AN/AJB-1 Low Altitude Bombing System (LABS)

Introduction

The Low Altitude Bombing System (LABS) was introduced to assist with nuclear weapons delivery, providing a pre-determined trajectory with delivery profiles to assist with escaping blast effects.

Controls and Indicators

Pitch and Roll Indicator

labs

The vertical needle indicates the current desired roll from 9 degress to wings level left and right. The horizontal needle indicates both the desired G load in pullup mode and desired pitch angle(straight and level) in pre-pullup mode. You will need to keep the wings level and thus roll at 0 and be on "G" during pull up for a correct auto release for the given LABS or LADD release mode. Maintain correct G by keeping the horizontal bar centered between the lines.

Pullup Light

labs_light

The LABS release light indicates when pull up should begin once extinguished. The time the light is on for is set on either the LABS and LABS ALT(left) or LADD(right) dials pictured below.

LABS and LADD Timer Dials

labs_dials The dials for setting the pull up time for LABS and LABS ALT (Left) and LADD (Right) are shown above. They have a range from 0–28 seconds.

Operation

All LABS delivery modes share the pullup timer. The pullup timer is the time set by the pilot to indicate the time taken for the aircraft to fly from a know identification point (IP) to the pullup point.

There are two variables which determine what the pullup timer should be set to:

  • Ground speed
  • Bomb travel distance
  • Distance from IP to target

pullup timer = (distance from IP to target—bomb travel distance) / ground speed

Both ground speed and distance from IP to target are determined during mission planning. A good identification point (IP) is something near the target area the pilot can easily locate and navigate to.

Bomb travel distance is determined by the bomb's release parameters, including:

  • Release angle
  • True airspeed
  • Target altitude
  • Aircraft altitude
  • Bomb type
  • Wind

Using all this information we can begin using LABS and LADD delivery as they function similarly. Pluging in all the correct data we want to be pointed at the target and press the weapon release at the indentification point (IP), the LABS release light will then illuminate. Once it is extinguished after our LABS timer setting has ended begin pulling and maintain wings level and be on "G" using the LABS gauge. Release will then automatically occur depending on the release mode chosen. 50 degress for LABS and 120 for LABS ALT.

LABS (Loft)

The LABS mode is the normal mode, lofting the bomb towards the target over long distances, at a release angle of 50°.

LABS ALT (Over the Shoulder)

The LABS ALT mode is the alternate method lofts the bomb vertically over the target, at a release angle of 120°.

Image of Loft Release

Low Altitude Drogue Delivery (LADD)

Low Altitude Drogue Delivery (LADD) is for delivery drogue assisted nuclear weapons. At the pullup point, the pilot is commanded into a 40° climb. The release timer determines the release. The release timer begins at the pullup point. When the timer runs out, the bomb is released.