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Utility and cargo helicopters operate throughout the entire battlefield during the conduct of their assigned missions. The purpose of this appendix is to discuss aircraft survivability.

Aircraft survivability encompasses a vast array of disciplines. There is a tendency to think of ASE as the complete picture of aircraft survivability. ASE is only a portion of EW that is one portion of EW supporting information operations and information warfare. The Joint Chief of Staff MOP-6 changed the Army's EW terminology to reflect the unity of these functions. The three functions of EW are described below.

a. Electronic Attack (formerly Electronic Countermeasures). EA is the division of EW involving the use of electromagnetic or directed energy to attack personnel, facilities, and equipment for the purpose of degrading, neutralizing, or destroying enemy combat capability. EA includes actions taken to prevent, or reduce, the enemy's effective use of the electromagnetic spectrum through jamming, destruction, and electromagnetic deception. EA also includes the employment of weapons using either electromagnetic or directed energy as the primary destructive mechanism. These weapons might include lasers, radio frequency, or particle beams. Finally, EA includes using sources of electromagnetic energy as the primary means of terminal weapons guidance to damage or destroy personnel, facilities, or equipment. ASE employed to defeat the EA systems include chaff, flares, radar jamming, and IR jamming.

b. Electronic Protection (formerly Electronic Counter-Countermeasures). EP is the part of EW involving actions taken to protect personnel, facilities, and equipment from effects of friendly or enemy EW actions that may degrade, neutralize, or destroy friendly combat capability. To minimize their vulnerability to EA, EP should be considered for all battlefield systems deriving operational capabilities through the use of the electromagnetic spectrum. Included are optical, electronic, infrared, and radar target acquisition, noncooperative target recognition systems, and smart weapons systems' sensors, fuses, guidance, and control components. ASE employed systems include antenna design, signature reduction, infrared absorbing paint, etc.

c. Electronic Support (formerly Electronic Support Measures). ES is the division of EW involving actions tasked by, or under the direct control of, an operational commander. The ES's responsibilities are search for, intercept, identify, and locate sources of radiated electromagnetic energy for immediate threat recognition in support of EW operations and other tactical actions, such as threat avoidance, homing, and targeting. ES focuses on surveillance of the electromagnetic spectrum in support of the commander's immediate decision making requirements for the employment of EW or other tactical actions, such as threat avoidance, targeting, or homing. ES is normally provided by organic intelligence and sensing devices based on EW technology integrated into other weapon systems, or assets from other echelons capable of providing combat information to the supported command. The purpose of ES is to ensure EA and EP applications receive the input needed to operate effectively. (Examples of ES include, battlefield systems that execute direction finding operations, detecting and identifying enemy missions, or other electromagnetically-measured signatures that enable immediate exploitation, locating high value targets for electronic attack, or providing threat avoidance information.) ASE systems include radar, laser, and infrared missile detecting sets.

d. Aircraft Survivability Equipment Philosophy. The role of ASE is to reduce the vulnerability of our aircraft, thus allowing aircrews to accomplish their immediate mission and to survive. The methodology for achieving survivability is supported by the ASE philosophy, a five-step approach to ensure that Army aircrews are able to accomplish their mission again and again. These five steps include the following, in order of least cost and most effective to the most cost and least effective:

(1) Step 1. Tactics (electronic protection). Proper tactics reduce exposure times to enemy weapons. NOE flight limits LOS exposure times and places the aircraft's radar, infrared, and optical signature in a cluttered environment. NOE tactics, combined with ASE protection, allow Army aviation to survive and perform its mission. ASE protection is severely degraded when the aircraft is not flown tactically sound (blue sky background).

(2) Step 2. Signature reduction (electronic protection). These measures are implemented through engineering or design changes, such as flat canopies, exhaust suppressers, and coating the aircraft with low-infrared reflective paint. Signature reduction alone greatly increases survivability. Without signature reduction, ASE effectiveness is degraded and, in some cases, erased. Signature control is also influenced by the aviator choosing how much signature to expose to the threat.

(3) Step 3. Warning (electronic support). The next step, in the ASE philosophy, is to provide warning to aircrews when they are about to be engaged, allowing time to react. Examples include radar, laser detecting sets, and infrared missile warning systems.

(4) Step 4. Jamming and decoying (electronic attack). When aircrews must stay on station despite warnings, there is a requirement for countermeasures capable of jamming, and/or decoying the fire control or guidance systems of threat weapons. Chaff, flares, and radar and IR jammers provide this type of protection.

(5) Step 5. Aircraft hardening (vulnerability reduction). This step provides for ballistic tolerance, redundant critical flight systems, and crashworthy features, to assist in minimizing the damage to an aircraft after it has been hit.

This section is not designed to be system specific in nature, rather to provide a general knowledge of threat systems, which can be applied to specific threats on a case by case basis.

a. Threat Engagement Sequence. All weapon systems must complete a series of events, called an engagement sequence, to actually have an effect on the target (aircraft). Missing any step in the engagement sequence forces the threat engagement sequence to be started over again. Weapon systems sensors must--

• Detect.
• Acquire.
• Track.
• Launch and guide (or fire and ballistics).
• Assess damage.

b. Example Threat System. Five elements required to a compute an AAA fire control solution are range, azimuth, elevation, velocity, and time of flight. If one of the fire elements is incorrect, the AAA system will not hit the target.

c. Target Acquisition. The threat must detect, acquire, track (establish fire control solution), and fire at the aircraft. The time of flight of the projectile must be determined. The threat must predict where the aircraft target will be (within a few meters) as the ordinance travels to a point in space and time.

d. Threat Avoidance. Tactics, signature reduction, warning, jamming and decoys are the tools available to preclude a successful threat engagement. If hit, you may have to rely on aircraft hardening.

e. Detection, Acquisition, and Tracking. The difference between detection and acquisition, versus tracking is very important. In detection and acquisition, the threat weapon system does not have enough refined data to facilitate firing at the aircraft. The threat weapon system must track the aircraft long enough to acquire range, azimuth, elevation, and velocity, to determine the time and position of firing. Indications of search or acquisition activity may provide the aircrew time to initiate a response. Tracking indications alert the aircrew to an immediate action requirement, such as masking, employing ASE decoys, or executing evasive maneuvers.

f. Engagement Envelope. All threat systems are confined by physics. Each threat system has a minimum and maximum effective altitude and range. These numbers are computed against a cooperative engagement (nonmaneuvering aircraft, blue sky background, flat terrain, steady velocity, etc.). The effective envelope for a threat system is based upon a 50 percentile. That is, at the maximum (or minimum) effective range (or altitude), the weapon system is able to hit the target one out of two times. As the target progresses further into the threat envelope, the probability of a first shot kill increases. As the target progresses further outside the threat envelope, the probability of being hit decreases, until the target has reached a point where it is impossible to be hit.

g. Decreasing the Probability of Hit. The aircrew has the ability to make the engagement more difficult for the threat. A stationary target allows the threat to adjust each shot from the previous shot, until it hits the aircraft. A moving, constant velocity target provides a more difficult engagement procedure. A prediction can be made from the previous shot and adjustments imposed to enhance accuracy. The most difficult engagement is the moving target that varies range, altitude, elevation, and velocity. This makes prediction nearly impossible, since four factors are changing at differing rates.

h. Threat Weapon Sensors. There are generally four major types of threat weapon sensors. These may be man-portable or transported by land, sea, or aerial platforms. It is important to determine the actual sensor type, and guidance package, for each threat and understand their inherent capabilities and limitations. (For in-depth information concerning particular threat systems, contact your unit electronic warfare officer or tactical operations officer.) The four major types of threat weapon sensors are radar, IR, laser and DEW, and optical/EO.

(1) Radar. Direct threat radar weapons require LOS to hit the target. Direct threat radar weapons are either fire controlled AAA or for missile systems command, semiactive radar homing, active radar homing, track via missile, or ground aided seeker. Radar weapons must detect, acquire, track, launch and guide (or fire a ballistic solution), and assess damage. Radar systems have trouble with ground clutter. To pick out targets from ground clutter, radar systems can detect movement though the use of moving target indicator, Doppler (continuous wave radar), or Pulse Doppler. Modern radar systems can track the movement of the aircraft, while some systems also detect the movement of rotor blades. A few older radar systems had blind speeds (called a Doppler notch), where they could not detect an aircraft flying a specific speed towards or away from the radar. Modern radar systems cancel blind speeds. Radar systems can be detected, avoided, decoyed, jammed, and destroyed by direct and indirect fires (self, artillery, and antiradiation missiles).

(2) Infrared. All IR direct threat weapons require LOS to be established prior to launch and the in-flight missile must maintain LOS with the target until impact (or detonation of the proximity fuse). IR missiles require the operator to visually detect the target and energize the seeker before the sensor acquires the target. The operator must track the target with the seeker caged to the LOS until it is determined that the seeker is tracking the target and not any background objects (natural or man made objects to include vehicles, the sun, or reflected energy of the sun off clouds, etc.). The IR sensor is also susceptible to atmospheric conditions (haze, humidity), the signature of the aircraft and its background, flares, decoys, and jamming. Generally IR systems are--

• Difficult to detect prior to launch (passive sensor).
• Difficult to predict where they may be located (portability).
• Difficult to respond to (short time of flight after launched).
• Difficult to hard kill (requires shooting at an in-flight missile).

(3) Laser and directed energy weapons. Laser/DEW weapons really fit two distinct categories--laser guided or aided weapons and pure laser/DEW weapons. Laser guided, or aided weapons, are those who use the laser to perform ranging, tracking, or guiding functions for conventional explosive missiles or projectiles. Pure laser/DEW weapons use Laser and other forms of DEW to inflict damage to the aircraft or its sensors, including the eyes of the aircrews. Pure laser/DEW weapons are not required to burn a hole in the target to destroy it (although these weapons are reaching that capability). Simply igniting fuel vapor near vents or burning through fuel lines are effective, as well as glazing the cockpit glass so the aircrew cannot see out. Inherently, laser/DEW weapons are short duration, hard to detect, extremely hard to decoy or jam, and hard to kill. Fortunately they must rely upon LOS, certain atmospheric conditions, and are somewhat short range, at present.

(4) Optical/electro-optical. Optical/EO sensors are used as either the primary or secondary sensor for all weapon systems. Although they rely upon LOS, they are, with very few exceptions, completely passive. They are limited by human eyes, atmospheric conditions, distance, operator movement, and in many cases, by darkness. The optical/EO sensors are most difficult to detect and seldom can be decoyed; however, they can be jammed by obscurants, and when located, can be hard killed.

a. Aircraft Signature Reduction. All cargo and utility helicopters are painted with nonreflecting IR absorbing paint. UH-60 and EH-60 aircraft are equipped with HIRSS, which reduces the IR signature by suppressing hot exhaust gases. HIRSS aids the effectiveness of the AN/ALQ-144A IR missile jammer. CH-47 aircraft do not presently have exhaust suppression. The CH-47 aircraft are protected from IR missiles by the combination of the AN/ALQ-156 countermeasures set and the M-130 flare dispenser. The radar and IR signature of utility and cargo helicopters is least when viewed from the front. The maximum IR signature is from the rear quadrants, whereas the maximum radar signature is from the side aspects. The aircrews have the ability of decreasing the signature exposed to threats by changing the aspect of the aircraft. This is least effective in the CH-47 aircraft.

b. Aircraft Survivability Equipment Suites.

(1) EH-60 aircraft survivability equipment suite capabilities. The EH-60 ASE suite provides for PW radar and CW radar signal detection, CW radar jamming, and decoying for radar directed threats. Additionally the ASE suite provides omnidirectional IR jamming and decoying for IR directed threats. The aircraft signature reduction capabilities includes both nonreflective IR absorbing paint and HIRSS, which suppresses hot exhaust gases (see Figure G-1).

(2) UH-60 aircraft survivability equipment suite capabilities. The UH-60 ASE suite provides for PW radar and decoying for radar directed threats. Additionally the ASE suite provides omnidirectional IR jamming for IR directed threats. The aircraft signature reduction capabilities include both nonreflective IR absorbing paint and HIRSS, which suppresses hot exhaust gases (see Figure G-1).

(3) CH-47 aircraft survivability equipment suite capabilities. The CH-47 ASE suite provides for PW radar signal detection for radar directed threats. Additionally the ASE suite provides omnidirectional IR decoying for IR directed threats. The aircraft signature reduction capability consists of nonreflective IR absorbing paint only (see Figure G-2).

c. Situational Awareness. All cargo and utility aircraft are equipped with PW RSDS (such as AN/APR-39(V)1, AN/APR-39(V)2, or AN/APR-39A(V)1), which provide the aircrew with alerts of radar activity. Aircrews use the cues from the RSDS to change modes of flight (contour to NOE) or to increase vigilance by actively seeking terrain features for masking. EH-60 aircraft also detect the presence of CW radar through the use of the AN/ALQ-162 continuous wave radar jammer.

d. Active Countermeasures. ASE countermeasures assist the aircrew in buying time when masking terrain is not readily available, and the aircraft must maneuver to masking terrain or move outside the threat range. IR threats can be jammed by AN/ALQ-144A(V)1 or through the combined use of the AN/ALQ-156(V)2/3 and the flare equipped M-130 general purpose dispenser. Radar threats can be decoyed by use of the M-130 with chaff. CW radar can be jammed by the AN/ALQ-162(V)1.

e. Radar Warning Receivers.

(1) AN/APR-39(V)1 radar signal detecting set. The AN/APR-39(V)1 RSDS is the basic version of RSDS, which uses a signal comparator, signal intensity strobe display, and audio cues to provide detection of PW radar. It provides coverage for C/D and E through J band PW radar. The system has the capability of detecting all pulse radars normally associated with hostile SAM, airborne intercepts, or antiaircraft weapons. Indications require direct aircrew interpretation since this system has no EID software.

(2) AN/APR-39(V)2 radar signal detecting set. The AN/APR-39(V)2 RSDS is a special version of RSDS, which uses a digital processor and alphanumeric display to provide detection of PW radar for special electronic mission aircraft. It provides coverage for C/D and E through J band pulsed wave radar. The system has the capability of detecting all pulse radars normally associated with hostile SAM, airborne intercepts, or antiaircraft weapons. The EID software is reprogrammable and must be specific theater selected before flight.

(3) AN/APR-39A(V)1 radar signal detecting set. The AN/APR-39A(V)1 RSDS is an upgraded version of the AN/APR-39(V)1, which uses a digital processor, alphanumeric symbology display, and synthetic voice warning to alert the aircrew to the presence of radar directed air defense threat systems. It provides coverage for C/D and E through M band PW radar. The theater specific EID software is reprogrammable.

f. AN/ALQ-144A(V)1 Countermeasure Set. This CMS is an active, continuously operating omnidirectional, IR jammer system for helicopters, designed to confuse or decoy threat IR missile systems. The AN/ALQ-144A(V) CMS is designed to provide jamming of all known threat IR missile systems, and it must be operated on an aircraft equipped with low reflective paint and engine exhaust suppressers. The system has specific jam program number settings that must be set prior to flight (see Figure G-3).

g. AN/ALQ-162(V)2 Countermeasure Set. This CMS provides warning and protection against SAM and airborne intercept missiles using CW illuminator radar for guidance. The CW signals detected by the system will be validated, and jamming initiated, in conjunction with threat identification given to the aircrew. The specific action taken by the system is determined by warning and jamming thresholds programmed into the system. The system has specific jam settings that must be set prior to flight.

h. AN/ALQ-156(V)1/2 Countermeasure Set. This CMS is an airborne radar system that provides protection to the aircraft by detecting the approach of antiaircraft missiles. Upon detection, the missile detector automatically initiates a signal that triggers the M-130 general dispenser system. The dispenser system releases a flare to decoy an IR seeking missile away from the aircraft.

i. M-130 General Purpose Dispenser. The M-130 dispenses chaff and flares. The system is operated manually or automatically through interface with other countermeasure systems. The chaff provides protection against radar directed antiaircraft weapon systems, while the flares provide protection against IR directed missile systems. When dispensing chaff, the M-130 reduces or eliminates the enemy's ability to hit and destroy aircraft by use of radar-controlled, antiaircraft weapons. When dispensing flares, the M-130 reduces or eliminates the enemy's ability to hit and destroy aircraft by use of IR guided missiles. When the M-130 is set to dispense chaff, the electronic control module must have the program setting installed prior to flight.

j. Tactical Operations Officer. For ASE to provide effective protection during a mission, configuration settings must be optimized for the threats encountered. The TOO at the brigade and battalion staff will assist the S3 operations officer in mission planning for aircraft survivability during mission accomplishment. TOE place the TOO in the aviation company as a CW3, in the battalion operations as a CW4 (CW5 at battalion for CH-47 Battalions), and in the brigade as a CW5. TOO is identified by the SQI I (such as 153BI). The ASE/EW officer is a CW2 in the aviation company. ASE/EW officer is identified by the ASI H3 (such as 153B0H3) ASE/EW officer ensures optimum ASE configurations settings are prepared for each flight.

a. Aircraft survivability functions must be included throughout mission planning, rehearsal, execution, and recovery operations. Mission planning begins with the receipt of the mission. It continues through mission execution, including the after-action review. It is important to plan and implement aircraft survivability functions when receiving the mission and enemy situation. Figure G-4 shows staff responsibilities for EW planning.

Legend: See the glossary for acronyms and abbreviations.

b. ASE and EW must be considered in all phases of mission planning. The level of planning involved is always predicated on the time, information, and personnel available. OPLANs and OPORDs for military operations are extensive in scope and contain information that serves as a baseline for most unit operations.

c. The generation of the OPORD begins upon receipt of the enemy and friendly situation, the mission, and the commander's intent. Figure G-5 links EW planning with OPORD/FRAGO development. The EW annex (Figure G-6) is created to support the OPORD or OPLAN, using this information. The enemy and friendly situations are further defined with the emphasis on the EW capabilities of both, and their ability to find, fix, jam, deceive, disrupt, or destroy each other. Once the situation is clearly defined, the mission is analyzed to evaluate the risk to friendly forces, while accomplishing the mission within the prescribed guidelines. After the risk assessment is complete, risk reduction techniques are specified in the execution instructions. These techniques may require the commander's approval if the mission constraints need to be altered significantly from the original intent. The next step is to determine service support for EW and the command and signal guidance necessary to accomplish the EW phase of the mission.

Legend: See the glossary for acronyms and abbreviations.

Legend: See the glossary for acronyms and abbreviations.

a. To perform a thorough risk assessment, detailed information about threat system operating procedures, tactics, system capabilities, and locations must be analyzed to determine the enemy's advantages or disadvantages in the use of EW. The capabilities and limitations of friendly EW systems must be compared to the threats to assess the level of risk associated with the mission. During mission planning, the following threats must be identified:

• Operating frequencies of radar threats.
• RF threats that can, or cannot, be detected.
• RF threats that may be affected by radar jamming equipment.
• RF threats that can be decoyed.
• IR threats that may be encountered.
• IR threats that can be detected.
• IR threats that can be jammed or decoyed.

b. The threat systems should be prioritized and the ASE settings optimized for the highest priority threats. Determine the level of risk based on the threat's capabilities and limitations, the capabilities and limitations of the ASE, and the mission. Figure G-7 shows a suggested format for a worksheet used to assess EW risk. Lethal threats that cannot be countered by ASE, must be identified and PIR developed and submitted to higher. For example, the SA-X is very lethal and no organic ASE counters it. This threat would pose a high risk to mission accomplishment and must be located within the AOs to ensure aircrew safety. Apply risk reduction techniques to minimize the risk and enhance the probability of survival. Risk reduction measures are as follows:

• Plan mission time earlier or later to take advantage of night operations.
• Use only suppressed aircraft for the higher risk portions of the mission.
• Request escort aircraft to suppress threats.
• Plan SEAD at critical points to reduce vulnerability.
• LZ/PZ preparation with indirect fires.
• Alter flight routes to avoid known air defense areas.
• Deception plan to include false insertion.
• Signature reduction (EMCON).
• Adjust formation/sortie size.

c. The ASE/EW mission briefing disseminates information and instructions to the aircrews prior to the mission. The briefing will alert aircrews to the risks associated with the threats, the optimum ASE settings, and a review of the tactics specific to the mission. These tactics include evasive maneuvers, actions on contact, multiship breakup and reformation procedures, and rules of engagement for countermeasures employment and crew served weapons.

d. Once the OPORD (and EW Annex) is generated, it becomes the base document. For specific missions, complete OPORDs may not always be required. In these instances, FRAGOs outlining the changes from the basic OPORD are created and issued to affected units. Upon receipt of the FRAGO, the staff planners must evaluate the information available and revalidate the EW Annex. Any changes to the EW Annex must be detailed and disseminated to the aircrews as part of the mission briefing. Figure G-8 is a suggested format for an ASE/EW mission briefing to assist EWOs in completing this task.

Legend: See the glossary for acronyms and abbreviations.

Legend: See glossary for acronyms and abbreviations.

e. During the conduct of mission execution it is important for aircrews to be familiar with the ASE situational awareness displays and the expected threat indications. Some actions must be performed without delay. When the visual indications reveal a gun or missile being fired at the aircraft, or the ASE indicates a radar track or launch, the aircrew has limited time to perform an action preventing the aircraft from being engaged. Crew coordination of evasive maneuver performance must be rehearsed, and standardized terminology, such as "missile three o' clock, break right," used to avoid confusion. There are situations when evasive maneuvering is not required, such as during radar search or acquisition. Three distinct elements of reacting to threat engagements are--

• Indication (determine immediate actions).
• Evasive maneuver (when masking terrain is not readily available).
• Actions on contact (decision to continue or abort mission).

f. Formation types, and spacing intervals, should be selected to provide all aircraft the necessary maneuver space for hostile fire avoidance. Standardized terminology, such as "chalk two breaking right...missile" or "chalk three breaking left...tracers at nine o' clock," should be used to alert the flight to your actions. Briefings should include evasive formation break up procedures and the method for reforming after breaking the engagement. It is important to communicate your ASE indications to other aircraft in the formation, since you may be the only aircraft receiving indications, due to terrain, narrow radar beam, altitude, or maintenance problems.