Pulqui II - A broken dream  

by Pablo Calcaterra

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"LITTLE BIT" OF HISTORY FIRST

 One of the several German scientists that immigrated to Argentina after the Second War World (along with some Nazi criminals) was the famous Kurt Tank. He had designed the great Focke Wulf 190 and by war’s end, he was working on a jet fighter called Ta-183.

Argentina was enjoying a prosperous time with the influx of money received in exchange for food exported to United Kingdom during the war.

 

Emile Dewotaine, unable to live in his France due to his collaboration with the Germans, designed in this South American country his jet plane that was called Pulqui I (Arrow in native language). It was a very basic concept that was not up to the expectations, though it placed Argentina in a good position as only the 8th country in the world to fly its own jet plane, and first in South America. Dewotaine's contract was cancelled.

 

The more advanced plane that Tank had in mind, derived from the Ta-183, took the place of the Pulqui I, with strong support from President Peron’s Government. After several tests with a wooden glider, the first two prototypes were built at the Fabrica Militar de Aviones (Militar Aeroplanes Factory or FMA). (01) was used for static tests of resistance and (02) was first flown by the Argentine Air Force pilot Edmundo Weiss on June 16th, 1950. After an accident provoked by a faulty seal in the main landing leg with German test pilot Otto Behrens in the controls, some modifications that were devised to improve the performance were made. This included the union of the wings to the fuselage, and the tail area. This plane was thus called 02m (modified).

Painting from Exequiel Martinez of Prototype 2 in flight.

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When Tank flew the plane for the first time, he tried to stall it at 9,000 mt and it fell like a rock; only Tank’s experience allowed him to regain control. He repeated the maneuver and the same problem happened: there was no indication that the stall was approaching. After studying some bibliography it was found that the T type of tail the Pulqui had could loose lift when a vacuum was created behind the wings at certain attack angles. As a consequence, ballast was added to the nose to prevent this from happening again. Now, when the plane stalled, it would dip the nose and allow the pilot to regain control rapidly.

 

On February 11th, 1951 the plane was presented to thousands of people in Buenos Aires, flown by Tank and with the presence of President Peron.

 

Prince Bernard of Holland visited the country and was shown the plane as his Air Force was looking for a jet plane. Though he was interested in the Pulqui, the Holland finally bought a batch of Gloster Meteors Mk 8.

  

The development was doing so well that the best Gloster Meteor fighter pilots of the Air Force were sent to start testing the plane. It is very important to remark that the Meteor demanded a lot of muscle to be flown, while the Pulqui (like all Tank’s planes) could be flown with “the tip of the fingers”. The first pilot that flew the plane was commander Soto on May 31st, 1951. After he landed, it was the turn of one of his pilots, Vedania Mannuwal. Trying to out perform his superior, during a high performance turn, one of the wings broke and Mannuwal ejected from the inverted plane. The primitive ejection seat required several steps before the plane could be abandoned and the parachute opened. Mannuwal ejected upside down and fell to his death as he did not have enough time to open the parachute. The prototype was completely destroyed. It was later found that one of the 2 main pieces that linked the wing to the fuselage had not been properly welded. This fact, probably added to the fact that Mannuwal had flown the plane as it were a Meteor, provoked the accident.

 

The third prototype was finished around the end of 1951. Some more modifications were made: fuel capacity increased from 2000 to 3000 lts, landing gear, rudder, adjustable control that could be modified in flight. After several test flights, Behrens trained intensively to make a demonstration to President Peron in October 1952. Just two days before the event and while practicing, Behrens dived towards the ground and then climbed back to 800 mt. The plane lost speed and suddenly stalled and went on a backspin. He succeeded in recovering control but the ground was too close and he did not have time to gain altitude again. The plane disintegrated and killed the famous World War II German pilot instantly.

 

The fourth plane, finished in 1953, had more modifications: 1 fence above each wing, and 4 on the fuselage, close to the tail to improve the lift on this area. This was the first plane that carried the 4 x 20 mm cannons and endurance was now 3 hours, WITHOUT external fuel tanks. A team of Air Force pilots was in charge of testing the plane. They were: 1st Lt. Conan Doyle (who made the first firing tests), Lt. Gonzalez and Lt. Balado. As Ricardo Burzaco says in his book “Las Alas de Peron” (Wings of Peron), it is probable that in any other country, a pre production series of planes would have been built at this stage, with the minor problems being ironed out in the future. Some other minor changes were made to fine tune the performance.

Pressurization was tested in a flight that reached around 45.000 ft, and the maximum speed (1080 km/hr) was achieved in a dive from 40.000 to 30.000 ft. This speed could not be exceeded because that was the maximum thrust the Rolls Royce Nene II could give. An all weather version with radar was under development as well.

 

Around this time, visits from the USA, USSR and other countries interested in this development took place. Egypt wanted to buy all the Pulqui II that were available…but the only one built was prototype 04!

 

Other projects like the Ia-35 Huanquero (another design of the Tank team that went into production) and the utilization of the installations of the FMA to build cars, drained resources from the Pulqui project.

 

In September 1955, after almost 10 years of Government, the Peron regime is overthrown by a military coup. Most of the Air Force officers in charge of the project are fired. Tank is persecuted by the new authorities under the charge of having a false identity. Tired of these games, Tank leaves the country along with most of his team. He went to India were he completed his next project, started in Argentina, which some call Pulqui III. It was the Hindustan Marut.

 

Because the plane was the son of the “wrong” regime and most of the team had left the country, the project looses momentum. In an effort to gain political support, a record flight is tried: take off from Cordoba, fly to Buenos Aires 800 km away, strafe an Air Force practice range in the area and return to Cordoba only on the internal fuel. The only oxygen equipment available for such a long flight was taken from a Meteor under repairs in the FMA. Pilot Balado successfully made all the flight (including the straffing) at an average cruise speed of around 900 km/h, but a failure in the oxygen system deprived him from this element on the return leg. As a consequence, at the end of his record-breaking flight, his judgment was impaired due to the lack of oxygen and he landed the plane heavily (at 300 km/h instead of 180) and though he only suffered some bruises, the plane was damaged beyond repair.

 

Towards the end of 1956, Brig. Ahrens of the Air Force asks Eng. Guillot, in charge of the FMA when 100 Pulquis could be delivered. There were enough fuselages and wings for 10 planes to be built immediately. And in 4 years, the Pulqui II number 100 would be in service in the Air Force. This plan was rejected as the Americans had offered the Argentines 100 new Sabre F-86 with the Orenda engine that could be delivered immediately. Thus, the Pulqui II was killed. The Americans did not full fill their promises, and only 28 second-hand Sabres (without the Orenda engine) were delivered…4 years later! But they had succeeded in getting rid of the Pulqui, a plane that could have been an important player in less important international markets.

 

Still, a fifth prototype was finished in 1959. By now, the plane was obsolete. The only difference between this plane and the other 3 prototypes was that it was painted in white, while the others were left in bare aluminum. Around a dozen flights were made but without passing 60/70% of what the plane could give, as all the experts were not longer available and records of previous tests "lost". This plane was then stored and sent to the Air Force Museum in 1960, 10 years after it’s first flight!

 

Interesting enough, the Meteors the Pulqui were supposed to replace stayed in service until 1970, and the F-86s that took the place that should have been the Pulqui’s flew for the Air Force until 1988 (by then in training duties)!

 

It is important to remark that, contrary to what some websites say about the Pulqui (“a killer plane”), all the accidents happened due to human error/deffect of construction and not due to failure in the design itself.

 

Just to understand the importance of this plane, here is a comparative chart that shows the impressive performances of the Argentinian plane (taken from Burzaco’s book):

 

 

Pulqui II

Mig 15

Sabre F-86

Weight (empty) in kg

3600

3382

4578

Load in kg

1950

1424

1850

Total Weight in kg

5500

4806

6400

Max. speed (km/hr)

1080

1050

1090

Cruise speed (km/hr)

960

900

790

Climb rate (mt/sec)

30

42

37

Ceiling (mt)

15100

14600

14630

Range (km) internal tanks

3090

1420

1690

Thrust (kg)

2300

2270

2683

Fixed armament

4 x 20 mm

2 x 23 mm

6 x 12,7 mm

It can be seen that the Pulqui could fly higher, faster and farther away than the other two contemporary famous planes.

 

This plane is still considered a proud example of what Argentina could have achieved…and in some ways is similar to what happened to the famous CF-105 Arrow in Canada (what a coincidence, they had the same name), a fine plane of the 60s that was better than anything any other country had at that time, and that had a performance that is better in several respects to the currently in service CF-18s of the RCAF!!!

 

This are pictures of Prototype 5, in display in the Argentine Air Force Museum (Thanks to the Staff for the pictures).

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BULDING THE KIT:

 

General preparation:

Lots of preparation is required to get the pieces ready.

The resin parts of this kit are covered in a sticky substance that can be removed after a cloth damped in acetone is rubbed on the surface. There are several bubbles in the pieces that I covered with two part epoxi glue. The upper and lower parts of the wings are not properly aligned. There is a lot of excess of resin to be cut and sanded.

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Left: The flash of resin in the main gear area broke the surface around it when I tried to remove it (see the shiny area. Also some bubbles in the gun ports can be seen).

Center: the misalignement of the molde in the top and low area of the wings .

Right: My kit was missing the nose wheel bay, which I received later on but my father had put it along some other things in his suitecase...it arrived in 20 pieces which I tried to put together as best as I could.

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Left: cockpit and instrument panel ready. A nice amount of the sides of the cockpit had to be trimmed to make it fit correctly inside the fuselage halves.

Right: note the weight added to the area around and behind the cockpit, as the kit is a tail sitter. The halves and tail were put together with tape and I hold the kit on my fingers (one under the nose, another one under main gear bays) and weight was added until the tail was not falling from my hand anymore. You can see the cracks in the nose bay due to the breakage during "shipment".

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Fuselage halves were glued (as most of the kit was) using a two part epoxi glue that I purchased in Canadian Tyre. Very easy to sand and very strong bond.

Wings: The left one was deformed close to the border of attack and the fuselage. It was like somebody had sunk a big thumb while the resin was still soft. I had to add layer after layer of epoxi, sanding in between. The final smooth surface was achieved using Tamiya Putty. The right wing was perfect, except for the fact that while sanding putty I had used on one of the  bubbles...I managed to destroy the thin area above the flaps. Unbelievable!! Luckily I managed to find the 10 or so different bits and assemble them like a puzzle. Again, epoxi and putty to the work! Finished product can be seen on the left. Both fences above the wings were broken so I opted to remove them and build them from scratch (see below). One of these that is located in the tail area was missing so I used the remaining one as a template.

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Fuselage halves union was sanded and perfected with Tamiya Putty. Then the tail was attached and the same procedure was followed (I had to sand off part of the union to have a straight fuselage joint...else it would have looked bent to one side).
 
The horizontal surfaces of the tail were glued in place. Epoxi was used to strenghten the area outside the T. When sanded, a minor amount of Putty was required. As it can be seen, some large gaps were found on the right side of these surfaces and another session of Epoxi, sanding and Putty followed.

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With the fuselage ready, I added the wings. As the top and bottom sides of the wings were missaligned and the conecting pins were practically gone, there was nothing to hold them in place while the epoxi was drying. I had to build a structure to hold them in place using some Legos. I first glued the right one, and the following day I did the same with the left one. Note the excess of epoxi in the left union, that was later sanded as the right one shows. More Putty was used to improve the surface.

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The airbrakes supplied with the kit are brittle and when trying to clean the resin, 3 out of 4 broke. Instead of trying to fix them, I scratch built them using an old credit card and some plasticard. The holes were made using a pin and then expanded. The template I used was the only surviving original brake I had left.

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The landing gear is made with white metal and very flexible. I removed the imperfections using a knife and then the pieces strenghten using several layers of instant glue. Later on, they were glued together with lots of glue to make sure the unions were going to hold the weight of the kit.

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Canopy is vacuum formed and there are two available, in case one brakes during work. They have imperfections and are not very clear. The little spots or bubbles were sanded with the most fine sanding paper I have, and then dipped in Future. The end result is quite good. I cut out the windshield and reinforced the area that sits on the fuselage to improve bind as more surface was now available. Once in place, a very detailed and carefull application of epoxi followed. At this point, it was already masked. Sanding and Putty improved the union. Once ready, a coat of black was given to the area.

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Painting: A coat of grey was given to the kit for two reasons: to check for imperfections, and to protect the resin from the Alclad, just in case...You can see the numerous areas that required more attention.

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The surface of the kit was smoothen using cotton and fabric (not a very good method, though). Then thin layers of Alclad II Aluminum were given to the plane, landing gear doors and air brakes.

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The plane was masked to paint the markings and guns discharge holes. As I had doubts about the density of the decals, I opted to protect the area where the roundels were going to be positioned. I first painted the red, and then the black areas. The rudder and the oval doors on the fuselage were painted in a different tone of aluminum.

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Decals: Finally, the best part started, when I applied the decals. They are very thin, follow the surfaces very well and have an acceptable color density. Thanks to R. Caballero, I was able to find that the markings for the wings were incomplete, as the IA33 P legend was painted above and below them. As the kit does not have them, F. Vera (Condor Decals) sent me a couple of them that he had. The "serial" on the rear part of the fuselage falls on top of the air brakes, so carefull measuring was required to cut these decals in 4 pieces. The correspondent small strips of decals were glued to the airbrakes.

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Decals were sealed with PollyS, which was previously filtered using old silk stockings. The antiglare panel and the exhaust were sprayed with matt varnish.
The ejection handle was made with thin copper wire, painted in yellow and black. The seat and the control stick were glued and with this the cockpit was finished.
After some searching in the spares box, the body of an old missile gave me the tiny supports for the airbrakes. These were glued in place with Cyano (gel).

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The wheels and bays doors were glued in place using the same product (nose doors were scratchbuilt as the originals were broken in several pieces)

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The last details was the antenna just ahead of the windshield. It is the white metal one supplied with the kit, slightly trimmed to size and painted in black.
 
NOTE: As I was originally missled by the pictures in Burzaco's book (they show Prototype 3 as if it were the 4th one), I thought that the canopy was framed. So I first used canopy and painted the frames. When I finally found a good picture of the 4th prototype (thanks, Ricardo, again) I used the other supplied canopy and painted it properly. I ended up with one framed and one without frames.  These pictures show the nose of the plane with different canopies. From this perspective, the prototypes 03 and 04 only differed in this detail.

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Though I believe that the area of the fuselage behind the wings should tapper more abruptly towards the tail, the overall look is very good. The plane sits like a Pulqui II. Almost seven months of work were worth the result. But I don't want to start a project like this for some time.

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This plane is dedicated to my friend Exequiel Martinez, Captain (Res.) of the Argentine Air Force. When he was a young cadet, he was priviliged to watch 04 and 05 flying during the tests. He is a very famous SAR helicopter pilot (he also flew during the 1982 war), and he has done uncountable number of paintings that describe the history of aviation (both militar and civilian) in Argentina.   

Pablo  

Photos and text © by Pablo Calcaterra