AN/APG-15 Fire Control(?) Radar on B-29B

[GUNDAM123dx]

There's some information about AN/APG-15 in "Radar and Communications: A Report Prepared for the AAF Scientific Advisory" and "USN.Radar.Vol.1.Summ.Rpt.and.Harp.Project.1946" mentioning that's kind of fire control or scanning/ranging radar. However, I could hardly find any info about how it works, or any photos of it.

Was it sort of similar to UK/"GERMAN" "AGLT"?

https://www.secretprojects.co.uk/threads/german-aglt.5469/

https://www.secretprojects.co.uk/threads/village-inn-aglt-developments.9450/

 

[T. A. Gardner]

Tail radar for gun aiming wasn't exactly new to US bombers:

 

[T. A. Gardner]

On 17 December, the 315th Headquarters received an important teletypewriter message (TWX). The TWX directed special modifications to the wing's B-29s, including the removal of the armament and central fire-control system. Instead, the B -29s were to be equipped with only a new radar-directed tail turret, the APG-15, having three 50-caliber machine guns. The Plexiglas gunners' blisters protruding from the sides of the B-29 were also to be removed and replaced with smooth enclosures. The 315th flight crews were reduced from 11 to 10 men by replacing the 3 original gunners with 2 visual scanner positions. The TWX also notified the 315th that the APQ-13 radar navigation and bombing system would be replaced by the new AN/APQ-7 radar, code named "Eagle." This TWX raised many questions about the future role of the unit.

315th Bomb Wing

Radar directed tail turret of Consolidated XB-24Q Liberator 44-49916. The waste gunner station has been replaced with a B-29 style sighting blister. It was scrapped at Olmstead Army Air Field, Pennsylvania on August 16, 1948

 

[GUNDAM123dx]

Tail radar for gun aiming wasn't exactly new to US bombers:

That seems a jamming device.

Equipment fitted included American AN/APS15 radar in the large radome under the nose, Airborne Cigar(ABC) radio-jamming equipment (shown by the large aerial on top of the fuselage), and an Airborne Grocer aircraft radar jamming installation, the aerials of which can be seen on either side of the tail turret.

20/21.03.1945 No. 214 Squadron Fortress III HB785 F/O Kingdon Location: Black Forest area, Germany.

 

[T. A. Gardner]

Tail radar for gun aiming wasn't exactly new to US bombers:

That seems a jamming device.

Equipment fitted included American AN/APS15 radar in the large radome under the nose, Airborne Cigar(ABC) radio-jamming equipment (shown by the large aerial on top of the fuselage), and an Airborne Grocer aircraft radar jamming installation, the aerials of which can be seen on either side of the tail turret.

20/21.03.1945 No. 214 Squadron Fortress III HB785 F/O Kingdon Location: Black Forest area, Germany.

You're correct. I was thinking of the earlier Monica tail warning radar .



While it was at best marginally effective, it gave the gunner some warning that a potential target was approaching and to open fire.
Of course, since it operated continuously the Germans soon figured out their nightfighters could home on the signal and put FuG 227 Flensburg into service to that end.

 

[GUNDAM123dx]

You're correct

Boeing B-17Gs in Coastal Command and Bomber Command’s No. 100 Group

Fortress Mk III The RAF used the B-17G (Fortress Mk. III) for RCM duties with squadrons of 100 Group during 1944/45. This Mk. III with black-painted undersides has the prominent fairing under the f…

weaponsandwarfare.com

Boeing B-17 Flying Fortress

Although it is sometimes introduced as the most famous of all US World War II aircraft, there are many who will argue that Boeing’s B-17 Flying Fortress ranks equally with several other super…

weaponsandwarfare.com

Yep that's a Airborne Grocer jamming device.

 

[Basil]

View: https://www.youtube.com/watch?v=l-39wbSe_0k

 

[TomcatViP]

It's a fascinating story.

But the apparent placement of the radar hanging under the gun barrels at a significant distance from their attach points would have been an invitation to vibration problems.