I guess in an ideal world, it would be useful to have combat aircraft at both ends of the spectrum. Highly sophisticated and expensive aircraft like the F-35 and simple cheaper aircraft like the Harrier. The F-35 would be used in advanced airspace with advanced SAM and fighter threats; the Harrier could be used in more secure airspace such as Afghanistan, where advanced systems are largely absent.
There is logic in having both; but practicality leads to choosing one. If you have the money you can have both; the USA is doing exactly that by operating F-22/F-35 as well as U.S. Marine Harriers (up to about 2030 I believe). No other country has pockets quite as deep.
The Harrier is an iconic unique aircraft; but in its way so is the F-35. Not only is it the most advanced 5th Generation aircraft, it is likely to be the last solely manned fighter developed (in the USA/UK anyway). Tempest is to be manned/unmanned; that could change as systems develop even further.
Having put my handkerchief away and stopped sobbing over the passing of the humbly superb Harrier from the UK inventory, I went for a stroll through 'F-35 land' and found out for myself a bit more as to why this aircraft is essential for future combat airspace.
It comes in two words: stealth and systems. The value of stealth cannot be overrated and it doesn't have to make you invisible, just a lot smaller.
Modern SAM systems are so lethal they could detect and engage 4th generation fighters from a very long way away with high probability of a kill. Stealth negates these systems (and airborne systems); a stealthy aircraft would need to be engaged at closer ranges. With 4th generation fighters there was ECM and manoeuvring to defend against hostile weapon systems. Even if those '4th generation' weapons systems could engage you, they could be defeated with proper use of ECM and defensive manoeuvring (as clearly shown in Vietnam).
Now modern weapon systems are so lethal that once they get a lock on the target, the target is toast. Modern systems are much more robust in dealing with ECM and have high agility to deal with the manoeuvres of aircraft. To survive in this battle space an aircraft needs to be difficult to detect.
An Australian pilot gave an account of an engagement flying against F-22's; he said he could see the F-22 but couldn't put a weapon on it (the onboard weapon systems couldn't see the F-22). That amount of stealth is a game changer.
Now that you can penetrate the highly lethal battle space, the stealth aircraft can engage them directly or gather and distribute information on where the enemy assets are, allowing older fighters to stand off and lob weapons onto the targets found by the stealth aircraft, without having to hang around in that battle space. The stealth aircraft will clear a path through hostile airspace, a bit like a mine detector clearing a path through a minefield. You wouldn't want to run through a minefield but if someone had a detector to at least tell you where the mines are, you could get through it or blow up the mines found.
Came across the following interesting article describing what happens when one side has 5th generation and the other side doesn't.
The Reason No One Can Kill an F-22 or F-35: "It’s Nearly Impossible to Fight An Enemy You Can’t See."
September 2, 2018
https://nationalinterest.org/blog/bu...357?page=0%2C1
Example of stealth against 4th Gen. aircraft; T-38 Talons & F-15E's represented 4th Gen aircraft at BVR distances. Friendly forces were F-22 and Typhoon coordinating together. The idea was for the T-38's to try and close to visual range on the F-22 friendly forces. The T-38 pilots included an F-22 Test Pilot and prospective F-22 trainee pilot. So the attacking force had good knowledge of how the F-22 operates.
The flight of three T-38's didn't know what hit them; two went down without realising they were under attack by a Typhoon. The remaining T-38 began defensive manouvring against a threat still not seen and was shot down by a Typhoon coordinating with an F-22. The Typhoon coordinating with the F-22 was a combination described as "lethal".
An article here states that four F-22's with four F-15's achieved a kill ratio in exercises of 41-1.
"The Next Generation F-15 Is Packed With Missiles"
https://www.popularmechanics.com/mil...neration-f-15/
I read about the proposed F-15 upgrade to allow carrying of upto 24 missiles (F-15X).
https://theaviationgeekclub.com/boei...-air-missiles/
Its not hard to see what giving the F-15 the ability to carry upto 24 missiles is all about; replace the F-22 with F-35 and replace the Typhoon with F-15X; that combination will sweep 4thG fighters from the skies.
I read that this is one of the fundamental uses of the F-35; it will allow not just itself, but older 4thG aircraft to operate safely and effectively in the modern battle space. It is a force multiplier, in effect. Also cost effective if it allows older aircraft to be retained instead of being replaced by more expensive 5thG aircraft (USA plan was to replace the F-15 with 750 F-22's; only about 187 F-22's will be acquired).
Found useful interesting short clips on F-35 below.
F-35 Range information
Good information here on what makes the F-35 the necessary choice.
https://www.f35.com/about/capabilities
Benefits of 5th Generation Fighters
F-35 - A Pilot's Perspective
Taking a 4thG fighter all by itself into a modernised battle space is like taking a knife to a gunfight. An F-35 will change that.