April 09, 2011

Mr. Honey, the Reindeer, and the Ethics of Fatigue



What advice might you give to help a person know how to proceed? Here's an attempt:
Therefore, go forth, companion: when you find
No highway more, no track, all being blind,
The way to go shall glimmer in the mind.


"The Wanderer" by John Masefield




This post tells its story in media res — the first scene is in the vivid recent moment, then the storytelling goes back in time to the beginning, and time proceeds through the opening moment and continues to the denouement. But if you'd rather watch a movie, I recommend that you watch No Highway In the Sky.

Recent and Vivid: Southwest Flight 812



From the Associated Press:
On April 1 2011, a Southwest Boeing 737 with 118 people on board rapidly lost cabin pressure after the plane's fuselage ruptured, causing a 5-foot tear. Passengers reached for oxygen masks as the pilots quickly descended before making an emergency landing at an Arizona military base.

While the incident is still being investigated, the jet had been pressurized and depressurized 39,000 times in its 15 years and metal fatigue is suspected. Cracks were subsequently found on five other Southwest jets with more than 30,000 cycles.

That came as a shock to the industry. Boeing engineers had forecast that the planes wouldn't need to be inspected for metal fatigue until at least 60,000 cycles.


From the Seattle Times, which follows Boeing closely:
...the in-flight rupture of a Southwest Airlines Boeing 737 on Friday has raised concerns about part of the fuselage they previously thought wasn't vulnerable.

"It's a much thicker skin there," said John Hart-Smith, a world-renowned expert on metal-aircraft structures and a retired high-level Boeing engineer. "Typically, that area has never been susceptible to cracking at the lap splices." The limited scope "is a blessing," Hart-Smith said. "But it's a warning."

Hans Weber said that maintenance procedures to check for fatigue were established after the Aloha Airlines event. "The whole community worked really hard after Aloha to get full control over this aging-aircraft problem," Weber said. "And until about last year, we basically had no more problems. This is not good. This is really a surprise."


I think Southwest's response has been admirable and consistent with their culture:
After last week's rupture, Southwest grounded 80 737s for immediate inspection, forcing the cancellation of hundreds of flights. Its inspectors found five more planes with signs of lap joint cracks; those remain grounded while the others returned to work.


From the Wall Street Journal:
Southwest Airlines' move to ground dozens of planes last Saturday, just hours after learning of possible structural problems, was an unusual move in the industry. Typically, airlines wait for regulatory direction and manufacturer recommendations before removing planes from service.

Faced with the question of whether to let dozens of 737 jets fly with potential structural problems unlike any faced by the industry in decades, Southwest grounded the planes, canceling more than 620 flights and delaying 2,700 others.

"I give Southwest's leadership credit for not waiting until someone was pounding on them," said Robert Francis, a former member of the NTSB.


You can see Southwest's dilemma. If we ground the 737 fleet then Southwest disappears, and yet they've been very consistent in prioritizing safety over economics.

The question is what we'll learn and then where "somebody" sets the balance point. Would somebody risk 130 passengers to keep Southwest flying, to maintain a major transportation system, and to avoid the economic effects of a travel ban on 737s? Is the loss of 150 people an acceptable cost to maintain a transportation network?

We seem to have no problem with the loss of 32,738 Americans a year in our automobile transportation system. There's no telling where people set the tipping point. The good news is: you're safer in a 737 than in your Volvo.





1948 - No Highway In the Sky

Southwest Flight 812 was the intro, the hook, the vivid recent story that we're all aware of. But there's really very little new under the sun (VLNUS); we've seen this several times before. Let's go way back, back to 1948 and a new book by Neville Shute.

Nevil Shute is a favorite author of mine. The first book of his that I read was On The Beach; it is tremendous. His full name is Neville Shute Norway; he writes under a pen-name to keep his engineering work separate from his writing. In a way, he was the Micheal Crichton of his decade.

One of Shute's early books was "No Highway", which was later made into a movie, "No Highway in the Sky".

It tells the (fictional) story of Mr. Theodore Honey, an aeronautical engineer who becomes convinced that the Reindeer, a new airliner his company makes, is likely to suffer from metal fatigue and have a catastrophic failure after a certain number of flights.

The establishment refuses to believe Mr. Honey, shuns him, and eventually attempts to have him declared mentally unfit. Events unfold and, in fact, the Reindeer's empennage falls off while taxiing.

Mr. Honey's reputation is restored, although that seems to mean little to him; he was just doing what he thought was right the whole time. Meanwhile, his demonstration of virtue under pressure makes him attractive to women.


Although the movie is set in 1952's new, glamorous world of aviation the story is ancient: how does a person proceed? How do they behave within their beliefs? How do we handle uncertainty? These are issues that predate Kitty Hawk, and these are questions that make flying seem rather simple.

Life Imitates Art: The de Havilland Comet Disasters of 1954

When pressurized aircraft were developed, and again when jet engines were introduced, the physics of aircraft moved into unprecedented altitudes and speeds. The implications of repeated cycles of pressurizing and depressurizing the cabin were not completely understood.

The deHavilland Comet was the world's first commercial jet airliner. It first flew in 1949 and was a landmark in aeronautical design. A few years after introduction into commercial service, in 1954 the Comet suffered from catastrophic metal fatigue, which in combination with the pressurisation, caused two well-publicized accidents where the aircraft tore apart in mid-flight.

The Comet was withdrawn from service. There were two courts of inquiry, and eventually the effects of compression cycles and the square window designs were understood. The early Comets were not returned to service. A new version, the Comet4, entered passenger service is 1958. (The cockpit photo at the top of this post is a deHavilland Comet4.)

In the meantime, the DC8 and B707 were introduced (both benefiting from the Comet's experience) and the Comet series never regained her initial status as a leading airliner. Some Comet airframes were flown until March 2011 in military service as the Nimrod ASW aircraft.

It appears that de Havilland and the airlines behaved responsibly; the risk was not understood, the aircraft were withdrawn from service after the second 1954 crash, and there was a public inquiry.

Life Repeatedly Imitates Art

A favorite shibboleth is, "The struggle of man against power is the struggle of memory against forgetting", and the questions described by Shute, seen in the Comet inquiries, and repeated in subsequent events demonstrate the need of memory and the value of remembering.

Boeing 737 Rudders

In the 1990's a problem developed with the 737 rudders. There was a crash in 1991 and then a crash in 1992, and there was an event in early 1994 but there was no Theodore Honey involved and the situation never moved from denial to acceptance until something really bad happened.

Back to the Reindeer: Skin Cancer in the 737



In April 1988, a Boeing 737 flying as Aloha Flight 243 suffered extensive damage after an explosive decompression in flight. The crew was able to land safely on Maui. The only fatality was flight attendant C.B. Lansing who was blown out of the airplane.

The age of the aircraft became a key issue (it was 19 years old at the time of the accident and had sustained a remarkable number of takeoff–landing cycles — 89,090, the second most cycles for a plane in the world at the time — well beyond the 75,000 trips it was designed to sustain).

According to the NTSB report, passenger Gayle Yamamoto noticed a crack in the fuselage upon boarding the aircraft prior to the ill-fated flight but did not notify anyone.

The National Transportation Safety Board (NTSB) blamed a combination of corrosion and widespread fatigue damage, the result of repeated pressurization cycles during the plane's 89,000-plus flights.

More Skin Cancer in the Boeing 737

  • July 2009: Southwest Flight 2294, a Boeing 737, experienced a football-sized hole in the fuselage and made an emergency landing.
  • October 2010: American Flight 1640, a Boeing 757, had a 1-foot by 2-foot hole develop.
  • Which brings us back to this post's opening scene:
    April 2010: Southwest Flight 812 had a five-foot hole open up.

This has nothing to do with airplanes

It does seem like there's a problem with the 737 sheet metal, but let me say (again) that you're safer in a 737 than you are in your Volvo.

Nevil Shute's book has nothing to do with airplanes, just like science fiction really doesn't have to do with technology; the frameworks provide a way to examine human behavior in contrived settings. It's about the philosophy of how to proceed within your beliefs.

Fatigue, Perseverance, and Virtue

Nevil Shute's story has a lot to do with modern times. With the country in three wars, the economy tanking, the failure of the political system, the attack on unions, the tax reductions for the rich, the service reductions for the weakest -- fatigue can set in and have pernicious cumulative effects just like the Reindeer experienced.

At what point do we say, "That's enough. Stop." One event? Two events?
Do we stay "stop" after Wisconsin, or Michigan, or Ohio?
In a time of multiple crises, how does one proceed in a crazy world?

Hopefully, by persevering and demonstrating virtue as in Theodore Honey's example.

3 comments:

Anonymous said...

No Highways In the Sky? Wrong!

Take a look at this RNAV/RNP/PBN brochure (page 1, middle panel) it says right there that there are too Highways In the Sky.

They've made a movie about it called Highways In The Sky (script). Shows what you know.

Dave Starr said...

Actually, in Norway's book, the 'real' tale of Mr. Honey's courage in the face of the industry/government 'party line''just follow orders' influence is a bit more dramatic than you recounted.

Believing the Reindeer he was traveling on was at Honey's own, discredited critical risk of failure point, Honey caused the landing gear to retract while parked on the ramp ... causing significant damage to the aircraft (and exposing himself to huge personal and departmental financial risk) but preventing an unsafe flight in the only way he could see open to him at the time.

Do we have any government employees or industry safety engineers of Theodore Honey's integrity today?

A very thought-provoking article and a very interesting use of an author and one of his better characters who are too little known today. Thanks, from a huge Shute fan.

Frank Van Haste said...

Dear Vannevar:

Have you read Slide Rule, the remarkable Mr. Norway's autobiography? If not, a brief review HERE.

Regards,

Frank

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