AV8NLVR's Blog

You may remember a few weeks ago a plane crash in Madrid, Spain in which 154 people died.  The plane crashed while taking off.

Today I was reading a new report that,  while the official cause won't be released for some time, says that the data recorder shows that the wing flaps were not extended in takeoff position,  and an electrical alert system for flaps not set may not have worked.  This reminded me of another crash that was very similar.  It happened in 1987 in Detroit.  I checked some facts on it and indeed,  the Spanair accident appears to be exactly identical to that of Northwest flight 255.

Both aircraft were McDonnell-Douglas MD-82 models.  Northwest 255 was a flight leaving Detroit for Phoenix on an August night in 1987 when the pilots did not do a required pre-flight checklist and did not set the flaps.  That plane only got about 50  feet up,  tipped left then right, then crashed and careened up to a highway overpass in a big fireball.  156 people died (compared to 154 in the Madrid crash) and there was one single survivor - a 4 year old girl whose parents and brother were among the casualties.   Also,  in a striking similarity,  the takeoff warning system in that plane also did not work.

In last month's accident,  the Spanair jet rose slightly from the runway, then crashed and exploded, ending up in the grass.  Many of the bodies were burned beyond recognition; however, 18 people did survive.  But the details of both crashes are so strikingly similar.

Those panels on the rear of the wing that extend out/downward are indeed very important to getting you off the ground - without them, as you can see, well.....you're dead.  The laws of physics are simple and the same no matter what kind or size of plane youi're on.  The wings create the force that causes the plane to go up (lift) by Bernouli's Principle - air moves faster over the top of the wing than under it because the top of the wing is curved and is a larger area.  The slower moving air across the bottom is a higher pressure than the air on top,  so the high pressure bottom causes it to rise.  But factor in that you have a quarter of a million pounds to lift - more lifting force is needed at the beginning so the flaps work by extending the wing - extending the surface area and extending the curvature,  which means even faster air at a lower pressure will produce more high pressure underneath,  enough to get it off the ground and headed upward.   While there are a couple of aircraft types that I've heard of that can do a zero-flaps takeoff,  on most of them the standard wing cannot create enough force to get the plane in the air. - it'll crash every time.

Of course there is more to it....things like speed, angle of attack, etc but the flaps serve the very basic principle.  Its fun to watch a plane sail gracefully off the ground when all the forces work together, whether its a small Cessna or the gargantuan Airbus 380.  They're all the same.  Pilots have checklists for every phase of the flight, and there are operating procedures for just about everything.  The same type of crash caused by human error should never happen twice.