Fiat Aero-Engine Designations

[Apophenia]

Fiat Aero-Engine Designations

When Fiat SpA entered aero-engine production in 1908, it had no dedicated aviation division. It was only when Fiat decided to build complete aircraft in 1916 that it founded the Società Italiana Aviazione. Fiat aero-engines were then branded as SIA products. In 1918, the generic SIA name [1] was ditched infavour of Fiat SpA, Divisione Aviazione - commonly known as 'Fiat Aviazione'.

In the 1920s did Fiat Aviazione's engine division become Fiat Motori (S.A. Fiat Motori d'Aviazione in its full form) with facilities at Torino and Firenze. In these early days, there were a range of designation styles and prefix letters. Here, we will cover the earliest Fiat aero-engine designations.

Early Fiat Engine Designation Styles

The earliest Fiat SpA aero-engine was the SA 8/75. The numbers refer to the number of cylinders in this air-cooled V-8 engine and the nominal output measured in Cavallo Vapore (CV or horsepower). [2] What the 'SA' prefix stands for is less obvious. Since the SA 8/75 was an aviation adaptation of a racing car engine, I'm tempted to suggest that 'SA" was for something like 'Speciali Aviazione' (Aviation Special) ... but I have no actual evidence for this wild guess.

Fiat/SIA's first production aero-engines were the S-series powerplants built primarily for dirigibles. Again, the 'S' may be for 'Speciali'. On the other hand, most of the S-series were limited- or pre-production engines ... so 'S' might also be for 'Sperimentali' (Experimental). The first suffix letter - A - could be added to S-series designations. That suggests 'A' for 'Aviazione' but, once again, I have no evidence to back up such a claim.

Early Fiat Engine Designation Style Anomolies

A designation prefix anomoly among dirigible powerplants was the N.16 (of which, as with the possibly-related D.16 engine, I can find no details whatever). A later designation anomoly was the 1930 Fiat A.N.1. That 6-cylinder diesel was physically based upon 4-stroke Fiat engines - the A.12bis (block) and A.22 (cylinder head). By then, 'A' series engine designations (covered in a later post) were well-established and yet the diesel was given its (to me) mysterious A.N. prefix. Why?

Fiat Aero-Engine Designation Style Presentation

There seem to be multiple styles presented for early Fiat aero-engine designations - even in contemporary sources. Engine designations will be seen rendered without spaces or 'punctuation'; with spaces; with full-stops; with hyphens in different locations; or in various combinations thereof. So, for example, early dirigible powerplants will be seen as 'S76A', 'S.76A', 'S 76A' or 'S76 A', 'S-76A' or 'S76-A', or in various combinations thereof. Mainly based upon what seemed to be the commonest presentation, I've fixed on S.76-A.

'Missing' Early Fiat Aero-Engine Designations

In the later Fiat A-series list, I will represent 'missing' designations in their numerical sequence. However, the 'gaps' are so huge with the earlier S-series designations, I have simply listed the designations that are know to me. Hopefully other forum members will be able to add to my rather skimpy list of early designations.

As always, all additions and corrections are highly valued and most welcome.

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[1] Ironically, in 1926, Fiat would combine newly-acquired Ansaldo with other absorbed aviation firms to create similarly-named Società Aeronautica Italiana (SAI).

[2] Technically, one Cavallo Vapore only equals around 0.99 horsepower. Since most sources round-off both horsepower and CV anyway, I've just used these measures interchangeably in my designation lists.

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Fiat Aviazione Aero-Engine Designations

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Anomolous Fiat Aero-Engine Designations

Fiat SA 8/75 - 1908 air-cooled 3.18L 90° V-8
- SA 8/75: Fan-cooled V-8, 50 bhp @ 2,000 rpm
-- SA 8/75 derived from Fiat racing car engine
-- https://upload.wikimedia.org/wikipedia/commons/1/1e/Fiat_A.8_motore_aeronautico.png

Fiat A.N.1 - 1929-30 water-cooled inline 6-cyl diesel
- A.N.1: 180 to 220 hp 16.625 L, 140 x 180 mm b/s
- A.N.1: Diesel deriv of A.12bis with A.22 head
-- Experimental A.N.1 tested on Fiat Ansaldo A.300
-- Some sources refer to the A.N.1 as the 'ANA' [1]
-- https://upload.wikimedia.org/wikipedia/commons/a/ae/FIAT_A.N._1.jpg
-- http://www.oldengine.org/members/diesel/duxford/aviat2.htm

Fiat A.N.2 - 193? liquid-cooled inline 6-cyl diesel
- A.N.2: Improved A.N.1 (no details)

Fiat D.16 - 19(??) inline 6-cylinder (no details)

Fiat N.16 - 19(??) dirigible engine (no details)


Fiat S-series Dirigible Engines


Fiat S.53 - 1909 water-cooled 60 hp 4-cylinder
- S.53-A: 65-to-80 hp, intended for airships
--Presented at 1909 Milan Aviation Exhibition

Fiat S.54 - 1915 water-cooled 80 hp 6-cylinder
-- 2 x S.56-A for Forlanini F.5 class M airship

Fiat S.55 - 1912 water-cooled V-8 (no details)
-- https://sirismm.si.edu/EADpdfs/NASM.XXXX.1183.B.pdf

Fiat S.56 - 19(??) water-cooled V-8 (no details)
-- https://sirismm.si.edu/EADpdfs/NASM.XXXX.1183.B.pdf

Fiat S.57 - (??) hypothetical designation
-- Poss. related to 1914 S.57-14B Corsa racing car?

Fiat S.61 - 19(??) 130 hp engine (no details)
-- Poss. related to 1905 S.61 Corsa, 10 L 4-cyl.?

Fiat S.71 - 19(??) water-cooled 4-cylinder (no details)
-- Poss. related to 190 hp 1911 Fiat S.71 Corsa?

Fiat S.76 - 1910-1911 water-cooled 29.48L 4-cylinder
- S.76 A: 190 x 250 mm bore/stroke, 200-280 hp
- S.76 A: 2 x 250 hp for Forlanini airship F.3 *
-- * each driving two variable pitch propellers
-- 2 x S.76 built as 200 hp racing car powerplants
-- http://jn.passieux.free.fr/images/Fiat_S76.jpg
-- http://jn.passieux.free.fr/html/Fiat_S76.php

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[1] In should be noted that, this this century, Università di Bologna experimented with adapting Fiat automotive diesel engines for use in light aircraft and helicopters. DieselJet of Forli used that UniBo research to create their Fiat-based TDA CR 1.9 8V and TDA CR 2.0 16V aircraft engines.

 

[Apophenia]

Fiat Aero-Engine Designations

'A' for Aviazione - Fiat A-Series Engine Designations

Compared with earlier Fiat aero-engine designation styles (above), the 'A' for Aviazione series is quite straightforward. For some reason, the A-series begins with the straight-six A.10 of 1914 ... with no evidence of any earlier, unbuilt aero-engine designs (or designations). Gaps in my list begin immediately with 'A.11' - marked as a place-holding 'hypothetical designation'. But, gaps aside, the A series list proceeds apace in a moreorless numeric chronology.

One oddity in the A-series designation style probably originates in the fact that all early A-series engines were water-cooled. Sometime before 1928, it was decided to commence designations for air-cooled Fiat powerplants at 'A.50'. So, liquid-cooled engines received designations between A.10 (1914) and A.44 (1944). Air-cooled engines began with the A.50 7-cylinder radial (1928) and progress to the A.84 RC.40 18-cylinder radial (1942-1943).

Fiat A-Series Engine Designation Suffixes

Fiat's 'A' for Aviazione designations accumulated a range of sub-type designator suffixes. The earliest was example was the A.12bis indicating a second variant - bis being Latin for 'twice'. Later on, bis would also be applied after sub-type letters (implying a variation on that sub-type).

Sub-type letters were applied alone and in combination. Some sub-type letters are distinct to Fiat engines while others are common to other Italian engine-makers or were applied on behalf of the Regia Aeronautica. First I will list the commonest Fiat engine sub-type letters known to me. These are:

AQ = Alta Quota or High Altitude [1]
C = Compressore or Supercharger
R = Riduttore or Reduction gear

Riduttore/Compressore - Supercharged Engines with Reduction Gears

Over time, the last two sub-type letters are frequently combined as geared, supercharged engines became the norm. Following Regia Aeronautica practice, 'RC' sub-type letters are commonly followed by rating numbers. These number gave rated power at altitude measured in 100 metre increments. So, an RC.40 suffix indicated a geared engine with single-speed supercharger producing the rated power output at 4,000 m. When 2-speed superchargers appears, the ratings were divided by a slash. So, an RC.14/50 suffix showed power outputs at 1,400 m in low supercharger speed and at 5,000 m in high supercharger speed.

One A-series suffix letter can confuse due to its variability - 'S'. In its earliest form as a suffix, 'S' stood for Spinto (eg: A.14 S). Most sources translated Spinto literally as 'pushed' but the inference is 'high performing' (the A.14 S powering the Fiat ARF long-range record attempt aircraft). [2]

In other cases, 'S' stood for Sperimentali (eg: A.20 S) but it could also stand for Sportivi or 'Sporting' (eg: A.50 S). To add further confusion, very late model radial engines could have 'S' added as a suffix letter to the suffix. So, there was an A.77 RC.24-52 'S' and an A.83 RC.24-52 'S' (along with an A.83 RC.24-52 'D'). But, other than slight engine variations, what these add-on suffixes referred to is a complete mystery to me.

Fiat A-Series Aero-Engines - More Mystery Suffixes

Here are the suffixes whose meanings have eluded me. Doubtless other forum members will have come across some of these suffixes and can fill in the gaps ...

Two earlier A-series engines received 'T' suffixes - the A.22 T and the A.24 T. Unfortunately, I lack details for both sub-types. The A.22 T first appeared in 1927 which is far too late for 'T' to be a reference to T-heads. [4] An obvious guess would be 'T' for Turbocompressore but, so far, I've found no evidence for turbochargers being trialled on Fiat aero-engines of this era. So, what on earth do this pair of 'T' suffixes stand for?

Another puzzle - for me at least - are the two 'RA' suffixes (eg: A.30 RA and A.30 RAbis). The 'R' for Riduttore is obvious but what about that 'A'? Could this indicated normally-aspirated (carburatore aspirato) as opposed to supercharged? [3] If so, why is this 'A' suffix omitted from other contemporary Fiat engine designations? And, in any case, why would a manufacturer draw attention to the absense of a supercharger? The Fiat A.30 series first appeared in 1930 - a time when superchargers were commonly offered on equivalent foreign engines.

Fiat Aero-Engine Designation Style Presentation

There seem to be multiple styles presented for Fiat aero-engine designations - even in contemporary sources. Engine designations will be seen rendered without spaces or 'punctuation'; with spaces; with full-stops; with hyphens in different locations; or in various combinations thereof. So, for example, early dirigible powerplants will be seen as 'S76A', 'S.76A', 'S 76A' or 'S76 A', 'S-76A' or 'S76-A', or in various combinations thereof. Mainly based upon what seemed to be the commonest presentation, I've fixed on S.76-A.

Using the same criteria, I've present later A-Series designations as A.xx. Finding a common presentation style for suffixes was trickier. For example, Riduttore Compressore might be seen as 'R.C.' or simply 'RC'. I've gone with the latter in the rare cases where altitude ratings are not listed (eg: A.30 RC). When altitude ratings are included, a full-stop is added simply to act as a divider between suffix letters and rating numerals. So, the 1933 A.30 RC prototype has no 'dot', while the A.33 RC.35 does. The alternative was the space-consuming and unweildy 'A.33 R.C. 35' ;P

'Missing' Fiat Aero-Engine Designations

As noted above, where designations seem to be 'missing' in the numerical sequence, I've included space holders. An example is:

Fiat A.13 - (??) hypothetical designation

The style of Fiat A-series designations doesn't make them all that search-engine 'friendly'. Doubtless I have glided over some search results without catching the odd gem. But most 'missing' designations are likely engine designs which never emerged or, at least, no mention of them was ever made in the popular aviation press of the day. In other cases, designations may have been reserved but never used or simply avoided (perhaps as in that 'A.13' ... do Italians consider 13 to be an unlucky number?)

Still other engine designs seem not to have been designated or, at least, those designations were not revealed in media coverage. An example is a Fiat concept for an aviation diesel engine. In 1926, Auto Moto Ciclo reported a novel Fiat engine - a 2-stroke 6-cylinder engine with 12 pistons (akin to Junkers Jumo diesels) and a patented supercharger. This concept engine was "derived from studies for racing cars, and intended for aviation." According to Nunzia Manicardi, [6] the proposed aero-engine was derived from the 1925 experimental tipo 451 racing engine trialled in the Fiat 806 racing car.

So, did that tipo 451 derivative ever receive an A-series designation? Might it be our 'missing' 'A.23'? Or, for that matter, did the Smithsonian get the contemporary A.21 'V-12' wrong? Was the A.21 actually been a 12-piston engine like our mystery diesel? Who knows? But maybe we'll find out some day.

Because I'm being long-winded, I'll put the actual A-series designation list in the post to follow. Okay ... bring on those additions and corrections

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[1] AFAIK, the experimental A.22 RAQ was unique in combining Riduttore and Alta Quota suffixes.

[2] With early Fiat automobiles, Spinto had racing connotations. Later on, special designations were devised for aviation racing - the Aviazione Spinto AS-series engines for Schneider Trophy races).

[3] It is also possible that the 'A' suffix referred to changes in fuel supply (alimentazione but, this too, is pure supposition.

[4] T-Heads come up a lot in references to the Fiat S.54. But that lumbering airship engine predates the A.22 T by more than a decade. As octane ratings rose in the second decade of the 20th Century, T-Heads lost their sole advantage - minimizing detonation when using early, low-octane aviation fuels.

[5] The Fiat AS.1 was a 1928 parasol tourer of then-typical mixed construction. The design began with Ansaldo which Fiat had just absorbed - hence the AS for 'Ansaldo Sport' designation.

[6] See: M.M. vuol dire Mario Mazzetti: Il costruttore, l’uomo, i record mondiali, le battaglie per la libertà, Nunzia Manicardi, Edizioni Il Fiorino, Modena, page 46

 

[Apophenia]

Fiat Aviazione Aero-Engine Designations

Fiat A (Aviazione) Series Liquid-Cooled Engines

Fiat A.10 - 1914 water-cooled 9.5L 6-cylinder
- A.10: Engine arranged in pairs of 3 cyl blocks
- A.10: 110 hp @ 400 rpm, 120 x 400mm bore/stroke
-- A.10 engine had a compression ratio of 4.5:1
-- http://www.century-of-flight.net/Aviation%20history/airplane%20at%20war/upload2/Fiat%20A-10.htm

Fiat A.11 - (??) hypothetical designation

Fiat A.12 - 1916 water-cooled 21.7L 6-cylinder
- A.12 : 210 hp at 1 400 rpm (sea level)
- A.12 : 160 x 180 mm, compr. ratio 4.5:1
- A.12bis: 300 hp, compression ratio 4.7:1
-- https://media.defense.gov/2007/Jan/10/2000522455/780/780/0/070110-F-1234S-022.JPG

Fiat A.13 - (??) hypothetical designation

Fiat A.14 - 1917 57.25 L 60° water-cooled V-12
- A.14: 720 hp at 1,700 rpm,* 1,500 built
- A.14: 170 x 210 mm bore/stroke, dry 750 kg
-- A.14 listed variously as 500 hp, 600 hp, ...
-- Largest, most powerful engine of its time
-- A.14 designed by Ing. Giulio Cesare Cappa
-- https://areeweb.polito.it/strutture/cemed/museovirtuale/image/memoria/photo/4201329.jpg
- A.14 S: (Spinto) 800 hp for the Fiat ARF
-- Spinto (pushed) ref. to performance

Fiat A.15 - 1918 400-450 hp water-cooled 60° V-12
- A.15 R: 120 x 150 mm bore/stroke, 6.78 litres
- A.15 R: 58mm (i.d.) prop shaft for machine gun
-- A.15 R: 4 x 3-cyl. forgings welded together
-- A.15 R designed by Ing. Giulio Cesare Cappa
-- https://www.flightglobal.com/pdfarchive/view/1920/1920%20-%200126.html

Fiat A.16 - (??) hypothetical designation

Fiat A.17 - (??) hypothetical designation

Fiat A.18 - 1919 9-cylinder water-cooled radial
- A.18 : 130 x 150 mm bore/stroke, displ. 17.919 L
- A.18 : 300 hp at 1,080 rpm, 320 hp at 2,000 rpm
-- https://www.flightglobal.com/pdfarchive/view/1920/1920%20-%200126.html

Fiat A.19 - 1929(?)* 9.782 L water-cooled V-12
- A.19 : Fitted with 2 x Roots superchargers
-- * Date seems late for desig., (no details)

Fiat A.20 - 1925 18.696 L 60° water-cooled V-12
- A.20 : 115 x 150 mm, compression ratio 5.7:1
- A.20 : 430 hp at 2,060 rpm s/l, 345 kg (dry)
- A.20 AQ: (Alta Quota) high alt., 430 hp at 1,750 m
- A.20 R: (Riduttore) 192? geared version
- A.20 S: (Sperimentali) 1928, 510 hp at s/l
-- A.20 designer was Tranquillo Zerbi

Fiat A.21 - 192? water-cooled V-12 (no details)
-- https://sirismm.si.edu/EADpdfs/NASM.XXXX.1183.B.pdf

Fiat A.22 - 1926 27.483 L 60° water-cooled V-12
- A.22 : 1926, 550 hp, 135 x 160 mm, 415 kg (dry)
- A.22 T: 1927, 570 hp at 1,900 rpm (sea level)
- A.22 AQ: (Alta Quota) 1926 high altitiude engine
-- A.22 AQ produced 570 hp, compression ratio 5.6:1
- A.22 S: (Sperimentali) 1928 580 hp experimental type
- A.22 R: (Riduttore) 1929 560 hp geared version
- A.22 RAQ: 560 hp experimental geared high-altitude type
-- A.22 designer was Tranquillo Zerbi

Fiat A.23 - (??) hypothetical designation

Fiat A.24 - 1931 32.327 L 60° water-cooled V-12
- A.24 : 1931, 700 hp at 2,050 rpm, 140 x 175 mm
- A.24 : Compression ratio 5.7:1 , 535 kg (dry)
- A.24 R: (no details, poss. same as A.26 R)
- A.24 T: 1935, 570 hp, direct drive (no details)

Fiat A.25 - 1928 1,000 hp V-12 (no details)
-- A.25 designer was Tranquillo Zerbi
-- Side-by-side double A.25 was proposed

Fiat A.26 - 1932 geared version of A.24 V-12
- A.26 R: 720 to 760 hp, 140 x 175 mm b/s
- A.26 R: For 1932 Fiat G.2 2-seat fighter project
-- A.26 R remained an experimental engine
-- A.26 R designer was Tranquillo Zerbi

Fiat A.30 - 1930 liquid-cooled V-12, AS.5 devel.
- A.30 : 24.047 L V-12, 135 x 140 mm bore/stroke
- A.30 : 550 hp at 2750 rpm @ 3,000 m, 94 octane
- A.30 R: 1930, experimental 600 hp engine
- A.30 RA: 1930 unsupercharged version
- A.30 RAbis: 1933, 700 hp (TO), 550 hp sustained
- A.30 RC: 1933 prototype, centrifugal compressor
-- A.30 RC: Experimental engine, not developed
-- A.30 designer was Tranquillo Zerbi

Fiat A.31 - (??) hypothetical designation
Fiat A.32 - (??) hypothetical designation

Fiat A.33 - 1934-35 supercharged A.30 devel't
- A.33 RC.35: 700 hp, centrifugal compressor
-- A.33 RC.35 was similar to earlier A.30 RC
-- http://www.flightglobal.com/pdfarchive/view/1934/1934 - 1252.htm

Fiat A.34 - (??) hypothetical designation
Fiat A.35 - (??) hypothetical designation
Fiat A.36 - (??) hypothetical designation
Fiat A.37 - (??) hypothetical designation

Fiat A.38 - 1939-41 34.58 L V-16 then IV-16 engine
- A.38: Advanced deriv. of AS.8 racing engine (qv)
- A.38: 138 x 145 mm, 1-stage. 2-speed compressor
-- A.38 RC.15/45: Est. 1,200 hp at rated altitude
-- A summary of A.38 development phases follows
- A.38: Mid-1939, upright V-16,* 3-bladed propeller
-- * Supercharger mounted aft of the engine block
- A.38: (??) 1940, IV-12,** 2-bladed contra-props
-- Regia Aeronautica preferred IV for fighters
-- ** Supercharger relocated below the engine block
- A.38: Mid-1941, as 1940 but with 1 x 3-blade prop

Fiat A.39 - (??) hypothetical designation

Fiat A.40 - 194? experimental X-24 engine
- A.40 RC.20-60: 2,100 hp (no details)
-- https://www.secretprojects.co.uk/forum/index.php?topic=14405.0

Fiat A.41 - (??) hypothetical designation

Fiat A.42 - (Project) 194? redesignated A.40
- A.42 : A.40 RC.20-60 (no details)

Fiat A.44 - 1941 experimental 135° X-32* engine
- A.44 RC.15-45: 69.4 L, 2,760 hp for take-off
- A.44: 138 x 145 mm b/s (as per A.38)
-- * Described by Skybolt as an 'H-32'
-- A.44 intended for CR.44 and BR.44 projects
-- A.44 designed by Ing. Antonio Fessia

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Fiat A (Aviazione) Series Radial Aero-Engines

Fiat A.50 - 1928 6.597 L 7-cylinder air-cooled radial
- A.50 : 100 x 120mm bore/stroke, dry weight 131 kg
- A.50 : Compression ratio 5.0:1, 100 hp at 1800 rpm
- A.50 S: (Sportivi) 1930 aerobatic A.50 development
-- A.50 S compression ratio 5.5:1, 105 hp at 2000 rpm
- A.50 R: (Riduttore) 1930 geared, 100 hp* at 1900 rpm
-- * Some sources list 110 hp for Fiat A.50 R
-- A.50 designer was Tranquillo Zerbi

Fiat A.51 - (??) hypothetical designation
Fiat A.52 - (??) hypothetical designation

Fiat A.53 - 1931 7-cyl radial, 110 hp @ 1,900 rpm
- A.53: Pre-series version of A.54 radial (below)
- A.53 derived from smaller Fiat A.50 7-cyl radial
-- Used in prototype Ca.100 (later repl. by A.54)
-- A.53 designer was Tranquillo Zerbi

Fiat A.54 - 1933 7-cyl radial, 140 hp @ 2100 rpm s/l
- A.54: 7.274 L, 105 x 120 mm, comp. ratio 5.5:1
- A.54 derived from smaller Fiat A.50 7-cyl radial

Fiat A.55 - 1932 7-cylinder radial
- A.55: 320 hp (no details)
-- A.55 designer was Tranquillo Zerbi
-- https://upload.wikimedia.org/wikipedia/it/4/48/Fiat_A.55_HP_320.jpg

Fiat A.56 - (??) hypothetical designation
Fiat A.57 - (??) hypothetical designation

Fiat A.58 - 193? double-row 14-cyl air-cooled radial
- A.59: Fiat-produced Gnome-Rhône 14K, disappointing
-- NB: Piaggio's P.XI RC.40 also based upon G-R 14K

Fiat A.59 - 1935 single-row 9-cylinder air-cooled radial
- A.59 R: Fiat-produced Pratt & Whitney Hornet
- A.59 R: Developed 690 hp at altitude of 2,000 meters
-- Powered Fiat APR.2, G.18, and prototype CR.40bis

Fiat A.60 - 1932 6.560 L air-cooled 4-cylinder inline
- A.60 : 120 x 145 mm b/s, 135 hp at 2,200 rpm *
- A.60 : Compression ratio 5.75:1, dry weight 135 kg
-- * Some sources - 142 hp at 2,400 rpm at sea level
- A.60R: 1933 geared version, 145 hp at 2,500 rpm**
-- ** Shaft rpm, propeller rotation ~ 1580 rpm

Fiat A.61 - (??) hypothetical designation
Fiat A.62 - (??) hypothetical designation
Fiat A.63 - (??) hypothetical designation
- Jane's lists '840 hp Fiat A.63', A.74 typo?
-- Jane's Encyclopedia of Aviation, Volume 4

Fiat A.70 - 1934 7-cyl air-cooled radial,
- A.70: 1934, 205 hp at 2000 rpm
- A.70 S: Higher compression 200 hp* engine
-- 200 hp Fiat A.70 powered Breda Ba.42, eg
-- * Jane's 1938 lists as 180 hp 'A.70/S'**
-- ** 180 hp 'A.70/S' powering Nardi FN.310
-- A.70 designer was Tranquillo Zerbi

Fiat A.71 - (??) hypothetical designation
Fiat A.72 - (??) hypothetical designation
Fiat A.73 - (??) hypothetical designation

Fiat A.74 - 1935 31.25 L 14-cyl air-cooled radial
- A.74 : 730-920 hp, 140 x 145 mm bore/stroke
- A.74 : Compression ratio 6.7:1, 590 kg dry
-- Fiat's A.74 based on licensed P&W R-1535
- A.74 RC.18: 900-920 hp RA service engine
- A.74 RC.38: 840 hp RA service engine
- A.74 RC.40: (no details)
- A.74 RC.42: 1940, 770 hp (sea level?)
-- Power: 858 hp at 2,520 rpm for TO
-- Power: 730 hp at 2,520 rpm, sea level
-- Power: 828 hp at 2,400 rpm, continuous
-- Power: 739 hp at 2,400 rpm, cruising
-- Power: 858 hp at 2,520 rpm
-- A.74 designed by Zerbi & Antonio Fessia

Fiat A.75 - 1940-41 A.74 RC.42 development

Fiat A.76 - 1940-41 air-cooled 14-cylinder radial
- A.76 : More powerful A.74 RC.42 development
- A.76 RC.40: 1,000 hp at 4,000 m
-- A.76 intended for G-50ter, Macchi C.201
-- A.76 devel. abandoned early-to-mid 1941

Fiat A.77 - 1945 14-cyl 2-row air-cooled radial
- A.77 RC.24-52 'S' - 1,100 hp

Fiat A.78 - 1935 (no details)

Fiat A.79 - (?) hypothetical designation

Fiat A.80 - 1935 45.7 liters, 751 kg (1655 lbs),
-- A.80 designer was Tranquillo Zerbi
- A.80 RC.20: 1,200 hp
- A.80 RC.41: 1,000 hp, for Fiat BR.20M
- A.80 RC.42: 1,000 hp, for SAI Ambrosini A.R.

Fiat A.81 - (?) hypothetical designation

Fiat A.82 - 1941* 47.1 L air-cooled 14-cyl radial
- A.82 RC.100: 900 hp stratospheric vers. for C.9
- A.82 RC.40 : 1,300 hp for the Fiat BR.25
- A.82 RC.42 : 1,250 hp for the Fiat BR.20bis
-- * Oct 1937 studies, bench runs Nov 1938

Fiat A.83 - 1942-43 14-cyl 2-row air-cooled radial
- A.83: Vortice, A.82 w/ 2-speed compressor
-- Intended for G.52, BR.30, R.23, and CZ.1018
- A.83 RC.24-52: 1,550 hp, intended for Fiat G.57*
-- A.83 RC.24-52 offered in 'D' and 'S' versions
-- Some sources list 18-cyl (conf. with A.84?)
-- * Orig. G.52, also BR.30, R.23, and CZ.1018

Fiat A.84 - 1942-43 18-cyl 2-row air-cooled radial
- A.84 RC.40: 1,700 hp (no details)

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Fiat AS (Aviazione Spinto) Series Aero-Engine Designations

As noted earlier, spinto translates literally as 'pushed'. But, here, it really refers to 'high performing' with racing connotations. The designations for Fiat's 'AS' racing engines are straightforward and I've found no evidence of sub-type suffixes or the like within this series. However, there are a few 'missing' designations as well as a puzzle.

The Fiat AS.2 V-12 racing engine for the Macchi M.39 appeared in 1926. Logically, one would assume that this AS.2 V-12 was preceded by an 'AS.1' engine. There was a 1928 aircraft designated AS.1 - in that case, the designation stood for 'Ansaldo Sport'. [5] Later, a metal-construction variant of this aircraft was designated AS.2. So, since we know there was also Fiat AS.2 engine, the existence of an aircraft designated AS.1 does not preclude an 'AS.1' powerplant design.

Other 'missing' Aviazione Spinto designations are the 'AS.4' and 'AS.7'. Those, like the 'AS.1', have been listed here as hypothetical designations.

Aviazione Spinto Series Air-Racing Engine Designations

Fiat AS.1 - (??) hypothetical designation

Fiat AS.2 - 1926 31.84 L water-cooled 60° V-12
- AS.2: Schneider engine for Macchi M.39/M.52
- AS.2: 140 x 170 mm b/s, 850 hp @ 2,500 rpm
-- Magnesium pistons, steel cyl, aluminum heads
-- Enlarged Fiat A.22T inspired by Curtiss D-12
-- AS.2 designer was Tranquillo Zerbi
-- http://en.wikipedia.org/wiki/Fiat_AS.2

Fiat AS.3 - 1927 34.60 L water-cooled 60° V-12
- AS.3: 1927 Schneider engine for Macchi M.52
- AS.3: 1,000 hp @ 2,400 rpm, 145 x 175 mm b/s
- AS.3: Compression ratio: 6.7:1
-- Larger displ. but same frontal area as AS.2*
-- * Accomplished by shortening connecting rods
-- AS.3 designer was Tranquillo Zerbi

Fiat AS.4 - (?) hypothetical designation

Fiat AS.5 - 1929 28.545 L water-cooled 60° V-12
- AS.5: For 1931 Schneider in Fiat C.29 racer
- AS.5: 138 x 140 mm bore/stroke, 1,000 hp
-- Reduced-scale, higher-compression AS.3*
-- * Compression ratio: 8:1 (vs AS.3's 6.7:1)
-- AS.5 designer was Tranquillo Zerbi

Fiat AS.6 - 1934 50.256 liquid-cooled 60° V-24
- AS.6: Designed in 1931, coupled Fiat AS.5*
- AS.6: 3,100 hp @ 3,400 rpm s/l, 138 x 140 mm
-- Single-stage compressor, comp. ratio 7:1
- * Tandem blocks, 2 x cranks, gearing between
-- AS.6 designer was Tranquillo Zerbi
-- https://oldmachinepress.files.wordpress.com/2012/10/fiat-as6-side-view1.jpg

Fiat AS.7 - (?) hypothetical designation

Fiat AS.8 - 1939-40 V-16 racing engine
- AS.8: 8.62 L, 'square' 140 x 140mm bore/stroke
-- Unlike twin-crank AS.6, only one crankcase*
-- * Driving contra-props via reduction gearbox
-- Intended for Fiat-CMASA CS15, a few built
-- 2,250 hp approx. at sea level at 3,200 rpm
-- Intended for CMASA CS.15, Dry weight: 790 kg
-- https://oldmachinepress.com/2014/07/23/fiat-as-8-engine-and-cmasa-cs-15-racer/
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RA-Series Aero-Engines Produced by Fiat

The RA.1050 RC.58-I Tifone was, of course, Fiat's licence-built version of the German Daimler-Benz DB 605A-1 inverted V-12 engine. But, does anyone know that the 'RA' prefix actually stands for? Since the Tifone was a licence-build, I'm guessing that RA.1050 was not an internal Fiat designation. The designation style is consistent with the Alfa Romeo-produced RA.1000 R.C.41-I Monsone (DB 601A). That makes me think 'RA' may stand for the client - the Regia Aeronautica.

So, if 'RA' was for 'Regia Aeronautica', 'RC.58' for 'Riduttore Compressore' at 5,800 m, and 'I' was for 'Invertita' (inverted), what did the number '1050' signify?

For completeness, it should be mentioned that there were wartime plans for the RA.1050 RC.58-I to also be built by another Fiat subsiary. Fiat-CANSA was intended to produce a version of the RA.1050 RC.58-I at a new facility at Baraggia - the firm's first venture into aero-engine production. In the end, no Tifone engines were ever built by CANSA. CANSA did, however, produce an aero-engine in 1942. This was a small, air-cooled, inverted 4-cylinder aero-engine designated C80 (presumably signifying 'C' for CANSA and '80' for the engine's output in CV).

Fiat RA-Series Aero-Engine Designation

Fiat RA.1050 RC.58-I: 1943-44 licence-built DB 605A-1
- RA.1050 RC.58-I: Tifone, about 1,750 built

 

[Apophenia]

Fiat Aviazione Jet Engine Designations

Fiat Aviazione turned its attention to original jet engine designs in 1953. The firm's first forays into such engines began a few years earlier with licence-built British de Havilland centifugal-flow turbojets. Fiat applied internal designations to these de Havilland products - the DH Ghost becoming the Fiat Model 4000 while the DH Goblin became the Fiat Model 4001.

The first original Fiat turbojet was another centrifugal compressor design. As such, this original design received a designation - Fiat Model 4002 - following on from the similarly-configured Model 4000 and 4001. Prototype engines received distinct, numeric suffixes. In the case of the Model 4002, these were the first prototype 4002.000 followed by the revised 4002.001.

So, centifugal compressor engines received Fiat designations in the Model 400x series. Axial-flow engine production led to a change in nomenclature with the Fiat 402x series designations - eg: the Model 4023 and 4024, both licence-built Bristol-Siddeley Orpheus. It may be that Fiat reserved its Model 402x series for licenced designs (although that would have broken with the earlier pattern of the Models 4000 and 4001). Regardless, the next know designation is for the Model 4032, a Fiat-designed axial-flow turbojet in roughly the same performance class as the the licenced Orpheus engines.

I've found no evidence for Fiat 'Model 410x' or '420x' series engine designs. The next series known to me is the Fiat 430x series designations covering propeller-turbine designs - eg: the Model 4301 (an interesting design with PT6A parallels). That Model 4301 is the only Fiat turboprop design that I have found ... but the designation suggests a missing 'Model 4300' concept. Perhaps there were others?

I can find no mention of Fiat Model '440x', '450x', or '460x' series designations. The next known designation is the Fiat Model 4700 - a gas generator for Fiat's Model 7002 cold-jet helicopter.

The Model 4700 was vertically-mounted, turbine-driven compressed-air generator. At the bottom of this 'stack' was a turbojet evolved from the Model 4002. Above this 'primary engine' (and mechanically independent from that turbojet) was the actual compressor. The object of the Model 4700 was to supply compressed air to the 'cold' tip-jets at the ends of the Fiat 7002 helicopter's twin-bladed rotor.

Neither the Fiat 7002 helicopter nor the Model 4700 compressor amounted to much. However, the Model 4700 was the progenitor of both the Model 4301 turboprop and the Model 4004 turbojet designs (the former, in particular, probably deserving a better fate). And those lineages serve to illustrate that Fiat turbine designations were arranged in their type 'silos', not arranged chronologically.

There is a possible alternative explanation for some of the 'missing' designations. Fiat assigned type designator numbers - the first two numerals in their designation - followed by model numbers - the next two numerals. It may be that Fiat grouped model numbers within related 'families' of designs rather than sequentially within their type 'silo'. In other words, 'family' groups trumped conceptual relationships.
This is, of course, pure speculation ... and it may not prove particularly helpful to us.

In the case of the Model 4700, this gas generator would represent the 'zero' design. The turboprop spin-off Model Model 4301 would be the 'one' design. But what are the 'two' and 'three' designs? The next known spin-off was the Model 4004 turbojet derivative. So, even if this Fiat designation style suppositon were correct, it creates more designation 'gaps' than it fills!

Hopefully, other forum members can answer some of these questions and help fill in some of those yawning designation chasms.

Licence-Built Turbine Engines Without Fiat Designations

Over the years, Fiat Aviazione - later Fiat Avio and now Avio - built a host of turbine engines under licence. In contrast with the two de Havilland products mentioned above, such engines never seem to have received a Fiat or Avio designation.

In the 1950s, Fiat Aviazione entered into agreements with the US General Electric and Pratt & Whitney firms for the production of turbojet components. In the 1960s, collaboration relations were intensified with GE and with Rolls-Royce for aero-engines. Yet none of the jet engines produced under these agreements received Fiat designations.

In some cases, the lack of Fiat designation may reflect a group effort or consortium involved in engine production. An early example would be Fiat's licence-built General Electric J79 axial-flow turbojets. Fiat is usually listed as the builder of these engine but this was actually a consortium effort involving Fiat Aviazione, Alfa Romeo Avio, FN of Belgium, and BMW of Germany. [1]

One other Fiat Aviazione turbine deserves mention - the more recent FA 150 Argo. [2] This is a small, twin-spool, centrifugal-flow engine which acts as an APU for the AMX attack aircraft. This modular engine was originally meant to form the basis for new family of small turbines (for the light aircraft and RPV/UAV markets). Although still on offer from Avio, I have omitted the FA 150 from this listing because its design actually originated with Plessey in the UK. [3]

The corporate name shifted twice during the firms involvement with the FA 150 Argo. In 1989, Fiat Aviazione became Fiat Avio SpA (sometimes rendered as a space-less FiatAvio). Then, in 2003, the cash-strapped Fiat Group sold off Fiat Avio SpA - which became simply Avio SpA. [4]

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[1] For the record, the Fiat-built J79-GE-11A engines were for F-104G [/i]Starfighter[/i]s, the J79-GE-19 were for the AMI's F-104S.

[2] Oddly, the Argo designation overlaps with that of the Fiat Allis FA 150 bulldozer. In the case of the Argo, the FA 150 stands for Fiat Aviazione (or Fiat Avio) and engine power output.

[3] Avio also currently lists an 'APU 36-170'. This is simply the Avio-built Honeywell 36-170 APU for the Eurofighter Typhoon.

[4] The irony was that, in 1996, Fiat Avio had aquired a controlling stake in Alfa Romeo Avio from Finmeccanica. Then, in 2003, Fiat Avio SpA was sold to a consortium which included Finmeccanica SpA.

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Fiat Aviazione Turbine Engine Designations

Fiat 400x Series Turbine Engine Designations

Fiat 4000 - Licenced de Havilland Goblin 35
- Model 4000: Length 2.718 m, diameter 1.27 m
- Model 4000: 3,500 lbf @ 10,200 rpm, 703 kg (dry)
-- Eg: Fiat G.80-3B trainer,* Fiat FB.52A Vampire
-- * As well as the first prototype Fiat G.80-1B

Fiat 4001 - Licenced de Havilland Ghost 48-1
- Model 4001: Length 3.31 m, diameter 1.34 m,
- Model 4001: 4,850 lbf @ 10,250 rpm, 986 kg (dry)
-- Eg: SNCASE Aquilon, French-built Sea Venoms
-- https://www.flightglobal.com/FlightPDFArchive/1954/1954%20-%201012.PDF

Fiat 4002 - 1953-56 centrifugal-compressor light turbojet
- Model 4002: Company-sponsored single-stage turbine
- Model 4002: Length 0.828 m, diameter 0.57 m, 88-100 kg
- Model 4002: Two prototypes - 4002.000 and 4002.001
- 4002.000: 595.0 lbf @ 25,000 rpm, wt 100 kg (dry)
- 4002.001: 716.5 lbf @ 25,000 rpm, wt 88 kg (dry)

Fiat 4003 - (??) hypothetical designation

Fiat 4004 - 1960 light turbojet, based on Model 4700
- Model 4004: 618 lbf @ 25,000 rpm, 89.8113 kg*
-- * 4004.001 weight, 4004.001 was 50.35 kg heavier
- Model 4004: Two prototypes - 4004.000 & 4004.001
- 4004.000: Length 0.92964 m, diameter 0.5699 m
-- 4004.000 retained orig. Model 4700-style air intake
- 4004.001: Length 0.9525 m), diameter 0.569976 m
-- 4004.001 repl. 4700 intake w/ conventional style
-- https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%200996.PDF
-- https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%200988.PDF

Fiat 4005 - (??) hypothetical designation

Fiat Axial-Flow Turbojet Engine Designations

Fiat's Lingotto plant began production of licensed Bristol-Siddeley Orpheus BOr.803 turbojets in 1959. Deliveries began in 1960 of what Fiat designated its Model 4023 for use in the NATO standard Fiat G.91R ground-attack aircraft. These were followed by the Fiat Model 4024 - for the Fiat G.91T - with an added fire detection system. Fiat's Orpheus production ran until 1965.

Since the Orpheus was the first axial-flow turbojet produced by Fiat, these engines received new 402x series designations. However, I've found no evidence of Model 4020, 4021, or 4022 axial-flow turbojets.

Fiat 402x Series Turbine Engine Designations

Fiat 4020 - (??) hypothetical designation
Fiat 4021 - (??) hypothetical designation
Fiat 4022 - (??) hypothetical designation

Fiat 4023 - Licenced Bristol-Siddeley Orpheus BOr.803
- Model 4023: Orpheus turbojet for Fiat G.91R 'Gina'

Fiat 4024 - Licenced B-S Orpheus BOr.803-02 turbojet
- Model 4024: Orpheus turbojet for the Fiat G.91T
- Model 4024: Fire detection system added to Model 4023

Fiat 403x Series Turbine Engine Designations

The first original axial-flow turbojet design from Fiat was the Model 4032. This engine was intended primarily as an Orpheus replacement - for future advanced versions of Fiat's G.91 and any other Orpheus-powered aircraft. Emphasis was on "trouble-free" operation. It was hoped that such reliability would also provide a place for the Model 4032 in the civilian aircraft market.

The Model 4032 was actually a turbojet development of the Model 4700 (q.v.). In effect, the gas generator component of the Model 4700 was removed and replaced by a simple propulsion nozzle. The 4032 designation suggests missing 'Model 4030' and Model 4031' designs. [2]

Fiat 4030 - (??) hypothetical designation
Fiat 4031 - (??) hypothetical designation

Fiat 4032 - 195? Fiat-sponsored single-shaft* turbojet
- Model 4032: 5,952 lbf @ 8,200 rpm, 489.8798 kg (dry)
- Model 4032: Length 2.56032 m, diameter 1.070102 m
-- * 9-stage compressor & 10-tube combustion chamber
-- Model 4032 intended as an Orpheus replacement**
-- ** Model 4032 meant for both military and civil use
-- https://www.flightglobal.com/FlightPDFArchive/1959/1959%20-%200805.PDF

Fiat Model 4032 axial-flow turbojet

Fiat 430x Series Turbine Engine Designations

The Fiat 430x series designations cover propeller-turbine engine designs - eg: the Model 4301. The 4301 is the only Fiat turboprop design that I have found. Based on a Fiat Model 4700 core, this turboprop was a contemporary of the well-known PT6A. [1] Like that P&WC engine, the Fiat Model 4301 was a reverse-flow, free-turbine turboshaft-drive (with an added axial-flow turbine 'downstream' to drive the propeller reduction gears).

Fiat 4300 - (??) hypothetical designation

Fiat 4301 - 1960 turboprop deriv. of Fiat Model 4700
- Model 4301: Free-turbine shaft-drive 4700 deriv.
- Model 4301: (no details) [3]
-- https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%200988.PDF

Fiat 470x Series Turbine Engine Designations

The Fiat Model 4700 gas generator was designed to supply cold compressed air to the tip-jets of the Fiat Model 7002 helicopter. The Model 4700 was arranged vertically with a turbojet [4] at the bottom and a separate compressor unit above. The Model 4700 formed the basis for the shaft-drive Model 4301 turboprop and the Model 4004 turbojet (effectively a Model 4700 without its compressor unit).

Fiat 4700 - 1960 cold tip-jet compressor/drive
- 4700: 610 gas hp (T/O), 505 ghp continuous*
- 4700: Length 1.30 m, diameter 0.61 m, 152 kg
- 4700: Based upon Fiat 4002-derived turbojet
-- * Some sources say 500 ghp continuous
-- Powered Fiat 7002 helicopter prototype [5]
-- https://www.flightglobal.com/FlightPDFArchive/1960/1960%20-%200378.PDF
-- https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%200997.PDF

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[1] It might be more accurate to say that Fiat's Model 3201 was contemporary with the December 1958 DS-10 design study which led to the PT6A. The Fiat Model 3201 would have been in the same class as the similar PT6A and the established Turbomeca Astazou.

[2] As noted above, the alternative explanation was that Fiat group 'type' designations into related 'families'. If true, in this case, we have the 'zero' (4700), 'one' (4301), and 'four' (4004), but are lacking the 'two' and 'three'.

[3] Some Model 4301 specs would have been the same as (or similar to) those of its Model 4700 progenitor and its sibling Model 4004 turbojet.

[4] The axial-flow turbojet component of the Model 4700 gas generator shared some components with the less advanced Model 4002 centrifugal-flow turbojet.

[5] The sole Fiat Model 7002 jet-tip helicopter prototype first flew on 26 January 1961.

 

[Apophenia]

FiatAvio and Avio Rocket Engine Designations

Shortly before Avio SpA became an independent company, FiatAvio began a developmental program for advanced composite-construction space-launcher stage and booster rocket motors. It's a stretch, but I've used this FiatAvio's technology demonstrator involvement as a justification for including Avio SpA rocket motor programs.

These programs will be divided up into Avio air-defence missile rocket motors - Aster 30 and CAMM-ER - and actual space-launcher motors. The latter will be presented by 'family' - the 'P' series (Vega C first-stage motors for the Vega launchers and now boosters for the Ariane 6) and the Zefiro or 'Z' series (second- or third-stages for the Vega). Both 'P' series and Zefiros are solid-fuel rocket motors with composite bodies (of filiment-wound carbon epoxy construction).

For the latest Avio P120C ('Common') motor for the European Space Agency (ESA), Avio partnered with Airbus through a joint venture company - Vegaspazio ('Vega Space'). Originally, Vegaspazio was established as a JV between FiatAvio and Aerospatiale to be prime contractor on the ESA Step 1 development contract. That, ultimately, led to the Avio P120C via the unrealized P100 project.

France's ONERA (Office National d'Etudes et de Recherches Aérospatiales) tested a series of sub-scale rocket motor 'families' representing the Avio P230. Test-fired horizontally, these model families were the:
- LP6 : 1/15 scale realistic representations of the Avio P230
- LP9 : 1/35 scale simplied representation of the Avio P230
- LP10: 1/35 scale realistic representations of the Avio P230

I have not included the LP series as designation because there is no sign of direct involvement by Avio.

A more dramatic joint project is that between Avio and KBKhA of Russia. This partnership is for the development of a cryogenic rocket motor - the Mira LM-10. Mira (aka 'Myra') is essentially a RD-0146 motor modified for liquid oxygen-methane fuel (aka LOx-LNG or LOx-Methane). The 73.5 kN thrust Mira motor will form the VUS (Vega Upper Stage) of the ESA's Vega-E (Vega Evolution) launcher. Avio has constructed the 3.0 m long Mira-D turbo pump (TP LOx) will assemble the Vega Upper Stages complete with LM10-Mira motors.

Avio's name is also associated with AVUM, the current fourth-stage for the Vega series. I have included the Avio APM (Attitude Vernier Upper Module, Propulsion Module) although I'm not sure if Avio has anything (beyond assembly) to do with the actual rocket motor - a Ukranian liquid bi-propellant (NTO/UDMH) rocket motor, the Yuzhnoye RD-869 which produces 250 kgf of thrust for manoeuvring in orbit.

For the actual orbital launch vehicles, I've simplified presentation. Where I have used 'Vega', it should properly read as the acronym VEGA (for Vettore Europeo di Generazione Avanzata or Next Generation European Launcher). The LM-10 names is often rendered as MIRA but, AFAIK, Mira is not an acronym.

Doubtless there are ommissions obvious to those more knowledgeable than me in this area - which is to say, almost everybody! Corrections and additions are most welcome.

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Avio Air-Defence Missile Rocket Motors

Avio SpA is a components supplier for the MBDA Aster program, including complete Aster 30 booster rockets. The original motor has a composite carbon epoxy body and moveable nozzles. This motor may be replaced by the PW216 rocket with metallic rather than filament-wound composite body.

Aster 30 first-stage booster and components for the second-stage sustainer are built at the Avio facility at Colleferro-Rome. The name Aster comes from the mythical Greek archer, Asterion.

Unconnected with Aster is another air-defence missile, the CAMM-ER. The Common Anti-air Modular Missile is a British program but the CAMM-ER - for Extended Range - began as an exclusively Italian program. (the Spanish are now a CAMM-ER customer). Avio has been contracted to build the CAMM-ER rocket motor.

Thus far, I have been unable to find Avio designations for either the Aster 30 or CAMM-ER rocket motors. I am guessing that the Aster 30 first-stage designation might relate to its proposed replacement - the PW216 - but I just don't know. Can anyone help?

Avio Air-Defence Missile Motor Designations

(??) - Aster 30 first-stage booster motor
- (??) : 338 kg solid-propellant rocket motor*
-- Constr. of filament-wound thermoplastic mat'l
-- Usually ref. to simply as First-Stage Booster
-- * Thrust-vectoring in initial flight stages
-- L 2.28 m, diameter 38.0 m, burn time: 3.6 sec.
-- Avio also makes parts for 2nd stage sustainer**
-- ** Second stage assembled by Roxel in France
-- http://www.aiad.it/aiad_res/cms/documents/AVIO_Aster30_2017.pdf
-- http://www.avio.com/en/tactical/aster-30/aster-30-first-stage-booster/

PW216 - Aster 30 first-stage booster motor
- PW216: Metallic-bodied version of rocket motor*
-- * As opposed to thermoplastic original vers.
-- 2010 - PW216 prototypes for acceptance trials
-- PW216 developed and supplied by OMS S.r.l.
-- https://www.officineoms.com/wp-content/uploads/2018/07/programma-pw-216-400x533_c.jpg

(??) - CAMM ER solid-propellant rocket motor
- (??): Next-gen ADM motor, bench-tested 2015
-- Common Anti-air Modular Missile-Extended Range
-- Under devel. with MBDA for the Italian MoD
-- http://www.avio.com/en/tactical/camm-er/

 

[Apophenia]

FiatAvio/Avio SpA Space Launcher Rocket Motors

Avio APM - Vega Upper Stage Manoeuvring Rocket Motor

As noted in the introduction, Avio SpA assembles AVUM (Attitude Vernier Upper Module) components including the manoeuvring section - the APM (AVUM Propulsion Module). However, the actual motor is of Ukrainian origin and may receive no Avio input beyond assembly.

Avio APM - ESA [i[Vega[/i] launcher fourth-stage rocket
- APM : Liquid bi-propellant (NTO/UDMH) rocket motor*
-- * Manoeuvring (oribital positioning/attitude control)
-- * Using a 250 kgf Ukranian Yuzhnoye RD-869 engine
- APM : Attitude Vernier Upper Module, Propulsion Module
- Lighter AVUM+ has 0.74 t propellant mass, 2.45 kN thrust
_____________________________________________________

Avio 'P' Series Space Launcher Rocket Motors

The 'P' series rockets are primarily first-stage motors for space launchers. [1] The key features of the 'P' series are: lightweight carbon-epoxy cases, EPDM thermal insulation (with glass microspheres), HTPB 1912 composite propellants, and flexible-joint moving nozzles (by Snecma).

I'm not clear on what the 'P' in this series stands for. My guess is that 'P' is for Propulsione. However, since the 'P' series are first-stages, 'P' may be for prima fase or fase primária. Then again, Avio may simply have inherited the 'P' designations from the original French orbital launch vehicle program's nomenclature. [2]

For some reason, the suffix 'FW' (for 'Filament-Wound') is often tacked on to the P80 designation. This is odd since all recent Avio solid-fuel rockets feature similar filament-wound carbon epoxy case construction. In academic works, 'P80 FW SRM' is often used - adding a seemingly self-evident 'Solid Rocket Motor' at the end. (Perhaps the writers of such papers think that fluffing up the designation makes their work seem more impressive?)

Variation in spacing is surprisingly common. For example, one will see 'P80FW' and 'P80 FW' within pages of each other in the same ESA document. On occasion, 'rogue' hyphens also find their way into designations - eg: 'P-80' - but this form not used by Avio itself. Also seen are unofficial 'designations' which more closely match the actual solid propellent - such as 'P88' for the P80 to more closely match its 88.365 tonne fuel mass.

To add to the confusion, the smaller Zefiro are often mis-assigned 'P' designations in place of 'Z' - eg: 'P7' (Z7), 'P9' (Z9 or Z9A), 'P16' (Z16), 'P23' (Z23), and 'P40C' (Z40). In some cases, the various forms are randomly lumped together - eg: 'P16 Zefiro' (sic).

So far, the only designation suffix is the 'C' in P120C. [3] Some reports have linked this 'C' with the Vega C launcher designation. That is not the case. In the Vega C designation, 'C' is for 'Consolidation'. In the P120C, the 'C' stands for 'Common'. That is, the P120C is the 'Common' motor for both the Vega C first-stage as well as acting as boosters for the Ariane 6 launcher. [4]

Avio P40C - (??) Prob. confusion with Z40 (qv)
- P40C: aka P36, seen in discussions of Vega L
-- Likely a notional VUS size for 'Vega Light'

Avio P80 --- ESA Vega first-stage booster rocket
- P80: L 11.714 m; diameter 3.005 m; 7,330 kg dry
-- P80 first test-fired 30 Nov 2006, CSG Kourou
-- aka 'P88' from 88.365 tonne propellant mass
- P80 FW: Vega 1st stage, later repl'd by P120C
- P80 FW: L 11.20 m, diameter 3.0 m, burn 114.3 s.
- P80 FW: Maximum thrust 230.56 t (sea level)

Avio P85 --- (Project) Orig. ESA Vega first-stage
- P85: Reduced mass Ariane 5's P230 (qv)
- P85: Lower-risk, two-segment* metallic case
-- * Fore/aft domes unchanged from P230 design
-- P85 soon eclipsed by high-technology P80 FW

Avio P100 -- (Project) Vega-E first-stage motor
- P100: aka 'P-100', ~100 tonnes of propellant
- P100: First-stage on 3- and 4-stage Vega-Es
-- Vega E (Evolution) in VENUS studies*
-- German 'Vega New Upper Stage' of July 2009

Avio P120C - 'Common' ESA solid-fuel rocket motor
- P120C : Vega C first-stage/Ariane 6 boosters
-- Ariane 6-2 (2 boosters) & 6-4 (4 boosters)
- P120C : 4,500 kN (1,011,375 lbf) average thrust
- P120C : L 11.70 m m,* diameter 3.40 m, burn time 132.8 sec.
-- * Some sources list P120C length/height as 13.50
-- P120C contains 141 tonnes of solid propellant*
-- Some sources list 143,600 kg capacity for P120C
-- Casing structure of filament-wound carbon fibre
-- The 'C' in P120C stands for 'Common'
-- ASL (Airbus Safran Launchers) partnered for P120C

FiatAvio P230 - 1966 Ariane 5/'G/'Gp/'GS solid-fuel booster
- P230: L 31.00 m, diameter 3.00 m, burn time: 123 seconds
-- aka Ariane 5-0 and SPB235, created with SNPE of France

Avio P241 - 2002 Ariane 5 EAP solid-propellant booster
- P241: L 31.60 m, diameter 3.05 m, burn time: 130 seconds
-- Lighter case* (-1.6 metric tonnes) compared to P230
-- * Welded case and larger 2.43 tonne+ propellant load
-- aka Ariane 5-0 P241

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[1] A seeming fly in my summary ointment is the Avio P40C. However, that 'P40C' (aka 'P36') is most likely a garbled reference to a proposed development of the Zefiro 40 (aka Z36).

[2] Examples would be the 1965 P6, SNPE's 29,400 kN thrust third-stage (tranforming the 2-stage Saphir into the Diamant launcher). Or the SNPE P4 - a 155,200 kN thrust second-stage for the Diamant B with the related P4 Rita on the MSBS M112 intermediate-range ballistic missile.)

[3] Assuming that we ignore that 'P40C' standing in for the Zefiro 40. If there is a 'Z40C', the suffix likely stands for 'Consolidation' (in reference to the Vega C) not to 'Common'.

[4] In the case of the Ariane 6, the number of P120C boosters will be determined by load. Fitted with two solid-fuel P120C boosters, the launcher will be known as Ariane 6-2 (or 62). Fitted with four boosters, it becomes the Ariane 6-4 (or 64).

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FiatAvio/Avio Zefiro Series Launcher Rocket Motors

The name Zefiro comes from the Esperanto for 'zephyr'. [1] The FiatAvio Zefiro series originated with the Zefiro 16 which successfully demonstrated filament-wound carbon epoxy composite construction combined with flexible-joint moveable nozzles. These experimental motors can be viewed as the ancestors of all later Zefiro series motors.

Despite its technological demonstrator role, the Zefiro 16 was proposed as stages for several launcher types. An early proposal was that Zefiro 16 should be used as a first stage for the Scout II TV. Starting in 1997, the ASI (Agenzia Spaziale Italiano) proposed a new-configuration Vega K launcher with various Zefiro 16 stage options. These were the Vega K0-L concept with Zefiro 16 first and second stages, and the Vega K Step 1 concept with Zefiro 16 second stage. [2]

The Zefiro series appears to be quite scaleable and multiple sizes have been proposed since 1998. Common useage is to shorten Zefiro model designations down to 'Z' and number - eg: Z23 or, sometimes, Z 23. Other times, redundancy is add - eg: 'Zefiro-Z23'. As noted earlier, the 'Z' and 'P' series are sometimes conflated into forms like 'P16 Zefiro' (sic). Also seen for the Zefiro series are 'P7', 'P9', and 'P23'.

For some reason, the reasonably well-known Z9 is sometimes referred to in ESA documents simply as the Zefiro SRM (Solid Rocket Motor) - a generic term that could just as easily be applied to the entire Zefiro family! So far, the only designation suffix in the 'Z' series is the 'A' in Zefiro 9A denoting changes to the original Z9's nozzle design.

Zefiro 7 - (Project) Vega K Step 2 third-stage motor
- Zefiro 7: Proposed for ASI Vega K Step 2 concept*
-- * First-stage was P80 FW, third stage was Zefiro 23
-- Zefiro 7 was presumably to be a shortened Z9A or Z23
-- Occassionally rendered as 'P7' or 'P7 Zefiro' (sic)

Zefiro 9 - ESA Vega launcher third-stage motor
- Zefiro 9 : 2005, 313 kN (70,365 lbf) maximum thrust*
- Z9 : L 3.174 m, diameter 1.92 m, burn time 117.0 seconds
- Zefiro 9A: 2008 revision, modified nozzle designs**
- Z9A: L 3.850 m, diameter 1.92 m, burn time 128.6 seconds
- Z9A: Third stage motor for Vega C and C+ configurations
-- * NB: In a vacuum, Z9 maxiumum thrust would be 305 kN
-- In a vacuum, Z9A maximum thrust would be 31.92 tonnes
-- Zefiro 9 was first test-fired in late Dec 2005
-- ** Correcting unexpected pressure drop experienced w/ Z9
-- Zefiro 9A test-fired 23 Oct 2008 and 28 April 2009
-- Z9A was also third-stage option on 4-stage Vega Evolution
-- http://www.avio.com/en/Vega/Vega/Vega-3-stadio-zefiro-9/

Zefiro 16 - 1998 Avio-funded experimental rocket motor
- Zefiro 16: Developmental solid rocket motor (SRM)*
- Zefiro 16: Composite structure, moveable noozle
-- Zefiro 16 designation based upon 16 tonne weight
-- Zefiro 16 test-fired June 1998, June 1999, Dec 2000
-- * Meant for ASI's proposed new config. Vega K (see intro)
-- Zefiro 16 program led directly to Z9 and Z23
-- Occassionally seen rendered as 'P16 Zefiro' (sic)
-- https://www.asi.it/sites/default/files/1_-_le_origini_di_Vega.pdf

Zefiro 23 - ESA Vega launcher second-stage motor
- Zefiro 23: 1,200 kN (269,700 lbf) maximum thrust
- Z23: Length 3.85 m, diameter 1.90 m, burn time 72 sec.
- Z23: Solid-propellant capacity of approx. 24 tonnes
-- Z23 was also 4-stage Vega Evolution 2nd-stage option
-- http://www.avio.com/en/vega/vega/vega-2-stadio-zefiro-23/
-- Z23 first test-fired 26 June 2006, Salto di Quirra

Zefiro 30 - (Project) Vega-E second-stage motor
- Z30: Diameter 2.20 m, ~ 30 tonnes solid propellant
- Z30: Second-stage option on 3-stage Vega Evolution
-- With P100 1st-stage, storable-propellant 3rd-stage
-- Zefiro 30 presumably enlarged Zefiro 23

Zefiro 35 - (Project) Vega-E second-stage motor
- Z35: Diameter 2.60 m, ~ 35 tonnes solid propellant
- Z35: Second-stage option on 3-stage Vega Evolution
-- With P100 1st-stage, storable-propellant 3rd-stage
-- Zefiro 35 presumably enlarged Zefiro 23

Zefiro 40 - ESA Vega C launcher second-stage motor
- Z40: 1,304 kN average thrust, 36.2 t propellant mass
- Z40: L 7.60 m, diameter 2.30 m,* burn time 92.9 sec.
-- * Some sources list Zefiro 40 diameter as 2.60 m
-- First Zefiro 40 bench-test run done in March 2018
-- 'P40C' aka 'P36' mooted for Vega L, prob. Z40 ref.**
-- ** 'C' may be for Vega Consolidation (not 'Common')
-- Z40 was also 3-stage Vega Evolution 2nd-stage option
-- http://www.avio.com/wp-content/uploads/2016/05/stadio_mortore_P80_header.jpg

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[1] The use of Esperanto is probably a nod to the multi-national nature of the European Space Agency. In Italian, 'zephyr' would be the very similar 'zeffiro.

[2] For the ASI's Vega K Step 2 concept, the Zefiro 16 second stage was replaced by a Zefiro 23 motor. Other Vega K Step 2 stages were also to be Avio products - with a P80FW first stage, Zefiro 7 third stage Zefiro 23, and an AVUM fourth stage.