Thread by @Justin_Br0nk

A quick thread on the prospects for Western fighters for the Ukrainian Air Force (UkrAF) in the short-medium term
First, what are they needed for? Well there are two primary tasks, alongside others like SEAD and strike:
First primary one is intercepting cruise missiles (1/n)

Russian cruise missiles regularly hit Ukrainian civilian, military and industrial buildings all over the country. They are launched from long-range bombers or ships.
The bombers will stay far out of intercept range, but the missiles can be shot down by SAMs and fighters. (2/n)

Ukraine's primary defence against cruise missiles are its long range S-300PS/PT and S-300V1 SAM systems, as well as shorter ranged SA-11 and SA-8 SAMs. However, it's Mig-29 and Su-27 fighters also regularly attempt intercepts, most likely with R-73 heat-seeking missiles.
(3/n)

This requires a fighter to scramble and vector towards an incoming cruise missile salvo detected by other long range radars, and then either pick up the small, often low-flying missiles with their own radar or infra-red scan and track (IRST) and then achieve a missile lock.
(4/n)

This is a difficult task, but UkrAF pilots have already had some success with their current jets. Since the main targets for Russian cruise missiles are in central and western Ukraine, it also doesn't required being in range of Russian medium-range SAM coverage or fighters.
(5/n)

Any potential Western fighter options could likely perform ok in this role. But, to have the best chance of detecting and hitting said cruise missiles, an AESA radar (for performance vs small targets against ground clutter) would be ideal. AESAs are also easier to maintain.
(6/n)

The second main task is combat air patrols to augment ground-based SAMs in preventing Russian fighter, ground-attack and helicopter sorties in Ukrainian airspace and pushing them back from the frontlines to protect Ukrainian troops from airstrikes. The latter is harder.
(7/n)

Russian SAM systems (long range S-300V and S-400, medium range SA-17 and short range SA-15) pose a lethal threat to UkrAF aircraft anywhere near the frontlines in Donbas or Kherson, forcing them to fly VERY low. This puts them at a big disadvantage vs Russian fighters.
(8/n)

The effective range of air-to-air missiles depends on the altitude and speed of both the launching aircraft and the target. Flying lower (and slower, due to denser air) against Russian fighters flying higher and faster means Ukrainian missiles have a shorter effective range
(9/n)

Russian Su-35S and Su-30SM fighters also carry more powerful radars and longer ranged active-seeker R-77-1 missiles vs the UkrAF's semi-active R-27, and jet engines are also much less fuel efficient at low level than higher up. The Mig-29 has notoriously short range too.
(10/n)

Western-supplied fighters would face the same problems, as even if supplied with AGM-88 HARM to suppress medium range threats, Russian long ranged SAMs will keep sorties near the frontlines down low. So whatever is supplied needs to come with long-ranged active-seeker AAMs
(11/n)

The only real choices are the US AIM-120C8/D that could be supplied with F-16 or most other NATO fighters, or the European Meteor. Meteor is only integrated on the Typhoon, Rafale and Gripen and only the latter feasible for the UkrAF on cost and complexity grounds...
(12/n)

AIM-120D and Meteor are the latest and best AAMs in NATO's arsenal so there may be security concerns about them falling into Russian hands, and stocks aren't huge. But, between them, Meteor offers much greater effective range from low-altitude against high flying Su-35/30s
(13/n)

Because Meteor's ramjet propulsion provides thrust for a much greater proportion of missile flight time at long ranges, it's effective range is less badly constrained by having to climb after a low-level launch than traditional rocket-powered missiles like AIM-120 or R-27.
(14/n)

Stocks-wise, Ukraine could be supplied with far more AIM-120's than Meteor, and it would provide some commonality with with NASAMS. However, Meteor would go further to addressing the tactical disadvantages UkrAF pilots face against Russian fighter CAPs near the frontlines.
(15/n)

The biggest challenge, however, will be creating a viable logistics and maintenance capability for the UkrAF with any Western fighter type. Let's look at the last time the US tried to build a new F-16 fleet with an allied country during a (lower-intensity) conflict; Iraq.
(16/n)

Iraq paid $3 billion in early 2011 for 36 F-16s with less advanced avionics and weapons than Ukraine would need. The first jets were delivered in June 2014. Ukraine could be more quickly given existing jets and pilots retrained to operate them in months rather than years..
(17/n)

However, the Iraqi F-16 fleet remained heavily dependent on US civilian contractors for maintenance, and when those were withdrawn due to the threat from ISIS in 2015 the fleet rapidly ceased to function (thedrive.com/the-war-zone/3…). Ukraine would face a huge challenge here.
(18/n)

Western fast jets are very different internally to the Migs and Sukhois that UkrAF maintainers are used to. They use fundamentally different components, software architectures and controls. It takes the USAF about a year to train mechanics to work on jets under supervision
(19/n)

Providing that supervision requires maintenance crew chiefs who understand the jet and its systems inside out, and how they all interact. That takes years to train. In Iraq, this role was provided by contractors, in Ukraine that would need to be done too for several years
(20/n)

Providing contractors, however, involves sending highly trained Western civilians to a country that is in the middle of a high-intensity war of survival, and is having to use dispersed operations to allow its fast jets to avoid regular Russian missile attacks. High risk.
(21/n)

The fact that the UkrAF has managed to keep its jets operational by dispersed basing at highway bases and other small runways makes logistics for Western jets more difficult and also imposes operational requirements. F-16 is designed to fly from long prepared runways...
(22/n)

Ideally, therefore, a Western fast jet for the UkrAF would have features that allow operations from highways and other shorter strips. The Swedish Gripen is the obvious candidate here, being designed for highway ops and maintenance by mobile teams including conscripts...
(23/n)

However, the Swedish government and/or Saab might not be willing to supply the Gripen C/D, and there is a much larger existing pool of potential donor F-16s, parts and spares due to the far larger global user base. In any case, it is vital that the process starts ASAP.
(24/n)

F-16 and Gripen are the obvious choices. Neither can ignore the Russian SAM threat near the front, but could force the VKS to stand off further, and improve cruise missile defences. Either will require political will to risk contractors in country for maintenance support.
(25/25)

One added clarification; Gripen C/D would be better suited from an operational point of view due to design CONOPS, internal EW suite optimised for Russian SAM defence at low level, ease of maintenance and Meteor option. But F-16 much more likely politically and logistically.
(+1)