Marine: A Guided Tour of a Marine Expeditionary Unit
Page 22
One of the lessons learned from the early Harriers was that vertical takeoff was usually both wasteful and unnecessary. A short horizontal takeoff roll saved a great deal of fuel, made it possible to carry a greater payload, and greatly eased the tricky transition from vertical to horizontal flight. In military organizations, every new concept generates a new acronym; hence STOVL, "Short Takeoff, Vertical Landing." For their second-generation Sea Harriers, the British further refined this technique with the development of the "ski jump." Providing an inclined ramp at the bow of a ship, or the end of an expeditionary airfield, gave the aircraft an extra "kick" at the moment of takeoff, and placed it in a safer nose-high attitude in the event of an engine flameout. During the South Atlantic war of 1982, both RAF Harriers and Royal Navy Sea Harriers proved the validity of the concept under difficult combat conditions. Suddenly, the Harrier had become a war-winner. Spain and India ordered various models of Harrier to operate off their small forces of aircraft carriers, and the little aircraft began to develop an international following.
A Marine AV-8B Harrier II of VMA-231, assigned to HMM-264, sits on the deck of the USS Wasp (LHD-1). Six of these birds from MCAS Cherry Point, N.C., were assigned to the air component of the 26th MEU (SOC) for their 1995/96 cruise.
JOHN D. GRESHAM
In U.S. naval aviation circles, where doctrine prohibits using the word "small" in the same sentence with "aircraft carrier," the Harrier was regarded as an aberration; and the Marines had to fight a series of bitter budget battles during the late 70s and early 80s to keep the program alive. But they did more than that. In cooperation with British Aerospace, McDonnell Douglas proposed an improved "big wing" version of the Harrier, the AV-8B, Harrier II, which entered service in 1984. The Marines originally hoped to procure 336 of these aircraft to equip every light attack squadron. But by the end of 1993, only some 276 were delivered, including 17 two-seat TAV-8B trainers. At the beginning of 1995, the Marine Harrier force, a small community of eight 20-plane squadrons, was evenly split between the East (Atlantic) and West (Pacific) Coasts. One squadron from Yuma has often been forward-deployed on rotation to Iwakuni, Japan. Squadrons provide detachments of six aircraft for six-month deployments aboard amphibious ships around the world.
The key feature of the AV-8B is an advanced graphite-epoxy composite wing, with integral fuel tankage providing up to 100% greater range than the AV-8A. A built-in-air-refueling probe makes it possible to extend the range even further. The larger wing provides six hard-points, rather than the four on the AV-8A, a 50% increase in armament options. The engine intakes and nozzles were redesigned to reduce drag, and an automatic stability-augmentation system was provided, with small "puffer" jets at the nose, tail, and wingtips, using high-pressure bleed air from the engine. The landing gear is unusual, with a steerable nosewheel and twin-wheel main gear retracting into the fuselage; spindly outriggers at half-span on the wings retract rearward, where the wheels dangle freely in the slipstream.
Visually, the Harrier's most distinctive feature is the sharp angle at which the wings droop downward from root to tip; aeronautical engineers call this "anhedral." This helps to trap a cushion of air under the wing during VTOL operation. The wingspan is 30 ft, 4 in./9.25 m, small enough to fit on shipboard elevators without the added design complexity and weight penalty of folding wings. The Harrier's length is 46 ft, 4 in./14.12 m, and the Harrier does not have (or need) a tailhook. Empty weight is only 13,086 1b/5,936 kg, compared with an F/A-18C fighterbomber, which tips the scales at 24,600 1b/11,182 kg empty! Maximum vertical takeoff weight is 18,930 lb/8,587 kg, while maximum horizontal takeoff weight is 31,000 1b/14,061 kg, showing the dramatic benefit of a short takeoff roll.
The heart of the Harrier is the Pegasus vectored thrust engine, which gives it such unique qualities. Over the years, the engineers at Rolls Royce have managed to tweak additional thrust out of the Pegasus engine through a series of incremental upgrades. These are shown in the table below:
Maximum speed in a "clean" (without external stores) configuration at sea level is 661 mph/1,065 kph. A new bubble canopy greatly improves the pilot's view to the sides and rear. The original twin 30mm ADEN-DEFA cannon (a joint British-French design from the late 1950s) in removable pods under the fuselage have been replaced by the awesome five-barrel rotary 25mm General Electric GAU-12, with the gun in one pod and a three hundred-round ammunition magazine in the other. There are six underwing hard-points, and one on the centerline. The four inboard hard-points have plumbing to accommodate 300-gal/1,135-L drop tanks; and for air-to-air missions up to four AIM-9 Sidewinder or AIM-120 AMRAAM air-to-air missiles (AAMs) can be carried. With regards to air-to-ground ordnance, the following maximum loads can be carried along with the GAU-12 gun pods: * Up to sixteen Mk 82 500-1b/227-kg general-purpose or Mk 20 Rockeye cluster bombs.
* Up to six Mk 83 1,000-1b/454-kg general-purpose or CBU-87/89/97 cluster bombs.
* Up to four 2.75-in./70mm Hydra 70 Rocket pods (each with ten unguided rockets).
* Up to four AGM-65 Maverick air-to-surface missiles.
Accurate delivery of unguided and laser-guided weapons is ensured by the Hughes AN/ASB-19 Angle Rate Bombing Set (ARBS). In addition, an ALR-67 radar warning receiver and ALE-39 chaff/flare dispensers are fitted in the tail. In high-threat environments the centerline hard-point would be occupied by an ALQ- 164 or ALQ-167 defensive-electronics-countermeasures (ECM) pod.
As with so many other weapons systems, the 1991 Persian Gulf War gave the Marines and the Harrier II a chance to prove themselves in combat. Only seventeen days after Iraq invaded Kuwait in 1991, forty AV-8Bs of Marine Attack Squadrons VMA-311 and VMA-542 arrived at Sheikh Isa Air Base (also known as "Shakey's Pizza") in Bahrain after a grueling trans-Atlantic flight. An additional twenty aircraft arrived with VMA-331 aboard the USS Nassau (LHA-4). And at the end of August 1990, VMA-311 moved up the Saudi coast to King Abdul Azziz Air Base. By late December, another squadron had arrived, VMA-231, flying eighteen thousand miles--more than halfway around the world--from Iwakuni, Japan, across the Pacific, the United States, and the Atlantic. As the start of the air war approached, in order to get really close to the action, a forward operating location was established at Tanajib, a helicopter field only 40 mi/64 km south of the Saudi/Kuwait border. The narrow 6,000 ft/ 1,828-m runway provided space for about a dozen Harriers at a time, but a good truck road allowed continuous delivery of fuel and ordnance. The Desert Storm air campaign plan envisioned holding the Harriers in reserve until they were needed for direct support of Marines in the ground war. But early on January 17th, 1991, Iraqi artillery batteries fired on Marine positions near the Saudi coastal town of Khafji, and the Harriers were called in to deal with the situation:
"We launched four aircraft. They made two passes each, releasing the
one-thousand-pound bombs right onto the artillery pieces themselves.
We watched the video of the sortie, and you could actually see the big
122mm guns going end over end as though they were toys."
--Lieutenant Colonel Dick White, USMC, VMA-311
You can appreciate the skill of the Marine pilots when you remember that these were unguided, "dumb"- bomb attacks. To avoid Iraqi SAMs and gunfire, Harriers tried to stay above 10,000 ft/3,048 m, making targets relatively difficult to spot. The typical attack profile was a 45deg jinking dive at 525-kt/960-kph airspeed, with bomb release at between 10,000 and 7,000 ft/3,048 and 2,134 m. Chaff would be dispensed on the way in to confuse enemy radar, and flares would be dropped on the way out to decoy heat-seeking SAMs. By the end of the war, Harriers were ranging up to 210 mi/338 km deep into Kuwait to find targets. Pairs of aircraft would attack from different directions, often relying on targeting information from a forward air controller in a low-flying Marine OV-10 Bronco or Navy/Marine F/A-18 Hornet.
A pair of Marine AV-8B Harrier IIs operate on the deck of the USS Wasp (LHD-1) during operations in a Norwegian fjord in 1994.
OFFICIAL U.S. NA
VY PHOTO
During the first week of the air war, Harriers carried one or two Sidewinders for self-defense, but the Iraqi Air Force was neutralized so quickly that no Harrier pilot even saw an enemy aircraft. Of eighty-six Harriers that operated over Kuwait, five were lost to enemy ground fire during the war, and one to a non-combat accident. Since they had experienced the joys of Yuma, Arizona, and Cherry Point, North Carolina, the desert heat of Saudi Arabia was nothing special to the Harrier squadrons, and there were remarkably few problems caused by the blowing powdery sand. In total, Harriers flew 9,353 sorties during Desert Shield and Desert Storm, including 3,380 combat missions, which delivered almost six million pounds of ordnance onto enemy targets. During the war, Harriers rarely flew more than two missions in a day, due to the bad weather.
During Desert Storm, the Harrier was largely limited to its designed role as a daylight/clear-weather aircraft, due to its lack of radar or precision-targeting electro-optical systems. Since wars don't stop at night or take breaks for bad weather, this was a serious limitation. Beginning in mid-1987 (with initial deliveries in September 1989), sixty AV-8Bs have been converted to Night Harriers through the installation of an FLIR sensor and new cockpit lighting compatible with night-vision goggles. The FLIR, mounted in a fairing above the nose of the aircraft, projects a green-and-white video image on the pilot's heads-up display (HUD). A color digital moving map display, using data stored on a laser disc, eliminates the hassle of fumbling with paper charts in a dark cockpit.
Even better things were to follow. With the Sea Harrier, the Royal Navy had already demonstrated that it was possible to fit a radar in the Harrier's nose. With the Harrier II Plus, McDonnell Douglas engineers did not just settle for a simple range-only or air-search radar. They essentially redesigned the airframe to accommodate the powerful Hughes APG-65, the same multi-mode radar used on the F/A-18 Hornet. This means that in the fall of 1996, the Harrier force will add the mighty AIM-120 AMRAAM missile to their weapons suite, making it one of the most dangerous birds in the sky. Since the radar adds some 900 lb/408 kg of weight, and extends the airframe by 17 in./43 cm, a completely new fuselage was fabricated, and a new engine installed. The last twenty-four production Harrier IIs were built to the Plus standard. After that, additional aircraft will be "remanufactured." To save money, the wing, tail surfaces, landing gear, ejection seats, and other major components of existing AV-8 Bs are being recycled to produce a new aircraft, at about two-thirds the cost of manufacturing a completely new aircraft. Italy (sixteen aircraft) and Spain (eight aircraft) are sharing in the development cost and production of the Harrier II Plus, under an agreement signed in September 1990. The Marine Corps plans to remanufacture seventy-three airframes to the II Plus configuration. The first Harrier II Plus made its inaugural flight on September 22nd, 1992.
A Pioneer Unmanned Aerial Vehicle (UAV) just before launch from the deck of a U.S. Navy ship. A small rocket motor ignites, powering the craft until the cruise motor takes over.
OFFICIAL U.S. NAVY PHOTO
Harriers will remain in service with the Marines well into the 21st century. Most likely, they will gradually be replaced sometime after 2010 by a variant of the Air Force/Navy STOVL joint strike fighter (JSF), which is currently in the early stages of development. Between now and then, the variety of weapons loads and mission capabilities are due to greatly increase. For example, there will soon be a competition for a laser targeting/designation pod for the centerline stores station, which will allow the Harrier to employ laser guided bombs and missiles by itself.
Pioneer Unmanned Aerial Vehicle (UAV)
They used to be called "drones" or "remote controlled" (R/C) aircraft. Today we call them UAVs ("unmanned aerial vehicles") to emphasize that they operate without a human pilot on board. The idea of a pilotless aircraft makes many pilots feel uneasy. ("This machine wants your job ... and it might cause a mid-air.") Since pilots become the Generals and Admirals who call the shots in military aviation, UAVs have had to overcome deeply entrenched institutional resistance to win acceptance. All the same, the advantages of a UAV are obvious. For one thing, compared to a manned aircraft, it can be made very small and cheap. For another, advances in software and miniaturized electronics have made it possible to provide relatively "intelligent" autopilots. And the development of miniaturized video cameras in stabilized mountings ("steadicams") provides high-resolution imagery, day or night. Even if the enemy manages to shoot one down, it makes a lousy hostage.
In early 1996 the Pioneer is the only UAV operational with the U.S. Navy, Army, and Marine Corps. Pioneer was developed in the 1970s by Israel Aircraft Industries (IAI), and it played a key role in the 1982 Bekaa Valley air campaign, in which the Israeli Defense Forces utterly smashed Syria's advanced Soviet-made integrated air-defense system. In 1985, following our own miserable experience in Lebanon, Secretary of the Navy John Lehman ordered the immediate procurement of an off-the-shelf UAV, to be carried on board the newly reactivated and modernized Iowa-class battleships, where they were to be used for gunfire spotting, reconnaissance, and battle-damage assessment, which had so far been impossible in Lebanon. Pioneer won the competition, and entered service with the fleet late in 1986. The following year, the Marine Corps procured additional Pioneers to operate from LPDs or mobile ground bases. In 1991, during Operation Desert Storm, six Pioneer units deployed to the Persian Gulf, flying some 523 missions. One of these unmanned aircraft earned a unique place in aviation history when an Iraqi unit attempted to surrender to it.
Pioneer has a wingspan of 17 ft/5.2 m, and a length of 14 ft/4.3 m, Empty weight is only 2641b/120 kg, and maximum takeoff weight is 4291b/195 kg. A 26-hp 2-stroke piston engine drives the pusher-type wooden propeller, located between twin tail booms. The engine also drives an electrical generator to power the sensor package, flight controls, and data link. Pioneer can reach a ceiling of 15,000 ft/4,600 m, but missions are generally flown at 3.280 ft/1,000 m or less. Top speed is 110 kt/204 kph, but the normal cursing speed is 65 kt/120 kph. Mission endurance is around five hours, allowing a tactical mission radius of about 100 nm/185 km. Fuel capacity is 12 gal/49 L of 100-octane aviation gasoline, mixed with a small amount of motor oil. Pioneer breaks down easily into modular components for storage in rugged shipping containers, which the crews call "bird boxes." For shipboard operations, Pioneer requires a rocket-assisted takeoff, which needs very little deck space. For ground operation, there is a truck-mounted pneumatic catapult. At the end of a shipboard mission, Pioneer is flown into a nylon recovery net rigged on the fantail of the ship, like a big volleyball net. When a runway is available, it can make a normal takeoff or landing on its fixed tricycle landing gear.
Pioneer can carry one of two standard electro-optical payloads, either of which can be swapped out in about an hour. The day package includes a stabilized, turret-mounted monochrome video camera with a full zoom. A full-color camera has been proposed as an upgrade, trading off contrast for color information. Color might also require a data link with higher bandwidth. The night package includes a high-resolution FLIR system, which can zoom to fixed lengths, and can be switched between "white hot" and "black hot" display modes. The radio command and data link uses the spread-spectrum technique, which is highly resistant to jamming. Since Pioneer is constructed from lightweight composite materials, it has a very low radar cross-section. It is equipped with a standard Mode 3 IFF transponder, allowing friendly aircraft to track it and avoid airspace conflicts. The system software automatically displays the time and date, geographic coordinates, and range to target on the imagery transmitted over the data link. It also generates symbology showing the aircraft flight direction and attitude, similar to the HUD (Heads-Up Display) of a fighter aircraft, but much simpler.
A Marine UH-1N assigned to the 26th MEU (SOC)'s HMM-264. The "IFOR" markings indicate that the unit was recently part of NATO's Bosnia "Implementation" Peacekeeping force.
JOHN D. GRESHAM
Four Landing Assault Ships (LPD
s) are currently equipped to operate Pioneer. A UAV detachment consists of about thirty personnel and five air vehicles. The control station is an air-conditioned shelter with separate consoles for the flight operator and the sensor operator, who work under the supervision of a mission commander. The flight operator hands off control of an aircraft to a remote Portable Control Station for landings and recovery. A tracking technician operates the tracking and communication system, which requires a pole antenna and a steerable dish antenna, which may be installed on the ship, or mounted on a light truck. A recording technician operates the videocassette recorders, which can feed their signals to other ships and ground stations.