IAR 80 / IAR 81

 

 

 

 

 

 

Specifications

1st Flight 1939

Crew: 1

Length: 8.97 m (29 ft 5 in)

Wingspan: 11 m (36 ft 1 in)

Height: 3.600 m (11 ft 10 in)

Wing area: 17 m2 (180 sq ft)

Empty weight: 2,200 kg (4,850 lb)

Max takeoff weight: 3,030 kg (6,680 lb)

Fuel capacity: 230 kg (510 lb)

Powerplant: 1 × IAR K14-IV C32 1000A 14-cylinder two-row air-cooled radial piston engine, 750 kW (1,000 hp)

Propellers: 3-bladed constant-speed propeller

Performance

Maximum speed: 510 km/h (320 mph, 280 kn) 524 Km/h at 5,350 m in tests of IAR 80 Nr.2 on 16.12.1940

Range: 730 km (450 mi, 390 nmi) on internal fuel only

Ferry range: 1,330 km (830 mi, 720 nmi) with extra fuel tanks

Service ceiling: 10,000 m (33,000 ft)

Time to altitude: 4’41” – 7’00” to 5,000 meters (depending on variant)

Wing loading: 132.35 kg / m2 (27.11 lb/sq ft)

Armament

Guns: 2 × 20 mm (0.787 in) MG 151/20 cannon and 4 × 7.920 mm (0.312 in) FN-Browning machine guns mounted in the inner portion of the wing

Bombs: one 250 kg (550 lb) SC250 bomb under the fuselage and/or 2 x 50 kg (110 lb) SC50 bombs under the wings.

Variants

Prototypes

Work began on the IAR 80 prototype in late 1937, originally with an open cockpit and the 870 hp (650 kW) IAR K14-III C32 engine which was a licensed Gnome-Rhône 14K II Mistral Major.

The prototype was completed slowly, and first took to the air in April 1939.

Test flights of the prototype were impressive; the aircraft could reach 510 km/h (320 mph) at 4,000 m (13,000 ft), service ceiling of 11,000 m (36,000 ft) with the ability to climb to 5,000 m (16,000 ft) in 6 minutes, which was respectable at the time, though not up to the contemporary Supermarine Spitfire or Messerschmitt Bf 109 fighters.

In comparison the P.24E was almost 450 kg lighter, yet over 80 km/h slower with the same engine.

The IAR 80 also proved to be enjoyable to fly and was manoeuvrable.

A number of minor problems turned up during the prototype phase, and were dealt with over the next year.

To improve power the design was updated to mount the newer 930 hp (690 kW) C36 version of the K14-III.

However this engine was slightly heavier than the C32, which required the rear fuselage to be stretched to move the centre of gravity back into the proper position.

The extra space in the fuselage allowed the fuel tanks to be increased in volume by 455 L (100 imp gal).

The wing was also enlarged and the tail was revised to eliminate the bracing struts.

A side effect of this extreme rearward position was that the pilot had even worse forward visibility while taxiing than most other tail draggers.

To address this somewhat, the pilot’s seat was raised slightly and a bubble-style canopy was added.

The updated prototype was tested competitively against the Heinkel He 112, which had arrived in Romania as the start of a potentially large order.

Although the He 112 was more modern and much more heavily armed with two machine guns and two 20 mm cannon, the ARR ordered 100 IAR 80s in December 1939 while only 30 He 112s were accepted.

The government in Bucharest ordered another 100 IAR 80s in August 1940.

Further orders for batches of 50 IAR 80s followed on 5 September 1941 and 11 April 1942, then another 100 on 28 May 1942, to be followed by 35 of the IAR 81C development in February 1943, with a further 15 in January 1944.

IAR 80

Production of the IAR 80 started immediately, although the armament proved to be a serious problem.

The prototype had mounted only two Belgian-made Fabrique Nationale 7.92 mm machine guns, a licensed modification of the Browning .30 cal.

This armament was not heavy enough against modern aircraft, and the production model was expected to mount six.

The German invasion of Belgium in 1940 suspended the supply from FN, and there was no suitable replacement.

Lacking armament, production was halted.

The Germans only allowed the delivery of the guns to resume after Romania joined the Axis in November 1940.

As a result the first production IAR 80 didn’t roll off the line until January 1941, although the first batch of 20 were delivered by the middle of February.

The armament supply remained inadequate so production models only carried four guns.

The initial batch of fighters was well received by the Romanian pilots, but they found the aircraft underpowered and lacking firepower.

In order to address this, the aircraft mounted the 960 hp (720 kW) K14-IV C32 engine in the 21st through 50th examples, but the firepower concern could not be resolved at the time.

IAR 80A

By April 1941 the Romanians were firmly in the German sphere, and as a result the Germans released more FN guns for their use.

These were quickly installed, and the resulting 80A model finally mounted the original complement of six guns.

Armoured glass in the windscreen, seat-back armour, and a new gun sight were also added at the same time, along with the newer 1,025 hp (764 kW) K14-1000A engine.

The extra engine power proved to be more than the fuselage structure was designed to handle, and it had to be reinforced with a duralumin “belt” just behind the cockpit in the first 95 A series aircraft built before the fuselage could be modified.

Although the IAR 80A had a more powerful engine, the added weight of the guns, ammunition and armour plating reduced the top speed slightly to 316 mph (509 km/h).

Nevertheless the new model was clearly an advancement, and the A model replaced the earlier one on the assembly line starting with the 51st airframe.

Eight of these had been completed in time for the invasion of the Soviet Union on 22 June 1941.

FN guns remained in short supply, so throughout late 1941 and early 1942, guns were stripped from PZLs and observation aircraft for use in the IARs.

IAR 80B

Combat over the Soviet Union proved that even six of the FN guns still lacked punch, and once again firepower was increased, with 13.2 mm FN machine guns taken from Romanian SM.79s were installed in the IAR 80 in a new lengthened wing.

The result was the IAR 80B, which also introduced new radios, an area where the aircraft had previously been weak.

A total of 50 of the new design were completed, including 20 airframes which were originally intended to be IAR 81As.

These last 20 were thus able to carry a 50 kg (110 lb) bomb or a 100 L (22 imp gal; 26 US gal) drop tank under each wing.

The entire series were delivered between June and September 1942.

IAR 81

The ARR had intended to replace its light strike and dive bomber aircraft for some time when the war opened in 1941.

The first role was to be filled by the IAR 37 (and later 38 and 39 models) but the plan was to fill the second role with the Junkers Ju 87.

Once again the Germans deferred and the ARR was left searching for a design.

The modification of the existing IAR 80 as a dive bomber was seen as a reasonable option, easier than designing an entirely new aircraft; as well as having obvious production benefits.

The result was the IAR 81, a minor change to the IAR 80A models that were then in production, adding a hinged bomb cradle under the centreline to throw a 225 kg (496 lb) bomb clear of the propeller (many dive bombers used a similar system).

Delivery consisted of a shallow dive from about 3,000 to 1,000 m (9,800 to 3,300 ft) with the speed around 470 km/h (290 mph).

Pilots disliked the aircraft, as the drag from the bomb cradle significantly hampered performance.

Fifty were ordered in mid-1941 but after 40 had been delivered, 50 kg (110 lb) bomb racks were added under each wing.

The wing racks could also mount 100L drop tanks, allowing the 81 to be used as long-range fighters.

IAR 81A

As the fighter model was converting from the A to B series with the addition of the 13.2 mm guns, likewise the 81 model was upgraded in the same fashion, creating the IAR 81A.

The only distinguishing feature between the 80B and the 81A was the 81’s centreline bomb rack, and both were built on the same assembly line.

The first order for 81As was cancelled and the airframes were instead delivered to fighter units as 80Bs.

Efforts to obtain the Ju 87 dragged on, so a second batch of IAR 81As was ordered in May 1943 to replace losses.

Once again fate intervened, and the Germans released the Ju 87 for delivery before the batch could be completed.

Like the first batch, these 10 airframes were delivered as fighters.

IAR 81B

The supply of the 13.2 mm guns was clearly limited, and in a further attempt to increase the firepower of the design the Romanians signed a deal with Ikaria in Germany for a supply of 20 mm MG FF/M cannon.

These were a licensed version of the Swiss Oerlikon FF, which had been in use in various German aircraft.

The new gun also required a redesign of the wing.

The 60 IAR 81Bs were intended to be dive bombers, but were delivered as IAR 80Cs fighters (a designation that appears painted on the tail of this model) without the centreline bomb rack.

After the first 10 were completed, self-sealing tanks were added along with improved seat-back armour.

The first 10 were delivered in December 1942 and the entire order was completed by April 1943.

IAR 81C

The final stage in the IAR 80’s wartime history was the 81C.

This version changed the guns once again, this time to the Mauser MG 151/20 which was replacing the MG FF/M in German service and had just been released for Romanian use.

The order for the 81C was placed in May 1942, predating the second order of the 81As.

The first order for 100 airframes was delivered, like all of the prior updates to the 81 series, with the centre line bomb rack removed to be used as fighters.

An additional order for 35 was placed in February 1943, and then another 15 in January 1944.

These aircraft were primarily to replace losses in earlier models, while production of the Bf 109G ramped up.

IAR 80M

By 1944 the ARR fighter units included examples of 80A, B and C models, as well as 81A, B and Cs.

In order to up-gun the earlier fighters as well as simplify logistics and maintenance, an upgrade program was started in mid-1944 to bring all existing airframes to the 81C armament suite of two MG 151/20s and four FN 7.92s.

The resulting A and B models of the 80 and 81s would become the 80M and 81M respectively, although at this point there were no dive bombers in use.

It is unclear how many conversions were completed.

IAR 80DC

IAR 80s remained in service until 1949, when they were replaced by La-9s and Il-10s.

Those airframes with the lowest hours were modified by removing a fuel tank in front of the cockpit and adding a second seat, resulting in a trainer designated the IAR 80DC.

These were used for only a short time before being replaced by Yak-11s and Yak-18s in late 1952.

448 aircraft were built of the 80 / 81.

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