Glomb

Last updated
Glomb
Pratt-Read LBE-1 Glomb.png
Pratt-Read LBE-1 Glomb
Type Glide bomb
Place of originUnited States
Service history
In service1944–1945
Used by United States Navy
Wars World War II (test only)

Glomb, from "glide bomb", was a project undertaken by the United States Navy during World War II to develop an unmanned aircraft for delivering bombs to high-value, well-protected targets without risk to aircrew. The project proceeded through the war, producing several prototype aircraft, but technical limitations meant no Glombs saw operational service and the program was cancelled at the end of the war.

Contents

Design history

During late 1940, the United States Navy began studying the possibility of developing gliders that would be remotely controlled to carry bombs to a target, reducing the risk to aircrew. [1] In 1941, the Joint Air Advisory Committee approved the creation of the Glomb project, recommending that the project be conducted as a joint effort between the War Department and Navy Department. [2] On 19 April the Navy's Bureau of Aeronautics officially initiated a project office at the Naval Aircraft Factory (NAF) for development of an operational glide bomb. [3]

In 1942, a defined specification was prepared for a series of glider aircraft capable of carrying either 18,000 pounds (8,200 kg) of explosives or 3,000 US gallons (11,000 l; 2,500 imp gal) of fuel in a tanker configuration; by 1944, when such an aircraft was able to be built, the course of the war meant that such a large aircraft was no longer needed. [2] However a project for a smaller glide bomb, based on a modified production glider, was underway, with tests of radio command guidance being undertaken using modified training gliders, [2] starting in September 1942. [4]

The Taylorcraft XLNT-1, Piper XLNP-1, Aeronca XLNR-1, and Waco XLRW-1 [1] were evaluated under Project George, [4] with the Taylorcraft model, designated XLNT-2 in definitive Glomb form, being considered the most suitable. [1] It was modified with a tricycle undercarriage to allow for ease of towing during takeoff, and television guidance was used, the only form of guidance that was sufficiently reliable given the state of the art at the time; a payload of up to 4,000 pounds (1,800 kg) could be carried. [2]

The results of the trials were considered sufficiently satisfactory for specifications for a production Glomb to be produced by the Naval Aircraft Factory and released to manufacturers for proposals in August 1943. [2]

Developmental testing

Piper LBP-1 Glomb Piper LBP-1 Glomb.png
Piper LBP-1 Glomb

The specifications produced by the NAF called for a payload of 4,000 pounds (1,800 kg) to be carried by the definitive Glomb, with a radius of action of 350 nautical miles (400 mi; 650 km); the towing aircraft specified as a baseline was the Grumman F6F Hellcat. [5] In September, contracts were awarded to Pratt-Read, Piper Aircraft, and Taylorcraft Aircraft for production of the LBE, LBP, and LBT, respectively, [2] for 100 aircraft of each type. [5]

In September 1944, the first full, expendable tests of the XLNT Glomb were conducted; [2] three aircraft being authorized for use. [5] While the aerodynamics and effects of the Glomb were considered satisfactory by the Navy, the guidance system was not, and work on an improved guidance system was undertaken. In addition, studies for the carriage of Glombs on aircraft carriers were carried out, but this concept was dropped as no longer needed by the fall of 1944. [2]

Continued issues with the guidance system, difficulty of generating electricity to power the onboard systems of the glider, and the changing state of the war, combined with the overall low performance inherent in a glider, led to the program being reduced in 1944; the LBT was cancelled outright in October, [5] after production of only 25 aircraft, [1] while orders for the LBE and LBP were reduced first to 85 aircraft in November 1944, then to 35 each in February 1945. [5] Handling issues while landing resulted in the cancellation of the LBP in June 1945, [5] and on 14 August, an analysis of the project resulted in the termination of the LBE, the sole remaining Glomb, with only four aircraft having been delivered. [5] Work on the LBD Gargoyle missile, which had been developed as an offshoot of the Glomb program, [1] continued, as it was considered more suitable for use by carrier aircraft and required less disruption to incorporate into Navy operations. [5]

Related Research Articles

AUM-N-2 Petrel Type of Anti-ship missile

The AUM-N-2 Petrel, also known as Kingfisher C and AUM-2, was an air-to-surface missile produced as part of Project Kingfisher for the United States Navy. Intended for use against enemy surface ships and surfaced submarines, giving aircraft the ability to deliver aerial torpedoes from outside the range of defensive armament, it saw brief operational service in the late 1950s. The project was never considered a high priority by the Navy however, as it was useless against submerged submarines, which were considered the greatest potential threat.

Project Gorgon Type of missile / test vehicle / target drone

The Gorgon missile family was a series of experimental air-to-air, air-to-surface, and surface-to-surface missiles developed by the United States Navy's Naval Aircraft Modification Unit between 1943 and 1953. The immaturity of the technology involved meant that none of the Gorgon missiles achieved operational service, however they were extensively used in the development of guided missile controls and guidance technologies.

Project Kingfisher Type of Anti-ship missilesAnti-submarine missiles

Project Kingfisher was a weapons-development program initiated by the United States Navy during the latter part of World War II. Intended to provide aircraft and surface ships with the ability to deliver torpedoes to targets from outside the range of defensive armament, six different missile concepts were developed; four were selected for full development programs, but only one reached operational service.

VB-6 Felix Type of anti-ship missile / guided bomb

The VB-6 Felix was a precision-guided munition developed by the United States during World War II.

LBD Gargoyle Type of anti-ship missile / guided bomb

The LBD-1 Gargoyle was an American air-to-surface missile developed during World War II by McDonnell Aircraft for the United States Navy. One of the precursors of modern anti-ship missiles, it was extensively used as a test vehicle during the late 1940s.

The Fletcher FBT-2 was a military trainer aircraft built in the United States in the early 1940s. Although it was never entered production as a trainer, it was ordered in small numbers as a target drone but when that was cancelled played a small part in the development of guided bombs.

Interstate XBDR

The Interstate XBDR was a design for an assault drone - an early television-guided missile - powered by two jet engines, that was designed by the Interstate Aircraft and Engineering Corporation during the latter stages of the Second World War for use by the United States Navy. Wind tunnel tests of a scale model were conducted, however no full-scale examples of the aircraft were built before the project was cancelled.

The Cornelius XBG-3 was an American "bomb glider", developed by the Cornelius Aircraft Corporation for the United States Army Air Forces. Using an unconventional design that included a forward-swept wing, a single prototype was ordered in 1942; however the contract was cancelled later that year before the aircraft had been constructed.

Pratt-Read LBE

The Pratt-Read LBE-1 was a prototype glide bomb, or "Glomb", developed for the United States Navy during World War II. Although there were high hopes for the concept, the limitations of the Glomb led to the production contract for the LBE-1 being reduced, then cancelled, and only four examples of the type were ever built.

Piper LBP

The Piper LBP was a glide bomb, or "Glomb", developed by Piper Aircraft for the United States Navy during World War II. Developed as one of three "Glomb" aircraft, the inherent limitations of the Glomb and the technology of the time, combined with difficulties encountered in testing of the prototype, led to the production contract for the LBP-1 being reduced, then cancelled, with none of the Glomb aircraft ever seeing operational service.

Taylorcraft LBT

The Taylorcraft LBT was a glider designed and built by Taylorcraft during World War II, in response to a United States Navy requirement for a glide bomb. One of three prototype "Glomb" models ordered by the Navy, the LBT suffered from technical and performance difficulties, and was cancelled early in production, none of the aircraft seeing operational service.

JB-4 Type of Air-to-surface missile

The JB-4, also known as MX-607, was an early American air-to-surface missile developed by the United States Army Air Forces during World War II. Using television/radio-command guidance, the JB-4 reached the flight-testing stage before being cancelled at the end of the war.

CTV-N-2 Gorgon IIC Type of Propulsion test vehicleTarget droneExperimental missile

The CTV-N-2 Gorgon IIC – also designated KGN, KUN, and CTV-2 – was an experimental drone, originally intended as a surface-to-surface missile, developed by the United States Navy near the end of World War II. It was used to test control and homing systems for guided missiles, and was also produced in small numbers as a target drone under the designations TD3N and KD2N.

KA2N Gorgon IIA Type of Air-to-air missile

The KA2N Gorgon IIA – also designated KU2N, CTV-4, and CTV-N-4 – was an air-to-air missile developed by the United States Navy near the end of World War II. Proving a failure in its designed role, it was repurposed as an experimental testbed for missile technology.

Pelican (bomb) Type of Guided bomb

The Pelican, also known as Bomb Mark 55 and, in one version, SWOD Mark 7, was a guided bomb developed by the United States Navy during World War II. Guided by semi-active radar homing, Pelican was produced in 1,000 lb (450 kg) and 1,500 lb (680 kg) sizes; the program reached the stage of live trials before being cancelled.

GB-1 Type of Glide bomb

The GB-1, also known as the "Grapefruit bomb" and as XM-108, was a glide bomb produced by Aeronca Aircraft for the United States Army Air Forces during World War II. Intended to allow bombers to release bombs from outside the range of enemy defenses, over one thousand GB-1s were used in combat before the end of the war.

ASM-N-6 Omar Type of Air-to-surface missile

The ASM-N-6 Omar was a short-range air-to-surface missile developed for and evaluated by the United States Navy in the early 1950s. Intended to use existing unguided rockets as a basis and using a novel guidance system involving optical beam-riding, the program was unable to resolve difficulties with the guidance system and was cancelled without entering service.

AUM-N-6 Puffin Type of anti-ship missile

The AUM-N-6 Puffin, also known as Kingfisher F and AUM-6, was an anti-ship and anti-submarine missile developed for use by the United States Navy in the late 1940s. Pulsejet-powered and intended to allow an aircraft to launch a torpedo or bomb from stand-off range, it was flight-tested but failed to enter operational service.

SUM-N-2 Grebe Type of Anti-ship missile

The SUM-N-2 Grebe, also known as Kingfisher E and SUM-2, was a rocket- and pulsejet-powered anti-ship and anti-submarine missile developed by the United States Navy in the late 1940s. Intended to allow a ship to deliver a torpedo at a significant distance from the launch location, it proved impractical in trials, and did not enter operational service.

References

Citations

  1. 1 2 3 4 5 Parsch 2005
  2. 1 2 3 4 5 6 7 8 Ordway and Wakeford 1960, p. 180.
  3. Grossnick and Armstrong 1997, p. 105.
  4. 1 2 Trimble 1990, pp. 269–270.
  5. 1 2 3 4 5 6 7 8 Friedman 1982, p. 201.

Bibliography

  • Friedman, Norman (1982). U.S. Naval Weapons: Every gun, missile, mine, and torpedo used by the U.S. Navy from 1883 to the present day. Annapolis, MD: Naval Institute Press. ISBN   978-0-87021-735-7.
  • Grossnick, Roy A.; William J. Armstrong (1997). United States Naval Aviation, 1910–1995 (PDF). Naval Historical Center. ISBN   0-16-049124-X. Archived from the original (PDF) on 2000-09-14. Retrieved 2013-02-11.
  • Ordway, Frederick Ira; Ronald C. Wakeford (1960). International Missile and Spacecraft Guide. New York: McGraw-Hill. ASIN   B000MAEGVC.
  • Parsch, Andreas (9 March 2005). "LB Series (LBD, LBE, LBP, LBT)". Directory of U.S. Military Rockets and Missiles, Appendix 1: Early Missiles and Drones. Designation-Systems. Retrieved 2017-12-24.
  • Trimble, William F. (1990). Wings for the Navy: A History of the Naval Aircraft Factory 1917–1956. Annapolis, MD: Naval Institute Press. ISBN   978-0-87021-663-3.