AIM-9 Sidewinder

RNLAF Use

The standard missile carried by RNLAF F-16s is the AIM-9L (Lima) Sidewinder manufactured by Bodenseewerk Gerätetechnik GmbH, a multinational consortium in Germany. In a typical air-to-air configuration, two of these Limas are carried (four for the pre-MLU F-16). In future, the more advanced AIM-9M (Mike) model — with lower-smoke motor, seeker with improved background discrimination, and better IR Counter Countermeasures (IR CCM) — will be purchased by the RNLAF.

General Description

The AIM-9L is an all-aspect missile, meaning that it can be fired at targets from all angles — including head-on — and does not specifically need to be homed at the rear of the target — at the target's hot engine exhaust — as was the case with previous models. When fired from a head-on position, the missile will detect the exhaust gases behind the target aircraft nozzle, since the exhaust gases coming from the target aircraft's engine nozzle will mix with relatively cold ambient air outside the engine.

The missile's in-flight stabilization system consists of four air-driven wheels, fitted in the rear outside corner of the four rear fins. These wheels provide a very cost-effective gyroscopic stabilization.

Since the missile is equipped with proximity fuses, it is not required that the missile actually impacts the target. Target proximity is continuously being measured by a laser, transmitting a coded signal under a specific angle with the missile longitudinal axis. When the missile is in range, the laser signal will be reflected by the target and the war head will be detonated, causing the target to be hit with many small particles and therefore causing fatal damage to airframe, engine and avionics systems.

The Sidewinder can be used in every day/night and electronic counter measures condition.

The AIM-9L/I-1 — with a new electronics-module — is more insensitive to the recognition and shadowing against IR-Flares.

Seeker Head

With an infra-red guided missile such as the Sidewinder, the discriminating ability of the seeker head — i.e. the ability to discriminate between different heat sources and their respective backgrounds — depends on the seeker head's own temperature, relative to the temperature of the ambient air. Therefore, the seeker head of an active missile is cooled up to minus 160 degrees Celcius in order to establish optimal sensitivity. The effective range of a cooled missile is 10-16 km, depending on the weather conditions — clouds tend to "mask" infra-red radiation — and the degree of humidity.

The seeker head is cooled with specially treated air (officially the expensive Argon should be used instead). The air is filtered and de-hydrated, then compressed to 345 bar (5,000 psi) and stored in a small stainless-steel bottle, which is placed near the missile foreplanes. The de-hydration process is necessary in order to prevent the head from being frozen. A small amount of compressed air is continuously being expanded, causing a small stream of air, cooling the seeker head. Within two minutes the seeker head temperature is at the required level. The initial cooling is taking up most of the air; maintaining the temperature at the required level is taking up relatively less air. Nevertheless, the time the seeker head temperature can be maintained at the required level is limited. During long missions, the amount of compressed air available must be used wisely. Therefore, in most cases the missiles will only be activated when they actually will be used.

During peace time, only aircraft of the Quick Reaction Alert or aircraft participating in live firing exercises are equipped with live Sidewinder missiles.

The seeker head permits pilots to launch the missile, then leave the area or take evasive action while the missile guides itself to the target.

AIM-9L Data

The missiles can be carried at single launch rails at the wing tips at stations 1 (port) and 9 (starboard), or at either single or dual launch rails at stations 2 and 8. The missile is attached to the launcher using bolts, which will break by the force of the missile once the rocket motor has been ignited.

The Lima is the third generation Sidewinder in production. It is the first all-aspect AIM-9 variant. It is equipped with double delta foreplanes with pointed tips, argon-cooled indium-antimony (InSb) seeker with FM-AM conical scan that improves the tracking stability and at the same time increases seeker sensitivity, active optical target detector, 8-diode gallium-arsenide (GaAs) laser fuse (in which the lasers act as "whiskers" around the warhead), and an improved warhead.

Note that the missiles carried at the wing tip launchers (stations 1 and 9) are required for aerodynamic reasons, in order to reduce wing tip induced drag. Therefore, when no live missiles are necessary, dummy missiles will be carried at wingtip stations 1 and 9. During exercises that do not require live missiles these dummy missiles can be equipped with actual seeker heads, which transmit actual data to related aircraft systems, offering the same seek capabilities as the real missiles, but without being equipped with explosives.

Manufacturers

The AIM-9 has been produced by several manufacturers:

• Loral Aeronutronics (formerly Ford Aerospace and Communications) [Newport Beach, California, USA]
• Raytheon [Lowell, Massachussets, USA]
• Bodenseewerk Gerätetechnik GmbH, German/British/Italian/Norwegian consortium [Germany]
• Mitsubishi Industries, also build current models [Japan]

Combat Use

First Use

The Sidewinders first combat use was in October 1958, when Taiwanese in F-86s launched them against Chinese MiG-17s, claiming as many as 14 shot down in one day. AIM-9s scored most of the air-to-air kills made by US Navy and US Air Force aircraft in the Vietnam War, and by the Israeli Air Force in the 1967 and 1973 wars in the Middle East.

During the 1982 air engagements over Lebanon's Bekaa Valley, 51 out of the 55 Syrian-flown MiGs shot down were hit by Sidewinders.

Falkland War

In the 1982 conflict in the Falkland Islands, between Great Britain and Argentina, British Sea Harrier Vertical Short-Take- off and Landing (VSTOL) aircraft used AIM-9L Sidewinders for 16 confirmed kills and 1 probable against Argentine aircraft (of a total 20 air-to-air kills; another 45 Argentine aircraft were shot down by surface-to-air missiles in that conflict).

Gulf War

Compared to its dominant role in the 1982 Falkland Islands campaign as well as the Israeli operation in Lebanon, the Sidewinder was used relatively little during Operation Desert Storm's air assault against Iraqi targets. This can partially be explained by the improvements of the longer-range AIM-7 Sparrow.

However, Sidewinders fired by US Air Force F-15C Eagle jets downed six Iraqi combat aircraft. Two more Su-22 Fitters were shot down by AIM-9s three weeks after the ceasefire. A Saudi F-15 pilot downed two French-built Iraqi Mirage F1s with Sidewinders in a single attack. Two F/A-18 Hornets and an F-14 Tomcat scored with AIM-9s, the Hornets shooting down MiG-21 Fishbeds and the Tomcat downing a helicopter.