.  
pitch mode engages in TO/GA and the Pitch Engaged Mode annunciation
on the FMA indicates TO/GA

.  
F/D pitch commands 15 degrees nose up until reaching programmed rate
of climb. F/D pitch then commands target airspeed for each flap setting
based on maximum takeoff weight calculations

Copyright . The Boeing Company. See title page for details.
Automatic Flight -System Description 737 Flight Crew Operations Manual

.  
F/D roll commands approach ground track at time of engagement. The
Roll Engaged Mode annunciation on the FMA is blank

.  
the IAS/Mach display blanks

.  
the command airspeed cursor automatically moves to a target airspeed for
the existing flap position based on maximum takeoff weight calculations.

With the second push of either TO/GA switch (if A/T engaged and after A/T reaches reduced go–around thrust):
.
the A/T advances to the full go–around N1 limit TO/GA mode termination from F/D go–around:

.  
below 400 feet RA, both F/D switches must be turned off.

.  
above 400 feet RA, select a different pitch or roll mode.

.  
if the roll mode is changed first:

.  
F/D roll engages in the selected mode

.  
the F/D pitch mode remains in TO/GA.

.  
if the pitch mode is changed first:

.  
the F/D roll mode automatically changes to HDG SEL

.  
F/D pitch engages in the selected mode.

.  
the A/T GA mode (if engaged) is terminated when:

.  
another pitch mode is selected

.  
ALT ACQ annunciates engaged.

Note:  Engaging an A/P in CMD automatically engages the A/P and F/Ds in LVL CHG for pitch and HDG SEL for roll.
Single Engine F/D Go–Around
With a push of either TO/GA switch:
.  
F/D roll commands hold current ground track. The Roll Engaged Mode
annunciation on the FMA is blank

.  
pitch mode engages in TO/GA and the Pitch Engaged Mode annunciation
on the FMA indicates TO/GA

.  
the F/D target speed is displayed on IAS/Mach display

.  
the F/D target speed is displayed on the airspeed cursor

.  
F/D pitch commands 13 degrees nose up. As climb rate increases, F/D
pitch commands maintain a target speed.

.  
if engine failure occurs prior to go–around engagement, then F/D target speed is the selected MCP speed.

.  
if engine failure occurs after go–around engagement, then F/D target speed depends on whether ten seconds have elapsed since go–around engagement:

.  
if prior to ten seconds, the MCP selected approach speed becomes target speed

Copyright . The Boeing Company. See title page for details.
4.20.20   June 1, 2003

Automatic Flight -System Description 737 Flight Crew Operations Manual
.  
if after ten seconds and the airspeed at engine failure is within five knots of the go–around engagement speed, the airspeed that existed at go–around engagement becomes target speed

.  
if after ten seconds and the airspeed at engine failure is more than five knots above go–around engagement speed, then the current airspeed becomes target speed.

Note:  The target speed is never less than V2 speed based on flap position unless in windshear conditions.
F/D commanded acceleration cannot occur until a higher speed is selected on the MCP IAS/Mach display.
Automatic Flight Go–Around Profile

Copyright . The Boeing Company. See title page for details.
June 1, 2003   4.20.21
Automatic Flight -System Description 737 Flight Crew Operations Manual

AFS Operation in Windshear General
The autopilot and flight director provide positive corrective action to counteract most windshears. The autothrottle system also aids in windshear recovery by providing quick response to any increase or decrease in speed. The commanded levels of power may be beyond what the average pilot considers necessary but, in fact, are required by the situation.
Takeoff or Go–Around
If windshear is encountered during F/D takeoff or go–around, the F/D pitch command bar provides commands to maintain V2 + 20 kts until vertical speed decreases to approximately +600 fpm. At this point, the F/D pitch bar commands a 15 degree nose–up pitch attitude. If vertical speed continues to decrease, the F/D continues to command a 15 degree pitch attitude until a speed of approximately stick shaker is reached. It then commands pitch attitudes which result in intermittent activation of the stick shaker. As the airplane transits the windshear condition, the F/D programming reverses. As climb rate increases above approximately +600 fpm, the F/D commands pitch attitudes which result in acceleration back to V2 + 20 kts. The A/P and F/D both operate in a similar manner during A/P or F/D go–around.
　
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