Comparing "what-if" ground attack Lightning and Sukhoi Su-7/Su-17

[Hammer Birchgrove]

If a strike version of English Electric Lightning had been produced (possibly instead of TSR-2), do you think it would be "fair" to compare it with the Soviet Sukhoi Su-7 (if it would be swept wings, possibly with blown flaps)* or Su-17 (if it would be swing-wing)?

I assume it would have one Rolls-Royce Thames jet instead of two RR Avons, thereby giving more space for fuel and electronics while keeping the same amount of thrust.

Would English Electric, Shorts and/or BAC been able to create a strike-Lightning, with the strenghts of Su-7 (able to start and land from short and/or damaged airstrips, take punishment and deliver bombs or missiles with good precision) without its drawbacks (high consumption of fuel)? ???

*I don't think Su-7 had blown flaps.

 

[Kokoro]

If a strike version of English Electric Lightning had been produced (possibly instead of TSR-2), do you think it would be "fair" to compare it with the Soviet Sukhoi Su-7 (if it would be swept wings, possibly with blown flaps) or Su-17 (if it would be swing-wing)?

I assume it would have one Rolls-Royce Thames jet instead of two RR Avons.

Would English Electric, Shorts and/or BAC been able to create a strike-Lightning, with the strenghts of Su-7 (able to start and land from short and/or damaged airstrips, take punishment and deliver bombs or missiles with good precision) without its drawbacks (high consumption of fuel)? ???

I'll attempt to speculate an answer, feel free to shoot it down in flames...

As I found out this week on this forum there was a swing wing lightning but it would have reduced the already small amount of fuel it carried. That version too was also intended for carriers so maybe the undercarriage could be redesigned to handle unprepared airstrips better than a stock lightning. Changing it to a single engine though would probably require so much of the aircraft to be redesigned that it would be an entirely new aircraft. Probably one not dissimilar to a su-7.

I have a feeling, a guess, that the export lightnings may have had the option to carry air to ground weapons, maybe just free fall ones, but I cannot be sure without a book in front of me.

Basically I think the lightning is a poor aicraft for air to ground work. It would be suprising if somone does post any designs or drawings of a lightning bomber. It'd make an interesting what if model though.

edit:
Just googled the RR Thames, similar size to an avon but about twice the power..... so maybe a single engined lightning with more fuel and space to spare would have been possible.

 

[Thorvic]

The lightning was fully orienatated to short range high spee, high altitude interception based upon the P1 test bed. There was the P6.1 which had a single engine but again this was orientated as a day fighter. Saudi & Kuwait export lightnings both had teh ability to dual role into strike role with SNEB rocket or bombs, but the airframe wasn't really optomised for that role although it had the revised wings of the later types.

Dont forget EE also created and built the Canberra for the light bomber & strrike roles, EE put its experience from both types to meet the GOR339 spec to create the P17 which was optimised for the supersonic strike role.

G

 

[Hammer Birchgrove]

Thanks guys. Interesting points you've made. B)

 

[Abraham Gubler]

While a VG Lightning and a Su-7 may look very similar from a distance they were very different aircraft. The VG Lightning wing was very thin and designed for supersonic flight. The Su-7 wing was hardly even transonic and a much simpler aerodynamic shape. The Lightning also had two turbojets compared to one in the Su-7 for almost twice the thrust. Finally the Lightning was a much bigger aircraft (those two engines take up some room), some 55% bigger by weight.

The Lightning would have been a very able strike aircraft if suitably modified. BAC offered a multi-role Lightning to the RAAF in competition with the Miro and F-104. The VG Lightning had a much higher fuel fraction than the original Lightning thanks to the extended belly.

 

[KJ_Lesnick]

I thought the Su-7 had a very thin wing for supersonic flight... I mean I remember something about it having a horrendously high landing speed and being capable of a touch over Mach 2

KJ Lesnick

 

[Abraham Gubler]

I thought the Su-7 had a very thin wing for supersonic flight... I mean I remember something about it having a horrendously high landing speed and being capable of a touch over Mach 2

The FITTER family (Su-7, Su-7B, Su-17, Su-20, Su-22) had a wing with a tc (thickness to chord) ratio of 4.7% at the leading edge. The Lightning has a more complex wing shape with its thickness at the chord centreline enabling delay of air compression. The Su-7 (only <200 built) had area ruling and was capable of Mach 1.6. The Su-7B (>1,600 built) was only capable of Mach ~0.9. Its high landing speed did not equate into high maximum speed. The Su-17 and onwards fixed the high landing speed by using variable geometry wings. Changes to the engine and fuselage boosted the Su-17/20/22 top speed up to supersonic but nothing near Mach 2.

 

[overscan (PaulMM)]

Umm, Su-7B had a max speed of 2,120km/h, Su-7BKL 2,150km/h.

http://www.sukhoi.org/eng/planes/museum/su7/lth/

Earlier Su-17s were Mach 2 capable, once the inlet cone was fixed on the Su-17M4 max speed dropped to Mach 1.5 or so.

 

[Abraham Gubler]

Umm, Su-7B had a max speed of 2,120km/h, Su-7BKL 2,150km/h.

http://www.sukhoi.org/eng/planes/museum/su7/lth/

Earlier Su-17s were Mach 2 capable, once the inlet cone was fixed on the Su-17M4 max speed dropped to Mach 1.5 or so.

Ahh yes so true... Embarrassed by my own hubris and quickly scanning a data sheet and taking maximum speed at SEA LEVEL as maximum speed overall...

But the actual point of my post is still valid: despite a cosmetic appearance similarity and a resort to VG wings to provide lower landing speeds (one realised for rough field operation, one on paper for proposed carrier operation) the Lightning and Su-7 are very different aircraft. Especially in the wing which despite its similarity in planform (high sweep) are very different in profile.

 

[Hammer Birchgrove]

Good points.

I imagine that the planes based on Focke-Wulf Ta-183, like the FMA IAe 33 Pulqui II, NAA F-86 Sabre, MIG-15/17 and Saab J-29 Tunnan, also have important differences compared with each other, despite looking very similar to a layman like me.