Warning Systems -System Description 737 Flight Crew Operations Manual
Resolution Advisory Aurals
The following table identifies the possible callouts associated with RAs and the vertical restrictions or maneuver recommended in each case.
YA721 - YA803
AURAL ALERTS  VERTICAL RESTRICTIONS/MANEUVER 
MONITOR VERTICAL SPEED, MONITOR VERTICAL SPEED  Present pitch attitude is outside the RA pitch command area. Keep pitch attitude away from red area. 
CLIMB, CLIMB, CLIMB  Climb at the displayed pitch 
DESCEND, DESCEND, DESCEND  Descend at the displayed pitch 
REDUCE CLIMB, REDUCE CLIMB  Reduce climb rate 
REDUCE DESCENT, REDUCE DESCENT  Reduce descent rate 
CLIMB, CROSSING CLIMB, CLIMB, CROSSING CLIMB  Climb at displayed pitch. Airplane climbs through traffic’s altitude. 
DESCEND, CROSSING DESCEND DESCEND, CROSSING DESCEND  Descend at displayed pitch. Airplane descends through traffic’s altitude. 
INCREASE CLIMB, INCREASE CLIMB  Increase climb rate from initial pitch attitude. 
INCREASE DESCENT, INCREASE DESCENT  Increase descent rate from initial pitch attitude. 
CLIMB – CLIMB NOW, CLIMB – CLIMB NOW  Reversal maneuver from initial descent RA. 
DESCEND – DESCEND NOW, DESCEND – DESCEND NOW  Reversal maneuver from initial climb RA. 
CLEAR OF CONFLICT  RA encounter terminated. Maneuver guidance no longer displayed. 

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June 1, 2003  15.20.21
Warning Systems -System Description 737 Flight Crew Operations Manual

YA613 - YA687, YA809 - YK104
AURAL ALERTS  VERTICAL RESTRICTIONS/MANEUVER 
MONITOR VERTICAL SPEED  Present pitch attitude is outside the RA pitch command area. Keep pitch attitude away from red area. 
MAINTAIN VERTICAL SPEED, MAINTAIN 
MAINTAIN VERTICAL SPEED, CROSSING MAINTAIN 
CLIMB, CLIMB  Climb at the displayed pitch 
DESCEND, DESCEND  Descend at the displayed pitch 
ADJUST VERTICAL SPEED, ADJUST  Reduce climb or descent rate 
CLIMB, CROSSING CLIMB, CLIMB, CROSSING CLIMB  Climb at displayed pitch. Airplane climbs through traffic’s altitude. 
DESCEND, CROSSING DESCEND DESCEND, CROSSING DESCEND  Descend at displayed pitch. Airplane descends through traffic’s altitude. 
INCREASE CLIMB, INCREASE CLIMB  Increase climb rate from initial pitch attitude. 
INCREASE DESCENT, INCREASE DESCENT  Increase descent rate from initial pitch attitude. 
CLIMB – CLIMB NOW, CLIMB – CLIMB NOW  Reversal maneuver from initial descent RA. 
DESCEND – DESCEND NOW, DESCEND – DESCEND NOW  Reversal maneuver from initial climb RA. 
CLEAR OF CONFLICT  RA encounter terminated. Maneuver guidance no longer displayed. 

Tail Skid YC153 - YK104
The tail skid assembly consists of a cartridge assembly, tail skid, fairing (skirt) and shoe. The fairing provides an enclosure for the actual tail skid structure. The shoe is fitted to the bottom of the fairing.
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15.20.22  March 29, 2004

Warning Systems -System Description

737 Flight Crew Operations Manual
The cartridge assembly consists of a crushable honeycomb material. When the tail skid strikes the runway the skid moves upward and the honeycomb material crushes. The tail skid is serviceable when the cartridge warning decal shows both green and red. The green disappears gradually as the cartridge is crushed. When the warning decal is all red, the cartridge must be replaced.
The shoe is what contacts the runway in the event of an over rotation. The shoe surface displays “wear dimples” which serve as a reference for shoe replacement.
Tail Skid Detail

REAR OF SKIRT
(LOOKING FWD)

FULL RED INDICATES CARTRIDGE CARTRIDGE IS USABLE. NEEDS TO BE REPLACED. .
VISIBLE GREEN INDICATES
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September 29, 2005  15.20.23
Warning Systems -System Description 737 Flight Crew Operations Manual

Intentionally
Blank

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15.20.24  June 1, 2003