AH-64D Longbow
The AH-64D Longbow Apache is a remanufactured and upgraded version of the AH-64A Apache attack helicopter. The primary modifications to the Apache are the addition of a millimeter-wave Fire Control Radar (FCR) target acquisition system, the fire-and-forget Longbow Hellfire air-to-ground missile, updated T700-GE-701C engines, and a fully-integrated cockpit. In addition, the aircraft receives improved survivability, communications, and navigation capabilities. Most existing capabilities of the AH-64A Apache are retained.
The AH-64D is being fielded in two configurations. The full-up AH-64D includes all of the improvements listed above. In addition, a version of the AH-64D [formerly designated the AH-64C] without the FCR will be fielded. This version will not receive the new Radar Frequency Interferometer (RFI) or the improved engines, but will retain the other Longbow modifications. The AH-64D without FCR is capable of launching the Longbow Hellfire missile. Boeing delivered the first remanufactured Longbow Apache in March 1997. A total of 501 AH-64A Apaches are to be upgraded to the AH-64D configuration, 227 of which will be equipped with the FCR.
Transportability requirements were initially identified in the ORD and further defined in the AH-64D System Specification. Both configurations of the AH-64D, including any removed items and appropriate PGSE, shall be capable of being transported aboard C-141B, C-5A, or C-17 aircraft. The aircraft shall also be capable of being transported and hangar stored below decks in the landing platform helicopter (LPH) type carrier, Fast SeaLift ships, Roll-on/Roll-off, LASH, SEABEE ships, and Military Sealift Command (MSC) dry cargo ships. Additionally, the aircraft shall be transportable by military M-270A1 trailer and commercial "Air-Ride" trailer or equivalent. For aerial recovery, the AH-64D with MMA will be externally transportable by CH-47D aircraft using the Unit Maintenance Aerial Recovery Kit. Two AH-64D plus one FCR aircraft will be transportable by C-141, six AH-64Ds (with a minimum of three FCR mission kits) are transportable by C-5, and three AH-64Ds and three FCR mission kits are transportable by C-17.
During Army operational testing in 1995, all six Longbow Apache prototypes competed against standard AH-64A Apaches. The threat array developed to test the combat capabilities of the two Apache designs was a postulated 2004 lethal and digitized force consisting of heavy armor, air defense and countermeasures. The tests clearly demonstrated that Longbow Apaches:
- Are 400 percent more lethal (hitting more targets) than the AH-64A, already the most capable and advanced armed helicopter in the world to enter service.
- Are 720 percent more survivable than the AH-64A.
- Meet or exceed Army requirements for both target engagement range and for probability of acquiring a seleted target. The specific requirements and results are classified.
- Easily can hit moving and stationary tanks on an obscured, dirty battlefield from a range of more than 7 kilometers, when optical systems are rendered ineffective.
- Can use either its Target Acquisition Designation Sight or fire control radar as a targeting sight, offering increased battlefield flexibility.
- Have the ability to initiate the radar scan, detect and classify more than 128 targets, prioritize the 16 most dangerous targets, transmit the information to other aircraft, and initiate a precision attack -- all in 30 seconds or less.
- Require one third less maintenance man hours (3.4) per flight hour than the requirement.
- Are able to fly 91 percent of the time -- 11 percent more than the requirement.
One issue uncovered during the Initial Operational Test that required follow-on testing involved the method of employment of the Longbow Hellfire missile. During the force-on-force phase, Longbow flight crews frequently elected to override the system's automatic mode selection logic and fire missiles from a masked position. This powerful technique can significantly increase the helicopter's survivability, but has not been validated with live missile firings during developmental or operational testing. DOT&E worked with the Army to develop a test plan that will confirm system performance using this firing technique. This test program will include computer simulation of the missile's target acquisition and fly-out as well as live missile firings at moving armored vehicles.
The AH-64D Longbow Apache (LBA) provides increased data transfer capabilities such as SPOTREPs, SITREPs, battle damage reports, target handover, and real-time images of the battlefield with use of the IDM. The IDM is a tri-service device that offers backward capability to the OH-58D airborne target hand-over system (ATHS) and tactical fire (TACFIRE). With TACFIRE integration, the Longbow can send target information to the entire TACFIRE net for immediate suppression. Besides target handover, the IDM provides the capability to send fragmentary orders (FRAGOs); enemy/friendly location updates; graphic updates and changes; and any other pertinent information from the commander to the Longbow Apache company/team--or from LBA to commander--while en route to or in the battle position. This timely exchange of information reduces the time of manually plotting information and increases operational tempo, allowing the commander to shape the battlefield. The data transfer module (DTM), mounted in the Longbow Apache, is used to quickly upload the mission data and initialize aircraft systems for the mission. Data can be loaded into all aircraft or loaded into the first aircraft and transmitted via the IDM to all other aircraft in the mission. When the mission is complete, the DTM retains all mission data debriefing information to carry back to the AMPS for the debrief. In addition, the DTM provides the maintenance section with data for troubleshooting, reducing maintenance downtime.
The Longbow Fire Control Radar significantly improves the adverse weather fighting abilities of the AH-64D helicopter, provides a true fire-and-forget capability and increases target acquisition efficiency and effectiveness, thus increasing battlefield effectiveness and survivability. The aircraft is able to detect and classify more than 128 targets, prioritize the 16 most dangerous targets, transmit the information to other aircraft and initiate a precision attack -- all this in fewer than 30 seconds.
With the addition of a new and highly sophisticated fire control radar (FCR), more commonly called the Longbow Fire Control Radar, the AH-64D has become the most advanced aerial fighting vehicle in the world. The FCR provides the Apache with the ability to detect, classify and prioritize stationary and moving targets both on the ground and in the air. With state of the art fire control, digital communications, automatic target classification and many other up to date features, the AH-64D Longbow Apache will dominate the battlefield for years to come.
The AH-64D Apache Longbow increases combat effectiveness over the AH-64A by providing a more flexible digital electronics architecture and integrating computer-based on-board Built-In Test Equipment (BITE), Automatic Test Equipment (ATE), and hard copy operator or Interactive Electronic Technical Manual (IETM) troubleshooting/maintenance manuals that will easily accommodate changes resulting from system growth. In addition, upgrades to electrical power and cooling systems and the expansion of the forward avionics bays to accommodate the installation of the FCR, and provide for future growth. Navigation system accuracy is improved through integration of a miniaturized integrated Embedded Global Positioning System (GPS)/Inertial Navigation Unit (INU) (EGI), and an improved DOPPLER Velocity Rate Sensor (DVRS).
The fully integrated AH-64D without Longbow Mission Kit incorporates greater ordnance capability and flexibility than the AH-64A by utilizing the family of Semi-Active Laser (SAL) missiles (including the HELLFIRE II) and Longbow HELLFIRE RF Missile. The AH-64D without Longbow Mission Kit can operate in harmony with the FCR-equipped AH-64D and can accept a target hand over and fire the Longbow missile with minimum exposure to hostile forces.
The AN/APG-78 FCR is a multi-mode Millimeter Wave (MMW) sensor integrated on the Apache Longbow with the antenna and transmitter located above the aircraft main rotor head. It enhances Longbow system capabilities by providing rapid automatic detection, classification, and prioritization of multiple ground and air targets. The radar provides this capability in adverse weather and under battlefield obscurants. The FCR has four modes: (1) the Air Targeting Mode (ATM) which detects, classifies, and prioritizes fixed and rotary wing threats; (2) the Ground Targeting Mode (GTM) which detects, classifies, and prioritizes ground and air targets; (3) the Terrain Profiling Mode (TPM) which provides obstacle detection and adverse weather pilotage aids to the Longbow crew; (4) and the Built in Test (BIT) Mode which monitors radar performance in flight and isolates electronic failures before and during maintenance.
The Longbow RF missile and the Longbow HELLFIRE Launcher (LBHL) are referred to as the LBHMMS. The system incorporates a fire-and-forget missile that accepts primary and/or secondary targeting information from the FCR and single targeting information from TADS or another aircraft to acquire and engage targets. Similar to the FCR, the RF missile provides the capability to engage threats in adverse weather and through battlefield obscurants. Two acquisition modes, lock-on-before-launch (LOBL) and lock-on-after-launch (LOAL), allow engagement of ground and rotary wing threats at extended ranges. In the LOBL mode, the missile will acquire and track moving or short range stationary targets prior to leaving the launch platform. In the LOAL mode, the missile will acquire long range stationary targets shortly after leaving the launch platform.
The Longbow Hellfire missile is a radar-guided version of the laser-guided Hellfire anti-tank, air-to-ground missile. The Army manages Longbow Hellfire missile as a separate program. The Longbow Hellfire features an active millimeter wave seeker and a dual tandem warhead designed to defeat reactive armor. Either the FCR or the Target Acquisition and Designation Sight can provide target location data to the missile prior to launch. The Longbow Hellfire can engage moving or stationary vehicles. The missile is being upgraded through the Home-on-Jam/Anti-Jam (HOJ/AJ) and Counter-Active Protection System (CAPS) programs. The HOJ/AJ upgrade is a software revision that changes the guidance logic to improve effectiveness against self-screening and standoff jammers. The CAPS upgrade includes hardware and software to provide active counter-countermeasures for the missile.
The combination of the integrated FCR, LBHMMS and the Apache aircraft enhances battlefield awareness by providing coverage of the battle area at extended ranges, by reducing operational dependence on weather and battlefield conditions, and by rapid display of detected targets. It further improves the Longbow system's war fighting capability and survivability by providing rapid multi-target detection and engagement ability, navigational aids, and a fire-and-forget weapon delivery system.
The addition of the Longbow FCR provides a second and completely independent target acquisition sensor which may be operated by either crew member or combined to provide a degree of multi-sensor synergy. When operated independently, the pilot could use the FCR to search for air targets in the ATM mode while the copilot/gunner (CPG) searches for ground targets using the Target Acquisition Designation Sight (TADS).
Using both TADS and the FCR together combines the unique advantage of each sight. The rapid search, detection, classification, and prioritization of targets by the Longbow FCR can then be quickly and positively identified by using the electro-optics of TADS. The center of view can be focused on the location of the highest priority target and the CPG, at the touch of a switch, can view either display. Alternately, the FCR centerline can be cued to the TADS so that a rapid and narrow search could be made of a suspected target area.
The RFI is an integral part of the Longbow FCR. It has sensitivity over an RF spectrum to detect threat emitters when a threat radar is in a search and acquisition mode and also when the threat emitter is "looking" directly at and tracking the Longbow system. The RF band has been extended over that which was developed for the OH-58D Kiowa Warrior at the low end of the RF spectrum to detect newly identified air defense threats. The RFI has a programmable threat emitter library to allow additional threat signatures to be stored and/or updated.
The Modernized TADS/PNVS program replaces six of the current LRUs with new ones. They are the PNVS, PNVS Shroud, NSA, BSM, TEU, TPS, and PEU. Also, slight modifications are being made to other components to address other maintenance drivers identified over the years. The DSA and Laser are not being modified. The modernization includes moving to a two-level maintenance concept for the new LRUs. The Line Replaceable Units (LRUs) are being designed to allow smaller Line Replaceable Modules (LRMs) to be fault isolated and replaced, rather than the entire LRU.
The basic configuration and outer look of the M-TADS/PNVS will almost be identical to the current system. The PNVS shroud will look different, because it now has two sensors, the new FLIR and an Image Intensification Sensor (basically a built-in 18mm NVG tube). The pilot will now be able to switch between the two sensors and to fly using the one best for the existing conditions. Complete provisions are included to fuse the two images, but image fusion is not yet being implemented. The shroud is broken into two LRMs (shroud and window), making removal much simpler. The current W-10 harness is being replaced with a two-piece design. The new FLIR will have much better image quality than the current system. It will have 4 pixels across and 480 pixels down (4x480), compared to the current common module 1x180 configuration. What this means is that the system will have much better wire detection and marginal weather performance -- at least 20/45 visual acuity, compared to today's 20/80.
The boresight module is being replaced with a new module to eliminate the need for the out-front boresight procedure. Boresight will be accomplished automatically after initiation by the CPG. The entire boresight procedure will take under 2 minutes to complete. The current target tracker is being replaced with a new, more robust design. The new multi-target tracker system will be capable of tracking up to six targets. The NSA will still have the three fields of view: wide, medium, and narrow. In addition, there will be a 2X zoom with no time limit. The system will incorporate extended range algorithms to provide even greater ID ranges. The should result in almost twice the range capability of the current system. The CPG pilotage mode (wide FOV FLIR) will equal today's PNVS pilotage performance.
Maintainers will have three methods to fault isolate problems, including the aircraft Fault Detection/Location System (FD/LS). In addition, select LRUs will have LCD displays on the front that will display an error code indicating the faulty LRM. The TEU, for instance, is broken down into individual circuit cards that can be removed and replaced. A small LCD display on the front of the TEU will show the maintainer which card is faulty and needs to be replaced. Finally, the system will have the capability to interface with the SPORT computer. Other maintainer-friendly changes are being made. Straps on the current TEU and TPS, for instance, are being replaced with real handles for easier handling.
The Army is also looking at replacing the current IHADSS with an upgrade to take full advantage of the increased performance of the new system. The replacement for the ORT, TEDAC, will be included as part of the M-TADS/PNVS upgrade for aircraft that haven't received it by the time we start fielding. We are also pursuing a digital TECA to be fielded in conjunction with the M-TADS/PNVS.
The Modernized TADS/PNVS is under a developmental contract signed in October 2000 and is currently on schedule. The schedule for the program is very aggressive. Following a 27-month EMD effort, the Army will start production in the FY 03 timeframe. First deliveries should occur around April 2004. The upgrade will be a field retrofit kit that will take about 8 hours to install. The current schedule will allow battalion size units to begin being retrofitted in the 2005 timeframe. There is currently an effort ongoing to accelerate the fielding of a limited quantity to Longbow units. The last Modernized TADS/PNVS IPT was conducted in Orlando, FL 14-16 November 2001. Representatives from the Apache Program Manager, AMCOM Engineering, TRADOC System Manager, Army Test and Evaluation Command and other agencies reviewed the current schedule and requirements for prototypes to be used in various test beds. Additionally, the training working group met in order to address strategies for: Documentation, Training Support Packages, Integration into LCT, Maintenance training devices and other lesser issues.
Three types of Army helicopters will be retired before 2005, and aviation battalions will be reorganized as part of the Army's 2000 Aviation Force Modernization Plan, which was unveiled in April 2000. Under the plan, AH-1 Cobras were divested by October 2001, and UH-1 Iroquois and A and C model OH-58 Kiowas retired by 2004. According to the plan, the UH-1s are replaced by UH-60 Black Hawks. The Cobras and Kiowas are replaced by AH-64D Apaches and eventually by RAH-66 Comanches, the new reconnaissance and attack helicopter scheduled to begin joining the Army in 2008. Later-model Kiowas are scheduled for retirement in fiscal year 2013, according to the plan.
The first McDonnell Douglas Apache Longbow for the US Army made its maiden flight 17 March 1997. All AH-64A Apaches in the fleet are to be upgraded to the AH-64D configuration: 227 will be equipped with the FCR, and the remaining 531 will not. Each attack helicopter company will receive three aircraft with FCRs and five without.
McDonnell Douglas Helicopter Systems is under contract for the first 18 Longbow Apaches and delivered the first remanufactured Longbow Apache in March 1997. The Army and McDonnell Douglas agreed to a five-year, multi-year agreement that will give the Army 232 Longbow Apaches in the first five years of production. The multi-year purchase increases the Longbow Apache production rate in the first year to 24 aircraft and 232 for the five-year period. Under the multi-year contract, the Army will field two additional combat-ready Longbow Apache battalions. The contract also includes funding for McDonnell Douglas to train pilots and maintenance personnel for the first two equipped units, development of interactive electronic technical manuals, development of training devices, first article testing of the production aircraft, initial spares, and a variety of program support tasks for the first production lot. The U.S. Army plans to remanufacture its entire AH-64A Apache fleet of more than 750 aircraft over a decade.
As of early 2001 work was continuing in the negotiation of the second multiyear procurement contract for the Longbow Apache. The Army planned to procure another 269, which will bring the total to 501. Deliveries of the radar continued to close on the total of 227 FCRs. The Army was also in the process of selecting a contractor to develop the modernized TADS/PNVS.
The Army started fielding Lot 5 aircraft in April 2001. This completed MYI aircraft delivery. The Army had recently completed the final design review of the first MYII (Lot 6) Longbows and the first design review of the Lot 7 Longbows. The MYI and Lot 6 aircraft are the same configuration and will have the same software load. The MYII Lot 6 aircraft differ only in the internal components for some of the black boxes. These changes were made to correct obsolescence problems. Lot 7 aircraft will have a much greater processing capability and, with the introduction of the fiber channel data bus, will enable significant growth in the future.
Fort Hood's 21st Cavalry Brigade (Air Combat) is responsible for receiving, equipping, fielding, training, evaluating and certifying all the Army's attack and cavalry aviation units, including the battalions which are scheduled to field the AH-64D Longbow Apache. Starting with 1st Battalion, 227th Aviation of Fort Hood's 1st Cavalry Division, all the units become non-deployable during the 204 days they're assigned to 21st Cavalry Brigade for the intense training process. All pilots receive their initial training at Fort Rucker, AL, while the unit's maintainers received their training at Mesa and Fort Eustis, VA. The Unit Fielding and Training Program, designed by the brigade and approved by the Department of the Army, builds a battalion into a unit that is combat-ready with its new equipment. The battalion then returns to its home station, ready to begin Mission Essential Task List training with its own higher headquarters. The fielding process culminates in a battalion-level exercise and evaluation by the 21st Cavalry Brigade, and if all the requirements are met, the battalion is certified combat ready and they return to their home station.
The Materiel Fielding Plan (MFP) is essentially a one-stop reference for all fielding activity requirements. It shows who develops, fields, receives, and stores a piece of equipment and its associated tools, test equipment, repair parts, and training devices. The MFP will outline what the piece of equipment is used for, who uses it, who repairs it, the maintenance and supply structure which will be in place to provide life cycle support, and the training requirements inherent to the system. Several draft version MFPs are published per the documents listed above in order to generate a dialogue between the developer and the end user in order to simplify and expedite the fielding process.
The Army's plan to activate and field eight Longbow Apache battalions since fielding began in FY98 is on schedule. As aircraft are being fielded, configuration changes are being planned to improve system effectiveness, reliability, and survivability. The changes include a modernized target acquisition designation system (M-TADS), the possible integration of the Suite of Integrated Infrared Countermeasures (with a focus on the advanced flare dispenser and the advanced flares), and the integration of the internal auxiliary fuel system (IAFS) (a new crash-worthy and ballistically tolerant fuel tank and ammunition magazine located internal to the aircraft). DOT&E will continue to monitor development and testing of these, and other, configuration changes.
The AH-64D Apache Longbow aircraft, Fire Control Radar (FCR), and Longbow Hellfire Modular Missile System (LBHMMS) were fielded starting with the 1-227 Attack Helicopter Battalion in July 1998. As this is a FORSCOM unit, the first MFP published will be for FORSCOM. Other MFPs, each tailored to the specific Major Command (MACOM) receiving the AH-64D, will be published at the appropriate time. Therefore, FORSCOM, TRADOC, USAREUR, EUSA, USAR, and the ARNG will each receive their own version of the MFP. Distribution varies with each subsequent draft prepared.
The Office of the Deputy Chief of Staff for Operations and Plans (ODCSOPS) makes the decision as to what units receive the AH-64D and in what order. The AAH PMO publishes and distributes MFPs based on ODCSOPS' schedule. The fielding schedules change from time to time, and the schedule in the MFP is, therefore, current as of the publishing date. The First Draft for each MACOM's MFP is published approximately 26 months before the first aircraft and equipment are fielded to a MACOM. A MACOM's Final MFP is published approximately 8 months prior to its first-unit fielding. The fielding schedule as of 1 June 1997, is attached. It does not include the aircraft destined for the TRADOC training fleet at Ft. Rucker. Ft. Rucker begins receiving its AH-64Ds in June 1999; the TRADOC First Draft MFP left the AAH PMO in May.
On April 3, 2002 the U.S. Army today accepted two milestone AH-64D Apache Longbow helicopters in a ceremony held at Boeing in Mesa, Ariz. The ceremony, attended by U.S. Army, industry and government officials, included delivery of the final Apache Longbow from the first five-year, multi-year production effort, known as multi-year I, and the first Apache Longbow for the Army's newest production effort, known as multi-year II. The aircraft were the 232nd and 233rd Apache Longbows to be delivered to the U.S. Army. Multi-year II, which will provide 269 Apache Longbows for the Army through 2006, was signed in September 2000. Multi-year I, which provided 232 Apache Longbows to the Army, authorized production of the next-generation Apache in 1995. In all, the Army has ordered 501 Apache Longbows for its 21st century combat needs.
Testing on the IAFS during FY03 is complete. Concerns with the accuracy and adequacy of the performance tables found in the operator's manual for the AH-64D prompted the initiation of Airworthiness and Flight Characteristics (A&FC) testing of the AH-64D Longbow Apache in February 2002. A&FC testing continues and requires approximately 300 flight hours to complete. The Army anticipated completion of this testing in early FY04. The Army Aviation Technical Test Center will test handling qualities and the latest software releases for the Embedded Global Positioning System Inertial Navigation System and the Flight Management Computer.
The Army planned to complete Lot 7 Preliminary Airworthiness Evaluation (PAE) early in FY04. The PAE consists of flight-handling qualities verification, crew workload assessment, crew interface evaluation, and verification of avionics system functionality associated with new and legacy capabilities.
The only remaining LFT&E item for the Longbow Apache concerns the engine fire and detection and suppression system (FDSS) test. The FDSS test, required by the Apache Longbow Test and Evaluation Master Plan, is being deferred so that it might be conducted with the Army Aviation Halon replacement. However, since a suitable dropin halon replacement is not forthcoming, the Program Management Office is in the process of planning to conduct this test with the existing Halon 1301 system. The Army intended to use a fully operational representative, but not flightworthy, aircraft as the ground test article to conduct this series of tests in 2QFY04.
The Army conducted ten Hellfire missile flight tests in FY03 to support the HOJ/AJ software regression testing and determine its effectiveness in countermeasure environments. Analysis of this testing is ongoing with results expected during 2QFY04. For the CAPS upgrade, pre-qualification testing was conducted in FY03 to address the radome design, antenna design, effective radiated power, guidance section performance, and radar cross-section. Because the CAPS is added to the exterior of the existing missile, aerodynamic impacts of the upgrade are being studied; sub-scale wind tunnel testing was proposed for FY04.
Opportunities to analyze and evaluate the effectiveness, suitability, and survivability of the AH-64A/D aircraft under combat conditions abounded during operations in FY02 against al Qaeda and Taliban fighters in Afghanistan and in FY03 during Operation Iraqi Freedom.
The Army found the IAFS effective and suitable and is fielding the subsystem. This addition/modification to the aircraft provides the units in the field with an aircraft that has an extended range capability with a fuel system that is crashworthy and ballistically tolerant. This is a much-needed improvement in the system, even though 30 millimeter round carrying capability is reduced from 1,200 rounds to 300 rounds due to the modification.
As expected, the A&FC aircraft testing confirms that the published performance charts for the AH-64D need refinement, but the magnitude and extent of the changes is not yet known. Early results of ongoing software regression testing show no significant anomalies.
The Lot 7 interoperability assessment confirms the aircraft's ability to send/receive joint variable message format and tactical fire direction system messages. In-flight workload assessment surveys and low airspeed testing are complete. Testing of the final software configuration is complete and a safety confirmation recommendation was forwarded to the Army Developmental Test Command for approval.
Results of recent combat deployments and training exercises confirm the results of the 1995 IOT&E assessment for the Longbow Apache helicopter - the AH-64D helicopter provides effective air-to-ground combat power. The Army afteraction reports from the Iraqi conflict conclude that the Longbow Apache aircraft survives, protects the crew, and can be quickly repaired and returned to combat. Still, improvements to the Apache aircraft and training devices could enhance the aircraft's effectiveness. The Army should consider accelerating the procurement and fielding of M-TADS to enable target identification at standoff ranges. Additionally, the Army should incorporate "running/diving fire" engagement tactics, techniques, and procedures, as well as dynamic engagements during peacetime training. This training would be especially beneficial in the Longbow qualification training at Fort Rucker, Alabama, and during unit aerial gunnery training.
