And yet somehow, the VTOL F-35 prefers to use the Forger's as a model for its VTOL system rather than the Harrier's.
The large intakes means an epic big RCS from the radar reflections off the engine blades. That will make the aircraft epic visible faster in radar and at longer ranges. The thermal concentration of the plane, unlike conventional jet fighters which tend to be at the tail, is right in the middle. So when a heater seeks it, its aimed right dead center of the plane, which reduces its chance of survival. The plane lacks any means to hide its thermal signature, and the layout prevents such means, all making it easier for heaters to acquire. The accident rate is one of the highest among Western aircraft, and in fact among US inventory (at least 45 marines have died). The plane is incapable of supersonic speeds, impossible to use afterburners, making it vulnerable to faster jets.
Point 1: The F-35B does not use the Forgers engine layout at all, it only has one engine not three. the forward lift fan is shaft driven from the single aft facing engine, which employs a single swivelling nozzle at the rear. In vertical mode it sits on a column of hot air at the rear and a column of cold air forward, produced by a single engine just like a Harrier.
Point 2. If a heat seeking AAM hits any fighter aircraft its time to find out how true the claims of Matin Baker Ltd really are,- EJECT EJECT EJECT! In fact the position of the Harriers nozzles reduces it's IR signature compared to most fighter precisely because of it's mid position, when viewed from above the nozzles are hidden by the wings and the hot air exhaust from the nozzles is mixed with cold air from the forward nozzles, reducing the overall temperature of the exhaust. Name another fighter that can pull that trick...
Point 3. The accident rate. Time to put this to bed once again. When the USMC first introduced the AV-8A in the early 70s, the first sqn formed was populated almost entirely by qualified test pilots because the USMC were unsure of the skill level required to fly the Harrier. The sqn had an excellent safety record and the pilots reported the Harrier was very easy to fly, no particular problems arose they said. For test pilots, this was true as they are of a higher standard than regular sqn pilots. The USMC took this onboard and decided that not only would regular pilots be posted to Harrier sqns, why not post Helicopter pilots too? They are used to landing vertically aren't they? As it turned out the former helo pilots were excellent at landing and taking off vertically, and no accidents occured in the vertical regime. They did have a bad habit of flying into 'Cumulo Granite' at 500 knots because helo pilots generally don't have the currency for fast jet ops. This situation continued into the 80s when the AV-8B was introduced, when the problem was that whenever there wazs an accident the fleet would be grounded and pilots would lose currency. USMC Harriers when deployed aboard LHAs/LHDs operate differently to Harriers deployed at sea by other nations, aboard ship they are 'second class citizens' as the troop carrying helos are the ship's raison d'etre, and the Harriers have to sit around until required, ie they are not getting as much flying time as they should and not honing their flying skills. Practice makes perfect. This is the USMCs own explanation of the situation, and when a sqn of Marine Harriers deployed aboard HMS Illustrious last year they found it to such a refreshing change to be the priority aircraft aboard ship. The new LHA6 class are designed to operate the F-35B primarily and troop carry helos will be mostly operated from other ships within the ARG so the problem has been recognised and will be addressed.
Point 4. Afterburners. A great way of emptying your fuel tanks and making yourself the 'brightest point in the sky', just what your opponent's heat seeking Mach 3 AAMs wished for. Ask any fighter pilot, the best way to avoid such a misslie is by dropping flares and turning hard, the faster missile will not be able to turn as quickly because of it's speed. Try turnig a car at 20 mph and at 70 mph, you'll see the difference. Harriers have the best turning performance of any Fast jet in service today, thanks to their nozzles. When a Harrier 'VIFFs' (Vectors the nozzles in Forward Flight), the aircraft's nose pitches upwards by anything up to 90 degrees allowing the aircraft to turn inside of any other aircrafts radius and any missile's radius for that matter.
Point 5. As for the RCS of the intakes, yes it is large. But the Harrier is smaller than most jets and is harder to pick up visually (where most air to air combat takes place thanks to rules of engagement in most conflicts) so this is balanced out somewhat. The intake RCS only makes a difference if the engagement is head on or from a forward vector. No difference at all from the side or the rear. From above the Harrier has low RCS and low IR signature, which is why Harriers prefer to operate at low to medium altitudes where the engine has best performance (ie below the altitude of marauding enemy fighters).
