Steve Trimble has posted new pictures of the Iranian-developed Saegheh fighter over on his blog, The DEW Line. Look past the Blue Angels colour scheme and you will see subtle but significant differences between the two aircraft featured that suggest Iran's "Lightning" is more than simply a reverse-engineered Tiger with two tails.
The first aircraft, presumably the earliest, looks pretty much like an F-5E and even the twin fins have a "tacked-on" appearance.
But the second aircraft, while similar in planform, has a number of differences including enlarged and reshaped inlets.
The first aircraft's inlets are F-5 sized and shaped. The second one (right) has rectangular inlets that appear larger, and the wing leading-edge root extensions are slightly different.
A closer look shows the second aircraft's intake trunk is bulged compared with the F-5E's classic "coke-bottle" shape, although the auxiliary inlet is still there.
The base of the fin also has a more faired-in appearance, so the second aircraft could be the production version. The reason for the inlet redesign is not clear as the nozzles of both aircraft look similar, suggesting the engines have not changed.
But maybe there is a bigger engine in the pipeline, making for a higher performing aircraft. Which might explain why they would spoil the classic lines of the F-5 by doubling up on tails.
Meanwhile, this picture from Tehran's military parade on 22 September shows two of the round-intake aircraft and one square-intake (top left)