OT - Greek 737 plane crash

| > Airplanes can do a lot without a rudder, but a fin is a different story. | >A rudder is a control surface attached to a vertical fin, aka vertical | >stabilizer. While flying, have you ever noticed that the airplane banks in | >a turn? In order to make a turn, elevators (control surfaces on the wing) | | Carl, I know you know but for those who may not, they are ailerons.

You're right. Ooops! Thanks for the correction. !

I have seen photos of ones with MUCH of vertical stab missing, but never whole stab. Same thing with horizontal. I have seen some with half missing, never whole (both sides).

Yes, losing elevator CONTROL is different than losing elevator surface, depending on the type of trim mechanism being used, and CG location at time of loss.

Do you mean AILERONS on wings? Also, the degree of rudder needed depends on the adverse yaw induced by ailerons. Modern aircraft with much differential built into ailerons do not need much rudder except in slip. Older planes with a lot of adverse yaw require LOTS of rudder, especially at low airspeed and heavy throttle, as in takeoff. One can get leg cramps from some of them.

Indeed, emergency procedure for runaway down trim on some planes was to invert plane and put into bank while troubleshooting cause of trim problem.

Holy Sheeeeit, Batman! I'll bet the passengers would just love the hell out of that maneuver. Half screaming, half puking, and the few people who didn't believe the pilot when he quickly announced to "Sit down, belt in, and hold on!" are bouncing off the overhead... ;-P

Are MD-80's or 747's (or any other large passenger jets) aerobatic rated? I really doubt it. You can run around inverted in a Pitts Special or an F-16 all day, but not a 727...

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If the fuel systems and hydraulics systems could feed inverted, what would be the problem? Below maneuvering speed, the wings could take it.

LLoyd

Locate a copy of Martin Caidin's book "Flying Forts" and you'll see some pictures of them, including one of the bird that was cut nearly in half.

The center photo section shows quite a number of "battle damage" photos taken AFTER the planes were landed.

One point of difference between the 299 and the 7x7s is that the 299 was not pressurized - thus no pressure bulkhead to fail catastrophically.

Try aileron :-) ...lew...

Makes me wonder if this is a case of shop terminology. Folks that build airplanes may very well make reference to components by a different name than those that fly them. Not that they don't know better, but more because the term may better serve the purpose at hand.

It's true of machine tools. Only when I started conversing with hobby machinists did I ever hear a mill mentioned as a "miller". I've been in the trade since '57, worked in several shops, some with hundreds of machinists, and they were never discussed in that manner. There are "milling" operations performed on "mills"---------or-------- "milling" machines.

Harold

harold - don't think so - pilots and aero engineers use the same terms for the control surfaces - off the top of my head:

Aileron - control surface at the trailing edge of the wing that is moved up and down to change the rate of bank spoiler - extension on leading edge of wing to enhance lift at low speed flap - extension to back of wing to enhance lift at low speed speed brake - panel that extends from top of wing to increase drag elevator - control surface at the back of the horizontal stabilizer used to control pitch or pitch trim rudder - control surface at the back of the vertical stabilizer used to control yaw stabilizer - horizontal or vertical wing at back of airplane providing directional stability

no, I'm not an aero engineer, but I did design the first digital automatic pilot certified for use in cat III landings on passenger carrying planes

| | Makes me wonder if this is a case of shop terminology. Folks that build | airplanes may very well make reference to components by a different name | than those that fly them. Not that they don't know better, but more | because the term may better serve the purpose at hand.

Yeah, too much stuff flopping through the brain. Glad someone's paying enough attention not to confuse anyone by letting that slip through.

I have seen the photo of the one nearly cut in half. The tail was still in place, so stability was not altered substantially. As to ones where entire horizontal or vertical surface was gone, I'll have to find the book again. I certainly read it, but do not remember any such photos, but there may have been, so I'll look for it again.

Mostly right. However, spoiler is surface deployed from top surface of wing to reduce lift. The extensions of the leading edge to enhance lift are called slats or leading edge flaps.

Speed brakes can be on virtually ANY part of plane, but ones on top surface of wings are generally spoilers. Exception is F-15 speed brake- which is on top of fuselage but over the wing area.

The horizontal stabilizer is to provide stability in pitch and altitude-hold-stability rather than directional stability.

william_b_noble wrote:

agree on spoilers, it was late. disagree slightly on horizontal stabilizer - it provides pitch stability, yes, but (ok, danger, aero type statement to follow) pitch angle really controls airspeed, not altitude.

Old argument. People on both sides. Elevators control BOTH airspeed and altitude. So does thrust. Too complicated an answer for many, who want a simple "one-control, one effect". Pitch response of airplane is more complicated than that. Further, it is a calculus problem, control really works rate of change of each more than the altitude and airspeed themselves, depending on aircraft and how pitch-stable it is.