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Intercept Geometry: Table of Contents
- Part I: Introduction
- Part II: Definitions
- Part III: Target Aspect & Lateral Separation
- Part IV: Modern Gameplans (P-825/17)
- Part V: P-825/17: DT, CT, Timeline
- Part VI: Modern Intercept Demo Videos (P-825/17)
- Part VII: 2000s Intercepts (P-825/02)
- Part VIII: Intercept Progression & Lead Collision (P-825/02)
- Part IX: “Unknown Procedures” & Fleet Conversions p1 (P-825/02)
- Part X: Fleet Conversions p2 & Advanced Intercepts (P-825/02)
- Part XII: In-Depth Timeline (from “Picture” to “Crank”)
- Part XIII: In-Depth Timeline (continuation: FOX 3/1/2)
This example of continuation of the Timeline discussed in Part XII, follows the procedure described in the P-825/02 and the P-825/08.
It consists of:
- FOX-3 employment;
- turn to Lead Collision, FOX-1 employment;
- stern conversion and FOX-2 employment.
This example starts where Part XII left, post FOX-3 employment and Crank. The goal now is assessing the situation and manoeuvring to place the Target Aspect within an interval compatible with the employment of the AIM-7 Sparrow (FOX-1).
Post FOX-1, the situation is assessed again, and the Section prepares for a stern conversion turn using a Displacement Turn, followed by a Counterturn. When the geometry is appropriate, an AIM-9 Sidewinder (FOX-2) is fired to the target.
Although hardly applicable in its integrity, this timeline is a great exercise that touches the majority of the concepts described in the basic intercept geometry: Target Aspect and Lateral Separation management, missile employment, transition from BVR to WVR and so on.
Resuming the Timeline
Cranking is a “Cut-away” manoeuvre, and hence it generates lateral separation even if the slant range is decreasing by increasing the Target Aspect. However, if left unchecked, the Target Aspect can drastically increase, creating less than optimal conditions for the following FOX-1 employment.
Since the plan is converging again towards the target to fire another missile, the Target Aspect should not increase past 45° – 50°, otherwise the manoeuvre to recover the TA may drag the contact out of the radar volume.
Whatever the case, the fist Cut should be aggressive, to immediately correct the geometry: reducing the Cut later is simpler than trying to predict the correct turn from the Crank.
Situational Awareness Assessment
On top of controlling the intercept and act by commanding the appropriate manoeuvres, the RIO must also ensure that his level of Situational Awareness is high. In particular, the target may jink or the fighter maybe under potential threat. If that’s the case, the Section may have to answer in an appropriate fashion.
If the conditions to press are not present, the Section can Abort. The suggested abort criteria were discussed in the previous parts.
The single most important criterium is being “Spiked” or “Naked”: if the fighters are spiked, then the threat probably have sensors awareness and may be engaging the Section (if it has not already with an ARH missile).
Crank is the first step of the mechanism that serves both the purpose of maintaining SA, guiding the missile and preventively defend from hostile actions.
“Notching” is a manoeuvre that aims to place the threat on the beam and also involves an altitude loss: beaming places the fighter in the MLC filter and the altitude loss prevents the threat to disable the filter and introduces ground clutter.
Abort is the maximum G manoeuvre, with full afterburner, to stay outside the WEZ the threat. The goal is creating maximum separation.
Crank, Notching and Abort are somewhat connected as they can happen one after the other.
Geometry: Controlling the Target Aspect
The AIM-7 Sparrow does not share the powerful rocket motor of the AIM-54, so its employment requires shorter ranges and a more accurate control of the intercept and the angles.
If the fighter is cranking and ATA is 45R at pitbull, an immediate correction is placing the target at 45L, hence correcting for the same amount in the opposite direction (90° in total – if ATA = 50L, then the quick correction would be 50R).
This manoeuvre is probably insufficient, but stops the increasing TA whilst giving time to the RIO to work the correct CB and sanitize the area.
A Sizeable Range Problem
When the AIM-54 reaches the A-Pole, it is activated by the WCS. The distance at which the missile is activated is defined by the Target Size switch located in the DDD:
- Small: 6 nm;
- Norm: 10 nm;
- Large: 13 nm.
If the switch is set to small, the RIO has less time to work the geometry to reduce the TA before the missile is activated by the WCS and vice versa for Large.
A simple test shows that an AIM-54A Mk47 launched on timeline at M1.0 at 20,000ft, followed by a crank is activated by the WCS at ~23nm from the target. Setting the Target to Small or Large change the A-Pole by ±2 nm circa.
Such range is usually sufficient to Cut into aggressively to decrease the TA to < 20°.
Saving the Day
If the RIO is late for whatever reason, he can:
- Cut more aggressively, commanding Buster;
- Skip the FOX-1 employment and prepare for a DT / CT for a FOX-2 employment, either from the FQ or the RQ post CT.
FOX-1 Employment [10 – 12 nm]
When the Target Aspect is satisfying, the RIO commands a turn to Lead Collision and employs.
The AIM-7 Sparrow can be launched in different modes, using a CW antenna via PSTT or using PD STT mode.
Before locking, the Section should re-sanitize the area using Search mode. The operation also allow the RIO to quickly lock from the DDD, an operation much more reliable than switching from TWS to STT directly.
STT ASE Circle
Both Single-Target-Tracking modes display the ASE circle when a lock is established (Figure 265). The visual indications allow employing the AIM-7 Sparrow in the optimal way by allowing the pilot to manoeuvre to place the indicator in the middle of the ASE circle.
Alternatively, the RIO can approximate the Lead Collision by calculating the value of the Lead ATA.
Displacement Turn [8 – 10 nm]
Post FOX-1 employment, it is time to assess the geometry again. To properly set up a FOX-2 shot from the RQ, in fact, the fighter needs to increment the Lateral Separation removed during the FOX-1 setup. This is done by executing a Displacement Turn between 6nm and 8nm depending on the Target Aspect.
The Displacement Turn was extensively discussed in the previous parts. It consists, fundamentally, in a Cut whose side depends on the amount of Lateral Separation available at that moment.
Failing to create enough room may hinder the RQ FOX-2 employment, but can also start a merge with the fighter in a non-advantageous position.
Counterturn and FOX-2 Employment
The Counterturn (CT) consists in a hook-like manoeuvre to place the fighter behind the target, using the space created by the Displacement Turn.
The flow of the manoeuvre depends heavily on the Target aspect, but it should terminate nevertheless within ½ nm and 1½ nm from the bandit.
Forward-Quarter FOX-2 Employment
The AIM-9 Sidewinder, depending on the version, can be launched from the Forward-Quarter. This technique is more dangerous than a conversion, as it exposes the fighter much more to the target. However, it is a valid option to keep in mind if DT and CT fail to position the aircraft to a more advantageous position.
Suggested parameters for proper employment:
- check the TA and the LAR (max TA is usually ~80);
- target locked in STT, AIM-9 selected, dot in the ASE circle;
- target range between 1.5 nm and 5nm.
Another occasion where the FQ FOX-2 can prove useful is versus a non-cooperative target which tries to place the fighters in pure pursuit or nose-on.
Rear-Quarter FOX-2 Employment
Launching the AIM-9 Sidewinder from the rear of the target increases its performance (or enables the missile usage, depending on the version).
Suggested parameters for proper employment:
- target locked in STT, AIM-9 selected, dot inside the ASE circle (pitch and azimuth ±8°);
- target range between ½ nm and 1½n m;
- closure between 0 and 100 kts, no opening;
- hard turn or less;
- drift stabilized (slight inward drift is acceptable).
F-3/2/1: Complete Flow
The image below recaps and shows the complete flow (not to scale).
Compare to the Simplified Timeline study discussed in Chapter 9.5 is very different. Besides the fact that it is a different procedure altogether, the impact of the Geometry is evident. The fighter does not simply point and assess and press, but have a much, much better understanding of what the targeted Group is doing. On top of that, the fighters have now a more clear and profound understanding of how different manoeuvres impact the intercept: for example, Cut Into or Away to manipulate the Target Aspect, or Collision Course to capture it.
This Part concludes the study of the Intercept Geometry as I envisioned it originally (at the moment, Part XI about the 70s and 60s is still Work In Progress as I want to find more sources). There are a couple of appendixes I prepared for my book and almost ready to be transposed to the website in the next few weeks, but the core of the opera is done (minus the mentioned Part XI).
An example of how studying this sort of topics helps, is exemplified by this short article, where I discussed a video made by Tactical Pascale executing a simple intercept. There is a lot going on under the hood!
That being said, I hope you have enjoyed this study, and you have learnt something useful!