What is the balance tab? I am assuming that is the trim tab for nose attitude.
Can someone please answer that question?
What's going on here? I don't get it?
Belongs in chat. Stop cluttering news. Thanks.
Military aviator here, not commercial.
Runaway trim is an emergency procedure and usually requires pulling a circuit breaker to stop the condition. Using brute force on a control surface at 200+ knots would require the Hulk to overcome.
At speed, control surfaces do not move a great deal (5-10 degrees as an example) and are hydraulically controlled. So the short answer is no, human strength cannot overcome the force on the surface.
In a 'Fly-By-Wire' aircraft, no. There is no physical connection, IIRC......................
The jackscrew that powers the elevator is a very heavy duty mechanical piece that has to hold the horizontal stabilizer true under load of the 737 in flight for stable flight. If the humans could do that I dont think there would be two crashed planes.
There is youtube video of the device in operation but I cant locate it.
Tell all the first class passengers to go sit on the aisle floor in the back of economy. Adjust accordingly. Maybe have to tell SkyDancer to go back there as well. (If she is still a first officer. If she is captain then she is the boss, so she gets to stay up front)
So, I'd say the answer is no.
It took about five minutes from failure to crash. They fought all the way down.
A commercial aircraft does not utilize direct input to control surfaces. Hydraulics & mechanics - in some cases electronics, aka ‘fly by wire’ - move control surfaces based upon pilot input. Some older models still utilized cables, but in the case of the elevator, depending upon the model the elevator is primarily controlled by a mechanism called the jackscrew, a mechanism with no manual override.
In the case of the 737 MAX - from which I presume your question originates - a single sensor inputs to the computer to determine angle of attack, prompting the computer to override manual input to move the elevator to push the nose down corresponding to sensor readings of the nose angle. The reason for the pitching up & down is rooted in pilot attempts to override the computer, for which it’s now asserted that there are 1 or 2 switches.
If the jackscrew were to jam - as in the case of Flight 261 - the aircraft is doomed. There’s a good video of jackscrew operation at this source I hate to reference:
https://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261
That’s the simple explanation if I understand the nature of your question. The mechanics are the same, T-tail or not.
I’ve mistakenly neglected to click ‘chat’ as well; just ping the moderator to change it.
I also have a question. They say that the 737MAX has more powerful engines which are HEAVIER and MOUNTED farther FORWARD than the previous 737’s. They say THAT is what causes the nose of the MAX to tilt up.
HOW does having more WEIGHT moved farther FORWARD cause the NOSE to tilt up ?
To expand, the pilot’s input in the case of the 737 MAX is conflicting with the computer, which was inputting a nose down configuration with the trim motor, if I understand correctly.
Thus pilot input was being offset by the computer. Hence the reports about disabling the MCAS system and cutting power to the trim motor.
If these mechanisms fail, the aircraft is doomed. I understand your concerns, but aside from maintenance considerations, modern aircraft design for commercial travel has proved to be incredibly-reliable. The MCAS system was designed to eliminate the potential for stalling based upon the one variable engineers cannot overcome with aircraft engineering: The pilot. In this case they failed miserably by relying upon a single sensor with no redundancy.
I am incredibly critical of Boeing for this major engineering failure and the consequent investigation will conclude a new chapter in aviation...a chapter which should never have been opened. Before this crash, I was unaware of the severe dichotomy in training between US pilots and foreign pilots.
To your point, I would never willingly fly upon a foreign aircraft without US pilots, but have no bones about flying with US pilots. Of course, I may never fly again commercially due to the TSA, but that’s another matter altogether...
What say you?
Since 737 Max is fly-by-wire then wouldn’t you be trying to overcome the computer? Strength doesn’t enter into it.
Simple answer - No
Whole answer - This is fly by wire. There is no mechanical/hydraulic linkage between the stick and the control surface. Think of your computer and a wireless mouse. If your computer crashes no amount of moving your mouse is going to do anything to the computer.
Crickets.
What is the balance tab? I am assuming that is the trim tab for nose attitude.
Not a pilot but I do know quite a lot about aircraft. As such, I would think the answer to your question would depend on the control system being used. Fly-by-wire? Or actual, physical cable control? Cables? Then it would depend on what has the trim jammed.
I guess you could do like Denzel Washington, and roll the airplane inverted.
/s