Publication:  Aviation Week
Date:  Febuary 5, 1996
Page:  26-27
Author: David A. Fulghum/Washington

Advanced coatings and unmanned designs appear to dominate efforts to 
keep new-generation, low-observable aircraft unseen both day and night

U S. military and aerospace officials contend that tests of improved 
stealth technologies, which are already underway and showing success, 
could make warplanes virtually invisible to radar, infrared sensors and 
the human eye. The claim puts an interesting light on a call by top U.S. 
Air Force scientists for the Pentagon to push rapid development of a new 
generation of stealthy, unmanned combat aircraft.
At least two classified aircraft programs, one unmanned and another that 
can fly with or without a pilot, are involved in current stealth 
research, according to a senior aerospace industry official.

The projects, reportedly being worked on within a block of each other at 
the Groom Lake development facility on the restricted government ranges 
north of Nellis AFB, Nev., involve aircraft built primarily of composite 
materials that use the same type engine and employ a special, next-
generation stealth coating that limits their visibility in at least two 
PENTAGON OFFICIALS confirmed lost year that there were at least two 
fixed-wing black aircraft projects at the facility, but denied that 
either had yet taken to the air. A senior Defense Dept. officials echoed 
that assessment lost week by saying, "If it's [already] flying, it 
belongs to some other agency." The industry official contends that the 
pure UAV, at least, has flown and evidenced some control or stability 
problems. These qualified affirmations leave open the possibility that 
more than two projects are involved.
The manned/unmanned aircraft's coating, considered a forerunner of the 
smart-skin concept, is activated by a 24-v. charge that helps trigger 
both radar and visual masking. The electrically charged coating 
attenuates radar reflections better than current stealth coatings. 
Dissipation of 10 dBsm. of radio frequency energy con reduce the 
operating range of an air defense radar by 40-50%. Moreover, the coating 
has properties that allow aircraft's skin color to be changed to blend 
the aircraft into the sky if viewed from below, or various hues of earth 
if seen from above. The aircraft also incorporates infrared limiting 
technology for a multispectral signature reduction effect.

Natalie Crawford, a long-time RAND official and chairman of the attack 
panel for the U.S. Air Force scientific advisory board, said the Air 
Force must raise the threshold for new stealth technology and pursue an 
"invisible air vehicle" so that U.S. stealth warplanes can operate in 
daylight. High visibility and distinctive shapes are a major limitation 
of the F-117, F-22, and, in particular, the large, black B-2 bomber. But 
being invisible means considerable improvement both in the infrared and 
visual spectrum. 

PARALLEL, ALTHOUGH not necessarily associated research, has shown that 
aerodynamic drag can be reduced and shock wave buildup on high 
performance aircraft delayed by putting an electrical charge on aircraft 

Both aircraft being tested at Groom Lake have hard points to carry 
weapons. Since U.S. combat rules currently do not allow UAVs to drop 
bombs or shoot missiles, some aerospace officials note that the larger 
aircraft could be flown by a pilot on strike missions and then be 
operated unmanned on reconnaissance missions, particularly where enemy 
air defenses are heavy. Air Force Chief Scientist Gene McCall predicted 
that unmanned aircraft and their sensors will be sophisticated and 
reliable enough to carry weapons within 10-20 years.

Other aerospace specialists suggest that the accommodations for a pilot 
were made simply to get through the testing more easily and with less 
fear of a crash that would delay or kill the project. This is a common 
practice within the UAV community where there often are one or two test 

An aircraft without a pilot can be maneuvered far more violently, 
thereby making it harder to shoot down. Both Air Force pilots and 
scientists concur that an aircraft capable of making 15-20g turns could 
outmaneuver most enemy missiles.

McCall called for uninhabited combat and reconnaissance aerial vehicles 
(UCAVs and URAVs) that can endure +10-+20g. The Nellis unmanned/manned 
aircraft project is reportedly designed for 12g. U.S. Air Force 
officials are more demanding, saying they need "15-18-20g," to ensure 
they can win aerial fights against newer missiles.

McCall estimates the UCAVs will be demonstrated within 10 years and 
operational within 20 years. Moreover, he predicted that the lost 
aircraft off the Joint Advanced Strike Technology {JAST) production line 
will likely be built as unmanned vehicles. Air Force officials hove 
suggested that operators on board the larger sensor platforms-such as 
the E-3 AWACS or E-8 Joint-STARS-will direct the unmanned JAST and 
reconnaissance UAVs during missions and return them to home base 
operators for the return flight and landing.

UCAVS, BY ELIMINATING the pilot, could present a completely smooth, 
seam-free surface to ground-based radars during a flight, McCall said. 
The landing gear, the seams of which are impossible to hide, would be on 
top of the aircraft. When ready to descend, the aircraft could simply 
roll over and lower its landing gear, a feat impossible with a pilot on 

McCall noted that stealth shaping has about reached its limits. To make 
an aircraft truly invisible, the Air Force would need to perfect the 
ability to repeat and reverse radar signals so that there appears to be 
no return and to further improve infrared signature reductions."