Autopilot/FD TCS Button

Question 1

What does TCS stand for? Does this button have authority over the auto pilot and flight director?

Answer 1

 Touch Control Steering button, sometimes referred to as the AP/FD
TCS button.
 Yes (AOM VOL 2 CH 14)

Question 2

Describe the Flight Directors interface with the TCS button.

Answer 2

 Pressing and holding the TCS button Synchronizes the Flight Director
with the current airplane attitude. (AOM VOL 2 CH 14)

Question 3

Building on the previous question - If the airplanes pitch is 30 degrees nosedown and the bank is 50 degrees right, will pressing the TCS button align the FD with that attitude?

Answer 3

 Yes, the FD will follow the airplane/pilot inputs when the TCS is
pressed. (AOM VOL 2 CH 14)

Question 4

We “Follow the Flight Director” as a normal mode of operation. However, when the TCS button is pressed, the Flight Director follows the airplane.
Can you identify a potential threat if the above statement is not
understood? Describe.

Answer 4

 The Flight Director is not guiding the pilot when the TCS button is
pressed. If attitude and/or position are not carefully monitored –
the Pilot could “follow” the flight director into an undesired aircraft
state. (AOM VOL 2 CH 14)

Question 5

When the TCS button is released, what happens to the Flight Director
guidance?

Answer 5

 The Flight Director returns to the lateral and vertical selection when
the TCS was pressed.
 With Roll/VS/FPA modes the FD maintains the airplane attitude
when the TCS is released. (AOM VOL 2 CH 14)

Question 6

How does the Autopilot interface with the TCS button?

Answer 6

 Pressing and holding the TCS will override the AP. Releasing the TCS
button will allow the AP to resume control.

Question 7

The AP is engaged with LNAV and VNAV active and the pilot presses the TCS button. The ERJ is then manually flown away from the lateral and/or vertical course then the TCS button is released – What will happen?

Answer 7

 The AP will resume control and attempt to bring the ERJ back to
course both laterally and vertically. (AOM VOL 2 CH 14)

Question 8

Reference the above question. If the ERJ had been maneuvered
significantly off of the CRS and/or PTH with the AP engaged, and then the TCS button released, could this create an unsafe condition in the cabin? How?

Answer 8

 The AP has significant authority to bring the ERJ back to CRS/PTH
and could be unsafe for passengers and cabin crew if they are not
seated with seat belts fastened.

Question 9

Have individuals been injured in the ERJ cabin from improper use of the TCS button?

Answer 9

Yes

Question 10

If a momentary “correction” of the ERJs flight path is desired, is the TCS
button a valid option?

Answer 10

 Absolutely, as long as the pilot understands its operation

Question 11

How can a pilot minimize the possibility of hazardous positive or negative G loading for “unsecured” passengers and inflight crew when using/releasing the TCS button (AP on)?

Answer 11

 Return the ERJ to the CRS and/or PTH before releasing the TCS
button.
 Or select new vertical and/or lateral modes that better align with
the new/desired flight path.
 Or turn the AP off.