It's a fact that many injuries and deaths in aircraft crashes these days are not as an instantaneous result of a fatal impact injury, but often something as seemingly survivable as passengers breaking their legs as the floor of the aircraft collapses or the seat-mounting bolts fail under a deceleration load. Then, unable to walk and thus unable to evacuate the aircraft wreckage quickly, they are overcome by smoke inhalation and perish from either that or a subsequent fire. Thus you most certainly do want an aircraft fuselage to deform and absorb some of the deceleration forces of a ground impact, but of course have it happen in the way that is a design choice and not because of a dodgy component. But it's interesting to note that despite there having been a few NGs which have broken up into sections upon crashing, it's actually rare to find an example of one then bursting into flames and killing passengers trapped inside the thing with broken limbs.Coming back to the FAA/NASA test crash of the 707 (actually it was a 720) which was using anti-misting kerosene jet fuel, it's worth noting that when the fuselage remained fairly intact as it crashed, the impact loads were then transferred to the telemetry-dummies inside the aircraft and the data suggests that would have resulted in many broken limbs; you can actually see this was likely if you watch how the dummies are being tossed about on that footage. The fuel additive under test failed to suppress a fire on account of the fact that one of the gas-jet razor spikes designed to cut open the wing tanks in order to see if AMK worked, actually sliced through the number three engine of the aircraft and started a fire. Anyone who has seen the well-known footage will of course know that the fireball as the starboard wing separates is fairly spectacular and does penetrate the cabin, but in actual fact that meant there was less fire engulfing the fuselage, nevertheless, the spilled fuel was enough to keep the wreckage burning for over two hours and completely destroy the airframe, so one can reasonably surmise that the casualties would have been fairly horrific if people were crippled by the impact and unable to evacuate the wreckage before being overcome by smoke inhalation.For comparison to the related point about a 707-type not breaking up upon a more fierce type of impact and a 737 supposedly being prone to it, one can examine the crash of Avianca Flight 52 at Long Island in 1990 after it ran out of fuel and came down in a stalled condition more akin to the Schiphol 737 impact. In that circumstance, the impact force was enough to break the front of the 707 completely off, resulting in the cockpit section ending up over 100 feet away from the bulk of the main fuselage wreckage and all the flight deck crew being killed.Most of this stuff is merely of interest rather than pertinent to the 737's alleged problems of course, but then again, that was my point in the first place in suggesting that the crash footage used in the Al Jazeera film was of little relevance to an investigation piece.Al

I don't agree with that, an airplane designed to break up to absorb impact energy would greatly endanger the passengers by exposing them to the outside where sharp heavy metal and violent forces are wrecking havoc. I think it would be safer to be thrown around inside the fuselage, than outside.

The laws of physics are against your argument, however. Let the aircraft take the stress of the impact and somehow break apart or deform as part of that process, or let it stand as a shield and let the body take the impact. Again, you need only look as far as crumple zones on cars - designed to break down, or deform - to see that something has to give. It's either the plane or you. Whatever takes the hard impact is the write-off though - you or the plane, but not both.

Just my two cents, but I think I would much rather have safety efforts focus on NOT CRASHING in the first place.Crashworthiness and flight are not very compatible - look at how fragile most birds are...the ability to defy gravity comes at a price. I don't think people are willing to pay what it would take to have all airplanes overbuilt like an eagle (continuing the analogy).

Having several escape routes when the wreckage settles is all fine and dandy, but it's not so great when all the passengers have been cut into pieces and laying around all over the crash field dead from massive injuries. Let the fuselage crumple, but don't let it split open like it did with the 737's, that's when people really get killed. A broken leg is better than being dead, which should be pretty obvious. To be honest though, I don't know how much a crumpling fuselage would help anyway. It's not like the plane crashes into another plane or a wall, like in a car. What it needs to do is to stay intact for as long as possible in order to protect its occupants. Designing a fuselage to split apart during a crash is just insanity. I remember watching Air Crash Investigation once and one of the passengers during an interview were talking about how it was like to be inside an airplane about to crash, and she said something like: "I prayed to God the airplane would stay in one piece, I knew I'd be dead if it didn't ".

In all the arguments I think the numbers speak for themselves on the 737 site http://www.b737.org.uk/accident_reports.htm 7 write offs for 3300+ NG's built....Only 2 structural failures for 6600+ 737's (not NG) in all and I know one of them was Aloha airlines which landed after the event.Only the future will tell if the 'former employees' are correct but I personally doubt it... A shoddy design doesn't keep going for over 40 years of service.Bumpy landing et al

funny anyway.John Ellison

[...]To be honest though, I don't know how much a crumpling fuselage would help anyway. It's not like the plane crashes into another plane or a wall, like in a car. What it needs to do is to stay intact for as long as possible in order to protect its occupants. Designing a fuselage to split apart during a crash is just insanity. I remember watching Air Crash Investigation once and one of the passengers during an interview were talking about how it was like to be inside an airplane about to crash, and she said something like: "I prayed to God the airplane would stay in one piece, I knew I'd be dead if it didn't ".

An impact is an impact, whether it's head on or at an angle. It is not designed to split, but it did, and when it did, that energy to break apart ended up taking some of the brunt of the impact. Simple, hard, physics-based fact. There's no disputing it.Whether or not that exposes people to extra risk is another story, and I see your point, but at least they're exposed to further risk. If you're dead because the aircraft did not take the impact and transferred it to you, that extra risk really doesn't matter.As far as the ACI comment goes, read back to my above post on credibility. You're citing a passenger, who likely has no clue into the design of an aircraft, or physics (elementary, if any physics at all). A split would not expose you to much extra external risk that would cause instant death over a plane that stayed completely in tact.As mentioned above, you're better off re-training the crews in the mentioned crashes, instead of trying to prevent the aircraft from splitting.