Adrian Tronaru

In order to start the mass production, the Ministry of Air and Navy (Ministerul Aerului și Marinei – M.A.M.) draws up a Statement of Work (SOW), annex to Contract No. 2072/18 Dec 1939. This SOW places an order for a first batch of 50 fighters of the IAR 80 type, which were going to be manufactured by Regia Autonomă I.A.R. of Brașov.

The SOW specifies that the first 50 aircraft will be equipped with the IAR-14K IIc32 engine with an option for a second batch of 50 aircraft. The M.A.M. was going to specify, by March 1940 at the latest, the final engine of choice. It was probably hoped that Junkers was going to keep its promise to deliver the Jumo engines as initially t1hought.

To be noted that in the SOW I.A.R. has preserved the characteristics of the prototype and not of the modified variant – no. 1.

Production will begin in January 1940, the first deliveries to be expected towards the end of the same year.

No. 1 aircraft flew for the first time on July 10, followed by No.2 on July 19. The first five aircraft were ready for delivery on November 29, 1940.
By February 20, 1941, the first batch of 20 aircraft had been delivered, and by April 16, the entire batch of 50 IAR 80 aircraft had been delivered.

During mass production several changes were made depending on the requirements of the beneficiary or from observations made following flight tests.

Starting with number 21, the existing gunsight is replaced with a Goerz type. The related story is quite interesting:

"The British Air Ministry has launched increasing orders for the Bar & Stroud reflex gunsight which was considered top secret as it was going to equip Spitfires and Hurricanes. The company could not meet the orders and the Air Ministry asked them to find an external supplier. This was going to be CP Goerz of Vienna. The British Ministry of Air approves the contract and a set of secret drawings together with a complete gunsight will be sent to Austria. Despite of the Anschluss (March 12, 1938) the Vienner company will honor the contract with The British Ministry of Air until the entry of Great Britain into the war delivering about 700 gunsights known as GM2 Mk II. 
Its quality was considered superior to the British original [4.] "

from left to right: The Bar & Stroud gunsight, the Goerz gunsight, the IOR-Telereflex gunsight

And this is how the IAR 80 ended up to be equipped with an Austrian-made gunsight, manufactured under British license, identical to the ones used on Spitfires or Hurricanes, and supplied by Germany!.

Regarding the fuselage, during testing it was found that deformations would occur at the level of the V frame. It was decided to reinforce it with a belt initially mounted on the outside, fixed with four rows of rivets.

From left to right: without the reinforcement belt; exterior belt; interior mounted belt seen from the outside

The reinforcing belt at frame V was kept on the outside until series number 95. From 96 onwards it was mounted on the inside and was riveted to 3 rows of rivets.

Production was split into several batches of aircraft, with different specifications as shown in the following table:

During production there were various problems reported by pilots flying the aircraft – components that malfunctioned abnormally often (instruments, sensors …) or serious structural defects – V-frame deformation, frequent rupture of the electron compass of the landing gear …

We will talk about all this in the next chapter.

to be continued: problems, problems …

Bibliography:

1. Dan Antoniu, George Cicos, IAR-80 "Le Héros Méconnu", Editura TMA Paris 2008

2. Horia Stoica, Dan Antoniu, Industria Aeronautică Romană I.A.R. 1925-1948, Braşov 2020

3. Radu Brînzan, Vânător Romanian Hunter - The I.A.R.80 & I.A.R.81 in ultimate detail, MMP 2014

4. http://spitfirespares.co.uk/gunsites.html

Following the completion of the prototype and of the corresponding flight tests it became obvious that changes were needed leading to specifications for the mass production aircraft. According to the “Technical Specifications, Part II”, Annex to Contract No. 2072/18 Dec 1939, the Defense Ministry launches a first order for a number of 50 IAR 80 fighter planes.

There is a legend that in brief says that the first IAR 80 resulted from the modification of the prototype. This statement must be carefully considered. After a thorough study of several photos with the first IAR 80 aircraft, it seems that a new prototype has actually been built, and the differences between the prototype and the number 1 are very large, both in shape and size.

Characteristics of the prototype (No. 0) vs. No. 1

Table legend: Wingspan; Length; Height; Empty weight; Weight; Speed; Ceiling; Weapons

From the available photos, it can be seen that this first plane also underwent several modifications, which is why it must be carefully analyzed to understand how it “evolved” to the first series of planes.

For analysis, we will consider three photos of the plane credited as number 1.

The first variant

From this first photo, we can observe the following characteristics specific to the entire mass production series:

the cockpit is redesigned, being closed with a sliding plexiglass canopy;
the engine cowl is completely new, with a circular profile at the front and an oval at the rear;
in this variant we also notice the cooling flaps of the engine, adjustable in flight, which we will find in all subsequent series;
the front fuselage has been completely redesigned and lengthened by 74 mm, due to the modification of the engine mount;
an carburetor air intake was mounted under the hood;
the wing is enlarged on the aileron area with a rib, which has three hinges compared to two of the prototype, the aileron being equipped with two counterweights; position lights are added at end of the wings;
the horizontal tail was completely redesigned, having a strengthened structure and increased surface;
the horizontal stabilizer struts were removed;
the tail was also completely redesigned, with an enlarged surface; distinctive from the prototype, the upper rib of the rudder is oblique;
for practical reasons, the movable cover from the base of the landing gear is removed;
last but not least, the wing was modified and two more FN Browning -7.92mm machine guns were installed.

Atypical to the following series, we can also notice the following characteristics specific only to this aircraft, possibly some found with the first 4 mass production numbers:

the engine that equipped the aircraft was the IAR-14K IIIc36 with 930 hp, the improved version of the IAR-14K IIc32, but different from the engine that will equip the first series;
Behind the exhaust, a specific cooling grid is observed, similar to that of the mass production airplanes from no. 250 upwards;
an interesting aspect, which we will detail below, is the fact that the windshield maintains the shape with curved sides, similar to that of the prototype, but with a flat front;
the rudder is provided with an in-flight adjustable trim tab, similar to that mounted on the elevator;
the logo on the propeller blade indicates that it is a VDM.

First variant of the closed canopy – we can observe the atypical shape of the windshield

By zooming on the tail area, we can observe the control system of the trim tab mounted on the rudder surface

We would like to mention that it is the only photo available so far, which confirms the existence of the in-flight adjustable rudder trim tab, this being observed in several original blueprints.

This confirms and explains drawing “C-1112 – Details of the rear end of the fuselage” in which we can observe two pulleys mounted on the IX frame of the rear fuselage as follows:

left pulleys – for adjustable depth compensator cables;
right pulleys – for adjustable steering compensator cables.

The second variant

In this variant, the cooling slots behind the exhaust were abandoned and the rudder was changed, so the in-flight adjustable trim tab was replaced with one adjustable on the ground, a solution that will be kept throughout the entire production. The windshield and the canopy remain the same, in the atypical version.

The tricolor cockade can be seen on the underside of the right wing.

mass production tim tab – adjustable on the ground

The final variant

On this plane, which will become the standard for the first series, the air intake is changed and the windshield is replaced with one with flat side windows. By default, the canopy also changes. An antenna mast is mounted and the gunsight grid system in front of the windshield.

The windshield in the new shape has a wider front window and the side windows are flat.

The grid of the gunsight can be seen in front of the windshield.

However, in early mass production, there were also airplanes that kept the old windshield, with semi-rounded sides.

to be continued … ” the mass production”

Bibliography:

1. Dan Antoniu, George Cicos, IAR-80 "Le Héros Méconnu", Editura TMA Paris 2008

2. foto "Numărul 1" - colecția Horia Stoica

Author: Adrian Tronaru

About the IAR 80 – the mass production

About IAR 80 – Number 1