INSTRUMENT LANDING SYSTEM HUD MODEA variation of the navigation mode HUD comes into effect when the Instrument Landing System is activated.
Take note of the information displayed at the bottom of the HUD and use it in conjunction with the HUD guidelines and the AoA Indexer to make a perfect landing.
REFUEL HUD MODEA variation of the air-to-air HUD comes into effect when you are set to refuel (see REFUELLING on page 33).
Instead of an enemy target, the HUD tracks the refuel aircraft. Note that all weapons systems are shut down for refuelling.
MILITARY SPECIFICATION FLIGHT MODEL
The HUD has a few extra features when using the Military Specification flight model.
ANGLE OF ATTACK INDICATOR ]
Your aircraft's - in 10 degrees increments.
VERTICAL SPEED INDICATOR
Shows the vertical speed of the aircraft in units of feet per second. The VSI is mainly used to perform good landings (a healthy VSI landing speed is up to 10 feet per second). "
From the manual