Grumman

Figure 1-29 Metal A-V Speedbrake (Courtesy of Northrop Grumman)...

The B-2 stealth bomber in Figure 1-38 is made by Northrop Grumman. Virtually all external parts are made of various composite materials because of their radar-absorption characteristics and/or their capability to be formed to shapes that naturally lower the radar cross section of the plane. However, the details are not publicly available, nor are they for the Lockheed Martin F-117A stealth fighter. 

Anthony J. Favale Director Advanced Energy System Northrop Grumman Corporation... 

There are few examples of mass produced MMW radars used for either commercial or military applications. An exception is the US Army s Longbow Apache attack helicopter that is equipped with the Northrop Grumman MMW Longbow radar. The Longbow fire control radar incorporates an integrated radar frequency interferometer for passive location... 

Boron fibres were used for specific aeronautic composites, for example by Grumman in the wings of the F 14, because of their structural properties. Now, because of their high cost, they are often replaced by carbon fibres. 

The Stealth Bomber, more accurately known as the Northrop Grumman B-2 Spirit Stealth Bomber, is cited as the largest composite structure produced with over 30%i of the weight being carbon-graphite-epoxy composites. The Stealth Bomber was originally slated to hunt Russian mobile missiles that were built in the 1980s. It was deployed in 1993 and has a... 

Northrop Grumman Systems Corporation Electronic Sensors and Systems PO Box 17319/MS A-255 Baltimore, MD, 21203 Ph 410.993.6848 321.726.7526 (Jim Stratford) www.es.northropgrumman.com Automatic Mine Detection System, AN/AQS-14 Post Mission Analysis System and Airborne Laser Mine Detection System (ALMDS). 

WILLIAM H. FORSTER, chair, Northrop Grumman Corporation, Baltimore, Maryland THOMAS L. MCNAUGHER, vice chair, RAND Corporation, Washington, D.C. (until 12/31/99) ELIOT A. COHEN, Johns Hopkins University, Washington D.C. 

WILLIAM H. FORSTER, Chair, Northrop Grumman Corporation, Baltimore, Maryland... 

A Grumman Avenger TBM flying approximately 20 m above the forest canopy applied the dyed spray with an emitted volume median diameter (vmd) close to 100 p. The spray mix, an aqueous fenitrothion emulsion, was applied at a rate equivalent to 1.5 1/ha and had a residual volume of 20% after evaporation of the water. Consequently, the evaporated vmd was approximately 58 p. 

The imager proposed in US-A-5030828 (Grumman Aerospace Corporation, USA, 09.07.91) has parallel elongate cavities formed within a substrate, photosensitive detector elements formed within the cavities and an optical insulating layer adjacent each of the cavities to optically isolate the cavities from each other. The elongate cavities provide an increased detector element surface area which increases the sensitivity. The optical isolation reduces cross-talk among adjacent detector elements. 

A method for aligning detector arrays on the surface of a signal processing module is shown in US-A-5075201 (Grumman Aerospace Corporation, USA, 24.12.91). 

P. I. Zappella, W. L. Robinson, i. W. Slemmons, P. J. Redmond and F. J. Woolston. "Implementation of a Hybridization Station for Mating Grumman Z-Plane Modules with HgCdTe Arrays . Proc. Soc. Photo-Opt. Instrum. Eng.. 1097, 117-125, 1989. 

The module of another embodiment uses a set of various sized wafers 152 stacked to form a mesa structure with the edges of the wafers comprising shelves 154. Each wafer has a pattern of metallized holes 156 therethrough, and a series of terminal pads 158 on the shelves. The method of manufacturing the imager is claimed in US-A-3970990 (Grumman Aerospace Corporation, USA, 20.07.76). 

In US-A-4618763 (Grumman Aerospace Corporation, USA, 21.10.86) a detector module is disclosed which is formed of stacked multi-channel integrated circuits, a detector array and a module header interface. The detector array and the module header interface are disposed transverse to the plane of the integrated circuits on opposite edge portions of the integrated circuits. Each integrated circuit is formed in a semiconductor material which has been deposited upon a thin sapphire wafer. 

One problem which arises when a detector array is attached to the face of a multi-layer module is the inability of the detector material to absorb forces generated by a mismatch of coefficient of thermal expansion between the detector array material and the module. Furthermore, it is difficult to isolate a fault that may be attributable to either the detector elements, module wiring or processing elements. A buffer board is introduced in WO-A-8807764 (Grumman Aerospace Corporation, USA, 06.10.88) which facilitates electrical communication between the detector elements and the module and conductive patterns formed on the module layers, and also enhances the structural characteristics and separate testability of the system components. 

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