Britain always believed a heavier weight (11t) would be needed to meet specs. 9.75 tonnes was a compromise with the other nations.

In low signal to noise (SNR) situation, the target could not possibly be localized on the single frame and hence the successive frames are used to detect the target. If the alignment is done properly the signals of the various images would add up and a signal with sufficiently large SNR is achieved with the noise getting eliminated. This approach of detection of target with low SNR is usually referred as track before detection (TBD) and generally used for detection of low SNR targets.

Perhaps this would help

First I’ve heard of a supersonic “bow-wave” being detectable by radar.

But anyway, I’m again taking issue with peoples perceptions of the YF-23’s top speed.

M = 1/(sin[A])

M is the mach number

A is the angle (at the aircraft’s nose) from the centreline to a line extending from the nose to the wingtip.

Its a very simple rule of aerodynamics.

Work it out (go ahead, grab a picture of both aircraft from above or below and measure the semi-span, and the centreline length to the semi-span location and use simple trig) and the YF-23 has a planform designed around a top speed of Mach 1.8* (ish). The F-22A is around Mach 2.2/2.3.

FSWs are different, they work in a different fashion altogether from RSWs and they can cut the nose shock at much nearer a right angle, which results in alot less problems across the wing.

Can anyone explain to me why Northrop would ignore one of the most basic rules of aerodynamic design… if their aircraft is capable of so much higher top speeds than the…. wait for it…. Mach 1.8* achieved in the flight tests :confused:

* Notice these 2 figures are remarkably similar…. concidence – I think not.

1) Try using an actual top view drawing rather than a photo. More accurate.

2) If you do, you will find that the YF-23 Mach angle indicates a speed of Mach 2.0, not 1.8. Your source photo (as seen on ATS forums previously) is not from dead above but is slightly foreshortened.

3) The Mach angle only determines the speed at which the supersonic shockwave from the nose will start to hit the wing. Its not some kind of magic barrier.

4) The design speed of the YF-23 for minimum drag is therefore just under Mach 2.0. That makes perfect sense, for a design supercruise of about Mach 1.8. It doesn’t mean it can’t go above Mach 2.0, with some penalty in additional drag due to the shockwave hitting the outer wing. Your calculation doesn’t really prove anything. Materials and airframe heating will be the limiting factor in reality.

That is because the MP-486 uses 486 chips and the performance is more than enough for the MKIs mission computing needs.

Yes and no. It makes it a very dated architecture based around a late 1980s model. For a fighter for the next 10 years this is deeply disappointing, a remaking of the F-15 avionics model rather than an integrated F-22 or F-35 style architecture (Or even a eurocanard federated model)

According to Ferranti, a nose mounted pitot tube is incompatible with highest radar performance, especially in medium PRF modes.

Originally Posted by Vortex
Russians are good aerodynamicists, but in my book the Brits are actually the best…too bad they really don’t have the political will and means…

Brits?? they are the worst when looking at their creations during past 50 years, they simply do not have enough know-how to be.

Best regards
Martinez

Well, I guess then that Oleg Samolovich was lying when he said the original conception of a “sinusoidal” wing came from a British journal of the early 1960s, which had shown extensive wind tunnel testing?

:rolleyes:

Ken, my understanding from Ildar’s book was that Oleg Samolovich said it was Mikoyan’s idea, but that GosNIIAS claim that they suggested two aircraft from the start in late 1969 (initially, a 6-10t light fighter and 24t heavy fighter).