I am a little confused by the decompression (or, rather, how you describe it.) The baggage handler didn't cause a "slow leak," as far as I can tell from your description. Instead, he weakend the fuselage with the cart; the fuselage then blew along the crease all in one go.

So how is this not an "explosive decompression"? As you describe it, the pressure dropped all at once as the crease turned into a gash. Is an "explosive decompression" just defined as whatever blows a plane to smithereens? To me it seems like it was essentially touch-and-go whether or not that gash would have continued to propagate as the growing distortion of the fuselage led to new and unexpected stresses.

I certaintly agree with you that once the moment was over and the pressure equalized there was no more danger of an explosion -- that's just basic physics. But I am surprised to hear you say that the crew could expect the plane to fly just fine. They would have had no idea of the extent of the gash (unless there is some device that can tell you how rapid the decompression was, and thus give a rough estimate), and whether or not the size of the gash was sufficient to compromise the integrity of the entire plane. My guess would be that the descent and landing was terrifying for them.

PS: don't worry about the private plane guy. Some people blog to share and learn, some people blog to preen.

It's just weird that the private-pilot blogger describes loss of cabin pressure as "unthinkable". Gee, every time I fly I think about it, when the cabin crew instructs me as to what to do in the event of a loss of cabin pressure.

I don't know what happened, in terms of the regulatory process on the Mallard engine mods. I do know that modifying and maintaining aircraft is the nexus at which regulator and owner/operator tend to meet. Most aircraft tend to run into issues that might suggest their end is near. In the lower levels of aircraft, I suppose these are the 'killer' AD's, or airworthiness directives. In theory, commercial types of aircraft, in passenger service, have extraordinary burdens on them, in terms of safety.

But just looking at this situation, it's hard to believe it would have been allowed. How could you really have enough engineering? What was the economic value? Could you really measure the risks?

So much of the aviation process seems to be 'regulo-tainment'. It's a process for the sake of a process. The regulator makes a grand proposal, the industry responds. How much pressure is brought to bear, and how effectively?

Is there an answer? The regulator might take the view of extreme caution. If there is a factual, scientific method to determine the risks of mounting X engine to Y airframe, 40 years into the life of that airframe, why not feed the data into a computer and say the answer is Z?

Maybe we will get an answer that is complex because that rainbow of blame protects the process, the 'system'. I have ancient fire bombers that cruise, lazily, over my rural home, grasping for altitude. Aircraft of the same vintage have, as I recall, lost wings and suffered other failures, in severe service.

I hope they find a fairly precise answer, myself...

I have a comment, not on Patrick's article, but on the letter from John Dellaportas he includes at the end.

Dellaportas asserts that the Spanish voted out the Conservatives (Partido Popular) in 2004 so that "they could get al-Qaida to leave them alone," thus proving to the terrorists that their bombs can have a political effect. I've heard this assertion by American right-wingers before. What they conveniently choose to ignore is that the main reason Spaniards turned against the Conservatives so decisively was because the latter lied to the people about the perpetrators: they tried to convince everyone that the bombs were planted by the Basque separatist terrorist group, ETA, while they actually already had evidence pointing to al-Qaida immediately after the bombings. They probably lied because they feared what Dellaportas asserts happened; that the voters would punish the Conservatives for making Spain more vulnerable to Middle Eastern terrorism.

However, the attempt to mislead leaked out in time before the election, turning the Spanish voters decisively against the Conservatives -- and incidentally, also proving that the Spanish are less blasé about being lied to by their political leaders than Americans seem to be.

Who knows, perhaps some of those voting for the Socialists did do so at least partly because of worries about Spain's troops in Iraq having made the country a terrorist target. And in truth, who can blame them? The Iraq war is misguided, counterproductive, illegal, and based on lies. Why should an informed public support such an adventure, when the alternative at elections is to pull out of the mess?

I fully agree with the letter posted in response to the one from Mr Dellaponte. It was the USA right wing media (ie Fox, WSJ) who started saying that we got out of Irak in fear of further terrorist attacks. The view that we Spaniards voted out the Conservatives "in fear" is short-sighted and fails to see the context just prior the general election of March 2004. First, 90% of Spanish population were already against the war _before_ the attacks. Besides, the polls showed a draw between the Conservatives and the Socialists. It was precisely this draw what made the incumbent president to try to convince (ie, to lie to) the public that the attack was done by basque separatists instead of Al Quaeda.

Almost two years after the attack, the debate still goes on in Spain, with the right wing party doggedly insisting that ETA was involved in the attacks. I guess some mad whacko in Fox News still claims that Saddam was best pals with Osama Ben Laden, and that there were plenty of WMDs in Iraq.

When I first heard that the Mallard had been repowered with turboprops, my thought was, "Gee, for X amount of its life, this plane had the benefit of smoother gas turbines instead of the original vibration of piston engines. How much sooner would it have failed with the original power?" I guess in my head was, this aircraft is rated for X amount of power and/or airspeed, and the new engines would not exceed (or be within the limits of) these parameters.

Thanks for clearing up (or pointing out) some misinformation I've been carrying around in my brain.