Trunkneck’s Blog

Osprey Deployment
The V-22 Osprey is a joint-service, medium-lift, multi-mission tilt-rotor aircraft developed by Boeing and Bell Helicopters. Boeing is responsible for the fuselage, landing gear, avionics, electrical and hydraulic systems, performance and flying qualities. Bell Helicopter Textron is responsible for the wing and nacelle, propulsion, rotor, empennage (complete tail system), ramp, overwing fairing and the dynamics.

“The nacelles rotate 90° forward once airborne, converting the aircraft into a turboprop aircraft.”
The aircraft operates as a helicopter when taking off and landing vertically. The nacelles rotate 90° forward once airborne, converting the aircraft into a turboprop aircraft.

The aircraft can provide VTOL (Vertical Take-Off and Landing) with a payload of 24 troops, or 6,000lb of cargo at 430nm combat range, or VTOL with a payload of 8,300lb of cargo for a range of 220nm. The helicopter is self-deployable worldwide, with a ferry range over 2,100nm. Normal operating range is up to 1,100nm.
The tilt-rotor aircraft is available in three configurations: the Combat Assault and Assault Support MV-22 for the US Marine Corps and the US Army; the long-range Special Operations CV-22 for US Special Operations Command (US SOCOM); and the US Navy HV-22, for combat search and rescue, special warfare and fleet logistic support.
The first of four LRIP (Low-Rate Initial Production) MV-22 models completed operation and evaluation in August 2000. Following an aircrash in December 2000, a number of upgrades have been implemented including redesign of hydraulics and wiring in the nacelles and improved flight control software. A two-year flight test program began in May 2002 and a second OP/EVAL phase began in March 2005. USAF CV-22 resumed flight testing in September 2002. The first CV-22 was delivered to the USAF in October 2005.

A further 11 LRIP aircraft (nine MV-22 and two CV-22) were ordered in May 2003, 11 (eight MV-22 and three CV-22) in February 2004 and 11 (nine MV-22 and two CV-22) in January 2005.

The V-22 was approved for full-rate production in September 2005. The MV-22 achieved initial operating capability in June 2007 and left for its first operational deployment in Iraq in September 2007, with USMC Squadron 263. Initial operating capability for the CV-22 is planned for 2009, but a CV-22 flew a first search and recovery mission from Kirtland AFB, New Mexico, in October 2007. 360 MV-22 (to replace CH-46 Sea Knight) and 50 CV-22 (to replace MH-53J Pave Low helicopters) are required.
In July 2006, two MV-22 Ospreys completed flights crossing the Atlantic to take part in the flying display at the Farnborough International Airshow.

DESIGN

The V-22 is fully shipboard compatible, with the world’s first complete blade fold and wing stowage system. It is able to operate off all US Navy L-class amphibious ships, the LHA/LHD assault carriers, and can be stowed on full-size CV/CVN carriers. For stowage, the wings are rotated to lie above and parallel to the fuselage to create a compact rectangular volume.

“The V-22 tilt-rotor aircraft is fully shipboard compatible.”
The automatic wing and rotor folding sequence, which can be completed in 90 seconds in a 60kt wind, is as follows: the aircraft lands in helicopter mode; the two outboard blades of each rotor are folded inboard; the nacelles are rotated forward to cruise mode; and the wings are rotated by 90° clockwise.

COCKPIT

The flight crew have a pilot’s night-vision system and a Honeywell integrated helmet display. The cockpit is equipped with six night-vision goggle compatible displays.
The standby altitude indicator and the standby flight display are supplied by Smiths Industries. The cabin and the cockpit are NBC (nuclear, biological and chemical warfare) protected with a positive pressure filtered air system.

GUN

The aircraft is armed with an M240G 7.62mm machine gun mounted on the back ramp.
BAE Systems has developed a remotely operated weapon turret for the MV-22, the Remote Guardian System (RGS), which provides 360 degree coverage. The RGS can be belly-mounted on the MV-22 and can be armed with a GAU-17 7.62mm mini-gun or other gun up to 0.50 calibre. If funded by the USMC, the system could be ready for installation in mid-2008.

SENSORS

The US Air Force and US Navy variants are equipped with a Raytheon AN/APQ-186 terrain-following, multi-mode radar. The helicopter night-vision system is the Raytheon AN/AAQ-16 (V-22) FLIR, which is mounted on the nose. This system contains a 3-5 micron indium antimonide staring focal plane array.

COUNTERMEASURES

The aircraft’s electronic warfare suite includes the ATK AN/AAR-47 missile warning system, which consists of four electro-optic sensors with photomultipliers, a signal processing unit and a cockpit display.

“The aircraft will be equipped with a 12.7mm turreted gun system.”
The aircraft is also equipped with a radar and infrared threat warning system and chaff and flare dispensers with 60 rounds of dispensables. The CV-22 will have the Suite of Integrated Radio Frequency Measures (SIRFC), being developed by ITT Avionics.

ENGINES

The aircraft is powered by two Rolls-RoyceT406-AD-400 turboshaft engines rated at 4,400kW maximum continuous power. The engines are fitted with Full-Authority Digital Electronic Control (FADEC) supplied by Lucas Aerospace, backup analog electronic control system, and fire protection system from Systron Donner.
A transmission interconnect shaft provides single-engine operation. The thermal signature of the aircraft is minimised with an AiResearch infrared emission suppression unit, installed on the nacelles near the engine exhaust.
The entire rotor, transmission and engine nacelles tilt through 90° in forward rotation and are directed forwards for forward flight, and through 7° 30′ in aft rotation for vertical take-off and landing.

There’s a strange wave phenomenon that’s plagued rocket scientists for years, a lurking threat with the power to destroy an engine at almost any time. For decades, scientists have had a limited understanding of how or why it happens because they could not replicate or investigate the problem under controlled laboratory conditions.

Scientists generally believe that these powerful and unstable sound waves, created by energy supplied by the combustion process, were the cause of rocket failures in several U.S. and Russian rockets. Scientists have also observed these mysterious oscillations in other propulsion and power-generating systems such as missiles and gas turbines.

Now, researchers at the Georgia Institute of Technology have developed a liquid rocket engine simulator and imaging techniques that can help demystify the cause of these explosive sounds waves and bring scientists a little closer to being able to understand and prevent them. The Georgia Tech research team was able to clearly demonstrate that the phenomenon manifests itself in the form of spinning acoustic waves that gain destructive power as they rotate around the rocket’s combustion chamber.

“This is a very troublesome phenomenon in rockets,” said Ben Zinn, the David S. Lewis Jr. Chair and Regents’ Professor in the Guggenheim School of Aerospace Engineering at Georgia Tech. “These spinning acoustic oscillations destroy engines without anyone fully understanding how these waves are formed. Visualizing this phenomenon brings us a step closer to understanding it.”

The research was presented at the 2008 American Institute of Aeronautics and Astronautics (AIAA) Aerospace Sciences Meeting in Reno, Nevada, and funded by the Air Force Office of Scientific Research.

During past investigations into this damaging instability, scientists were able to observe initial stages of the problem but were forced to shut down engines before the waves could fully develop and cause serious damage to the engine. Researchers were also hindered by their inability to clearly observe the complex processes inside the investigated rocket engines.

But with a great deal of help from Dr. Oleksandr Bibik, a visiting physicist and research scientist from Ukraine, the Georgia Tech research team developed an experimental setup and imaging technique that provides detailed information on how these waves form and behave — without blowing up an engine or endangering lives.

First, the researchers developed a low-pressure combustor that serves as a true simulator of larger rocket engines. Bibik then used a very-high-speed camera in combination with series of fiber optic probes that together allowed researchers to clearly observe the formation and behavior of excited spinning sound waves within the engine. Additionally, Bibik’s new imaging method enabled researchers to determine the conditions under which these waves are excited and how they can be controlled.

Bibik’s method uses a high-speed camera to view the reaction zone via a system of filters that allow only specific light radiation generated in the combustion zone to reach the camera’s lens. This strategy eliminates all background light interference and provides clear images of combustion (and sound) waves spinning around the engine’s periphery. Simultaneously, strategically placed fiber optic probes collect information on the reaction process oscillations in various locations in the combustor.

Using these new techniques, the research team discovered that the destructive waves gained energy as they spun around the engine’s periphery at a rate of 5,000 revolutions per second.

The capability to simulate and observe these destructive oscillations in a controlled laboratory environment could help researchers develop techniques to prevent their occurrence in real engines.

“Better understanding this phenomenon could very likely lead to safer tactical and space missions and save billions of dollars for technologies that use combustors,” Zinn said.