Tag Archives: VTOL

Here is Pentagon’s Future Tilt-Rotor Drone

Aerial Reconfigurable Embedded System will perform cargo resupply, CASEVAC and ISR missions

According to Darpa “ARES is a vertical takeoff and landing (VTOL) flight module designed to operate as an unmanned platform capable of transporting a variety of payloads. The ARES VTOL flight module is designed to have its own power system, fuel, digital flight controls and remote command-and-control interfaces. Twin tilting ducted fans will provide efficient hovering and landing capabilities in a compact configuration, with rapid conversion to high-speed cruise flight.”

ARES is the transformer-like, UAV (unmanned aerial vehicle) capable to move between an airport, a warship, or an improvised landing zone and the battlefield, and perform a wide variety of missions, including cargo transportation, casualties evacuation as well as Intelligence Surveillance and Reconnaissance.

In other words, ARES will replace the V-22 Osprey tilt-rotor aircraft and a few other platforms.

Obviously, using a drone to perform such missions in a contested airspace reduces the risks of losing airmen.

By the way, ARES will be remotely piloted using smartphones and tablets: we are moving towards air war 2.0.

ARES Darpa Battlefield Operations

Image credit: Lockheed Martin

 

Enhanced by Zemanta

Harrier: the story of the “Jump Jet” fighter jet that helped Margaret Thatcher win the Falklands War

One cannot speak of Margaret Thatcher, who passed away on Apr. 8, 2013, without mentioning the 1982 Falklands – Malvinas a war, a conflict that the UK was able to win thanks to a revolutionary airplane: the Harrier.

The origins of the “Jump Jet” date back to the Cold War-

The historical context imposed by the Cold War made the tactical experts wonder how to get rid off one of the basic drawbacks of an airplane – airplane is dependent on runways. The reality of nuclear war to come was brutal, airstrips and their coordinates were not secret, both in the West as well as in Soviet Russia. Obviously they would be destroyed  in the beginning of any conflict.

Assisted Take-off was another approach towards making take-offs shorter. It was issued by the Germans during the WWII. They were pioneers in the field nowadays referred to as JATO or RATO (Jet/Rocket Assisted Take-Off). This approach resulted from severe damages made to the German airstrips by the allied bombers at the end of the WWII.

The lenght of the airstrips was limited because of them being damaged. The air superiority can be achieved by destroying the infrastructure needed for the airplanes to operate.

Dispersing the aircraft was an idea which was often talked about after the second world war. Some countries have developed a concept of highway strips – section of a highway that is specially built to allow landing of (mostly) military aircraft and to serve as a military airbase.

And this was the basic assumption that led to the development of Harrier Jump Jet

The advantages of using RATO not only included shortening the required runway lenght but also limit fuel consumption and prolong the range of the aircraft.

Using rocket engines had its downsides as well. First of all, the fuel is sensitive and requires special treatment. Second, the additional trained crew for rocket maintenance is needed.

JATO technology was broadly researched in the USA.

Bombers and other jets had big requirements towards the runways. Without long runways they were not able to operate. Nevertheless, use of RATO throughout the Cold War period was limited. Tactical danger of a nuclear strike has contributed to emergement of ZLL or ZLTO programme (Zero Lenght Launch / Zero Lenght Take-Off).

F-84 ZEL

Image Credit: airvectors.net

The system has been developed by the Martin company, which, in the early stage of the test programme has used disabled F-84 fighter jets. F-84 had a rocket engine installed in the back section of the fuselage and it was shot into the desert. Test programme was started on Dec. 15, 1953.

On Jan. 5, 1954 the first piloted launch took place. The worries (to be proven wrong later) considered the high G-loads the pilots were to face during the take-off procedure. 3.5Gs were recorded, not much more than G-load of an aircraft carrier catapult take-off.

F-84 was driven up to 175MPH – well above the stall speed. Nevertheless the programme was abandoned.

An interesting application of the JATO technology was the C-130 Hercules destined to the Credible Sport operation. The U.S. planned a hostage rescue mission in Iran in the 1980. The plan was corageous – it assumed C-130 landing and taking-off from a football stadium the hostages were held in proximity of.

The XFC-130H planes had been modified by installing rocket engines on the fuselage, not only to assist take-off but also to shorten the space required for landing. Additional modifications included arrestor hook so that big plane could land on an aircraft carrier.

Nevertheless, the problems which occured at programming the rocket sequence made the tacticians turn towards a different rescuing plan.

British Rolls-Royce started  its VTOL experiments from the early 50s.

The Flying Bedstead project used 2 engines – one for vertical flight and the second one for horizontal movement. The project is notable because of the first use of jet engines for providing the control in hover later applied in the lunar landing module. The platform was the springboard for what was to become a foundation for the best known VTOL jet in history.

Revolution came together with introduction of Rolls Royce Pegasus Engine and P.11.27 known today as Harrier.

It was developed in mid 1960s, as a first of the practical VTOL concepts. The thing that made the Harrier different from other designs at the time was its engine – the Pegasus. The concept surpassed the contemporary VTOL designs in a sense that they either took-off standing on their tail – that was far from being conveinient for the pilots – or needed several powerplants to achieve VTOL.

The designers had to overcome meny difficult problems in designs such as Convair Pogo or Lockheed Salmon and Rolls-Royce Flying Bedstead. And the British approached the issue from completly different angle,  succeding.

Harrier was designed by Hawker Company in 1957 in a form of P.11.27 Kestrel prototype in cooperation with other NATO countries.

The Pegasus Engine was the strong point of the new aircraft since it simplified what other designs (e.g. French Balzac) complicated. The concept works as a basic thrust-vectoring – nothing unusual now, in 2013, but quite extraordinary in the ’60s.

Nevertheless the concept was not really trusted, and it took almost 20 years for it to prove it was useful.

In the mid ’60s the Harrier was the only VTOL aircraft in the market. But its performance in comparison with the conventional designs of that period was not really satisfying. It was subsonic and it could not carry much of armament. Still the U.S. Marines considered it was extremely useful as it did not need runways. In the context of nuclear danger, that feature was a clear advantage.

U.S. Marines bought the Harrier in 1968, and in the following year so did RAF.

In the RAF, Harrier did not play a role of a frontline fighter, it was rather a CAS aircraft which did not need runways to operate. However, changes were to come, as the Royal Navy did not have big carriers at the time.

Being faster than a helicopter, Harrier would be a perfect means for providing cover to the Royal Navy. This is when Sea Harrier was created. It was basically a Harrier fitted with a radar what would make it less of a CAS aircraft and more of a fighter.

It is hard to describe the Harrier history without mentioning the Falklands intervention. The concept was still regarded as not very useful until 1982, when the Falklands intervention was conducted.

The engineers were saying that they need a small local war to let the Harrier prove its capabilities, and they had it. If it was not for the 20 Harriers that initially took part in the campaign, Margaret Thatcher would have probably lost the war.

Nevertheless, the inequality in air-power was signifcant, as at the beginning of the conflict it was 20 Harriers vs. 200 airplanes of the Argentinian Air Force.

Additional details on the Falklands intervention can be found in this article by Richard Clements published on The Aviationist for the 30th anniversary of the war.

Harrier Falklands

Image credit: Fleet Air Arm Museum Facebook page

The war started on May 1, 1982 with the attack on Port Stanley. The enemy for the Harrier – Mirage airplanes – had twice the speed and performance of the Jump Jet. Nevertheless, unique thrust vectoring feature and the hook maneuver let the British pilots achieve the first 2 kills during the war.

However, on May 6, 1982, two Harriers were lost due to the terrible weather conditions and fog: they collided mid-air. There were only 18 aircraft left protecting the Royal Navy. Until May 21, Sea Harriers achieved 9 kills, and RAF GR.3 Harriers were on their way on a container ship – Atlantic Conveyor. When they arrived they overtook the air-to-ground tasks, leaving the air-to-air sorties to the Sea Harrier.

The Argentinian pilots were undertrained. The objectives given to them during the briefings were to avoid the RAF and Royal Navy’s fighters and to bomb the ships at all costs.

On June 6, the Argentinian Skyhawks were attacking the British Fleet, when Harriers intercepted them only one of the four taking part in the attack escaped.

However, it was not easy for the British pilots either. The weather conditions were terrible, with the fog and 50 feet waves on the Atlantic. The Argentinian planes also suffered from what the sea l0oked like, because after Port Stanley was overtaken they had to fly from the mainland, continental part of the country.

The combat was not easy. Eight planes at a time were stationed on board tha aircraft carrier and one pilot spent the entire night on alert in the Harrier cockpit. That was really excruciating for the crews.

The war ended on June 14 when Harrier jets flew their last sortie disabling the Port Stanley. Without them, winning that war so far away from the UK would be practically impossible.

And Margaret Thatcher would not be probably that well known.

Jacek Siminski for TheAviationist.com

 

Enhanced by Zemanta

AgustaWestland unveils Project Zero, the world’s first electric powered unmanned tilt-rotor aircraft

The aircraft is built in the tilt-rotor technology, with rotors that can be rotated 90 degrees in order to change configuration from VTOL (Vertical Take Off and Landing) to conventional, similarly to U.S. CV-22 Osprey.

It differs from the American tilt-rotor aircraft in the way the tilting is achieved.

In the V-22 Osprey the rotors are mounted at the end of the wings; the Project Zero‘s rotors are located within the wings’ surfaces.

This gives the rotors a bit of ducted fans appearance, making the transition from vertical to horizontal easier – the ducting provides a bit of the lifting force.

The Project Zero is said to be unmanned and the date of first flight is unknown, even if some sources say it was last June, and some say it was in August 2011.

The first flight was tethered, with the aircraft connected to the ground. It is said it made a few secret flights during last year.

Exif_JPEG_PICTURE

Image Credit: AgustaWestland

Daniele Romiti, CEO of AgustaWestland gave the only press statement that is currently available on the Internet saying:

This is a wonderful achievement of the AgustaWestland Advanced Concepts Group. A team of passionate and brilliant engineers worked extremely hard in a secure facility to conceive, design, build and test this technology demonstrator in an exceptionally short period of time,” said Dr. James Wang, Vice President of Research and Technology at AgustaWestland. “This group lives to dream, and if it can be dreamed, it can be built. The team did not just build an electric powered airplane or helicopter; that would have been too easy. They went all out and built a twin rotor electric tiltrotor with no transmission or swashplates.

There is little we know about this aircraft, but here’s what can be found:

The design follows a few trends that might be considered to be placed within the breaking grounds of the aviation nowadays.

Firstly, it is not powered by any combustion engine. The energy comes from battery power, however the official statement of the company does not exclude using hybrid power in the future with help of diesel engines.

A feature which may be interesting is that the aircraft does not use any hydraulics whatsoever. This eliminates the need for faulty fluid-operated on board systems.

The fuselage is a blended lifting body. Company officials claim that additional detatchable set of wings may be used in order to provide the lift for missions which will be carried out in the helicopter mode exclusively.

Steering is achieved through the use of elevons for pitch and roll in the horizontal mode, while the longitudinal stability is provided by a V-tail.

Since the aircraft is driven by electric power, the transmission is simplier.

Then it is possible for the machine to fly in heavily polluted conditions, or at extreme altitudes as, unlike traditional engines, no oxygen is required for combustion. This makes the aircraft a perfect vehicle for examining volcanic eruptions, similar to the one on Iceland in the year 2010 that stopped most of the air traffic in Europe.

Another interesting feature is that, when the aircraft sits on the ground, the blades may be pointed in the wind direction, recharging the batteries.

Lastly, the electric drive gives the design very low noise and heat signatures that would particularly useful for military covert ops.

The aircraft is not Agusta’s first tilt rotor since the company has already designed the AW609, which looks similar to CV-22 Osprey, but has pressurized cabin and has a civilian purpose.

There is no information regarding the Project Zero’s purpose. It may be simply a technology demonstrator without any prospects.

It is not known whether Project Zero will evolve into manned aircraft. In the meanwhile, performance figures in the patent say that the aircraft can reach speeds of 500 km/h and a ceiling of 7,500 meters.

Jacek Siminski for TheAviationist.com

Enhanced by Zemanta

Here is why U.S. Air Force real Flying Saucer never did make it to operational service

Even if newly declassified documents concerning the U.S. flying saucer projects already made the news when they were released by the U.S. National Archives on Oct. 8, new details about round experimental aircraft were recently published by the U.S. Air Force.

Information about these Government’s UFOs were available for several years but diagrams included in the most recently disclosed documents relighted general interest in such weird flying machines whose prototypes can be found on display at the National U.S. Air Force Museum at Wright-Patterson Air Force Base, Ohio, and at U.S. Army Transportation Museum at Fort Eustis, Virginia.

The Avro Canada VZ-9AV Avrocar was a 5-foot tall and 18-foot wide flying saucer of the early ’50s when Canada was studying a way to develop a supersonic bomber capable of vertical take off and landing (VTOL). It was a Canadian project owned and controlled by Washington.

Although it was never implemented (because of its costs) the design concept of the prototype featuring exhaust from turbojet engines to drive a circular rotor to create a cushion of air under the aircraft, served as a testing and teaching tool.

According the Air Force the service was interested in the Avrocar for its VTOL capabilities: it could potentially hover below enemy radars and accelerate to supersonic speed to strike ground targets. The U.S. Army needed a durable and adaptable, all-terrain transport and reconnaissance aircraft to replace their light observation craft and helicopters.

Even if the circular design was believed to satisfy both service’s requirements, it was soon discovered that the flying saucer was unable to perform as predicted.

Here’s why the project was dropped:

Tests with scale models at Wright-Patterson AFB indicated the cushion of air under the Avrocar would become unstable when the aircraft passed roughly three feet off the ground. It was determined the aircraft was not incapable of reaching supersonic speeds, nor would the circular shape of the craft allow the Avrocar to have stealth capabilities. Although the aircraft did not meet the expectations of the Air Force, testing was continued to examine if a suitable model could be developed to fit the Army’s needs.

The first prototype was sent to the National Aeronautics and Space Administration’s Ames Research Center at Moffett Field, Calif. Wind-tunnel tests proved the aircraft had insufficient control for high speed flight and was aerodynamically unstable. Although engineers attempted to perfect the design, the project was marred with problems.

[…]

The second Avrocar prototype underwent flight tests. Project engineers discovered once the craft rose beyond three feet above the ground, it displayed uncontrollable pitch and roll motions. The lack of computer technology and design flaws required pilots to control each engine separately, making it very difficult even for two pilots to properly control.

In December 1961, project leaders discovered the Avrocar could not reach a maximum speed higher than 35 mph. This, along with the crafts other shortcomings, led them to cancel testing permanently.

Meant to operate at supersonic speed, the flying saucer could not fly as fast as a car.

Still, it’s considered a perfect concept, ahead of time. But the technology of that era wasn’t advanced enough for it.

However, research made in the ’50 can be found in many current aircraft, like the AV-8B Harrier, V-22 Osprey tilt-rotor aircraft, F-22 Raptor and the F-35B, the first combat plane to combine STOVL (Short Take Off Vertical Landing) and stealth capabilities.

All images: U.S. Air Force

World Exclusive: U.S. Navy MQ-8B Firescout drone copter returns to service after grounding. And conducts Dual Air Vehicle operations too.

Following two unrelated operational mishaps with the MQ-8B Fire Scout unmanned helicopter, in April 2012, the U.S. Navy temporarily suspended flight operations for 14 air vehicles in inventory while reviewing system performance and operational procedures.

The grounding came after a Fire Scout operating off USS Simpson was ditched at sea on Mar. 30, as the drone was unable to achieve UAS Common Automated Recovery System (UCARS) lock on and could not be safely landed aboard the ship; and, on Apr. 6, an MQ-8B crashed during a routine ISR (Intelligence Surveillance Reconnaissance) mission in northern Afghanistan.

Although the news was not publicly advertised, the Fire Scout grounding has been lifted as the following exclusive images show.

They were taken by aviation photographer and author Erik Hildebrandt, who was shooting MQ-8B ops at sea for “Unblinking”, its up coming book, due in December.

Actually, photographs don’t only prove that the drone copter is flying again. They show an unprecedented achievement: on Jun. 11, HSL-42 based at NAS Mayport, Florida, succesfully conducted dual air vehicle operations (DAV) of 2 MQ-8B Firescouts off the deck of the frigate USS Klakring FFG-42.

The activity consisted of multiple launch and recovery cycles of 2 Firescout drone as well as live, on-site surveillance of mobile inland targets presented by the Camp Lejuene training complex.

With support by Northrop Grumman, the team was able to accomplish this critical milestone in littoral maritime VTOL (Vertical Take Off and Landing) UAS (Unmanned Aerial System) operations and, in a matter of few weeks, the Klakring will get underway on a 5 month deployment off the coast of Africa to relieve the USS Simpson currently stationed in the region.

Noteworthy, one of the two MQ-8s involved in DAV sported a Transformers insigna on the Rotormast Pylon (RMP).

The Fire Scout has been used during the air war in Libya: one MQ-8B drone copter was shot down during an ISR mission in support of NATO’s Operation Unified Protector.

Salva