Glide bomb

The only effective countermeasure in most cases is to shoot down enemy aircraft before they approach within launching range, making glide bombs very potent weapons where wartime exigencies prevent this.

Flight testing was performed under the supervision of an engineer called Dorner from January 1915 onwards, using airships as carriers and different types of biplane and monoplane glider airframes to which a torpedo was fitted.

Design work started as early as 1939, and a version of the guidance package mounted to standard 500 kg bombs was tested in September 1940.

It was found that the bomb was unable to penetrate a ship's armor, so changes were made to fit an armor-piercing warhead before the system finally entered service in 1943.

A more widely employed weapon was the Henschel Hs 293, which included wings and a rocket motor to allow the bomb to glide some distance away from the launch aircraft.

When launched, a small liquid-fueled rocket fired to speed the weapon up and get it out in front of the releasing aircraft, which was flown to approach the target just off to one side.

Its combat debut was made on August 25, 1943, when the sloop HMS Bideford was slightly damaged by a missile which failed to fully detonate, but killed one crewman.

Over one-thousand Allied soldiers died on 25 November 1943 when a Hs 293 sank the troopship HMT Rohna from Mediterranean convoy KMF 26.

Ships capable of maneuvering at high speed were instructed to make tight turns across the weapon's flight path in order to complicate the missile operator's efforts.

While early models proved inadequate, by the time the Allies were preparing for the invasion of France in 1944 more capable systems were deployed, and the success rate of guided weapons declined considerably.

The Hs 293 was also used in August 1944 to attack bridges over the Sée and Sélune at the southern end of the Cherbourg peninsula in an attempt to break US general Patton's advance, but this mission was unsuccessful.

A similar mission against bridges on the river Oder, designed to slow the Soviet advance into Germany, was made in April 1945 but failed.

The US Army Air Force started a wide-spanning development program of both glide bombs, known as "GB", and similar systems designed to fall more vertically, as "VG".

It was intended to allow the 8th Air Force bombers to drop their payloads far from their targets and thus avoid having to overfly the most concentrated areas of anti-aircraft artillery fire.

This was addressed with the introduction of small jet engines that greatly extended the range, producing the anti-shipping missile class that remains widely used today.

Similarly, the need to attack well-defended targets such as airbases and military command posts led to the development of newer generations of glide bombs.