Frati Torpedo Bomber


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25 July 2007
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Frati F.43 or AF.43

"Stelio Frati and his first aircraft design, a torpedo bomber done for his master's thesis in 1942."


Does anyone knows if this design was pursued further during Frati's time at Aeronautica Lombarda? It was the AL 12P assault glider that got me wondering (the shape of the vertical tail/rudder is very similar - see provisonal sideview). (dead link)

I know that Frati worked on the AL 12P (as well as the Assalto Radioguidato along with Ermenegildo Preti) while at Aeronautica Lombarda under Sergio Stefanutti. Frati left Lombarda in 1944 but relations must have been good since, along with Ambrosini*, the firm produced Frati's F.4 Rondone after the war.

Again, it seems reasonable that Lombarda (or Ambrosini) might have taken Frati's torpedo bomber concept seriously. Any further info on this?


[* Relations between SAI Ambrosini and Aeronautica Lombarda were obviously pretty incestuous. Ing. Angelo Ambrosini was director of SAI, his brother Romolo Ambrosini started Aeronautica Lombarda. Stefanutti designed for both companies.]


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It seems to have some Japenese influence in the design.
It is interesting to observe the use of two Isotta-Fraschini, liquid cooled engines as the SIAI's fighters S-207 and S-407.
But is unlikely that this thing could go further in the caotic climax of 1942.

At that time there were too much projects coming togheter in Italy and few resources to produce them, not speaking about the fact that a lot of projects (espcially fighters) were concurrents and duplicated (or triplicated).
Taking, for example, the history of "5 series" fighters (MC 205V, G55 and RE2005).
Agreed archipeppe. From a Regia Aeronautica point of view, there'd be a host of reasons not to accept the Frati design. The SM.84 already existed and fighter-based torpedo carriers were in the works.

If a smaller torpedo bomber was desired, the CMASA AS.14 or CANSA FC.20 could have been adapted without impinging upon supplies of RC.21 engines.

Aeronautica Lombarda may also have been too small a firm to launch such a project. Mostly I was just curious to know if Lombarda might have tried it on anyway.


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Three observations: the S-207 and 407 fighter were from SAI, not SIAI. SIAI was charged to produce some 600 SAI-403 (never started).
The problem with Frati design wasn't that the situation was chaotic, it was that the Regia had already a lot of torpedo bombers projects up in the air, and no one produced to substitute the SM-79... (BZ-303, a Caproni, a SIAI, etc etc).
Frati and Aeronautica Lombarda hadn't a chance. Besides, by that time all aeronautical production was organized in "rings", linking a lot of companies on a little numer of projects (e.g. Centauro Rings, "anelli Centauro" to mass produce the G-55). The "5" series story is different from that, there was no intention to produce all 3. The 205V was mass produced only because the winner, G-55, was so late in series production. Besides this, the C-205V and G-55 would have been a fine couple: first excellent at low and medium height, G-55 at high height (above 8000 mts). Despite all was said, the Re-2005 was doomed. BTW, the real Macchi contender to the competition was the C-205N, but still the G-55 was better at altitude.
And the SAI fighters engine were Deltas III, air cooled. ;D
Cheers Skybolt -- I knew that you would know! ;D

So, as for "trying it on", you're saying that Aeronautica Lombarda was outside of those "rings"? If so (and all that pre-existing competition aside), it wouldn't have mattered if the firm had wanted to pursue the Frati design anyway.

Just from cowling appearance, I'm assuming that the Frati design would use the same Isotta-Fraschini Delta RC.21/60s as the SAI.207.

Re: the S-407 fighter. Excuse my ignorance. Was that an outgrowth of the SAI.207 or Dardo??
O-Oh all of you have right folks!!

S-207 and S-407 were SAI and not SIAI it was my mistaken and of course Delta was air-cooled.

Sorry again.... :'(
Apo, Aeronautica Lombarda AFAIK was in the Centauro ring, doing parts work. I'll have to check this night the work distribution.
Thanks Skybolt.

So ... Aeronautica Lombarda was in the Centauro ring but fairly far down the food chain.
Okay ... Aeronautica Lombarda to be counted among the bottom-feeders of the industry then. ;D

Skybolt, is there room for an SAI light fighters thread? The SAI-207 and -403 maybe don't qualify as "Secret Projects", but they're not all that well known (at least among us uni-ligual Anglos). For me, the SAI-407 is a complete mystery -- hint, hint. :D
Regarding the starting of a thread on the built SAI fighters, I cannot agree. This is a projects forum. But if you have new material, not already published everywhere, I think you can give a try in the General Aerospace section of the forum. Better still, why not a good discussion on the pre-war "light fighter" controversy ? There are a lot of poorly known airplanes, and a good number of projects too. Since it is one of those eternally returning themes, it would be a nice introduction for the youngsters and novices here on the way the old cats of secret projects love to entertain themselves with in the long winter nights.. ;)
I must correct myself :mad: ::) ;D
Aeronautica Lombarda wasn't in the Centauro rings, AVIA was, in the second one, that headed first by SIAI and then by Macchi. The second ring was composed then by: Macchi (program leader, final assemly and fuselage); CANSA (wings); AVIA (impennages). Probably, but I must check, AL was in one of the other rings (there were nine in total, three of them on the Centauro).
Skybolt said:
Uh, simply the 407 is a mistyping of 403 ... ;D ;D ;D

Aaahh ... mystery solved.

So, no project SAI-407, no need for a thread as you say.

And, if Aeronautica Lombarda wasn't in the Centauro rings, they are unofficially demoted from bottom-feeder to aviation industry bivalve status. ;D
Uh, I'd not be so malignant regarding AL status until checking the documents... this afternoon.
Checked: no space for AL in the late war production rings. The two Ambrosini brothers were really at odds.
Thanks Skybolt.

Personal friction between the Ambrosini brothers would explain why two smaller firms were maintained rather than officially joining forces.
I' am on the tracks of the Frati's master , thanks to the folks at the Milan Polytechnic's library, so maybe we'll have a 3-view rather soon...
My dear Apophenia,

the Ambrosini 400 series was completed after the war,and as I think it began
with SAI-401 and ended by NF-409,the later was developed from the Frati
F.15 aircraft.
I have noticed that Frati Torpedo Bomber concept seems built around Isotta Fraschini Delta
Yes. In reply #4, Skybolt identified the engines as Delta IIIs ... so, Delta R.C. 40-I (III Serie).
Hi FIAT CMASA AS.14 land base attack bomber.
AS.14 base was RS.14 seaplane.
Only one AS.14 was made in 1942 and tested.
Wing span, m 19.54, Length, m 14.10,
Wing area 40.00 m2
Mass, kg
empty aircraft 2650
normal takeoff 8150
Engine type 2 DD Fiat a. 74 RC 38
Power, HP 2 x 840
Maximum speed, km/h 420
Cruising speed, km/h 375
Range, km 2750
Service ceiling, m 5500
Crew, pers 3
Armament: one (45) 47 mm Breda cannon with ammunition in 36 rounds
five (two) 12.7-mm 0.303 machine guns and
one or two 7.62-mm machine gun Breda-SAFAT MACHINE GUNS
bomb load of up to 600 kg in bombootseke


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It seems to have some Japenese influence in the design.
It is interesting to observe the use of two Isotta-Fraschini, liquid cooled engines as the SIAI's fighters S-207 and S-407.
But is unlikely that this thing could go further in the caotic climax of 1942.

My dear Archippepe,

what was SAI.407 or S.407 ?.

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