Closer to 2.5. Interesting but very dated, not so much in the facts themselves, but in how Serling has a clear agenda of defending the Lockheed L-188 Electra to the point that it seems rather biased. It hurts even more because it actually succeeds as a primary source, but the author's narrative almost puts what he has written into doubt with his peppered asides and "this author" moments sprinkled about.

A short engaging read on a venerable and interesting aircraft. A recommended read.

Well told story of one of the most ominous airliners of the world. Very well put out for a book that’s 50 years old.

Working in the aerospace industry we see the age old story of there are no new incidents. Only rehashes of the same in different ways. (Comparing to the recent B738 Max accident)

There are many interesting parallels in this story to the current issues with the 737 Maxx: The CAA ( predecessor to the FAA) was heavily involved in certifying new aircraft, but because of reduced staffing many of the tasks were left to the company. For years the CAA had utilized a “designee” system to assure compliance with its regulations. Under this system, key employees of the applicant manufacturer were delegated to approve test methods and data, blueprints, design work, etc. The perennially money-starved CAA simply did not have the manpower to monitor aircraft design.  Sound familiar? The DC-6, Martin 202, and Constellation all developed bugs that made it through the certification process. 

Engineering progress is often measured by learning from mistakes. Unfortunately disasters are essential to help us learn as Henry Petroski has so eloquently written about in To Engineer is Human: The Roles of Failure in Succesful Design.

The Lockheed Electra, one of the most tested and lauded aircraft in the early sixties, was a marvel -- until the wings began to fall off.  It was a ship that fulfilled the pilot’s prerequisites for a transport better than any other plane in history. It had enormous reserve power. It handled smoothly, docilely, responsively. It was fast, versatile, uncomplaining and even — for such a huge aircraft — forgiving of mistakes. In brief, it was a pilot’s airplane.

Investigation following two crashes showed that the outboard engine mounts were not strong enough to damp a phenomenon called "whirl mode flutter" (analogous to the wobbling of a child's top as it slows down). "When the oscillation was transmitted to the wings and the flutter frequency decreased to a point where it was resonant with the outer wing panels (at the same frequency, or harmonically related ones), violent up-and-down oscillation increased until the wings would tear off."

After two violent crashes where the wings had been torn off, a crash (pathetic pun) effort was made to determine the cause. Resources of competing companies like Boeing and Douglas were offered and used. Wind tunnel tests and thousands of hours of test flights finally revealed the problem." Basically the trouble had nothing to do with the Electra’s strength. It involved stiffness — stiffness of the nacelle structure. Stiffness is not the same as strength. If one confuses the two, it is like thinking glass and air are the same because both are transparent. And in an airplane, stiffness is the chief resistant force against flutter. What had happened to the Electra was devastating in its deadly simplicity.

At enormous cost to Lockheed, the planes were all retro-fitted and it went on to have a reasonably successful commercial life. The hull plan is still being used in P-3 Orions. It took a while for the aircraft to get beyond its "jinxed" reputation, especially following a crash where on takeoff three of the planes engines shut down after ingesting hundreds of starlings. Yes, birds are still a problem. (The book was written in 1963.)

I remember flying in an Electra in 1968, several years after the problem was fixed. It was a nice airplane. But I won't get on a DC-10.