio beacon on the ground) until the pilot changes the VOR frequency in the navigation radio
• keep the wings level and don’t worry if the heading drifts
• keep the pitch constant and don’t worry if the altitude drifts
• track the localizer (left-right) beam of the ILS but hold present altitude; do not descend to follow the glide slope
• track both localizer and glide slope of an ILS down to the ground (or until disconnection), letting the airspeed be determined by the pilot adjusting the throttle
• track both localizer and glide slope of an ILS but adjust the thrust levers (“autothrottle”) to hold a set-by-the-pilot airspeed

Managing the autopilot is actually more complex than hand-flying the airplane (there are only three mid-air controls (elevator, aileron, and throttle) and each control can be moved in just two directions, giving a total of six possible choices for control inputs at any time).

The little lights and indications that distinguish one autopilot mode from another are subtle. Of course, as pilots it is our job to pay attention to subtle lights and indications, but in practice humans have demonstrated inconsistency at this task. Is it prudent to assume that somehow human pilots are going to get better at something that they’ve never done well in the past?

Considered as a human applicant for an FAA certificate, the autopilot would fail every checkride due to a failure to participate in a positive exchange of flight controls. Here’s the relevant passage from the FAA Practical Test Standards for a Private certificate (the very first step on the path to the left seat of a B777):

During flight training, there must always be a clear understanding between students and flight instructors of who has control of the aircraft. Prior to flight, a briefing should be conducted that includes the procedure for the exchange of flight controls. A positive three-step process in the exchange of flight controls between pilots is a proven procedure and one that is strongly recommended.

When the instructor wishes the student to take control of the aircraft, he or she will say, “You have the flight controls.” The student acknowledges immediately by saying, “I have the flight controls.” The flight instructor again says, “You have the flight controls.” When control is returned to the instructor, follow the same procedure. A visual check is recommended to verify that the exchange has occurred. There should never be any doubt as to who is flying the aircraft.

[A similar passage is contained within the Airline Transport Pilot PTS, but it says “between the pilots” instead of “between students and flight instructors”.]

Potentially a significant improvement in safety could be obtained for $100,000 in engineering cost (and another $100 million in FAA regulatory paperwork, if going to be installed in a transport jet!). The autopilot would feed voice announcements into the pilots’ audio panel and these announcements would occur after every change of mode and also upon big changes in aircraft speed, attitude, heading, or vertical speed. Here are some examples:

• Upon leveling off at a preset altitude: “I have leveled off at sixteen thousand feet. I am tracking a GPS course. You have the throttle.”
• Upon switching legs: “I have switched legs to fly to the Carmel VOR. I have the throttles and am holding present altitude and airspeed.”
• Upon intercepting a glide slope: “We have intercepted the glide slope. I am descending to follow it and track the localizer as well. You have the throttles and airspeed.”
• After a big thrust lever chop: “We are in flight level change mode, planning to level off at FL240 [about 24,000′ above sea level]. I am holding 300 knots. Vertical speed has increased to 4000 feet per minute. You have the throttles.”

Thoughts from fellow pilots and human factors folks?

[Separately, it is worth noting that the autopilot is over 100 years old. See Wikipedia for Lawrence Sperry’s early success with this technology.]

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I’m going to close my Asiana 214-inspired series on the real world of airline flying and visual approaches with one more story from my Comair days.

Generally my life at Comair was antiheroic. For example, we were stuck at the gate in Cincinnati because we had just three seat belt extenders on board and five morbidly obese passengers (out of 50 total seats) who required belt extensions. As this was our home base I called Maintenance on the radio and they drove out in a little truck to deliver the items required to meet federal regulations. Pulling in towards our parking spot at JFK, the captain said to the relaxed ramp workers, without keying the microphone, “Now put down the crack pipe and pick up the wands.” The airline’s fee-for-every-bag policy combined with the design characteristics of the CRJ meant that we were often not legal to fly with the small number of checked bags in the baggage compartment. The only way to restore weight-and-balance was to put sand bags back there but at JFK they would always run out and we’d be delayed while the ramp workers prepared new ones.

On my last day based at CVG I was done at around noon, having flown a simple out-and-back. This was ideal because I needed to drive my car and all of my stuff to New York City, to take up a new base at JFK starting the following day. A woman whom I’d been seeing had flown out as a “non-rev” passenger to join me for the trip.

Scheduling called me to say “We need to you fly one more trip today. It is just out and back to Grand Rapids, Michigan and it leaves in 20 minutes.” For the captain, however, this was to be the start of a three-leg day. He would end up in a Hilton Garden Inn somewhere in the Midwest, rather than comfortably at home with the wife and kids. Captains at Comair were wily 20-year union veterans with bitter memories of the spring 2001 strike that shut down the airline, happy memories of the fat pay deal that followed, and raging anger against heartless corporate owner Delta Airlines whose 2003 bankruptcy resulted in some scaling back of their pay (see “Unions and Airlines”). As far as the senior pilots at the airline were concerned, Delta had filed Chapter 11 purely in order to piss them off. They would take it out on the company in a variety of ways. One captain refused to allow me to use thrust reversers after landing. He wanted to burn up the company’s brake pads (no doubt rather costly parts on a $28 million airplane!). Even when we landed on a wet runway following a thunderstorm I was forbidden to use reverse thrust (the brakes worked fine, thanks to the fact that nearly all American runways are grooved, which prevents hydroplaning).

My captain for the trip to Grand Rapids wasn’t angry but he didn’t want to spend the night in a crummy hotel either. After I finished preflighting the airplane I discovered the captain talking with our flight attendant, an equable woman in her mid-50s. She had related that a friend’s husband had died recently and she was sad about it. The captain declared that she was obviously too upset to work the short trip that we had planned and instructed her to go home. Scheduling, the natural enemy of all pilots, then had to come up with another flight attendant. Flight attendant salaries are low but health insurance costs are so high in the U.S. that airlines tend to run slightly understaffed. They don’t have a room full of spare people waiting to step in. So it took about six hours for a replacement flight attendant to arrive, fresh off a plane from JFK. The captain had correctly figured that by the time a new flight attendant was found, the CVG-GRR-CVG trip would be delayed so long that he wouldn’t be legally able to fly the third leg.

Though I was anxious to begin the 11-hour drive to New York City there was nothing that I could do but wait. One of the ways that I killed time was to have a long dinner in the terminal with my female companion. Finally, however, it was time to go. I left her in the terminal and go into the plane to GRR.

By the time we got to Michigan it was pitch black outside. The airport was in the throes of a major construction project. The first 2000′ of the runway to which we were assigned was closed. The instrument landing system (electronic glide slope) and the PAPI (red/white lights that provide visual glide slope information) were shut down because they guide pilots to touch down roughly 1000′ down the runway, i.e., on a closed portion. So I had no electronic glide slope (just like the Asiana 214 pilots) and no visual glide slope (Asiana 214 had an operating PAPI prior to the accident; the wreck of the airplane destroyed the lights) and nothing to see out the window except the lights along the edges of the runway.

Making matters worse was the fact that I was sitting in the right seat of the airplane and, given the direction that we were flying in from, we’d been assigned to fly a traffic pattern involving left turns. I would have to look across the Captain and out the window to see the runway at all. This is challenging because, to save electricity, the runway lights are designed for best visibility when one is looking from a position that is aligned with the runway. It is also challenging because a Canadair Regional Jet is crammed full of switches and dials. The windows don’t provide nearly the angles of view that the windows of a light airplane or helicopter do. Heavy jets are designed to be flown by reference to instruments so the instruments are more prominent than the visual world.

If there are no red and white PAPI lights and no green needles in the airplane to indicate “too high” or “too low” how is it possible to land at all? The outline of the runway lights is critical. If the runway looks like a rectangle with 90-degree corners you’re flying right over top of it. If the runway looks like a little squashed trapezoid you’re probably grazing the treetops a couple of miles back. Somewhere in between these two sight pictures is what it should look like when on a 3-degree glide path. Unless one is completely familiar with the airport it is generally best to treat night landings as instrument landings and rely more on the PAPI and ILS than on one’s perceptions. But there was no PAPI, no ILS, and I’d never been to Grand Rapids before. It wouldn’t have been legal or practical to use the autopilot for the important parts of the approach.

Nobody was more surprised than I when the airplane touched down in the first third of the runway, the automatic ground spoilers popped up, and we turned off about two-thirds of the way down the runway and the captain took over for the taxi to the terminal (there is only one “tiller” on the airplane for making tight turns on the ground and it is on the captain’s side).

I was headed into the terminal to pick up our dispatch release (weather, flight plan, recommended fuel load, etc.) for the next flight, my mind fully occupied in congratulating myself on a job well done and reflecting on how lucky everyone was to be alive after an 80-hour jet pilot had done a visual approach at night to the kind of runway (flat pavement with edge lights) that normally only a local pilot in a Cessna 172 would use. My reverie was interrupted when a passenger pointed at me and started shouting to the gate agent and all the exhausted travelers getting off our plane and those who’d been waiting in the GRR terminal for six hours. “That’s the pilot who made our flight late. He wanted to have dinner with his girlfriend so we had to wait in Cincinnati for hours. I saw him in the restaurant and he wasn’t even hurrying.”

Related:

• My visual approach, and Asiana’s
• Asiana 214: Training with passengers in the back?
• Asiana crash thought: Positive exchange of flight controls between autopilot and human crew

 

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