Author: Valpolini, Paolo
Date published: December 1, 2011
Dilion Aero's current main business is oriented towards Mi-17 mounts. Work on this Soviet-era helicopter started when the US Department of State launched support programmes aimed at re-equipping the Iraqi and Afghan armies following the coalition intervention in both countries in the early 2000s. Interestingly though, once the product was developed, the market proved to be much broader than expected, as many other nations had also acquired helicopters of that type, mostly due to its favourable cost-effectiveness ratio.
In Central and Latin America Mexico, Venezuela and Peru have recently acquired the type, and while the Mexican Navy Mi-17s are being armed with Gatling guns, the Peruvian Army declared its intention to equip eight Mi17s with door guns, the Chavez regime putting of course Venezuela on the black list for such hardware.
The system, that leverages the Black Hawk mount, comes hi a weapons pallet that is attached to the aircraft's hard points, making it very quick to install and remove, the average time being half an hour. Of course the system is compatible with the company's M134D 7.62 mm Gatling gun (for which a 3000-round magazine and feed system are available), but other weapons can be installed such as the M240 and M60, both in 7.62 Nato, and the PKM that fires 7.62 × 54R rounds.
The company's other best seller, given the number of helicopters of that type in service, is the Black Hawk mount. According to Dillon Aero its window mount has two major advantages over the competitors': its weight, only 10.4 kg due to the use of titanium for the beam, and the fact that its vertical arm was designed for the M134 equipped with flash suppressors, an item that modifies the weapon's behaviour with a propensity to put it off target.
The mount can be installed both on left and right window stations, allowing to store the weapon inside the aircraft when not in use, and besides, the M134 can also accept the M240 machine gun. The Black Hawk mount is also in service in Colombia, where it accommodates Mk 19 automatic grenade launchers on board the Air Force Black Hawks, and in the United Arab Emirates.
Other mounts available in the Dillon Aero catalogue cater to the Huey series of helicopters, the Chinook and the Fennee. The Huey mount is made in such a way that it can accommodate up to three machine guns hi a row. The Huey installation is flying on board Norwegian and Canadian helicopters. As for the CH-47, Dillon Aero provides a folding system that can be fitted to the right side window or the left side door, and can be quickly removed. The weapon is attached to a standard Dillon Vertical Arm that is then fixed to the folding pintle.
FN Herstal weapons, the Mag 58M and M3M/GAU-21 machine guns respectively in 7.62 and 12.7 mm calibres, are among the systems of choice for many helicopter operators worldwide. It was thus a logical move for the Belgian company to move into the pintle mount world in order to provide integrated weapon systems for the most widely spread rotary-wing aircraft. In its current portfolio the company offers two systems, one aimed at the small-calibre weapon while the second is dedicated to the bigger one. Both can be door-, ramp- or window-mounted.
The Light Pintle Head consists of the 7.62-mm Mag 58M and of a soft mount that absorbs recoil forces. The 250-round ammunition box is fixed on the left side of the pintle head, a link and cases collector being installed on the right. The pintle is then attached to type-specific mounts developed as interface with the helicopter. The head is 323 mm long, 500 mm wide and 600 mm high, and weighs 7.9 kg.
The Medium Pintle Head is dedicated to the M3M/Gau-21 medium-calibre machine gun and features an ammunition box placed on the pintle that can house up to 300 rounds when mounted on the ramp or 600 when installed at the door or window. Links and cases can be either ejected or collected. A Picatinny rail allows one to install an optical sight or laser pointer. The Medium Pintle Head is 890 mm long, 535 mm wide and 757 mm high, and weighs 31 kg. According to FN Herstal over 1 400 helicopters around the world are equipped with its weapons and mounts.
Aerea of Italy, specialised in carriage and release systems, started to produce pintle mounts in the 1980s in the wake of evaluations carried out with then MBB (Messerschmitt-Bölkow-Blohm) aimed at endowing the Bo-105 helicopter with such amenities. Operational considerations showed that in Central Europe the average open field between forests is 1200 to 1800 metres long and that to cover such distances a 12.7-mm machine gun was required. Aerea proposed a retractable door gun post with a damping cradle in order to minimize recoil and increase accuracy, gunner protection being the other major concern.
The Door Gun Post (D.G.P.) was the first system developed for use on Bo-IOSs and on AB-412s and is still today among the offerings from Aerea, since its rotating support is able to host any machine gun in 12.7 mm, 7.62 mm and 5.56 mm Nato standard calibres. The system is attached to the helicopter via a honeycomb plate equipped with two rails that allow the gun mount to slide inside the chopper when not in use. The support is equipped with a seat, the gunner rotating together with the support, a kinematic system, based on slotted cams allowing the aiming sight to remain at gunner's eyeline at all firing angles. Azimuth and elevation arcs can change slightly according to the aircraft, average values being ±65° and +5%60°.
Typically four spare ammo boxes are carried as well as one or two spare barrelsArmed with an M3M machine gun, one ready box of ammo plus four spares, the D.G.P. has a weight of 183.5 kg, the assembly itself weighing 62 kg. A version for the AW139 has recently been developed, traverse being limited to ±40° by the helicopter's geometry, but the interesting feature is that the full-width base plate allows a single mount to be moved from the right door to the left one even in flight. In the 12.7 mm configuration the mount cum base píate weighs 80 kg, dropping to 50 Jcg Jn the 7.62 mm configuration.
For 7.62 mm machine guns only and for use on the EH-101, Aerea developed the Window Gun Post (W.G.K), which has been adopted by the Royal Air Force as well as by the Italian and the Royal Navies. A four ammo-box magazine and a support for a spare barrel can be added as an option. Without accessories the bare W.G.P. has a weight of 13 kg. Maximum azimuth arc is ±45" while elevation goes from 0° to -60°. During ferry flights the weapon can be retracted in the stowed position inside the aircraft.
A derivative of the W.G.P. is the Pintle Mount, developed to fit a 7.62-mm machine gun to the EH-101 doors and ramp. The system consists of a base plate, a moving arm and a pivot, and has a weight of 15 kg without accessories, weapon or ammo. The machine gun can be aimed in azimuth on a ±60° arc and in elevation from 0° to -60°. A 250-round box can be installed on the pintle, but a rack with four other boxes is also available.
The Pintle Mount then evolved into a system tailored to the 12.7-mm Browning, since being adopted by the Royal Navy on its EH-IOl Merlins. A further derivative of the W.G.P, known as the Window Gun Mount (W.G.M.), has been developed for the AW139 as a lighter weight alternative to the dedicated D.G.P. Slightly heavier than the W.G.P. at 15 kg, it bolts directly onto the floor without a base plate interface, its azimuth arc is limited at ±45° on the left and+45%330 on the right, its depression is -45°.
To answer the numerous requests for militarised A 109s, a specific pintle installation has been developed to allow the installation of a 7.62-mm machine gun on the helicopter window. The Gun Mount System is fixed to the window thanks to a base plate that holds the G.M.S. arm which, in storage position, parks the machine gun inside the aircraft. The weapon can be aimed forward at an angle of + 69° and rearwards at -44°, the elevation going from 0° to -45°. The overall weight of the mount without accessories is less than 20 kg.
Overall the helicopter pintle mount business represents about ten per cent of Aerea's annual turnover, the company is also involved in the manufacturing of airborne weapon pods for helicopters and light aircraft. The advantage of having a full compatibility both in the high segment (weapons interface) and low segment (helicopter interface) allows Aerea to adapt its mounts to numerous helicopters, including the German NH90s armed with the MG-3 and CH~53s armed with the Browning M3, not to mention systems on AB-212, AB-205, Eurocopter EC635, and Hughes H530, with the Middle East remaining one of the most successful market areas. To further extend its portfolio Aerea is currently carrying out a feasibility study for CH-47 door and rear ramp systems.
Oto Melara's involvement in the pintle mount field is relatively new. The catalytic factor was the Italian Army's decision to equip its NH90 medium transport helicopters with its M134 Catlings, which were previously used in the M27E1 and M21 pods on board AB-206 and AB-205 helicopters. The prototype was first shown at Le Bourget 2005 and firing tests from the NH90 were carried out in June 2007.
The requirements stipulated a system that allowed the machine gunner to operate seated with minimum exposure to enemy fire, and that offered a maximum number of rounds available for selfdefence and suppressive fire. Weight was also a major concern, thus Oto Melara decided from the outset to look at composite material. Another requirement was its ability to be easily stowed away with minimal intrusion around the two lateral doors that must remain free when embarking/disembarking troops, even if the NH90 ITH also has a rear ramp access.
Oto Melara Heliborne Pintle Mount System has the gun mounted on the left side, a rail in the floor allowing to rotate the assembly towards the right for stowage. To the right is the 4400-round magazine as well as the battery that allows firing a whole ammo load in case of power supply failure. The training arc is ± 70° while the elevation arc is 0°/-50°. The system including the weapon does not exceed 150 kg, to which another 150 kg of ammo must be added.
Oto Melara also carried out the M134 upgrade with the Dillon Aero kit that includes a new bolt assembly and removable track, feeder/de-linker, clutch assembly and gun control unit. Following the development contract Oto Melara obtained a contract for 70 such mounts and for the upgrade of 70 weapons, deliveries are currently underway (see author's title picture). An Italian Navy NH90 contract is expected soon as indeed the ITH helicopters earmarked for amphibious support may well adopt the same configuration as the army's NH90S, while ASW aircraft could be armed with a single weapon in the antipiracy role. The pintle mount developed by Oto Melara has been proposed to other NH90 users, Finland has expressed serious interest.
The Italian armed forces are receiving numerous new types of helicopters, the navy has adopted the EH-IOl and the NH90. the air force awaits the AWlOl for the combat sar role, while the army has decided to replace its CH-47C Chinooks with the new CH-47F. So there is room here for Oto Melara to make use of experience so far garnered with the NH90.
The Italian Navy has decided to equip its EH-1Ö1 amphibious support helicopters (to be used also by navy special forces) with a larger-calibre weapon in the form of the three-barrel General Dynamics Gau-l/A 12.7-mm Galling. Two mounts are to be installed, one on the ranip door and one on the cargo door. The mount had to be redesigned to take the heavier weapon, and some 20 kg have been added compared to the 7.62 mm version. Oto Melara has received a contract for the development and the qualification of the two mounts, a production contract for equipping a sufficient number of aircraft for special forces and to be deployed to Afghanistan is awaited for 2012.
As part of the AWlOl csar helicopter programme the Italian Air Force decided to acquire the Dillon Aero M134D-T, the lightweight version of the M134D with titanium components that weighs 24.1 kg instead of nearly 30. The csar chopper is to be equipped with three weapons, two lateral and one on the rear ramp. The lateral mounts are lighter compared to the NH90's since there is no need to fold them (they just need to retract far enough to close the windows), while the training arc is slightly reduced. The rear mount is new from the ground up and folds away into the helicopter tail, totally freeing the ramp access. The ammunition magazine is located on the right-hand side, and the mount maintains the same features of the other ones, such as the seat for the gunner. The development contract has already been assigned.
For the CH-47F Oto Melara aimed at a cost-effective solution, as Dillon Aero already has a Chinook mount in its portfolio, these will be coupled to the same ammunition system as the NHQO's, but with only 3000 rounds due to height limitation. As for the rear ramp, the pintle will be mostly derived from the NH90's with 70% design commonality and a 4400-round magazine. The system will be quickly removable (in less than 15 minutes) in order to allow the aircraft reconfiguration.
The Italian Army Aviation has ordered 16 CH-47F with an option on four more, but the expected contract will cover systems for ten to twelve aircraft. An interim solution for arming some CH47Cs currently deployed in Afghanistan may be adopted, the qualification of the CH-47 package being considered quite simple, as the pintles are derivatives of existing ones.
Looking at the international market, Oto Melara is carrying out a feasibility study with a view adapting the pintle mount used on Marina Militare's EH101s so that it could accommodate the M134, the GAU-19/A and the M2 Browning, as well as possibly mediumcalibre low-recoil weapons. A similar study on the CH-47 rear mount is also under consideration and should be carried out together with Dillon Aero and AgustaWestland.