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REMOTE CONTROL BY BOB YOUNG Unmanned aircraft – Israel leads the way UMAs have developed over many years from craft that have showed promise to devices which are important in the modern defence arsenal, as shown by their extensive use in the Gulf War. However, the country which has really shown the way has been Israel with its Mastiff & Scout aircraft. This month, we will look at some of the more exotic modern UMA systems but first a few observations. I am forever amazed at the reader reaction to each monthly column and to some extent my own views of each column. Columns that I am happy with often pass unnoticed or even attract adverse comment. On the other hand, some that I am not happy with, despite my best efforts, can attract a favourable reaction. By far the most persistent cause of headaches is the choice of topic. When I settled upon the subject of UMAs for a purely electronics magazine, I did so with some trepidation and they were difficult columns to write. I had to spend weeks in the NSW State Library researching the subject, bringing my knowledge of the subject up to date. It appears that my fears on this series of articles were unfounded for they have attracted possibly the most reader reac­tion of all of the columns I have written to date, with the exception of the speed controller articles. This is not to say that all readers agree with what I have written, so here are a few comments from readers who felt moved to communicate their The IAI Scout is a notable Israeli UMA that began operational flying with the IDF in 1981. Its wingspan is 4.96 metres, maximum take-off weight is 159kg & its maximum speed is 176km/h. The endurance time is quoted as seven hours. interest. My thanks to them and all of the others who wrote or otherwise commented on the articles. First, Tony Mott of Blackburn, Victoria sent me a very interesting extract from the book “German Aircraft” by J. R. Smith and Antony Kay. It gives the most detailed description of the Mistel (Mistletoe) composite aircraft (mentioned last month) that I have yet encountered. Tony pointed out that according to Smith and Kay, not only did I get the name of this project wrong but I also gave incorrect details of the operation of this intri­guing unit. What can I say, except “OOPS!” Contrary to what I stated in the June 1993 issue, the upper fighter unit of the pair was the mother ship and the larger, lower (bomber) unit was the disposable missile. Here is a classic example of not checking the facts. The details, sadly, came from my own (faulty) memory. Despite all the research I did, the one thing I did not refresh my memory on was wrong. Whilst on the subject of the Mistel project, Smith and Kay give some very interesting details of this and similar weapons. They claim the earliest use of a guided UMA in combat was when the Italians launched a Savoia Mar­ c hetti S.M.79 bomber packed with explosives and fitted with radio control against British warships off the Algerian coast on the 13th August, 1942. This aircraft was set on course by the pilot who then bailed out but the mission failed due to a radio malfunction. Further to my comments on the improvements in warhead design in the June 1993 issue, the Mistel was fitted August 1993  53 The IAI Helstar from Israel is one of the most notable UMAs flying. It has twin co-axial rotors some two metres in diameter & its maxi­mum take-off weight is 500kg. It can stay airborne for six hours & has a maximum speed of 185km/h. with a 3500kg hollow charge warhead made up of 1725kg of high explosive and a 1000kg steel core. This core had a theoretical armour penetration of 7.5 metres. In actual tests, it burst through some 18.5 metres of concrete, a staggering result. As stated previously, men have an absolute genius for de­signing ways to kill each other. The thing that really impressed me in regard to the Mistel was just how advanced the German technology was in those days. The original Mistel was aimed at the target and launched, under control of the autopilot, at the target. This left much to be desired as regards accuracy and a proposal was put forward to fit a wire guidance system similar to that designed for the Henschel Hs 293D. In this system, television cameras in the bomber relayed pictures back to the fighter. Wire guidance was used very successfully in many early missiles. It is easy to see where the inspiration for the smart bomb, used to such great effect in Iraq, came from. Wallace Beasley of Hillbank, SA sent in a fascinating tale he picked up on the rumour mill whilst working for the RAF at Lympne as a young lad. Several British fighter pilots were al­ leged to have been arrested because 54  Silicon Chip they planned to fly to Spain in their Hawker Fury fighters to fight against Franco in the Spanish civil war. Not only that, but it was rumoured that they had managed to get hold of a Queen Bee complete with ground control equipment and had planned to load it with explosives and use it as a guided missile against some strategic target. As primitive as all of the foregoing appeared, they were to spawn a deadly breed of UMAs and guided missiles in a very short space of time. All of this reminds me of Charles Fort and his theory on the steam engine. Fort held that when it came time to invent the steam engine it would appear spontaneously around the world. This certainly seems to have been the case with UMAs. New breed UMAs Returning now to the Middle East and the 1990s, we come face to face with the new and very deadly breed of UMAs. As stated previously, the Israelis now hold the dominant position in the design and supply of UMAs, so we will have a quick look at some of these and their uses. The leading Israeli UMA company is Israeli Aircraft Indus­tries (IAI), which absorbed the Tadiran UAV division in 1984. Tadiran developed the Mastiff series of UAVs and Mastiff III was Israel’s first generation production mini-UAV. Mastiff is now fairly primitive by modern standards but it served Israel well for almost a decade. The experience gained from this UMA and its evaluation by the USMC led directly to the US Navy requirement for Pioneer, more of which later. Mastiff does not have a preprogramm­ ed opera­ tion option and is purely operator controlled. It is due to be re­ placed by the new IAI Searcher. Mas­tiffs were bought by the US Navy in 1984-85. Mastiff has a wing span of 4.25 metres and weighs in at 138kg at take-off. Its maximum speed with a 16.4kW (22hp) engine is 186km/h, while its operational ceiling is 4480 metres (14,700ft). In 1976, IAI started development of the Scout and in 1981 Scout II began operational flying with the Israeli Defence Forces. Scout is slightly larger than the Mastiff but has the same basic appearance. Most IAI UMAs feature a short fuselage fitted with a pusher propeller. The wing is shoulder mounted on this pod. The tail­plane is mounted on twin booms which attach to the wing. All are fitted with a tricycle non-retractable undercarriage – very basic stuff by modelling standards. The pusher propeller leaves the nose free for TV cameras and other sensors, and keeps the air­craft and camera lenses free from exhaust waste. Scout has a wingspan of 4.96 metres and maximum take-off weight is 159kg. Its speed with a 16.4kW motor is 176km/h (95 knots) and the ceiling is 15,000 feet. The endurance of the Scout is quoted as seven hours. Takeoff is via a truck-mounted catapult (standard), but wheeled take-off is also an option. The Scout has been the Israeli Defence Force’s mainstay UMA since 1982 when it was introduced over the Beka Valley with some outstanding results in defence suppression missions. Scout has the option of being able to switch between pre-programmed and operator-controlled flight. This allows the uplink (the radio control channel from ground to aircraft) to remain silent during most of the mission except for any unforeseen events which need operator intervention. The sensors fitted vary and include a daylight TV camera, FLIR and laser rangefinder/target designator. Recovery is by net in standard configuration but wheeled landings are an option. Scout has been exported to Sing­apore, South Africa and Switzerland and, like Mastiff, will be replaced by the Searcher. Interestingly enough, both Switzerland (IAI joint venture) and South Africa have since developed their own versions of the Scout, both a little larger but with the same basic layout. However, the 6-metre South African Seeker is far and away the more elegant looking vehicle. It has a very interesting “return to base” mode in the event of the primary or backup UHF control links being broken or jammed. The Swiss Ranger has a parachute recovery for peace-time emergencies or, for normal operations, a wheeled or skid under­carriage which can be used in conjunction with an arrester cable. Pioneer In 1985, the US Navy purchased the first of nine Pioneer units from IAI. Developed by IAI and produced as a joint IAI/AAI venture, Pioneer is derived from the earlier Scout and maintains the same basic layout. Its wingspan is 5.11 metres and maximum take-off weight is 200kg. Power is by a Sachs SF 350 2-cylinder, 2-stroke engine rated at 21kW. The service ceiling battleships Missouri and Wisconsin. Pioneer flew more than 500 missions during Desert Storm, totalling in excess of 1700 hours. Its missions included mine-hunting, naval OTH (over the horizon) targeting and route recon­ naissance for AH-64 helicopters, as well as the more commonplace overland surveillance and target location. Sensor options include TV, FLIR, EW/ECM, decoy, communica­ tions relay and laser rangefinder/designator. The guidance system is either pre-programmed or it can be flown by an operator. Recovery is either by wheel­ed undercarriage with an arrester or, on ship, by net. Since 1986, IAI has developed a stream of more and more advanc­ ed UMAs including Ranger, Impact, Search­er (wingspan 7.22 metres, speed 204km/h, ceiling 7620 metres), Hunter and the very interesting Helstar. Helstar (Heliborne Loitering System with Thermal imager and Radar) is an unmanned maritime helicopter featuring twin co-axial rotors some two metres in diameter (not much larger than the usual model helicopter). Designed to operate from Israeli naval corvettes and other missile carrying boats, the Helstar take-off weight is a staggering 500kg. It is fitted with an Allison 250C20B turboshaft engine rated at 313kW (420hp) and can stay airborne for six hours. Its maximum speed is over 185km/h (100 knots) and the mission radius is 185km. Pioneer flew more than 500 missions during Desert Storm. Its missions included minehunting, naval over the horizon targeting & overland surveillance & target location. is 4575 metres (15,000ft), while the endurance is six hours. It is launched using wheels, catapult or rocket boost along a rail. The EI-Op TV or FLIR camera is carried in a ventral turret and EW (electronic warfare), decoy or other payloads are option­al. The USN and USMC now have nine Pioneer units, each comprising up to eight air vehicles. Six of these were deployed before and during the Desert Storm operations, with two operated from the I have chosen to devote some considerable time in describ­ing the IAI aircraft for one simple reason. In essence, they are little more than typical model aircraft, yet they form the nu­cleus of the practical UMA movement. Here are front-line minia­ture aircraft, the likes of which can be found on model flying fields anywhere in the world. This really is no accident as many of the designers are active modellers who spend their weekends on model flying fields. Of course, UMAs are much more sophisticated and expensive than model airplanes. Teledyne UMAs Two other UMAs of interest before we close for this month are the Teledyne Ryan Model 410 and the Teledyne Ryan Scarab/BQM-145A. The Model 410 is large enough (9.55 metres wingspan) to carry fullsized payloads but looks for all the world like a grown-up IAI twin boom UMA. It was designed for long-range or long-endurance missions and was first flown on 27th May, 1988 with an on-board check pilot under a tear-drop canopy. Here the circle is complete, for we finally have what is little more than a man-carrying model aircraft. The Model 410 has a take-off weight of 816.5kg and the 119kW (160hp) flat 4-cylinder Lycoming engine pushes it along at 322km/h (174 knots). Its maximum endurance is 22 hours, the service ceiling is 30,000 feet and the range is 2300km. Here is the ultimate modeller’s toy – just hop in and fly to the field, then whip out your transmitter and have a nice day of R/C flying. At the end of the day with your Model 410, you could then stow the Tx, change back to manual control, hop in and fly home. What a way to go! For the ultra-sophisticated, we have the Teledyne Ryan Scarab BQM-145A. It has a wingspan of 3.35 metres, a length 6.15 metres and weighs in at 1077kg. Fitted with a Teledyne CAE 373-8C turbojet engine rated at 970lb thrust, the Scarab can nip along at a handy 851km/h (459 knots). Its mission radius is 966km, while the service ceiling is 43,000ft. The Scarab was designed primarily for Egypt in the mid-1980s as a groundlaunched reconnaissance UMA and 56 were subse­ quently delivered. It is launched by booster rocket from a truck-mounted “zero length” rail and recovery is by parachute or airbag landing. Here we have left the model movement far behind and on this note we leave this most fascinating field of human endeavour. Acknowledgement My thanks to Bill Herbert, Flynn, ACT for the photo of the Jindivik aircraft featured in the May 1993 issue SC of SILICON CHIP. August 1993  55