1960s NATO VTOLs

[LostCosmonaut]

Just about everyone has heard of the (in)famous F-35B VTOL aircraft, along with its predecessor the Harrier. The Soviets also dabbled in vertical takeoff aircraft throughout the latter half of the Cold War. However, did you know that during the 1960s, NATO seriously considered developing a supersonic VTOL strike fighter? It was thought that airbases would become unusable after the first hours of the war, so having a VTOL strike aircraft would allow NATO to continue striking at Soviet ground forces.

 

Numerous designs were proposed. One of the most sane the P.1154.

 

(a conceptual image of the P.1154)

 

The connection between the P.1154 and the Harrier (via the Kestrel prototype) is easy to see. The P.1154 was itself developed from the earlier P.1150, the original contender for the NATO strike aircraft competition. Like the Harrier, the P.1154 uses a single engine to provide thrust for both vertical takeoff and horizontal flight. This is in contrast to most designs of the era, which used dedicated lift jets. Though the P.1154 was never built, it was a major technological step in the development of VTOL aircraft.

 

 

The Mirage IIIV is clearly derived from the highly successful Mirage III airframe. However, it can be seen that lift jets have been added in the fuselage aft of the cockpit. No less than eight (!) lift jets are located in the fuselage, in addition to the single main engine. This would certainly have been a maintenance and reliability nightmare, especially in the austere environment of an ongoing (possibly nuclear) conflict. Unlike the P.1154, the Mirage IIIV actually made it to flight status, with two prototypes undergoing testing during the 1960s.

 

 

The West German VJ101 was an attempt to convert the F-104 Starfighter into a VTOL aircraft. Like the Mirage entry, the VJ101 had lift engines (two in the central fuselage). However, it also had pairs of engines in swiveling pods on the wingtips, which could vary their angle to direct thrust downward or forward (similar to the Bell D-188A. Like the IIIV, the VJ101 made it to flight, and was tested extensively (it has been claimed that the aircraft was capable of supersonic flight without afterburner). With six engines, including four in moving nacelles, the VJ101 would also have been difficult to maintain and keep active.

 

 

The G.95/6 was the Italian entry (read more about it here). It was the ultimate development of the G.95 VTOL design, which went through several iterations (the G.95/3 resembles a VTOL F-101). In terms of layout, it was closest to the Mirage IIIV, with main engines for forward thrust (two of them) augmented by multiple lift jets (six in this case). Like the other VTOL aircraft, it would have been difficult to maintain, produce and keep reliable. Additionally, like the French and German designs (and the Yak-38), it would have suffered all of the drawbacks associated with lift jets, namely that they are dead weight for 90% of the flight.

 

 

The failure of the NATO Supersonic VTOL program of the 1960s shows the difficulty in making VTOL practical for a military aircraft. It would take until the 1970s for a subsonic VTOL combat aircraft to be successful (the Harrier), and until the 2010s for a supersonic VTOL aircraft to become workable.

 

 

[Sturgeon]

You forgot the VAK-101, you heathen! That thing would have been at least as bad as the Yak-38!

[cm_kruger]

You forgot the VAK-101, you heathen! That thing would have been at least as bad as the Yak-38!

 

You mean the VAK-191B? It was pretty similar in stats and layout to the Yak-38 but one of the lift engines was moved to the tail section instead of having both of them up front. It was intended to be a strike fighter with a secondary dash-to-intercept role, and like the Yak-38 turned out to have crap performance.

 

There was also the Do 31 transport, which was intended to be used to supply rough airfields operating the aforementioned VTOL fighters. The internal pods each housed a Rolls-Royce Pegasus engine (same as the Harrier) and the outer pods each have four Rolls-Royce lift engines as used on the Mirage and VAK191B. Useful load would have been around 3,500kg.

 

It also had a large analogue-digital hybrid computer for preforming the differential equations needed for takeoff/landing.

 

(Interestingly the lift engines found a much longer life on the Hawker Trident airliner, being mounted conventionally in the 3B version to give the airplane a boost in thrust for takeoffs in hot conditions.)

 

Lockheed also made a couple joint ventures. They cooked up the CL-704 with the Shorts Brothers, which was a F-104 Starfighter, the main engine would have been replaced by a more powerful Rolls-Royce Spey, while the tip tanks would each be replaced by 7(!) lift engines. It was canceled due to the development of the Kestrel/Harrier, to the presumable relief of the wives of Marine aviators. I can only imagine how quickly it would go through it's fuel with seven lift jets and the bigger Spey engine.

 

And the Ryan triangle wing proposal. From what I can find the triangle was intended to spin around like a helicopter blade for takeoff, then lock into position for regular flight.

[Sturgeon]

You mean the VAK-191B?

 

...Yes, I did. I momentarily had the dumbs, it seems.

[Sturgeon]

Lockheed also made a couple joint ventures. They cooked up the CL-704 with the Shorts Brothers, which was a F-104 Starfighter, the main engine would have been replaced by a more powerful Rolls-Royce Spey, while the tip tanks would each be replaced by 7(!) lift engines. It was canceled due to the development of the Kestrel/Harrier, to the presumable relief of the wives of Marine aviators. I can only imagine how quickly it would go through it's fuel with seven lift jets and the bigger Spey engine.

 

One wonders why these tip jet proposals didn't choose alternative methods of vertical thrust for the tip lift. Rockets with drop LOX tanks seem like they might even be lighter.

[LostCosmonaut]

It's like the F-104 and E-3 had a weird, malformed baby.

[Collimatrix]

 

The Lockheed XV-4 Hummingbird in formation with a T-33.  This aircraft initially used ejector tubes that were supposed to entrain a larger amount of airflow an augment VTO thrust.  These performed much less than calculations had suggested, and the plane was later switched over to lift jets.  The Rockwell XFV-12 also was to use ejector lift, and in that case it also performed far less than originally calculated.  What's with that?

 

 

The US Army was for some time interested in the XV-4, this before the agreement that the Army wouldn't have any fixed wing aircraft fun.

[Toxn]

Designs like these convince me that the designers were paid by the engine...

[Sturgeon]

 

The Lockheed XV-4 Hummingbird in formation with a T-33.  This aircraft initially used ejector tubes that were supposed to entrain a larger amount of airflow an augment VTO thrust.  These performed much less than calculations had suggested, and the plane was later switched over to lift jets.  The Rockwell XFV-12 also was to use ejector lift, and in that case it also performed far less than originally calculated.  What's with that?

 

 

The US Army was for some time interested in the XV-4, this before the agreement that the Army wouldn't have any fixed wing aircraft fun.

Man, calculations are only as good as the stupid hairless apes calculating them. Wannabe bet "calculations" involved translating horizontal thrust to the Y-axis without accounting for loss of engine power due to poor airflow?

One single missed link thanks to a lack of imagination from a dirty ape, and you get this sort of failure. That's just the way it is.

[Toxn]

Man, calculations are only as good as the stupid hairless apes calculating them. Wannabe bet "calculations" involved translating horizontal thrust to the Y-axis without accounting for loss of engine power due to poor airflow?

One single missed link thanks to a lack of imagination from a dirty ape, and you get this sort of failure. That's just the way it is.

True in general, but I sort of think this particular issue might have had more to do with the fact that boundary layer aerodynamics are black magic and the calculations cannot encompass all the fuckery that turbulence will do to ejector efficiency.

[Sturgeon]

True in general, but I sort of think this particular issue might have had more to do with the fact that boundary layer aerodynamics are black magic and the calculations cannot encompass all the fuckery that turbulence will do to ejector efficiency.

 

You're right, and my analysis may have more to do with the difference between 4 and 8% ABV than something something something hairless apes and their limits at mathematics.

[Toxn]

You're right, and my analysis may have more to do with the difference between 4 and 8% ABV than something something something hairless apes and their limits at mathematics.

Expensive drinking ho!

[Sturgeon]

Expensive drinking ho!

 

Is less than 10% so goddamn expensive in South Africa, for fuck's sake?

[Toxn]

Is less than 10% so goddamn expensive in South Africa, for fuck's sake?

We're the land of SAB, so the concept of beer not being a 4-5% lager took a while to filter into our heads.

 

When it did, we apparently all decided that slapping a 'craft beer' label on a bottle means that you can double the price at will.

 

Hence, anything over 5% = double price.

[cm_kruger]

Another similar "huh we just don't know why it's not working" failure was the XFV-12, designed for the Sea Control Ship.

 

Lab tests showed 55% thrust augmentation should be expected; however, differences in the scaled-up system dropped augmentation levels to 19% for the wing and a mere 6% in the canard.^[1] While the augmenters did work as expected, the extensive ducting of the propulsion system degraded thrust, and in the end the power-to-weight ratio was such that the engine was capable of vertically lifting only 75% of the weight of the aircraft in which it was mounted.

 

Convair also proposed a great looking light fighter for the Navy. The model 200 would have had a F100 with a F-35 style three-section rotating exhaust plus two 10k lbf lift jets (The Rolls-Royce ones on the previously mentioned aircraft had around 5k lbf) behind the cockpit, while the Model 201 would have been a conventional fighter.

 

 

(The tiltwing in the back looks to be a Canadair CL-84)

 

And apparently after General Dynamics bought up Convair they further refined it's lines into the Rafale Model 218.