MD-80 split elevators

[tscottme[_2_]]

Anyone know why the elevators on MD-80s, while parked or taxiing on the
ground, are almost always split? By that I mean the elevator on the left
side is up and elevator on right side of rudder is down. I don't recall
seeing thie elevators split left/down and right/up and I don't recall 737s
showing split elevators, but that may just be a faulty memory.

--

Scott

"while there are Muslims who are moderate, there is no moderate Islam"
http://www.jihadwatch.org

[Robert Moore]

"tscottme" wrote
> Anyone know why the elevators on MD-80s, while parked or taxiing on
> the ground, are almost always split? By that I mean the elevator on
> the left side is up and elevator on right side of rudder is down. I
> don't recall seeing thie elevators split left/down and right/up and I
> don't recall 737s showing split elevators, but that may just be a
> faulty memory.

Speaking for B-707s, the elevators are not connected to each other and
are not even connected to the control column, they free float. They are
positioned by airflow over the control tabs which are pilot controlled.
At rest on the ground, the wind positions them, at random.

The MD-80 might be similiar.

Bob Moore
ATP B-727, B-707, L-188

[tscottme[_2_]]

Thanks Bob, I recall somethign similar about the MD-80 aero surfaces. I
believe the MD-80 uses a jackscrew to adjust the flying tail and aerodynamic
forces to trim.

I've definitely seen the trailing edge of the tail feathers swing up and
downdue to wind when the aircraft I was refeiling was parked at the gate.
Perhaps I am only remembering the left/up and right/down phenomenon and that
is reinforced by the networks' habit of reusing the same stock footage of a
line of taxiing aircraft.

--

Scott

"while there are Muslims who are moderate, there is no moderate Islam"
http://www.jihadwatch.org
"Robert Moore" > wrote in message
. 15.205...
> "tscottme" wrote
>> Anyone know why the elevators on MD-80s, while parked or taxiing on
>> the ground, are almost always split? By that I mean the elevator on
>> the left side is up and elevator on right side of rudder is down. I
>> don't recall seeing thie elevators split left/down and right/up and I
>> don't recall 737s showing split elevators, but that may just be a
>> faulty memory.
>
> Speaking for B-707s, the elevators are not connected to each other and
> are not even connected to the control column, they free float. They are
> positioned by airflow over the control tabs which are pilot controlled.
> At rest on the ground, the wind positions them, at random.
>
> The MD-80 might be similiar.
>
> Bob Moore
> ATP B-727, B-707, L-188

[Sam Spade]

tscottme wrote:
> Thanks Bob, I recall somethign similar about the MD-80 aero surfaces. I
> believe the MD-80 uses a jackscrew to adjust the flying tail and aerodynamic
> forces to trim.
>
Jammed MD-80 jacksrews caused one bird to nose dive into the ocean off
So California.