The last carrier-based A-4s involved in the Vietnam
War overlapped with the introduction of laser-guided
bombs (LGBs). These were conventional bombs
modified with a laser seeker, simple guidance computer,
and controllable fins. The target was designated by a
laser beam that the LGB could detect and home in on.
The accuracy was outstanding, with the LGBs hitting
within a few feet of the designated spot. The first laser-guided
bomb drop at China Lake was made in early
1970, using a ground-based laser and a simple deviation
meter in the cockpit of the A-4 carrying the bomb.
Since the Navy A-4s were in the process of being
replaced, the implementation of laser designation
capability was very limited. Some of the VA-164 A-4Fs
deployed on Hancock with Air Wing 21 in 1973 were
equipped with a Laser Spot Tracker (LST) in the nose
and a Ferranti gun sight that displayed the spot being
designated by a laser in another aircraft or by a person on
The pilot of an accompanying single-seat A-4 dropped a laser-guided bomb on the spot.
In spite of the limitations (the 8-pound weight of the LWL precluded the TA-4F pilot from pulling any g load if the guy in back was to hold the spot steady), the trial was a success. The TA-4F would precede a small strike group by 2 miles and search for targets of opportunity, flying at an altitude of 5,000 to 7,000 feet, which was above the effective range of small arms fire. When a suitable target was spotted, the TA-4F pilot would pull up and circle it at 10,000 feet while the observer would begin to designate it. Laser designation was also useful for attacks employing non-laser-guided munitions, since the pilots flying the LST-equipped A-4s could use the laser spot in lieu of smoke rockets or geographic references to locate the target that had been found by FACs.
The successful trial proved the validity of laser designation and the LST hardware for development and adoption in the final iteration of the Skyhawk.