Message posted by Slick on May 15, 2002 at 9:27:20 PST:

Hello all. Once again you guys raise the "bar" in excellent commentary and photographs. Here is an exerpt from a Technical Description of the F-117A. The "window" in question in some of your messages is a Downward Looking Infra-Red sensor. Nothing really "fancy" or mystical about it. I hope this helps to quell some of the mystery surronding the airplane, which does still have a mixed-bag of "tricks" up her sleeve. Enjoy, and have a great day, and thanks for the pictures, discussions, and comments!
The F-117A cannot rely on radar for navigation, weapons aiming, or weapons delivery because the transmission of a
radar signal would tend to give away the location of the aircraft and hence defeat the whole purpose of stealth. For
low-level navigation and weapons-aiming purposes, the F-117 aircraft is provided with forward-looking infrared (FLIR)
and downward-looking infrared (DLIR) systems. Both systems are built by Texas Instruments. The FLIR is mounted in
a recess just ahead of the cockpit front windshield. It is located in a steerable turret containing a dual field of view
sensor. When the FLIR is not in use, it is rotated 180 degrees to keep debris from damaging the sensor. The DLIR
sensor system is located in a recess mounted underneath the forward fuselage and to the right of the nose landing gear
well. Both the FLIR and the DLIR recesses are covered by a RAM mesh screen to prevent unwanted radar reflections
from the active elements, and the edges of the recesses are serrated, with the fasteners being covered with RAM putty.

The DLIR is provided with a bore-sighted laser for illuminating the target for attack by laser-guided weapons. Together,
these systems form the infrared acquisition and designation system (IRADS). The laser is slaved to the IRADS and is an
integral part of the infrared system. The spot size of the laser on the ground is about 12-18 inches, and the spot is
stabilized in position by the IRADS.

In Reply to: F-117 Stealth Fighter photos posted by Joerg (Webmaster) on May 13, 2002 at 21:43:47 PST:

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