Aerfer XS.1 ZEL interceptor - 1959

[Skybolt]

Behold the Aerfer XS.1, much cited but never shown last Stefanutti's project for Aerfer, 1959. It was a further evolution of the Leone formula (turbojets plus rocket engine) taken to its logical consequences, a zero-lenght takeoff point defence interceptor tailored to the European theater of operations during the early cold war: prospective menace by high-flying Mach 2 Soviet bombers, few minutes of warning time, lot of possible targets, first of all airports. The XS-1 intended modus operandi was different from that of the preceding Stefanutti's mixed propulsion machines. The rocket, unspecified, has a thrust of 3000 Kgs and burns kerosene with nitric acid as an oxidant. Some sources say that it is a Napier Scorpion, but I beg to differ for two reasons: first, the Scorpion did 3650 Kgs of thrust, and, second, the Scorpion used HTP (High Test Peroxide) as an oxidant, not nitric acid. The rocket was to be used to take-off and accelerate, complementing the turbojets (two Rolls Royce RB.145R, 1700 Kgs thrust each with a/b), until reaching Mach 2 at 11.000 mts in level flight (2' 30 " after take-off). The attack, either level or with a final climb to the max height of 21.000 mts was to be under jets alone (see graphic), after discarding the empy rocket fuel tank (nitric acid). The launcher was mobile, mounted on a standard truck (Italians will recognize a well known '50s lorry) and meant to be dispersed in case of war. The XS.1 was to be integrated in a two layer air defense system, with short range missiles as last resort. The early warning and control system (radar, fighter control, missile launch, etc) had to be integrated (a tall order in late '50s Italy, I fear) and commander were to be able to use the weapons based on the tactical situation. Naturally, the project was never pursued. First, there was no money: the preceding Stefanutti's planes had been funded by US money, and, second, by 1959 Aeronautica Militare had already chosen the F-104G for a primarily fighter-bomber role, using Nike-series missile for medium range intercept, and later Hawk for short-range.
Data for the XS.1:
Length: 8.80 m
Span: 5.60 m
Wing surface: 9 sqm
Weight:
empty 2050 Kgs
MTOW 4870 Kgs

Radius: 150 Km
Landing lenght: 150 m
with arresting hook 80 m

Armament: 2 not specified guided missiles (weight 100 kg each)

 

[Justo Miranda]

Nice project,new for me!

 

[starviking]

On the picture of the launcher there is what looks like a Genie missile on the dorsal hardpoint of the fighter. Quite a lot of "bang" to be trucking around Italy...

Starviking

 

[Skybolt]

Ventral hardpoint, you mean.
Yes, the original reports hints to a nuclear tipped air defense weapon. But that could be the nitric acid fuel tank.

 

[Petrus]

I think it is rather a missile (very similar to the Genie) than a fuel-tank.

 

[archipeppe]

I think it is rather a missile (very similar to the Genie) than a fuel-tank.

I agree, in principles the object attached under the belly of XS.1 it looks very like the Genie (with the warhead larger diamter on top and four stabilizers on the body of rocket). Even dimensionally speaking it appears "too small" for a propellant tank.

Perhaps (but this is my mind...) there should be at least two tanks attached under the wings.

 

[Skybolt]

mmm, but then were's the tank ? The actual Genie was different. And definitively the tank (a single one, says the report) was not under the wings.

 

[archipeppe]

mmm, but then were's the tank ? The actual Genie was different. And definitively the tank (a single one, says the report) was not under the wings.

The two things doesn't seem to match togheter, if it isn't the missile but the tank (I've still some uncertainity about it...) where's the missile anyway?
The report (and the enclosed flight profile) tells about only one missile also. ???

The same flight scheme shows the skectch of something "big" as tank, under the XS.1 belly, that is detached at the end of rocket burn phase.
The thing illustrated in the truck-launch drawing is still too much "tiny" to be a tank (for comparison take the auxiliary tank of B58 or that ones of X15....).

 

[Skybolt]

Agreed, but I'd not take the schematics of the interception phase as normative on the aircraft configuration. If you look at what seems the plane on top of the tank in the scheme it is too tiny. Compare it with the lorry...
The fuel were 1300 Kg for the nitric acid and 1200 kg for the kerosene. Since the kerosene was housed internally, the external tank had not to be too large. The nitric acid has a density of 1.51 gram per cu.cm, kerosene is 0.75-0.81 grams per cu.cm... So for an equivalent amount you'll need half the volume
As for the missile carried, the specification says up to two missiles with a total weight of 200 Kg. I don't have info on the XS.1, but for its immediate predecessor, the Leone, Aerfer was hinting to the use of Firestreaks. And, as a final nail in the coffin ( ), the launch weight of the Genie was 372 Kg...

 

[archipeppe]

As for the missile carried, the specification says up to two missiles with a total weight of 200 Kg. I don't have info on the XS.1, but for its immediate predecessor, the Leone, Aerfer was hinting to the use of Firestreaks. And, as a final nail in the coffin ( ), the launch weight of the Genie was 372 Kg...

In effect explained in this way it makes sense.
Especially if we consider that it is not likely that Italy could have any Genie armed with nuclear device, considering American policy on the matter at that times....

 

[Petrus]

As for Italian nuclear plans, in the late 1950s they contemplated, if I am not mistaken, several nuclear weapons programs. The Italian navy, for instance, built a cruiser that was to be armed with the Polaris missiles. So, perhaps, the country's air force may have had some similar projects and it could seem quite possible to design a Genie-armed fighter.

 

[Skybolt]

As for Italian nuclear plans, in the late 1950s they contemplated, if I am not mistaken, several nuclear weapons programs. The Italian navy, for instance, built a cruiser that was to be armed with the Polaris missiles. So, perhaps, the country's air force may have had some similar projects and it could seem quite possible to design a Genie-armed fighter.

In theory, yes, although the XS.1 was more a "last hurra" by Stefanutti. AMI had already decided: air defence against bombers to the Nike missiles, Hawk as point defence of high value targets, fighter-bombers to the F-104Gs in the secondary, Sidewinder-armed, role. It was an altogether different way to see air-warfare. The same shift had happened before in Germany, with the Saunders-Roe P-177 in the same (although less extreme) role of the XS.1 (or, better, the Leone). That even in the new look probably from a purely technical/operational point of view a plane like the Grumman SuperTiger would have been a better choice, it's another matter. And now, having opened a can of worms, and confirming my love to the Starfighter, cheers to you all.. ;D

 

[Skybolt]

BTw, I'm really at loss on the rocket engine (or motor ?) intended. If it used ntric acid probably it wasn't a British one, since by late '50s the British oxidizer of choice were HTP and LOX. The French used nitric acid. Was it a French rocket ? Like the Durandal and the Dassault 550 ones ? Those who know of rocket engines, please help.

 

[XP67_Moonbat]

Nice one! I would have to agree with the external store being a Genie. Hey, I'll bet if there were an Italian "Secret Projects" volume, this bad-boy would be in there.

 

[starviking]

Ventral hardpoint, you mean.

Doh! I had a 50% chance and I blew it!!