Messerschmitt-Bölkow-Blohm Bo 105

Aircraft manufacturer Bölkow began to develop what would become the Bo105 in 1964, and when the Swedish Defence Administration was looking for a new light helicopter to replace the Hkp2 they considered the Bo 105, but soon resumed their search, as that helicopter was at that time still in the prototype stage. However had the situation been a little different, the Bo 105 would have become the Hkp6. Instead the Bell Jet Ranger 206 was selected to become the Hkp6.

Of course the development of the Bo 105 continued. Unfortunately the first prototype was destroyed by ground resonance, but the second prototype first flew on February 16, 1967. The Bölkow company entered a merger, so that the first serial production helicopter, the Bo 105A, rolled out in 1970 with Messerschmitt-Bölkow-Blohm as the manufacturer.

Several improved versions followed, and the helicopter was also licence-built in the Philippines, Indonesia and Spain.

The Bo 105 became known as a very manoeuvrable helicopter, that unlike most other helicopters was (and is) capable of performing some advanced flying such as steep dives, tolls and even loops. It is admittedly not renowned for its beauty, but is very pleasant to fly and has excellent lift off characteristics. This is partly due to the rotor, which is rigid and without hinges, which means that it can withstand powerful forces, allowing for more agile flying. The rotor head itself is made of titanium and the rotor blades of a fibreglass composite.

The lift off characteristics and the ability to rapidly, or even briskly, be able to rise straight up is, for a stealthy armoured helicopter obviously an excellent feature.

A Bo 105 serving in the Mexican Navy. Photo: Wikipedia commons

The Bo 105 gained popularity as an ambulance helicopter for both civil and military use, and also as a reconnaissance and light transport helicopter. Versions for maritime reconnaissance were developed, and still today are in use by Mexico. At the same time, both the Spanish and German military saw its potential as a weapon platform, not least in the form of an armoured helicopter.

Over 1,500 Bo 105s in all variants have been manufactured, and are still in use all over the world. They are renowned for being reliable, fast and nimble.

Helicopter versus tank

There is some confusion in respect of armoured helicopters. Usually one refers to attack helicopters, which means those specially designed for battle, with armour plate and heavy weapons. Even though the most important task of an attack helicopter is to fight enemy armoured vehicles, they are equipped to be able to perform other tasks and be armed with a variety of weapons.

Besides attack helicopters, there are also today fighting helicopters that may have built-in weapons but are not meant to be used for tasks best performed by attack helicopters. The latter are meant to be able to go deep into enemy territory and are thus heavily armoured. A fighting helicopter carries less armour and is not able to carry out this type of task.

The first true attack helicopters were such armoured transport helicopters as the Bell 204 and Soviet Mi-8. They were heavily armed but lacked armoured protection. Experience during the Vietnam War led to the USA developing the first helicopter specifically intended to go into battle, the Bell AH-1 Cobra. I, whilst the Soviet Union took a rather different approach and developed the Mi 24, a combined attack and transport helicopter. This proved its value during the Soviet operations in Afghanistan. There they could follow up an attack by landing a group of special services soldiers to complete the task.

An interesting line of attack helicopter development consisted of the Soviet Mi-24. This helicopter is armoured and carried heavy armament but is also able to carry troops, which makes it unique and feared. Photo: Peter Langsdale

A stealthy hunter

In connection with the Second World War the tank became established as one of the most powerful weapon systems in land warfare. When complemented by self-propelled artillery and infantry closely following the tanks in their own armoured personnel carriers, large armoured units were formidable opponents. The Soviet Union invested heavily in preparing a large fleet of tanks, supported by mobile artillery and armour-protected infantry. A large part of the effectiveness of armoured units is the psychological effect they have on opponents, especially if they do not have their own armoured vehicles.

The French were early in developing a new weapon against tanks, in the form of armour-piercing missiles. One example is the SS.11 from the 1950s, which was a wire-guided missile which could be steered towards the target. Unlike such weapons as the bazooka and rocket-propelled grenade, which usually need the tank to come relatively close for the defender to expect a successful shot, early anti-tank missiles had already a range of up to 2 kilometres, which enabled infantry to defend against tanks at long range. There were also attempts at the end of the 1950s to fire SS 11 missiles from an Alouette II helicopter.

The advantage of armour-piercing missiles is that the helicopter does not need to get particularly close to enemy tanks, but can use its mobility to find a good shooting position, fire its robots from a long range and then fall back.

Lamson 1971

In January 1971 the final major helicopter operation began in Vietnam. The target was North Vietnamese supply and communication lines along the Ho-Chi-Min trail. In connection with this it became apparent that the North Vietnamese started to use tanks, to begin with the elderly Soviet type T-34. This led to the employment of two UH-1 (Swedish type Hkp3) equipped with a new weapon, the TOW armour-piercing missile (“Tube-launched, Optically tracked, Wire-guided”), aided by a sight in the nose.

A UH-1 armed with heavy machine guns and rocket pods. It was helicopters like this that were equipped with TOW missiles instead of rockets. Photo: Peter Langsdale

The helicopters fired their first missiles on May 2, 1971. This was from a height of 3,000 feet, at a range of 3,280 yards (almost 2 miles). From May 2 Maj to June 12 a total of 81 TOW missiles were fired, said to have destroyed 57 targets. Of these, 24 were tanks or other vehicles, along with other targets, such as bunkers or similar. Some of the destroyed tanks were of the relatively new T-54 type.

AS a result, the US Army decided to equip a new version of the AH-1 Cobra attack helicopter with eight TOW missiles. In the meantime another new weapon made its appearance during the Lamson operation, namely the man-portable SA-7 anti-aircraft missile that in Vietnamese hands resulted in a number of Cobras being shot down. This prompted a new tactical approach. If armoured attack helicopters turned out to be vulnerable to this new anti-aircraft weapon, an approach at about 3,000 feet altitude, even as far away as 2 miles, would pose a great risk.

However, even though the USA and even the Soviet Union chose to invest in specialized attack helicopters, other countries looked for more cost-effective alternatives. The then West Germany decided in 1975 to acquire a version of the Bo 105 armed with six HOT (French: Haut subsonique Optiquement Téléguidé Tiré d’un Tube, or High Subsonic, Optical, Remote-Guided, Tube-Launched) wire-guided armour-piercing missile. Altogether 212 such helicopters were ordered under the designation Bo 105 PAH-1. They were really only intended to be a temporary stop-gap because the Defence Ministry was not satisfied with the ability of the Bo 105 to defend itself and its night operations capability. The helicopters were delivered between 1979 and 1984, and have now been replaced by the Eurocopter Tiger.

Lebanon 1982 – Armed helicopters in battle

A currently forgotten and relatively unknown conflict took place in 1982 when Israeli forces crossed the border of its neighbour Lebanon in order to intervene in the civil war there. Within Lebanon Syrian forces had been present for some time, and these were also attacked in the same action. For the Israeli Army the principal task was to force the Syrian Army out. In previous wars the Israeli armed forces had generally been shown to be superior to the Syrian Army, and the latter found itself from the outset to be outnumbered.

However Syria had decided to develop its ability to fight against the renowned Israeli armoured forces, and the subsequent battles were extremely hard fought. As both sides have released official casualty figures that differ, and both have obviously toned down their own losses, and over-estimated those of the enemy, exact figures cannot be determined. The Israeli Air Force succeeded in gaining control of the air, which gave them a decisive advantage.

One of the two Syrian SA. 342 Gazelles that were forced to make an emergency landing and captured by Israeli forces after being fired on and damaged. It was test flown before going on display in a museum Photo: Wikimedia commons

One of the most effective weapons was Syria’s armed helicopters. The country had access to Soviet Mi-25 attack helicopters, an inferior version of the well-known Mi-24, along with a number of type SA.342 Gazelle light helicopters equipped with armour-piercing missiles. Their 18 Gazelles were however armed with HOT missiles, just like the Bo 105 PAH-1. While the battle raged the Syrian helicopters carried out several surprise attacks against Israeli armour. The helicopters utilized terrain for cover while they were flying very low, between hills and clumps of trees. Two Gazelles were shot down by Israeli forces, two were forced to land and captured, and another one was damaged but managed to get back to Syria.

The amount of damage caused by the Syrian helicopters is not clear. Syria claims that the, among other things, their helicopters incapacitated 71 Israeli tanks and over 150 other vehicles. This is probably and overestimate and a more neutral assessment is that the Gazelle helicopters hit 30 tanks and about 50 other vehicles. Comparing the information from both sides, it is clear that the Syrian Air Force Gazelle helicopters were certainly effective and inflicted losses far beyond their limited numbers. The Israelis found it was very difficult to detect the helicopters and even after they had succeeded in acquiring air superiority the Syrian anti-armour helicopters were able to continue their attacks. In many cases the helicopters were not detected before they opened fire.

Israeli anti-aircraft vehicles were stationed well in front in order to be better able to repel attacks. The Israeli forces mistakenly shot down their own MD 500 Defender armed helicopters identified wrongly as Gazelles. One of the two Gazelles that were destroyed was shot down by an AH-1 Cobra helicopter armed with a TOW missile, and the other by an Israeli tank with its 105mm canon!

After the war, the Israelis repaired one of the Gazelles they had captured and tested it against their MD 500 Defender.

In all, Syria lost five Gazelle helicopters and in turn at least 80 or so Israeli tanks and other vehicles were knocked out. The Israeli MD 500 Defender helicopters were also successful but because the Gazelle helicopters were forced to face a well-equipped and numerically superior enemy that in addition ruled the air, their efforts were even more spectacular and show what a small force of anti-armour helicopters can achieve even when their opponent has air superiority. Also despite their lack of armour protection the Gazelles managed surprisingly well.

So on the whole it showed that light but fast anti-armour helicopters can be very effective. In addition the Israelis found that the psychological effect of the threat from the Syrian Gazelle helicopters on the Israeli forces was an even greater problem than the losses they caused.