LO Principles

Question 1

Stealth reduces __________

Answer 1

Active and passive signatures

Question 2

Objective of stealth

Answer 2

Reduce the probability of detection

Question 3

Active signature examples (3)

Answer 3

RF Signals: comm, navigation, radar

Acoustic: engine noise, prop noise

Infrared: engine exhaust, skin temp

Question 4

Passive signature examples (2)

Answer 4

EO/Visual

EM (radar)

Question 5

Radar signature is dominated by………

Answer 5

Shape

Question 6

Why is RCS the most critical signature of most aircraft?

Answer 6

Radar provides all weather, long range detection capability (**provides early warning)

Radar provide target range, azimuth, and velocity data (**provides tgt tracking)

Question 7

Stealth is enhanced by …. (3)

Answer 7

Forcing Threats to use active sensors sparingly

Using intel data to minimize onboard active and passive sensor exposure

Use tactics that combine w/ order of battle as well as man made environment

Question 8

Radar signature is expressed as aircraft…….

Answer 8

RCS

Question 9

Define RCS and explain the factors that determine its size

Answer 9

The measure of a targets ability to reflect RF signals in the direction of the radar receiver

Factors:
Azimuth
Elevation
Frequency of viewing radar
Polarization of viewing radar

Question 10

List 4 basic methods to make an aircraft stealthy

Answer 10

Shaping (by far the most important)

Absorption

Cancellation

Transparencies

Question 11

Describe shaping

Answer 11

Reflect radar energy into any direction other than back to the radar site

Question 12

Describe absorption

Answer 12

Utilize RAM to turn radar energy into heat

Question 13

Describe cancellation

Answer 13

Actively or passively reflected radar waves add together to cancel each other out

Question 14

Describe transparencies

Answer 14

Allow radar energy to pass thru the material w/ minimal reduction in energy or change in wave characteristics

Question 15

Describe faceted shaping

Answer 15

Orient flat surfaces to deflect radar energy away from threat radar

Question 16

Describe compound curve

Answer 16

Replace straight edges with curved edges to reflect less radar energy towards threat radar

Question 17

Describe planform alignment

Answer 17

Return a radar signal in a very specific direction away from the radar emitter

Question 18

Goals of radar absorption materials

Answer 18

Reduce specular and multibounce reflections

Reduce energy diffracted from trailing edges or discontinuities by absorbing energy as the wave travels along the surface

Question 19

Characteristics of E-RAM

Answer 19

Narrowband

Thick, but light

Question 20

Characteristics of MagRAM

Answer 20

Broadband

Thin, but heavy

Question 21

Characteristics of large volume RAS

Answer 21

Broadband

Thick, but light

Question 22

How does the aircraft surface breaks and gaps affect total RCS

Answer 22

Residual reflections are caused by surface discontinuities

Question 23

Engine inlet design methods used to reduce RCS

Answer 23

Screen grids

Buried engines

Intakes on top

Question 24

Canopy design methods used to reduce RCS

Answer 24

Made of radar absorbing materials

Smoothly blended into aircraft

Shape deflects radar away

Question 25

Other methods used to reduce RCS

Answer 25

antennas

Windows for sensors

Air data sensors

Access doors

External stores

Question 26

List 4 basic systems used to counter stealth

Answer 26

Low freq radar

High freq radar

Bi/multi static radar

Passive coherent radar

Question 27

2 limitations of low freq radar

Answer 27

Few frequencies available and heavy clutter

Poor range resolution

Question 28

2 limitations with high freq radar

Answer 28

Short range

Atmospheric attenuation

Question 29

2 limitations with bi/multistatic radar

Answer 29

Synchronization

Widebeam antenna or long scan time

Question 30

2 limitations of coherent radar

Answer 30

Reliance on third party illuminators

Azimuth/range only

Question 31

discuss mx practices that assure LO properties

Answer 31

Mx tracking records

Visual inspections

True RCS measurements

Diagnostic imaging

Question 32

Elements that contribute to Cost of stealth

Answer 32

Cost per flying hr

Acquisition cost

Infrastructure cost (security, support, etc…)

Inspection cost

Personnel cost

Question 33

What is the value of stealth

Answer 33

• provides a method of breaking the kill chain

Question 34

Discuss limitations of stealth

Answer 34

Operating cost

Limited number of assets

Complex MSN Planning

Lacks flexibility

Threats