Kfir jet

Hi to all...I tought that one of the best jets were the F-20 TigerShark but the Kfir in the US is named F-21 Kfir i would like to know if the F-21 is better than the F-20...thanks.

Turn performance of F-5E vs Kfir at various altitude:

At 5000 ft

ITR (instataneous turn rate) of Kfir is 20.9 degrees/seconds, ITR of F-5E is around 20.1 degrees/second

STR (sustained turn rate) of Kfir is 11.9 degrees/second, STR of F-5E is around 12.9 degrees/second

At 15000 ft

ITR of Kfir is 16.8 degrees/seconds, ITR of F-5E is around 16.7 degrees/second

STR of Kfir is 8.7 degrees/second, STR of F-5E is around 10.1 degrees/second

At 25000 ft

ITR of Kfir is 13 degrees/seconds, ITR of F-5E is around 14 degrees/second

STR of Kfir is 6 degrees/second, STR of F-5E is around 7 degrees/second

In short, turning performer of Kfir is inferior to F-5E in most altitude.

That because the delta wing of Kfir has more gradual CL/alpha curve than the near straight wing of F-5E (and for extension F-20), at low altitude then Kfir can get higher ITR by going higher AoA (because delta wing have higher stall AoA), but at higher altitude, where air is thinner, you need to go faster to generate enough lift, it harder to turn at high AoA, therefore both ITR and STR of Kfir is inferior to F-5E at altitude greater than 15000 ft

Sure, the F-5 has superior turn performance, but note the listed combat thrust to weight ratios. All things being equal, the Kfir could probably beat the F-5 handily by taking advantage of its superior thrust to weight ratio.

I think garrya was using the F-5 to stand in the for the F-20, which would also enjoy a TWR advantage over the F-5.

does any one have more flight model or mechanical information on the kfir?

F-20 is much more modern than the Kfir. It also enjoys a significant more thrust than the F-5, about 70% more (Wikipedia) and that is huge.

The Kfir is a Mirage V equivalent with the F-4 Phantom’s engine in it. By the early 80s, the development era of the F-20, this was already an old engine.

The “competitor” of the F-20 was the IAI Lavi - the latter enjoyed an unstable delta + moving Kanards design similar to Eurofighter / Rafael / Grippen and was extremely maneverable. When the Lavi was cancelled, Northrop proposed the F-20 as a substitute. Eventually, the F-16 manufacturer won the bribes war and shot down both the Lavi and F-20 programs, thus eliminating all its alternatives and cementing the F16s status as the greatest fighter of its era.

Well i think both can handle their jobs the f-21 Kfir at low altitudes and the F-20 Tigershark at higher altitudes personally i like more the F-20 because it is a F-5 Tiger II with more upgrades and greater specifications the missiles on the wing tips with no more armament always makes me wonder about airplanes.