5.2 Surface Attack Definitions.

Several surface attack terms must be understood for the fighter pilot to fly the attack and arrive as close as possible to the planned weapons release window. While these concepts are introduced and defined here, specific mechanics and further discussion of how to use them starts at the “Roll-in” section later in this chapter. For more information regarding the calculations and T-38C specifics, refer to Technical Order (T.O.) 1T-38C-34-1-1, Air Crew Weapon Delivery Manual.

5.2.1 AIM Off Distance (AOD).

AOD refers to a distance beyond the target that is predictable for any weapons delivery. That distance is the no-wind projected flightpath of an aircraft (where the aircraft would hit the ground if the pilot did not recover) in a dive delivery.

5.2.2 AIM Off Point (AOP).

AOP is the point on the ground, long of the target, to which the aircraft must fly during the weapon’s delivery pass. The AOP provides a ground reference to fly the aircraft to until a track reference can be set.

5.2.3 Dive Angle.

Dive angle is the planned angle of dive for weapons delivery.

5.2.4 Initial Pipper Placement (IPP).

IPP is the angle from target to a point in the HUD in mils at track altitude.

5.2.5 Initial AIM Off Angle (IAA).

IAA is the angle between the AOP and the target at track altitude. IAA is setting the FPM a planned number of degrees above the target at track altitude.

5.2.6 Initial Target Placement (ITP).

ITP is the angular “distance” measured from the horizon to the target in degrees (adding IAA to the planned dive angle at track will always yield ITP). It is an excellent reference for knowing what type of wire you are on, but it is NOT a “track reference” and cannot be “set" at track altitude.

5.2.7 Mil.

Mil is a term commonly used by pilots as an abbreviation for mill radian (1/1,000th of a radian). Mils are used to measure sight depression or relative positions and sizes of objects as seen through the HUD. One mil is equal to 1 foot at a range of 1,000 feet. Another useful relationship is approximately 1° equals 17.45 mils. “Mils” are also sometimes used to reference the delivery parameters on the lineup card.

5.2.8 Minimum Release Altitude (MRA).

MRA is a contingency altitude. It allows the fighter to be fast, steep, or both (up to a limit), and still satisfies safe escape, safe separation, and fuze arming criteria. Units may compute MRA differently to reflect mission design series (MDS)-specific considerations.

5.2.9 Planned Release Altitude.

The expected release altitude based on attack planning and assumptions.

5.2.10 Percent Bomb Fall Line (%BFL).

Percent BFL is an alternate HUD track reference. In principle, it is exactly the same as IAA and serves the same purpose. The only difference is that the angular distance from the FPM to the pipper is described as a percentage of total BFL. It is similar to IPP in that it is setting the pipper a known amount of mils below the target.

5.2.11 Release Altitude.

Release altitude is the altitude above the ground at which weapons delivery is accomplished.

5.2.12 Track Reference.

Track reference is a position or point in the HUD that is used to maintain or correct the aircraft to the planned wire. Some common track references used in weapons delivery are IAA and BFL (IPP).

5.2.13 Tracking.

Tracking refers to a portion of any dive weapons delivery that is devoted to the final alignment of aircraft sighting systems with the target. The amount of time associated is referred to as wings-level or tracking time.

5.2.14 Track Altitude.

Track altitude is the preplanned altitude at which your HUD track reference is valid. BFL and IAA relationships are only valid at track altitude.