Aircraft Factfile and Recognition Guide - AH-1 Cobra

Background

The AH-1 Super Cobra is a two-place, twin-engine attack helicopter capable of land- or sea-based operations. It provides rotary-wing close air support (CAS), anti-armor/anti-helicopter, armed escort, armed and visual reconnaissance, and supporting arms coordination (SAC) during day/night and adverse weather conditions.

The Bell AH-1 Cobra helicopter has struck fear in the hearts of the enemy for more than 30 years. Armed helicopters came into widespread use in Vietnam in the early Sixties. Limitations of the modified armed utility helicopters used led to the specially configured attack helicopter. Instead, the AH-1F Cobra, with its proven firepower and maneuverability, went on to fight in every major US military operation since Vietnam. The Cobra continues its service with the US Marines, as well as eight other foreign nations.

The Cobra traces its lineage from the UH-1 Huey and was originally developed for the US Army in the mid-sixties. The original Cobra retained the Huey's engine, transmission, and other major parts, but replaced the Huey's bulky fuselage with a thin profile fuselage with tandem seating. The Marine Corps later adopted a twin engine variant of the airframe to perform troop helicopter escort and provide autonomous tank killing capability. Through the years, the Cobra has gone through extensive modernization. Today's Marine Corps AH-1W Super Cobra boasts an advanced Night Targeting System (NTS) and a full suite of survivability equipment.

The primary missions of the Cobra are helicopter Close Air Support (CAS), escort of transport helicopters and ground convoys, armed reconnaissance, helicopter air-to-air attack, anti-shipping operations, and coordination and terminal control of fixed wing CAS, artillery, mortars, and naval gunfire. It is the only western attack helicopter with a proven air-to-air and anti-radar missile capability. The rear seat pilot is primarily responsible for maneuvering the aircraft. The front pilot controls the aircraft's weapons systems, but he also has a full set aircraft controls.

There are at least eight different variants of the baseline AH-1 Cobra model. I will describe two variants on this page that you will most commonly see in the United States.

AH-1F Cobra

The AH-1F Modernized Cobra is identical to the AH-1S Modernized Cobra, and can be identified by the air data sensor mounted above the right side of the canopy. The AH-1F Cobra is equipped with the Allied Signal Engines (ASE) T53-L-703 1800 shp turboshaft engine, gearbox, and transmission introduced to the Production AH-1S Cobra.

Armament consists of the three-barrel M197 20mm automatic gun mounted on the M97A4 armament subsystem. The Modernized AH-1F is equipped to fire eight TOW (Tube-Launched, Optically Tracked, Wire Command-Link Guided) anti-tank missiles, and the Hydra 70 2.75 inch rocket system. It is equipped with the M65 TOW/Cobra missile system, the M147 Rocket Management System with the M97A4 armament subsystem. The Cobra can also disperse chaff and infrared jamming flares using the M130 general purpose dispenser. Some AH-1F Cobras have received the C-NITE upgrade, which allows the gunner to designate and acquire targets during night or adverse operating conditions.

In March 1999 the soldiers and pilots of the 25th Infantry Division (Light) said farewell to the AH-1F Cobra helicopter, the Army's first dedicated attack aircraft. The last active-duty unit to employ the Cobra -- the 1st Battalion, 25th Aviation Regiment -- retired the Vietnam-era gunship following a final show of force 15 March 1999 in the skies over Oahu. The battalion's AH-1F Cobras will go to the National Guard. All of the aircraft will be replaced with 24 OH-58D Kiowa Warriors, a revamped version of the Kiowa scout helicopter.

As of April 2001 there were over 395 AH-1F Cobras in the Army fleet, including 395 in active units and 43 in storage. Their scheduled obsolescence extends over the 2002 - 2015 period.

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.

AH-1W (Super) Cobra

The AH-1W Super Cobra is a day/night marginal weather Marine Corps attack helicopter that provides enroute escort for assault helicopters and their embarked forces. It is the only western attack helicopter with a proven air-to-air and anti-radar missile capability. The primary mission of the AH-1W aircraft is as an armed tactical helicopter capable of helo close air support, low altitude and high speed flight, target search and acquisition, reconnaissance by fire, multiple weapons fire support, troop helicopter support, and point target attack of threatening armor. The AH-1W provides fire support and fire support coordination to the landing force during amphibious assaults and subsequent operations ashore.

The AH-1W is a two-place, tandem-seat, twin-engine helicopter capable of land- or sea-based operations. The rear seat pilot is primarily responsible for maneuvering the aircraft. The front pilot controls the aircraft's weapons systems, but he also has a full set aircraft controls. The AH-1W distinguished itself with its more powerful T700-GE-401 fully marinized engines and advanced electronic weapons capability. The AH-1W has significantly improved power available in high altitude, hot environment, and single engine performance. The Super Cobra is armed with a 20mm turret gun, TOW, Hellfire, Sidewinder, Sidearm missiles, and 5 inch or 2.75 inch rockets. The HELLFIRE Missile System increased ordnance delivery and firepower capabilities. The AH-1W Super Cobra provides full night-fighting capability with the Night Targeting System (NTS). The Night Targeting System (NTS) further enhanced the AH-1W's war fighting capability by adding FLIR sensor, CCD TV sensor, Laser Designator/Rangefinder, Automatic Target Tracking and FLIR, and CCD TV video recording.

Current AH-1W assets are comprised of a mixture of new production AH-1Ws and aircraft block upgrade AH-1Ts remanufactured into the AH-1W aircraft. By the early 1980s, USMC aircraft inventory was declining due to attrition; a fully navalized helicopter was sought. In 1983, the USMC contracted with BHI for 44 AH-1Ws. An upgrade to the AT-1T, the AH-1W was received in 1986. The Tactical Navigation System (TNS) was placed in all production and block upgrade AH-1W aircraft delivered since February 1991. Previously delivered AH-1Ws are retrofit with TNS prior to CCM/NTS induction. The NTS/Canopy/Cockpit Modification (CCM) replaces the existing canopy, nose faring, and copilot/gunner instrument panel to make provisions for the NTS and adds the TNS, CDU-800, to the front cockpit. Additionally, a communication/ navigation upgrade, ECP 1686, incorporated an ARC-210(V)Electronic Protection (EP) Radio, an ARN-153 V-4 TACAN, and an AN/ASN-163 Global Positioning System/Inertial Navigation System (EGI) commencing in 1996.

Night Targeting System (NTS) TECHEVAL was conducted from May through September 1993 by VX-5 at Naval Air Warfare Center, Weapons Division (NAWC-WD), China Lake; Yuma Proving Ground, Arizona; White Sands Missile Range, New Mexico; Bridgeport, California; and on amphibious ships at sea. Follow-on Operational Test and Evaluation (FOT&E) (OT-IIIA) commenced in February 1994 and concluded in May 1994. NTS OPEVAL was conducted from May through September 1993 by VX-5 at Naval Air Warfare Center, Weapons Division (NAWC-WD), China Lake; Yuma Proving Grounds, Arizona; White Sands Missile Range, New Mexico; Cold Lake, Canada; and on amphibious ships at sea. Follow-on Operational Test and Evaluation (FOT&E) commenced during July 1994 and ended in April 1995.

The NTS upgrade provides increased mission, safety and performance characteristics and incorporates a Canopy/ Cockpit Modification to the front cockpit. The approved OSIPs which include the ARC-210 (v) EP Radio, the ARN-153V(4)TACAN and the Global Positioning System/Embedded Inertial Navigation System (EGI) AN/ASN-163 (V) will also enhance the AH-1W Weapon Systems upon their incorporation.

The NTS is a modification of the existing M-65 TOW Missile System that offers a fire control system providing the flight crew with the ability to detect, acquire, track, lock-on, range, and designate targets under day, night, and adverse weather conditions. ECP 1648R4, Canopy/Cockpit Modification is the ECP that modifies the aircraft to accommodate the NTS. The front cockpit of the AH-1W has been modified to facilitate the addition of the NTS. This modification has also resulted in increased efficiency in the front cockpit and helps divide cockpit workload between the front and rear cockpits. Specifically, the additions and deletions are: Expansion of the ASQ-205 Cockpit Control System (CCS) to include the front cockpit; re-design of the instrument panel to include a more IFR compatible flight instrument cluster; addition of a 5" x 5" Multi-Function Display (MFD) in the front cockpit; and addition of the ANVIS HUD system with control heads in both cockpits. The Night Targeting System (NTS) includes the following hardware changes to the AH-1W: modification of the M-65 telescopic sighting unit (TSU) to accommodate the FLIR; an extended Optical Relay Tube (ORT) to accommodate a CCD TV camera; and a addition of a Laser Designator/Rangefinding System (LDRS).

ECP-1674 Electronic Warfare (EW) Suite reduces aircraft vulnerability with electronic countermeasures. The suite is designed to alert and protect the aircraft from surface-to-air and air-to-air missiles. The AN/AAR-47 Missile Warning System (MWS) provides a visual and aural warning to flight crews of missile detection, while at the same time the MWS will initiate countermeasures by sending an eject signal to the AN/ALE-39 Countermeasures Dispenser Set (CDS). The AN/AVR-2 Laser Warning Receiver detects pulsed laser light (such as a rangefinder) directed at the helicopter and warns the crew of this activity. It provides an audio alert and identifies the threat by its type and location relative to the helicopter. The AN/APR-39A(V)2 Radar Detection System is a passive omni-directional detection system which receives and displays information to the pilot concerning the radar environment surrounding the helicopter.

The AH-1W is operated in eight composite HMLA squadrons composed of 18 AH-1 and 9 UH-1 aircraft. The AH-1W is currently being outfitted with a Night Targeting System/Forward Looking Infrared Radar that provides laser rangefinding/designating and camera capabilities.

The Marine Corps deployed 4 of 6 active force squadrons (48 AH-1Ws) to Southwest Asia during Operation Desert Shield/Desert Storm. The deployment required no additional augmentation to squadron support personnel and only one Bell Helicopter technical representative. During Operation Desert Storm, the AH-1W comprised less than 20% of the attack helicopter force deployed, yet flew more than 50% of the total attack force flight-hours. In the entire Desert Shield/ Desert Storm campaign, Super Cobras flew more than three times the number of hours per aircraft per month than any other attack helicopter. And during the "100 Hour War," its reliability and 92% mission readiness rate were superior to all other attack helicopters by as much as 24%... without any factory-supported maintenance augmentation. Perhaps most impressive, this record was amassed under some of the most adverse environmental conditions ever endured in modern warfare. Temperatures consistently reached the 57-63°C (135-145°F) range. A mix of fine granite/limestone sand dust the consistency of talcum powder, was a constant threat to man and machine. And the air was often filled with a black concoction of burning oil and blowing sand The final result? Marine Corps crews and their AH-lWs destroyed 97 tanks, 104 armored personnel carriers and vehicles, 16 bunkers and two antiaircraft artillery sites.

Future Upgrades include provisions for an Inflatable Body And Head Restraint System (IBAHRS). The IBAHRS itself will be incorporated upon receipt of the system. An operational requirement has been identified for a Wing Tip Armament Station modification and retrofit. Upon approval, this upgrade will be incorporated into the AH-1W airframe and will include as a minimum provisions for integration of up to six (6) universal weapons stations. The Cockpit Integration Requirement identified in the Operational Requirements Document for the AH-1W Mid Life Upgrade will be targeted by the 4 Bladed program which is being studied as another future AH-1W weapon system enhancement.

AH-1Z Viper

A four bladed version of the AH-1W was designated the AH-1Z. The addition of the extra blades dramatically improves the performance envelope of the AH-1W. The AH-1W was also to be retrofitted with a Kollsman-manufactured Night Targeting System (NTS). The aircraft was also undergoing a cockpit reconfiguration to allow for easier copilot/gunner access to the NTS. The upgrade of the AH-1W, including the new cockpit, was initially referred to as the Four Bladed AH-1W (4BW) and the upgrade of the UH-1N drive train was initially referred to as the Four Bladed UH-1N (4BN). Collectively, the 4BN/4BW effort constituted the USMC H-1 Upgrades Program.

The Marine Corps planned to upgrade 180 of the AH-1W gunships to the new AH-1Z standard (formerly referred to as AH-1W (4BW)). The first flight was conducted in December 2000, with planned low-rate initial production beginning in February 2002, and deliveries planned to run from 2004 through 2013.

In July 1998, Bell Helicopter competitively selected Lockheed Martin for development of the AH-1Z Target Sight System (TSS). The TSS would provide advanced third generation thermal image processing, eye-safe laser range finding, target designation, and full fire control integration. In August 1998, four AH-1Ws were delivered to Bell Helicopter for conversion into AH-1Z test aircraft. In September 1998, engineers completed a highly successful critical design review of the airframe, which featured a state-of-the-art, computer generated electronic mock-up to convey design details. The design review paved the way for manufacturing development. Also in 1998, the program delivered seven AH-1Ws to the Marine Corps, bringing the aircraft inventory to 201. Additionally, several other improvements for the AH-1W (night targeting system and communications/navigation) continued.

The H-1 upgrade program combined upgrades of two USMC H-1 aircraft: the AH-1W Cobra attack helicopter and the UH-1N light utility helicopter. The common element of the two would be identical twin engines and drive trains, including a new four-bladed rotor previously developed but not fielded. In addition, the AH-1 attack helicopter would gain a new integrated cockpit and night targeting system. The upgrade was intended and expected to extend the life of the two H-1 models well into the 21st century. The AH-1 would contribute to precision engagement and full-dimensional protection.

Bearingless, composite main rotor systems were successfully tested at BHTI in the early 1980's and were standard on the Bell 430 helicopter. Based on the performance of this rotor system, the USMC decided to incorporate it in their new AH-1Z helicopter. This unique rotor system was stated by the manufacturer to provide unprecedented agility, substantially increased speed, a smoother ride, a more stable weapons platform, and excellent reliability. It would also reduce crew fatigue and enhance combat mission effectiveness.

A Sikorsky Bearingless Main Rotor (SBMR) was successfully tested in the 40- by 80-Foot Wind Tunnel test section of the NASA Ames National Full-Scale Aerodynamics Complex (NFAC). The five-bladed 44-foot diameter demonstrator rotor system was designed using existing S-76 composite main rotor blades and a new five-bladed hub, employing design features similar to the rotor proposed for the subsequently canceled RAH-66 Comanche. The rotor was first tested on the Sikorsky Main Rotor Whirl Stand, concluding in August 1991. A Memorandum of Agreement (MOA) was then signed to perform a wind tunnel test at Ames. Under the MOA, Sikorsky performed additional qualification testing and analysis to support the test program. NASA provided technical support during the pre-test effort and then tested the rotor system for a 14-week period during the summer of 1992.

Under the initial 4BW/4BN upgrade plan, fully integrated cockpits would be phased into the development after initial work on the drive system was underway. Initial work would consist of simultaneous design efforts for the 4BW and 4BN. Major modifications would include: a new rotor system with semi-automatic bladefold of the new composite rotor system, a new performance matched transmission, a new 4-bladed tail rotor and drive system, a more effective stabilizer, upgraded landing gear, tail pylon structural modifications and common cockpits.

The remanufacture was expected to add 10,000 flight hours to 4BW/4BN airframes. The 4BW would increase aircraft maneuverability, speed, and payload (ordnance) capability. The fully integrated cockpits would reduce operator workload and improve situational awareness, thus increasing safety. It would provide growth potential for future weapon systems and avionics, which would increase mission effectiveness and survivability. As discrete systems had previously been added to both aircraft, pilot workload had progressively worsened. The cockpits would include integration of on-board mission planning, communications, digital fire control, self navigation, night targeting, and weapons systems in nearly identical crew stations reducing training requirements.

The 4BN/4BW program was instituted in the summer of 1996 by combining several lesser upgrades planned, but not executed by the Marine Corps. Prior to entry into EMD in September, 1996, DOT&E approved the program's alternative LFT&E plan and USD(A&T) approved a waiver from full-up, system-level LFT&E. The AH-1W would be tested full-up, system-level. The H-1 Upgrade ORDs required that both helicopters (the upgraded AH-1W and UH-1N) be tolerant to impacts by 12.7mm rounds and have crashworthy enhancements. Additionally, the drive components of the AH-1W were to be tolerant to 23mm rounds.

The H-1 Upgrade had the most comprehensive and realistic aircraft LFT&E program approved to date. The program would include full-up, system-level testing of an AH-1W and testing of all but the tail (which is common to both aircraft) of the UH-1N. It would explore in detail various potential kill mechanisms related to the expected threat. The LFT&E program was integrated fully into the systems engineering effort and was expected yield a reasonable opportunity to incorporate improvements if deficiencies were found.

Accoridng to DOT&E, the AH-1Z attack helicopter demonstrated a doubling in payload and a 20 percent increase in range and endurance over the AH-1W aircraft during 2003 testing. The digital cockpit enhanced pilot situational awareness and reduced workload in some areas. However, poor targeting performance of the newly installed Targeting Sight System (TSS) degraded mission effectiveness and increased pilot workload. Problems with TSS stability, focusing, target loss during field-of-view changes, and anomalous TSS behavior must be resolved before this aircraft can be considered operationally effective.

A decision had been made to produce the UH-1Y portion of the program as new aircraft, rather than as conversions from existing UH-1Ns. Program officials were studying the feasibility and cost of also building the AH-1Z’s new. A date for that decision had yet to be determined as of mid-2005.

In May 2006, the Navy initiated the program's fourth major restructuring effort, resulting in an approximate 18-month delay in the full-rate production decision (expected for July 2008 as of March of that year), a reduction in production quantities from 47 to 38 (UH-1Y and AH-1Z) in FY06 to FY08, and the extension of low-rate production. At the same time, the contractor had failed to meet the commitments of an increased production rate. Program officials stated that the prime contractor's delivery schedule was a key risk that could affect the UH-1Y initial operational capability. The prime contractor had experienced challenges with supply chain management, manufacturing standards, and built-in quality, affecting program schedule and resulting in aggressive training timelines with little margin. If the planned September 2008 initial operational capability was not met, the program may face an acquisition program baseline breach and risk undergoing a fifth restructuring. Additionally, the contractor's earned value management system was decertified. The program expected recertification during spring 2008.

The program office reported to the Government Accountability Office for a March 2008 assessment that it had all 2,611 AH-1Z drawings, a measure of design stability. The program did not track data for critical process control in manufacturing, but utilized postproduction quality metrics. The H-1 upgrades program was approved for Low-Rate Initial Production Lot 4 in July 2007 and currently had 34 aircraft on contract (UH-1Y and AH-1Z). The program reported that three AH-1Z had been delivered to date. Program officials reported that the third AH-1Z and fifth UH-1Y were delivered in October and November 2007, respectively. The program was undergoing its fourth major restructuring, which had delayed the expected full-rate production decision by 18 months, then expected for July 2008.

An operational test report identified performance issues with key technologies that would need to be resolved prior to initial operational capability. For example, the program's target sight system continued to experience a high failure rate, which could affect the AH-1Z's readiness for fielding. Further, flight restrictions were in effect for both the AH-1Z and UH-1Y during operational test and evaluation due to the poor performance of the helmet-mounted sight displays (HMSD), a key weapon system upgrade. The visual sharpness of the HMSD did not support shipboard landings at night, depth perception cues were misleading, and HMSD components were not reliable. The program reported designed improvements were being tested to address these challenges.

The program office was using FY07 funding for preliminary engineering for new AH-1Z airframes. The program had experienced significant delays and cost growth in the manufacturing of initial production aircraft, leading to 140 percent cost growth and 36 percent schedule growth by the time of the 2008 GAO assessment. The cost growth experienced by the program was due primarily to revised estimates for labor, material, and tooling based on manufacturing performance data from development and initial production aircraft. The program reported that requirements changes in previous years had also contributed to cost growth.

Recognizing the AH-1 Cobra

The Cobra is a rather easy helicopter to identify on the ground and in the air. Here's some tips to help you identify the AH-1F and AH-1W Cobras:

Wings: Large, dual-blade main rotor. Weapon-carrying wings are mid-mounted, short, and stubby. If you see a Cobra with a four-bladed main rotor, it is the new AH-1Z.
Engine(s): The AH-1W has two turboshaft engines mounted on top rear of cabin and two exhausts just above the tail boom. The AH-1F has one turboshaft engine mounted on top of the body forming a hump-like appearance. It has one exhaust.
Fuselage: Thin, oval body with short, pointed nose. The AH-1W has a stepped, glassed-in canopy and tapered rear section. Low-mounted, tubular tail boom. The AH-1F has a stepped, flat-plated canopy and tapered rear section.
Tail: The elevators of the AH-1W are mid-mounted, swept-back, tapered, and square-tipped. The elevators of the AH-1F are mid-mounted, swept-back, tapered, blunt-tipped, and forward of the fin. On both the AH-1F and AH-1W, the fin is swept-back and tapered. Rotor is on the right.

Specifications

AH-1W Super Cobra Specifications:

Primary function: Attack helicopter
Manufacturer: Bell Helicopter Textron
Power plant: Two General Electric T700-GE-401 engines
Thrust:
Full: 2082 shaft horsepower for 30 minutes (transmission limited),
Continuous: 1775 shaft horsepower
Length: 58 feet (17.67 meters)
Height: 13.7 feet (4.17 meters)
Rotor Diameter: 48 feet (14.62 meters)
Speed: 147 knots (169.05 miles per hour) in basic combat attack configuration
Maximum takeoff weight: 14,750 pounds (6,696.50 kilograms)
Range: 256 nautical miles (294.4 miles) in basic combat attack configuration
Ceiling: 18,700 feet (5703.5 meters) in basic combat attack configuration (limited to 10,000 feet (3050 kilometers) by oxygen requirements)
Crew: 2 officers
Armament: One 20MM turreted cannon with 750 rounds; four external wing stations that can fire 2.75"/5.0" rockets and a wide variety of precision guided missiles, to include TOW/Hellfire (point target/anti-armor), Sidewinder (anti-air) Sidearm (anti-radar).
Introduction date: 1986

Sources: USMC AH-1W Cobra Factfile, Globalsecurity.org Information on the AH-1 Cobra

© 2003-2010 Steven Holzinger