LANDING SPEEDS

As in the takeoff planning, there are certain speeds that must be taken into consideration during any landing in a jet airplane. The speeds are as follows.

• ò VSOùStall speed in the landing configuration.
• ò VREFù1.3 times the stall speed in the landing configuration.
• ò Approach climbùThe speed which guarantees adequate performance in a go-around situation with an inoperative engine. The airplaneÆs weight must be limited so that a twin-engine airplane will have a 2.1 percent climb gradient capability. (The approach climb gradient requirements for 3 and 4 engine airplanes are 2.4 percent and 2.7 percent respectively.) These criteria are based on an airplane configured with approach flaps, landing gear up, and takeoff thrust available from the operative engine(s).
• ò Landing climbùThe speed which guarantees adequate performance in arresting the descent and making a go-around from the final stages of landing with the airplane in the full landing configuration and maximum takeoff power available on all engines.

The appropriate speeds should be pre-computed prior to every landing, and posted where they are visible to both pilots. The VREF speed, or threshold speed, is used

• Downwind leg-VREF plus 20 knots.
• Base leg-VREF plus 10 knots.
• Final approach-VREF plus 5 knots.
• 50 feet over threshold-VREF.

The approach and landing sequence in a jet airplane should be accomplished in accordance with an approach and landing profile developed for the particular airplane. [Figure 15-23]

Figure 15-23. Typical approach and landing profile.