Bell Helicopter and the UH-1Y Venom
In a new feature for Aviation Classics, we had the opportunity to put a series of questions to the team at Bell Helicopter regarding the latest addition to the Huey family, the extremely advanced and potent UH-1Y Venom, often referred to as the ‘Yankee’ in service. We would particularly like to thank Dana Schenk, communications manager at Bell Helicopter Military Programs for her work in acquiring answers to all our questions.
Arecurring theme throughout the development of the Huey family recorded in this issue has been the quest for greater performance, greater payload and more power to meet the expanding needs of military and civil customers. The parallel technological development of sensors, weapons, avionics and flight safety systems added weight and complexity to the airframe, all of which had to be accommodated to keep the design able to best fulfill its various roles. This quest has seen the military Huey in particular grow in size and capability far beyond the original design as Bell engineers have sought and developed solutions in response to the problems that emerged from actual combat and operational experience with the helicopter. The range of missions the military UH-1 variants have been used in and adapted for fell far outside the design intentions set out at the very beginning, the original utility transport becoming an armed gunship from its first deployments to Vietnam. That the Bell team has successfully risen to these challenges has been a crucial factor in the success and longevity of the type in service. The latest variant, the UH-1Y Venom, is intended to fulfill the needs of the US Marine Corps for the next 40 years, so will complete an utterly remarkable 100 years of UH-1 operations with the US armed forces. Aviation Classics was given the opportunity to put some questions to Bell Helicopter regarding this success, to get the manufacturer’s viewpoint on this remarkable machine and to get a feel for the thinking behind the UH-1 and its future. We would like to thank everyone at the company for their time and trouble in providing answers.
In 1996 the US Government approved an upgrade programme for the US Marine Corps H-1 helicopters, the AH-1W Super Cobra and UH-1N Twin Huey, the aim being to develop a modern attack and utility helicopter that would offer significant cost effectiveness and remain in service for the next four decades. The original concept was to convert 100 UH-1NS and 180 AH-1WS, fitting a new glass cockpit with its attendant avionics, engines and rotors. The two designs had a remarkable 84% commonality, the same tail booms, main and tail rotors, engines, drive trains and transmissions being used on both types, as well as a great deal of the avionics, software, displays and controls, making the four cockpit positions similar across both aircraft. This has many advantages, not just in terms of training and familiarity for air and ground crew across the fleet, but also in terms of the cost of spares and the simplification of the attendant supply chain for the Marine Corps. Combined with these upgrades are a state of the art sensor and defensive aid suite, including helmet mounted targeting and flight displays. The main rotor is an entirely new design, featuring composite broad chord blades and a head that has no hinges or bearings, being both simpler and lighter than the original. Likewise, the tail rotor is a new four bladed unit, mounted on top of the fin. The elevators have moved further aft to the base of the fin and are tapered toward the tip, both modifications offering improved control effectiveness across the speed range. The new engines were a turboprop already familiar to Bell, as it had been used on the 214ST and AH-1W Super Cobra, but in an upgraded form. The General Electric T700GE-401C produces 1546hp, but can boost this to 1828hp for up to two and half minutes. Not only does the pair of T700s offer nearly three times the power of the original Huey design, but at greatly reduced fuel consumption, increasing the speed and lifting capability at the same time as providing much greater range from the 352 US Gall (1333 litre) internal fuel capacity. The weapons pylons on either side of the rear of the cabin doors can carry the LAU-68 seven tube or the LAU-61 19 tube rocket pods, capable of carrying any of the versions of the Hydra 70 (Mk.66) 2.75in (70mm) unguided rockets. They can also carry the new Advanced Precision Kill Weapon System (APKWS) II laser guided rocket based on the Hydra 70 in the same tube launchers, able to designate targets themselves or use those marked by other platforms. In a trial in April 2013, 10 rockets fired by a UH-1Y all struck both stationary and moving targets at ranges of between two and four kilometres, a remarkable success. The door mounts can also each carry a M240D 7.62mm or a BMG GAU-16/A .50 cal, both single barrelled machine guns. Alternatively, the six barrelled GAU-17/A electrically driven ‘minigun’ can be mounted and fired by the pilots when it is in the fixed forward position, or used by the rear crew as a door gun to provide close air support to ground forces. The first UH-1Y was converted from a UH1N and flew as an aerodynamic testbed for the first time in December 2001. This had a dorsal fin under the main fin and large engine exhausts angled at 45º, close mounted on either side of the transmission. Both of these were changed in the production versions, the dorsal fin being deleted and the exhausts now lying flat and spread out, angled outboard. This arrangement was far more effective at dissipating the heat from the engines and reducing the heat signature of the UH-1Y considerably. The first fully configured UH-1Y flew in October 2003, and a low rate initial production (LRIP) order was placed for six more in December, with four more being ordered in April 2005. Experience with these first two batches found that it was cheaper and more efficient to build the aircraft from new, as opposed to the original plan to upgrade existing UH-1NS. The plan to acquire 100 helicopters was also changed to 160, all except the first 10 being new build aircraft. Developmental testing of the UH-1Y by the USMC began after the first test example was delivered in October 2005, operational evaluation occurring during 2006. The first full production version UH-1Y was delivered in January 2007, the type achieving initial operating capability in June the following year and being sent on its first deployment with the 13th Marine Expeditionary Unit (MEU) on board USS Boxer in January 2009. The high performance of the new helicopter was such that the first combat deployment to Afghanistan also occurred and full rate production was approved in the same year. The 100th UH-1Y was delivered to the US Marine Corps on January 16, 2013, the last of the 160 being intended for delivery in 2016.
QUESTIONS AND ANSWERS
1.The UH-1 first flew in 1956 and is still in production today, the longest continuous production run of any helicopter in aviation history and a family that includes the most produced single engined helicopter of all time, incredible achievements for an aircraft design. What would you say are the major factors in this remarkable longevity and success?
The Bell UH-1 is a remarkably rugged aircraft that was designed to provide aerial delivery of supplies and personnel, operated in direct support of infantry forces. Since its inception, it has been continually developed and improved upon working jointly with the US Marines and Army who were flying the aircraft aggressively during Vietnam and every combat environment since then. With each new variant, Bell Helicopter has redesigned the aircraft to improve performance, speed, range, maintainability and all-weather reliability for maximum readiness. The UH-1Y is the world’s most versatile and capable utility helicopter based on decades of combat experience and will serve the US Marine Corps for the next 40 years.
2.The UH-1 is designated and termed a ‘utility’ helicopter, inasmuch as it can fulfil a wide range of missions for an operator. Could you describe the kind of roles the Yankee is intended for and used in?
The UH-1Y has evolved in its mission capabilities far beyond its ‘utility’ designation, and enables the US Marine Corps the most efficient means of accomplishing an array of missions, anywhere in the world, including:
Combat assault transport Air delivery Airborne command and control Insertion and extraction (fastrope) Active air defence Strike coordination and reconnaissance Armed reconnaissance Close and deep air support Recovery of aircraft and personnel Aerial escort Operations from sea and shore Emergency resupply Firefighting
3. Since 2009, the UH-1Y has been operational with the US Marine Corps. Have you had much in the way of feedback from the front line as regards the reliability and utility of the UH-1Y? How is it performing in the field?
The limited payload, engine power, and high altitude performance of the UH-1N aircraft restricted Marine Corps operations in Afghanistan.therefore, the Marine Corps chose to accelerate the introduction of the UH-1Y into Afghanistan in 2009.The introduction of the UH-1Y into these environments with its vastly increased speed, range, and payload returned the utility mission to the Marine combat forces. The Bell UH-1YS have been continuously deployed in Afghanistan since 2009 and have been engaged in sustained, hightempo combat operations since their arrival. The UH-1Y’S increased payload and weapons capabilities have afforded ground commanders more options and the US Marine Corps is currently refining its tactics, techniques and procedures to exploit the enhanced capabilities.the USMC has now fully transitioned to the new UH-1Y with the last of UH-1N aircraft retired in August 2014. Marinization, which includes corrosion resistant treatments, blade fold, enhanced rotor brakes, and minimised electromagnetic environment effects, have benefited maintenance and reliability in allweather environments.the commonality of maintenance-significant components to the AH-1Z reduces the US Marine Corps total cost of ownership, with less maintenance training and logistical footprint required for both aircraft.
4.The UH-1Y is obviously far removed from the original design in terms of construction, equipment and technology. What are the major changes in the development of the Yankee?
The new Bell UH-1Y has incorporated a new drivetrain and two upgraded GE engines which offer significantly better lift and operational reach than the Bell UH-1N. Upgrades in ISR, targeting, and precision fire controls represent a giant leap in the capability to support the utility and light attack mission spectrum.
5. Regarding these engineering changes, what effects have they had on the performance of the UH-1Y over its predecessors?
The UH-1Y was designed and built for the modern day battlefield and has a 125% payload improvement and a 50% increase in range and maximum cruise speed as compared to the UH-1N.
Specifications include: Max speed: 170 knots Cruise speed: 147 knots Combat Radius: 119 nautical miles Max Gross Weight: 18,500lb
6.The integrated glass cockpit is a new feature on the UH-1Y. How easy has it been for aircrew to transition onto the new system and what advantages are there in this type of information display for pilots?
The integrated avionics system improves the aircrew’s situational awareness by providing multiple data streams through the multifunction displays and the helmet mounted ‘heads up’ display.these multifunction displays are common to the AH-1Z and deliver navigation, weapons systems, flight management, aircraft systems, communications, and sensor management. The incorporation of ‘Hands On Collective and Stick’ allows the aircrew the ability to engage the aircraft systems without taking their hands off the controls.the weapons systems on the AH-1Z and the sensor systems on the UH-1Y are controlled via dedicated mission grips similar to a game controller popular with video games in use today. The layout and functionality of the crewmember stations, side by side in the UH1Y or fore and aft in the AH-1Z, are virtually identical, minimising training and allowing a pilot to fly and fight from either station.
7.The advanced helmet mounted sighting and information system is another new feature of the UH-1Y. What are the benefits of this system and how has it been working in practice on operations?
The Optimized Topowl Helmet Mounted Sight and Display is combat-proven and offers day and night avionics to present a ‘heads-up display’ of visual aids to the pilot, reducing pilot workload.the helmet display provides aircraft status information analogous to a systems page on the multifunction display. The presentation to the pilot in his day or night helmet display frees up a multifunction display for sensors, navigation, etc. without a loss of situational awareness with regard to the aircraft. Additionally, the helmet allows for sensor cue information, line of sight of the other pilot, and weapons reticules.the helmet superimposes information in front of the pilots’ right eye either in a day form or over the night vision goggles for night operations. Supplemental hover symbols aid the pilot in reduced visibility approach and landings. Coupled with a high precision head tracking system, the helmet affords aircrew ease of target identification, engagement and hand off to the other crew member.
8. Much is spoken of ‘survivability’ in military manned aircraft today. What systems does the UH-1Y feature to aid its battlefield survivability?
Both the AH-1Z and the UH-1Y were designed with survivability in mind.the rotor hubs, fuel tanks, and gear boxes are ballistically tolerant, while the rotor blades are capable of withstanding 23mm munitions. The landing gear is rated for 12 feet per
second descent and is designed to reduce the impact during a hard landing and should the landing exceed 12 feet per second, the failure modes of the landing gear are designed to spread, break, and depart the aircraft in such a manner as they will continue to dissipate the impact forces.the aircrew are protected by crash attenuating seats. Engine infrared suppressors and infrared reflective paint make the aircraft harder to detect, plus the aircraft is outfitted with a robust, combat-tested suite of threat detection and countermeasure equipment, including radar, missile and laser warning systems and countermeasure dispensing systems. The ability to fly at a higher altitude above and a faster speed away from the threat also greatly improves survivability. However, combat often requires flight operations in close proximity to enemy forces for the H-1 aircraft mission set.the USMC UH-1YS in Afghanistan have sustained multiple hits on several occasions, but completed their missions and returned safely to base. 9. What are the future plans for the UH-1 in terms of development and additional capabilities?
Bell Helicopter continues to work with the US Marine Corps to advance the aircraft capabilities to include potential options for extending the range of the H-1 fleet, incorporating more advanced avionics, digital connectivity, and advanced weapons capability.
The following answers were provided by Tony Randall, head of flight safety at Bell Helicopter and former US Marine Corps Lt Colonel.
10. From a pilots’ perspective, what is the aircraft like to fly? What would you say are its chief characteristics as a handling machine?
In comparison to the aircraft it’s replacing (the UH-1N), it is a sports car. Due mostly to the new rotor system, the helicopter is extremely responsive and agile. In addition, the power available under normal conditions allows for excess power for manoeuvrability.
11. From your long experience of the UH-1, do you have a favourite story about it, or an illustration of a particular capability peculiar to the aircraft?
During certain combat operations we were able to decrease the total number of aircraft required to complete the mission. With the weight carrying capability of the UH-1Y combined with the onboard ordnance and the sensor package, we would not only transport and insert the troops into the LZ, we would then remain on station to provide surveillance and reconnaissance of the route and the objective during ingress and close air support during actions on the objective. This capability resulted in two UH-1Y aircraft doing a mission that would traditionally require four or five aircraft of differing capabilities.this is something we did many times with small or special operations units.
US Marine Corps UH-1YS from several units took part in the 100th anniversary celebrations of Naval Aviation at San Diego in 2011. Here, two are seen with an AH-1W on the right, and the aircraft that is replacing it at the moment, the AH-1Z in the centre of the image. Note the common tailbooms, rotors, engines and transmissions between the AH-1Z and UH-1Y. The early form of the UH-1Y included sharply angled exhausts and a dorsal fin.
A UH-1Y of HMLAT-303 with the BMG GAU-16/A .50 cal machine gun mounted on the door pintle above a seven tube rocket pod. A UH-Y and AH-1Z on display at the Paris Air Show in 2013. External fuel tanks can also be carried on the weapons pylons to extend the range as seen here. Note the multi sensor FLIR Systems BRITE Star thermal imaging and laser designation turret under the nose. BRITE Star consists of a triple field-of-view thermal imager, a high-resolution CCD TV camera and an eyesafe laser rangefinder and designator.
The four bladed main and tail rotors, aft mounted elevators and under nose sensor turret are all features of the UH-1Y, seen here during early trials with an air data probe mounted on the nose.
The high performance of the UH-1Y makes it ideally suited to deploy to hot and high altitude theatres, meaning it was sent to Afghanistan from its acceptance into service. Here a UH-1Y delivers water to a security detachment during Operation Centrum.
A UH-1Y lifts off from Camp Bastion in Afghanistan, an operational deployment for the type almost as soon as it entered service. Note the flat, widespread exhausts evident in this view, which excel at dissipating the heat from the T700 turbines.
One of the alternative door guns is the six barrelled GAU-17/A electrically driven ‘minigun’.this can be fired by the pilots when it is in the fixed forward position as seen here on a UH-1Y of VMM-263, or used by the rear crew as a door gun to provide close air support to ground forces.
The commonality of the design between the AH-1Z (nearest the camera) and UH-1Y are evident in this shot of the two on the deck lift of a helicopter carrier.the ‘marinization’ process of the designs included the blade fold system demonstrated here. The first ship the UH-1Y was deployed aboard was USS Boxer (LHD 4). Here, in an exercise in November 2008 prior to that deployment, a UH-1Y of HMM-163 takes off after refuelling aboard the ship, a taste of things to come.
Captain Karla Cumbie, left, and Lance Corporal Timothy Miller perform a preflight check on a UH-1Y of HMM-364. Reinforced, before flight operations aboard the amphibious transport dock ship USS Green Bay (LPD 20) in January 2013. Note the new tail rotor design, four bladed and a much simpler rotor head than previously.
The fully integrated Northrop Grumman glass cockpit is night vision goggle compatible and includes the Thales ‘Top Owl’ helmet mounted sight and display.
The UH-1Y is also fitted with a comprehensive and sophisticated defensive aids suite. Here, a UH-1Y releases infrared decoy flares during an air power demonstration for Tiger Cruise participants aboard the amphibious assault ship USS Makin Island (LHD 8) in June 2012.