F-4E Air-to-Air I: First Steps

The Westinghouse AN/APQ-120 is the radar chosen for the F-4E Phantom II, a compact and full-solid-state system capable of providing a good compromise between performance and dimensions. This solution was necessary due to the introduction of the M61A1, a six-barrel, air-cooled, Gatling-style gun in the nose.
Compared to the US Navy AWG-10, the APQ-120 is limited to Pulse mode. Therefore, it shows significant sensibility to ground clutter and reduced detection range.

The F-4E is the most produced Phantom version. It entered the Vietnam War in November 1968, departing from the airbases located in Thailand. Its primary role was interdiction and ground attack, along with interception. Other nations employed the F-4E, such as Iran, Israel, Greece and Turkey. The APQ-120 served these nations well, no matter the role their Phantoms were tasked to accomplish.

DCS, being a game, will see the F-4E play almost every possible role. The versions of the Phantom-E portrayed in the game are almost contemporary of the F-14 Tomcat. Nevertheless, the difference in “human interface”, ease of use of systems and avionics, and weapon employment is staggering, especially in the Air-to-Ground department.
Regarding air-to-air, the limitations on modes mentioned before are not irrelevant and require the crew to step up their game to succeed. Another “problem”, but a good one, is the depth and quality of the simulation. Heatblur’s F-4E is raising the bar even more, reaching new heights and complexity.

Understanding the avionics

Using this radar system is relatively straightforward, but the limitations mean that the WSO must use more time, focus and mental energy to build Situational Awareness. The F-4E’s Low PRF radar is highly affected by ground clutter. The WSO can try to offset them, depending on the circumstances, by adjusting the antenna elevation and the radar gain.

Too much gain would saturate the radar screen, and not enough will not highlight contacts, at least at longer ranges. Depending on the altitude, not only the ground returns from the main lobe will be displayed, but also the ones from the sidelobe, clearly identifiable to the presence of the altitude line.

The F-4E is equipped with the AN/APX-80 IFF system. Interestingly, the range of the interrogator outpaces the radar’s in most situations. Therefore, friendly contacts can be immediately located at a reasonably long range. Unfortunately, “Spades” are not marked by any means.

The AN/ALR-46 is the Radar Warning Receiver mounted in this version of the F-4E. One of the first digital RWRs, it provides information about sources illuminating the Phantom with acceptable accuracy. Although it lacks advanced target recognition, it provides vastly more information in an intuitive manner than its soviet counterpart, the SPO-10.

Search Routine

Putting everything together, a good ab initio WSO search routine consists of manipulating the antenna elevation with a 1-bar set without nutation and adjusting the gain to provide a clean radar picture, challenging the APX-80 as required. Later, developing a personal routine is highly recommended, tailored to the experience the player is looking for, mission, terrain, threats, et cetera.

For instance, if the radar screen is entirely blank but a Threat is called, and operations are being conducted feet-wet, then setting 2 bars narrow plus nutation can help to maximise the scanned volume, taking advantage of the reduced clutter. Another example is using the ALR-46 to expedite the search for a contact illuminating the Phantom by providing a general idea of the relative bearing.
When operating at low altitudes, reducing the gain can partially offset the clutter generated by the ground’s proximity, but the search range will be consequentially reduced. If possible, obtaining a lockon before reducing range and altitude is preferable, as the target would “stand out” more. The antenna elevation should be carefully managed to minimise clutter, especially from the main lobe, by looking upwards when possible.
Vice versa, look-down search and engagement are still possible in certain conditions. In particular, if the main lobe illuminates the target at a range different than the ground, the target should stand out on the radar screen.
Generally speaking, finding a target’s azimuth is simpler than its relative altitude, especially with limited radar bar settings.
An important point to remember is the radar’s limited range, which makes the F-4E dependent on good human GCI.

Clutter susceptibility, with the caveat that the Phanom II is a new module and there is a lot to discover, seems to be the primary variable when searching for targets.
The following is a quick detection range test conducted feet-dry. The scope’s set to 50 nm. Values refer to the moment the radar blip is clearly identifiable, a value that, as discussed, is subject to innumerable factors.

The more focused the radar is, the sooner the target “pops” against the background noise and more fainted returns can be appreciated.

Radar Display

The radar display is simple to interpret and provides basic information, similar to the DDD in the F-14 Tomcat when operated in Pulse Search. Depending on the presence of a lockon, information about the target may be displayed, and it is controlled via the Aspect knob.
The scope also includes information such as the range scale, the antenna elevation, the horizon depending on the familiar Stab switch, the radar cursor and the Home-on-Jam indication.

Air-to-Air Operations: Recap and next steps

Summarising what was discussed so far, the APQ-120 is a relatively short-range radar capable of air-to-ground operations and self-defence rather than search and intercepts. The workload for the WSO is considerable, and the proficiency and good coordination of the crew members are crucial. Often, in fact, contacts will present themselves close to the engagement range, and geometry and manoeuvres will have to be computed rapidly and efficiently.
Unfortunately, the game’s current state, with EW, omniscient AI, and awful GCI in primis, gravely worsens the experience, and we can only wait for updates in these aspects.

Given these premises, to maximise the odds of success, the crew must be capable of interpreting a situation and quickly acting and manoeuvring. Examples from various sources will be considered and used to discuss the avionics, geometry, and crew workflow. The goal is to provide the necessary elements and theory to eventually transform lengthy considerations into seconds-long effective decisions.

Although many tactics and procedures will be discussed, they can all be grouped into two categories: intercepts with a lockon and intercepts without a radar lock. Since Track-While-Scan is unavailable in the APQ-120, the crew cannot determine the target’s parameters without a “hard lock”. However, this operation can trigger a long series of issues and consequences, in primis alerting the target. On the other hand, intercepts without a lock-on require more effort and a certain degree of approximation.

The APQ-120 is, therefore, a compromise between performance, features, and design, but it nevertheless proved to be a very successful radar system. In DCS, the limited detection and search capabilities will make creating Situational Awareness challenging and will benefit from the presence of Ground or Airborne intercept controllers.
The F-4E requires a well-coordinated crew to excel in the air-to-air arena and will reward proficiency, quick thinking, and aggressiveness.