In the early 1943 and 1944 the British experimented with very heavy bombs(Tallboy and Grand Slam) carried by Lancaster bombers. The USAAF also felt the need for such a weapon but the Boeing B-17s did not have the power nor the size to carry these large bombs. Therefore the USAAF looked for other methods to carry a large bombload to a target. One of the projects was a concept to mount a fighter aircraft on top of an unmanned medium bomber. This was known as project Gershwin or Mistletoe, a combination of two aircraft, one mounted on the other.
The Mistletoe was the larger, unmanned component of a composite aircraft configuration developed in the USA during the later stages of World War II. The composite comprised a small piloted control aircraft mounted above a large explosives-carrying drone, the Mistletoe, and as a whole was referred to as the Gershwin Device or "Daddy and Son"
The most successful of these used a modified North American B-25 bomber as the Mistletoe, with the entire nose-located crew compartment replaced by a specially designed nose filled with a large load of explosives, formed into a shaped charge. The upper component was a fighter aircraft, often a Curtiss P-40, joined to the Mistletoe by struts. The combination would be flown to its target by a pilot in the fighter; then the unmanned bomber was released to hit its target and explode, leaving the fighter free to return to base. The first such composite aircraft flew in July 1943 and was promising enough to begin a programme by USAAF code-named "Gershwin", eventually entering operational service.
The medium bombers used were mostly combat-weary aircraft which were patched up enough to fly one last mission. Often parts from multiple aircraft were used to create one flyable airframe. Early experiments showed that just stuffing the nose full of explosives did not direct enough of the blast to the target, so special nose configurations were designed. At first, a number of steel plates were welded over the nose and cockpit. Later versions had a purpose designed hollow charge nose cone mounted on the aircraft. The aircraft depicted here is one of the interim types with the cockpit faired over.
Although initial trials looked promising, when the devices were used operationally their vulnerability quickly became apparent. The combined device was a sitting duck for enemy fighters and when released the bomber parts proved very hard to control by the pilot of the fighter.
Of the 54 operational flights carried out from the UK, only 4 succeeded in actually damaging their targets. Over 30 never reached their target areas, being either shot down, crashing due to mechanical failures or aborting back to base. The rest reached their targets but missed.
After 6 months the program was aborted. A total of 83 Gershwin combinations were produced. After the program was aborted all remaining devices were scrapped.