IAR 80 max speed question...

[Victor]

[quote] Some articles I read said experiments with the Jumo 213 was tried as other Romanian craft used the engine too, and it failed due to too much vibration (and from other articles this a problem when fitted to ME109's and FW190's too) as it was a bobmber engine, but if the alternative is nothing, why not keep trying. [/quote]

The test, which Jason Long (the author of that article) is referring to, was done on the IAR-80 no. 13, but with a DB-601Aa from a Romanian Bf-109E (no. 4) with the no. 11210. The first flight was on 21 April 1941 and the pilot was Dudu Frim. After take off the vibrations started. He was ordered to abandon the airplane, but he refused and brought it back. The project was canceled.
In June 1943, the IAR-80 no. 326 was modified to receive a DB-605A (1475 HP). The first flight was made on 29 June 1943. The performance of the airplane improved greatly and an order was issued to Daimler Benz. They, however, refused to take it (apparently they were already overstretched by the Luftwaffe orders).
Radu Manicatide mentioned also an IAR-80 fitted with a 1600 HP Gnome-Rhone, but which was destroyed by the US raids in 1944.

[Florin]

QUOTE

QUOTE It's too bad IAR didn't know how to design and build their own engines. After the man that could have very well found a way to improve the K14 engine was thrown out, there was not anyone who could do it.

Hi Victor,

Can you add some words about this? Or to highlight an Internet link?
I smell a story about an engineer fired, dismissed, something alike...

Florin

[toniyona]

Here is the link to the Jason Long article mentioned earlier, hope he does not mind.
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http://www.geocities.com/CapeCanaveral/2072/IAR80.html
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As I read it, the Romanian plane, just like the Italian planes, could have risen to world standards with the German engines.
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For just sheer numbers, it seems to me that more numbers of a plane that is already in production can be had than an entirely new one, plus, it should minimize retraining of pilots and ground crews, save for the new engine.
.
If anything more on this or if there was a projected successor / development of the IAR 80 /81 that would be appreciated.

[Huck]

[quote]Jason Long's article contains many mistakes and is not based on actual research in the Romanian archives. I trust mr. Antoniu and Cicos (the authors of the already mentioned source), since they have p[ut more than a decade of study into their book. It is by far a reference for any article related to this aircraft. The rest are just speculations.[/quote]

Victor, I'm afraid you are wrong on this account.

A6M5 Model 21 developed 950hp max power at sea level and had a max speed of around 450km/h at sea level and 530km/h at aprox 5000m. Aerodynamically it was similar with IAR-80, though IAR had better profiled fuselage, canopy and smaller and higher aspect ratio wings. Also Zero was a larger aircraft. Therefore it is obvious that IAR with more power and less drag will be faster than Zero. 470km/h is max speed at sea level and 550km/h at around 5000m are very realistic values.

IMO the major problem with IAR, beside that it was underpowered from '42 on, were the supradimensioned controls. It must have been incredibly heavy at high speeds. Though this was easy to correct if IAR80 were to serve as front line fighters again.

Check the ailerons and the elevator. They are huge :shock:
Twice as big compared with those of Bf109(F and later).

[Victor]

The 534 km/h of the A6M2 Type 21 were reached at 4551 m, not 5000 m. Also note that the Zero was lighter (empty) than the IAR-80 and only slightly longer (16 cm). The IAR-80's height was actually 55cm bigger.

[C-2]

The Zero had no armour and no self seeling fuel tank
No protected wind screen and that's why he was more manovrable!

[PanzerKing]

Man the IAR 80 looks so damn sleek in that picture! It's too bad it didn't have 1400hp in that nose.

[Victor]

[quote]Man the IAR 80 looks so damn sleek in that picture! It's too bad it didn't have 1400hp in that nose.[/quote]

Take note that this replica is not exact. Only the tail is perfectly identical. The rest isn't that good.

[PanzerKing]

QUOTE

QUOTE Man the IAR 80 looks so damn sleek in that picture! It's too bad it didn't have 1400hp in that nose. Take note that this replica is not exact. Only the tail is perfectly identical. The rest isn't that good.

Oh...bummer! :?

Thanks for the clarification.

[tempesta]

Victor, on your site you give the same speed for all the IAR 80 variants. It is hard to belive that an airplane would have the same speed performance while it's weight is increased by more then 400 kg and the engine and shape remain the same.
The data on your site seems good for the later versions, but for the early, lighter ones you give that quote from the german tester wich gives "20-30 km/h slower then Bf 109 e", and that will be faster than the 485 km/h you mention.
Do you have exact informations about each specific version of the IAR 80?

[PanzerKing]

QUOTE

Victor, on your site you give the same speed for all the IAR 80 variants. It is hard to belive that an airplane would have the same speed performance while it's weight is increased by more then 400 kg and the engine and shape remain the same. The data on your site seems good for the later versions, but for the early, lighter ones you give that quote from the german tester wich gives \"20-30 km/h slower then Bf 109 e\", and that will be faster than the 485 km/h you mention. Do you have exact informations about each specific version of the IAR 80?

I was thinking the exact same thing.

[Victor]

QUOTE

Victor, on your site you give the same speed for all the IAR 80 variants. It is hard to belive that an airplane would have the same speed performance while it's weight is increased by more then 400 kg and the engine and shape remain the same. The data on your site seems good for the later versions, but for the early, lighter ones you give that quote from the german tester wich gives \"20-30 km/h slower then Bf 109 e\", and that will be faster than the 485 km/h you mention. Do you have exact informations about each specific version of the IAR 80?

The specifications are for every version, not general.

[tempesta]

It seems strange that the plane didn't got slower when the weight increased, but I'm not an expert like mr. Antoniu and mr. Cicos.
Could you offer more details about the propsed 1600 HP Gnome-Rhone engine? It seems that such an engine would be easy to fit in the IAR 80 airframe (easier then the inline DB605).

[PanzerKing]

Yeah, how on earth could a plane stay at the EXACT speed for every version, when there were weight & armenent changes?

[Huck]

QUOTE

Yeah, how on earth could a plane stay at the EXACT speed for every version, when there were weight & armenent changes?

Actually it is possible, as long as aerodynamic shape of the plane is not altered, by means of externally attached loads, like fuel tanks or bombs.
For the usual ww2 fighter, with a max speed in level flight somewhere between 500-600 km/h indicated, max speed is the same with full internal fuel tank or with it almost empty. The reason for this is simple: induced drag, the drag generated by lift, which increases with additional weight, counts for less than 5% of total drag of the fighter at max speed, and this is for the total weight of the airplane!

This is why 10-15% weight increase won't modify the max speed significantly. Normally max speeds are recorded at loaded weight, which is the weight with full internal armament and fuel, but no external loads attached.

On the other hand I disagree with Victor about IAR-80 max speed. Zero is a larger aircraft, with large wing area and thick airfoil, like all carrier planes at that time, no doubt that it produces quite a lot more drag than IAR-80. Since Model 21 has also less power it clearly indicates that IAR should be faster than Model 21. The speeds I gave in my previous post are from memory and I did not have the intention to be precise for a comparison at altitude, because engine performance at altitude is very much dependent on supercharger capabilities - even if we know that the engine had similar HP ratings at sea level, it is impossible to say if this difference was preserved at altitude. Otherways I have good data from R. Francillon book on Japanese ww2 planes.