Tuesday, June 24, 2008

Northrop QM-74 Chukar series

Like the Ryan Firebee the Northrop Chukar is a long-serving UAV which entered service in the 1960s and continues in service and development to the current day. The Chukar is a target drone but saw combat service as a decoy drone later in it's career.

BQM-74F launch (c) Northrop Grumman

The Chukar is a small (just over 3.5m long and with a wingspan of 1.69m) zero-length launched UAV sent into the air using JATO rockets from a ground or ship based launcher and can also, with the Chukar III, be launched from an aircraft such as a Hercules if fitted with an air launch kit. At the end of it's mission or if there is a loss of contact the Chukar deploys a parachute for recovery. A floatation kit can also be fitted. The Chukar is intended to provide for a realistic target for gunnery or missile training.

There have several major versions of the Chukar :

MQM-74A Chukar I
Development began of the Chukar in the early 1960s for the US Navy and it went into production in 1968. Powered by a Williams WR24-6 turbojet and launchable with the assistance of JATO rockets from ship or ground the Chukar I entered service with the US Navy, Royal Navy and Italian Navy.

2300 Chukar Is were built by 1973 when production switched to the Chukar II. The Chukar I platform was also developed into the NV-128 surveillance drone but did not enter service and XBQM-108A experimental UAV (using the engine and guidance system from a Harpoon missile) to research "tailsitter" VTOL.

The Chukar I had a maximum level speed of 489mph / 787km/h and a service ceiling of 40,000ft / 12, 200m. Range (at 20,000ft was 273 miles / 439 km).

The Chukar was guided by radio control with automatic stabilisation using gyros and altitude sensors when the target was out of range. The Chukar was fitted with equipment to augment it's radar reflection and also had infrared flares and visual aids such as flashes to aid visual identification.

MQM-74A being prepared for launch

MQM-74C Chukar II
Fitted with a more powerful Williams WR24-7 turbojet the Chukar II had a higher performance. Speed was increased to 593mph / 954 km/h. Range was also increased. The Chukar II was fitted with an autopilot system for guidance. It replaced the Chukar I in production in the early 1970s.

MQM-74C Chukar II launch

BQM-74C Chukar III
The Chukar III was a further developed target drone from 1978 with a computerised A/A37G-13 flight control system to allow more complicated pre-programmed flight operations, including the ability to be air launched, and powered by a Williams WR24-7A. Over 1,600 Chukar IIIs have been built to date.

In the mid 1980s the engine was changed to a more powerful J400-WR-404 and has improved guidance and flight control systems to allow it to simulate an anti-ship cruise missile. Using a radar altimeter it can fly as low as 3m. The target augmentation equipment has also been upgraded.

This is the latest version now in development by Northrop Grumman. Guidance will be GPS/IMU with speed further increased to Mach 0.92 at sea level. The target will also be capable of 8G turns. The BQM-74F can have 6 missions with up to 70 waypoints pre-programmed and the mission can be selected either before or after launch. Northrop say this makes the BQM-74F "the foremost cruise missile replicator available".

The Chukar goes to war

In the 1991 Gulf War Chukar IIIs were used as decoy drones in the second wave of attacks. 37 were launched and began to orbit Baghdad. As the Iraqi radar stations illuminated the Chukars this allowed anti-radiar missiles to strike the radar stations. The decoys were operated by a special team of specialists set up purely for this operation, the team was disbanded after the war. The Chukars were fitted with radar reflectors to mimic the signature of strike fighters. The decoys helped reduce allied aircraft losses from the high number feared to the low number that was suffered in the end.

Thursday, June 12, 2008

History & development of Chinese UAVs

At the November 2006 air show in Zhuhai the Shenyang Aircraft Design and Research Institute unveiled an interesting UCAV concept called Anjian or Dark Sword. The impressive looking model raised eyebrows when it was declared to be for the air-to-air role. A2A is considered to be decades away for UCAVs so it is likely the model is just to show off current thinking in Chinese design and aerodynamics. Given the secrecy that usually surrounds new aviation projects it is unlikely that the real next generation UCAVs are too much like Anjian but it certainly shows that they have come some way like the rest of their aerospace industry.

Dark Sword

China is putting a lot of effort into indigenous UAV development with UAVs being seen as key to the development of tactical C4I and airborne ISR. One problem the army is having is integrating data from UAVs into their operations, it is only recently that Chinese UAVs have been able to relay information back in real-time.

Air force reconnaissance

The first operational reconnaissance UAV with the Chinese air force was the WZ-5 which was based on the Ryan Firebee and entered service in 1981. It is thought the WZ-5 was reverse engineered from captured Firebees downed during missions over Vietnam and China in the 1960s but using Chinese designed surveillance and support equipment. The WZ-5 has been used operationally but has a number of drawbacks such as the lack of real-time datalinking and control. It can only fly a pre-programmed flight profile and has to be retrieved in order to get the imagery taken. Recent WZ-5s are said to be able to carry TV and infrared cameras but still lack real-time datalinks.

A much more advanced UAV is the GAIC WZ-2000 (or WZ-9) which was unveiled for the first time in 2000. The WZ-2000 has a similar configuration to the US RQ-4 Global Hawk. The WZ-2000 has a thermal imaging camera and synthetic aperture radar to give it a full all-weather capability (the WZ-5 was only usable in daylight) and sends data back to base in real time via satellite. The WZ-2000 first flew in the early 2000s.


Army UAVs

A number of UAVs have been developed by Xi'an ASN Technology Group and are in PLA service. The ASN-104/5 was the first indigenously designed UAV for army service and entered service with the PLA in the late 1980s. Piston engined, it can carry a variety of sensors and could be controlled from the base station or fly along a pre-planned route. The ASN-105B can relay information back in real-time.

The ASN-15 is a battlefield surveillance and intelligence UAV that is in service with the reconnaissance battalions of Chinese army divisions. The 1.8m long UAV is hand-launched by a soldier and can fly for up top an hour returning imagery back to the base station in real time.


The ASN-206 is one of China's most advanced UAVs and as well as surveillance and reconnaissance can also be used for electronic warfare and radiation sampling. The ASN-206 employs a twin-boom pusher propeller design and has a real-time datalink back to it's operators. It was one of the first Chinese UAVs to offer real-time datalinks as earlier UAVs in PLA service like the ASN-104 needed to be recovered to get the data back. The ASN-206 was developed in the mid-1990s, reportedly with the assistance of the Israeli company Tadiran Spectralink.

Target drones

A major type of drone used by the PLAAF is the ChangKong-1, a reverse-engineered copy of the Soviet era Lavochkin La-17C. The CK-1 is a subsonic radio controlled target powered by a turbojet. The CK-1 entered service in the 1970s and has also been used for atmosphere sampling after nuclear tests. Later versions of the CK-1 were optimised for low-level and high-agility to enable a variety of training scenarios.


Xi'an ASN Technology Group have also produced a number of propeller driven target drones such as the ASN-7, a simple propeller and straight winged radio controlled aeroplane. Some of these are China's earliest UAVs being developed from the late 1960s onwards.

A more recent development has been the TianJian-1 which is intended to simulate cruise missiles. The TJ-1 entered service in 2005 and can be guided by remote control or by GPS.

The next generation?

Chinese UAV development started off reverse-engineering or copying US and Soviet types and along the way there has been some help from Israel but now China has a thriving UAV industry. Many new types of UAVs now in development in China from a number of companies. Beijing Black Buzzard Aviation Technology unveiled a couple of new types to be powered by micro-turbines. The 3.2m long rail-launched HFT-60A is said to be capable of 600km/h with an endurance of 3 hours on a pre-programmed flight, the similar HFT-40A is slower. It is intriguing that the company have gone for high-speed yet low-endurance UAV which is the opposite of most other manufacturers!

The company also demonstrated another UAV that is able to take off from unprepared strips (and presumably land again) and has a joined wing and pusher propeller configuration.

Joined wing UAV

Wednesday, June 11, 2008

Autosub6000, Britain's new robot submarine

Undersea volcanoes 6km below the Caribbean will be searched for and explored by Britain's new robot submarine the Autosub6000. The Cayman Trough between Jamaica and the Cayman Islands is the world's deepest volcanic ridge and unexplored. Autosub6000 can dive to more than 6000 metres and operate without control from the surface. First of all it will try and find the volcanic vents, once found the sediments, gas and life living there will be catalogued.

Autosub6000 is an Autonomous Underwater Vehicle (AUV) that can be equipped with a variety of sensors such as cameras, sonars and samplers. It is guided using "an Ixsea PHINS Fiber Optic Gyro (FOG) based Inertial Navigation System".

Sunday, June 8, 2008

Not Classic Jetliners (6) : Shanghai Y-10

The Y-10 was the first attempt by China to produce it's own jet airliner and until the ARJ21 takes off later this year the only attempt. The Y-10 was developed by the Shanghai Aviation Industrial Company in the 1970s as a four engined passenger transport to free China from dependence on foreign suppliers. The Y-10 looks very much like a Boeing 707, which China did have a small number of at the time, though it has been denied that it was an example of reverse engineering.

The programme was also started to give the Chinese aviation industry experience with large jet powered transports and for national pride. Politics in fact were heavily tied up in the project which was spearheaded by Wang Hongwen. As he, and the Mao era, fell out of favour so did enthusiasm for the Y-10 which was increasingly seen as a throwback to the days of isolationism.

In 1980 the Y-10 made it's first flight but the only flyable Y-10 (another airframe was used for static testing) made 130 flights before being retired in 1983. The project was cancelled for cost and technical reasons though politics is likely to have been the main reason. No high-up party officials attended the Y-10's maiden flight because it was tainted with Wang Hongwen. Instead China began to licence produce the McDonnell Douglas MD-80.

As the 707 is my favourite jet airliner of all its a shame the Y-10 never took off (so to speak). There was some development work on a possible AWACS version however in the end China used the Il-76.