Fiat G.55 vs. ___________

[Graham Boak]

Sqeelig: it was me. Thanks for the description, I can confirm that it was the maritime expert, who was visiting Italy to consult on the establishment of a trials base there. my source is the MCP book on German experimental establishments. It does not say whether or not he had a fighter expert with him.

[Squeelig]

Nick said, "I think you mean replacement of the G.55 with the Bf 109 don't you, not the other way around?"

No. I have seen German manufacturing/production reports on the costs of replacing the production of the Bf-109 with the G.56. In the field, I have no doubt that Bf-109's replaced G.55's for a variety of reasons like supplies of spare parts (production related issues for G.55 parts), familiarity of mechanics with the Bf-109, and so on. Italian production (the only production there was) just wasn't sufficient as were the Italian production problems for everything.

Graham said, "I can confirm that it was the maritime expert, who was visiting Italy to consult on the establishment of a trials base there."

??? This is rather odd because I can confirm that it was indeed Edgar Petersen as his signature was all over the documents which had a Rechlin letterhead. Can you please elaborate on this other Oberst Edgar Petersen, a maritime expert, who was setting up fighter aircraft trials for the Luftwaffe? If it was the same man, then apparently aeronautical engineering was not outside of Edgar Petersens expertise.

[Ruy Horta]

The Petersen report of 27-2 is praiseful of the G.55, puts it on a more or less equal footing to the G-4 and A-5, but certainly not the best axis fighter.

There is an interest in a DB 603 powered version, but for reasons already explained it doesn't really make the G.55 superior.

Why introduce a new type when you can continue mass producing types of equal or superior performance (both Bf 109 and Fw190) with equally promising development potential (especially the Fw 190)?

Back to your original post.

Yes, there were plenty of a/c with equal performance (or better).

It's even stated in that / a Petersen report (Bericht über Jagdflugzeug-Vergleigsfliegen bei der ital. E-Stelle in Guidonia 27-2-1943).

[Andrew Arthy]

Hi,

Here is something I came across while going through some documents. The source is an Air Historical Branch Translation from the Australian War Memorial.

AWM 54 423/4/103 Part 63, Report of a Conference held by Reichsmarschall Goering on 22 February 1943.

Milch: ... Perhaps Petersen can inform us on this question and also about the comparison flights in Italy.

Petersen: ... There will be a further report about comparison flights with all the Italian types ... Against this, the Italian fighter is equal to the German fighter, especially as regards rate of climb. They are also superior in armament. The Fiat 55 aircraft has four cannon and a performance similar to that of the German aircraft, although powered by an engine that
is a hundred horsepower less.

Peltz: Were they series or experimental aircraft?

Petersen: There is an experimental series of ten aircraft, but these trials concerned new aircraft that had been 'titivated up'.

Goering: I'm glad that the Italians at long last have produced a respectable fighter. And I can only say; let them build them to capacity.

Milch: We also should do something in that sphere. It is indeed a disgrace to our own industry.

Goering: The Italians have never built inferior aircraft and have always been competent in the construction of aircraft and engines. I remember the Fiat and Alfa. They have also held the world speed record. The ability of the Italian aircraft industry has always been of the best. They are unable to mass produce however, and there we must help them. We can consider ourselves lucky, if they have produced a good fighter aircraft. It's one in the eye for our own people anyway.

Petersen: We must attend to this at once. The airframe of the Fiat G 55 can accommodate the DB 603 engine, while the Me 109 is unable to do so any longer. The G 55 with the DB 603 would be an ideal fighter aircraft.

Galland: From our experience the Italians have always forgotten something in their fighter aircraft, either the armour or guns.

Goering: It's to be hoped however that for the purposes of these comparison flights, they've been informed about this, otherwise it's a waste of time.

Petersen: The fighter specialist has flown the aircraft. With the exception of the radio it carried complete equipment, and fuel for one and a half hours, whereas we carried fuel for only one hour. We can't ignore the fact that the Italian aircraft has a performance equal to that of our latest types.

Milch: Then please obtain three Italian aircraft at once, and fly them here, in Rechlin. I would have the DB 603 installed in these aircraft that we have been discussing this morning. It would mean a considerable advance towards the Me 209. I can't imagine the FW 190 with the BMW 801 engine as it is today being sufficient for the next two and half years [in the event it had to be!!! - AA] Especially as we don't know what the English and the Americans are building.

...

Goering: I'm also in favour of the proposal. However I consider it more than likely that the English will effect an improvement with their own types. I would like to ask what is our best means of improving our fighters other than the jet propulsion business?
Milch: The Me 209 and especially its engine. ...

...

Goering: If the Italian aircraft is good, then we won't deny the fact, and we'll mass produce them here. We don't want any false pride.

Milch: Thereby we could advance a year.

Galland: And it would also do our designers good.

Goering: On top of that perhaps we could include the Italian pilots as well, in our complete programme. Anyway I'm very pleased to hear this about the Italians.

---- END OF QUOTE



Cheers,
Andrew A.

"You'll never silence the voice of the voiceless" - Rage Against The Machine

[Squeelig]

Petersen: We must attend to this at once. The airframe of the Fiat G 55 can accommodate the DB 603 engine, while the Me 109 is unable to do so any longer. The G 55 with the DB 603 would be an ideal fighter aircraft.

This is consistent with the documentation I have seen as well. Except that I saw a reference to the climb rate at high altitude being better.

Do you have any other gems concerning the flight trials or the performance of the Series 5 fighters (Macchi Mc.205 - Reggiane Re.2005 - Fiat G.55/56)

Thanks

[Graham Boak]

It is the same Petersen: he was with KG40 before being appointed to the head of KdE, Rechlin and the other experimental estabishments. Note the reference in the quoted documents above to the existence of a fighter expert who had actually flown the G.55.

It is very interesting to see that the Luftwaffe High Command actually took this idea seriously, however briefly, and the G.56 is known to have been tested several months later. The key perhaps lies in the comment that the airframe was capable of taking the DB603 without major modification, unlike the more compact Bf.109. Has anyone seen reports of the testing of the G.56 - to this (ex)aerodynamicist it seems obvious that fitting a longer heavier engine would affect the stability and handling, requiring a increase in the tail moment arm - bigger tail or fuselage extension (as on the Fw.190D). I don't think this is visible in the photos of the G.56? Not all promising designs achieve their designers' hopes.

However, think what the German industry could produce in the time it would take to clear production lines and set up for the G.56 (about a year?). A casual ruling from on high rather ignores the practical problems. German industry will not have been set up to the same production methods and tolerances as the Italian: time would have been needed to create new drawings, new tools, new jigs requiring manufacture and assembly. Consider how much production would have been lost in this interregnum. Add the failure of the DB603 to achieve its promise.

[Ruy Horta]

Taktisch – technische Gegenüberstellung.

Von den 4 Flugzeugen, die am Vergleich beteiligt waren, ist die Fiat G 55 in der Beurteilung so gut, dass eine taktisch – technische Gegenüberstellung erforderlich ist:
Die Vorteile der Fiat G 55 sind: Grössere Fläche, besseres Seitenverhältnis, geringere Flächenbelastung (175 kq pro qm). Vergleiche: Bf 109 G 4 = 195 kg pro qm und Fw 190 A 5 = 210 kg pro qm. Hierdurch erhält das Flugzeug bessere Eigenschaften, die sich auswirken in grössere Gipfelhöhe, bessere Kurvenwendigkeit und bessere Steigleistung in der Höhe. Letzteres erscheint nicht ganz zutreffend, da die Leistungsbelastung höher ist als bei der Bf 109 G 4.

Ein weiterer Vorteil ist der Waffeneinbau. Die z.Zt. vorhandene Bewaffnung von 4 12,7 mm MG und 1 151/20 Kanone (200 Schuss),

die zentral in Rumpf angeordnet sind, haben auch einen ausreichenden Munitionsvorrat, je 360 Schuss. Die Bewaffnung der Bf 109 G 4 dagenen mit 1 151.20 Kanone und 2 7,9mm MG mit je 500 Schuss ist a;s viel zu gering zu bezeichnen. In der Weiterentwicklung sind 3 151/20 Kanonen und 2 12,7 mm MG vorgesehen Diese Bewaffnung ist sehr gut und wird erreicht, ohne dass die Fliegerische Eigenschaften und Leistungen so stark beeinträchtigt werden, wie es z.Zt. bei den deutschen Jagdflugzeugen durch Anbau der Rüstsätze der Fall ist.

Die Fliegerische Eigenschaften sind nicht so gut wie bei der Bf 109 G 4 und der Fw 190 A 5. Ein wesentlicher Nachteil der Fiat G 55 gegenüber den deutschen Jagdflugzeugen ist die Ungeeichnetheit für den Jaboeinsatz. Dieses darf nicht ausseracht gelassen werden, da an allen Fronten der Jaboeinsatz in den Vordergrund getreten ist.

Als Vorteil der Fiat G 55 erscheint, dass die Zelle für den Einbau des DB 603 sehr geeichnet ist. Damit tritt eine erhebliche Leistungssteigerung ein und der vorhandene Nachteil, dass sie in der Geschwindigkeit unterlegen ist (ca 25 km pro Stunde langsamer als Bf 109 G 4 and Fw 190 A 5, wird überholt. Es kommt hinzu, dass das Flugzeug zusätzlich eine 3 cm Kanone aufnimmt.


Zusammenfassend ist also festzustellen:

Die Fiat G 55 ist den deutschen Jägern ebenbürtig in der Steig- Höhenleistung, überlegen in der Bewaffnung und Reichweite, unterlegen in der Geschwindigkeit (z. Zt. 25 km/h), wobei zu berücksichtigen ist, dass der ital. DB 605 100 PS weniger leistet.

Da nach Angabe des Konstrukteurs, der DB 603 ohne wesentlichen Umbauen gezw. Änderungen einzubauen geht, gewinnt bereits unter Berücksichtigung der derzeitigen Leistungen das Flugzeug sehr an Interesse, da es mit dem DB 603 allen derseitigen Jägern in jeder Hinsicht ünterlegen wäre.


1.) Fiat G 55. Eingebauter Motor DB 605.

Luftschraube: VDM
Flächergröße: 21,11 qm
Fluggewicht: 3700 kg
Brennstoffvorrat: 625 l
Bewaffnung: 1x 151/20 Motorkanone mit 200 Schuß
4x 12,7mm im Rumpf gesteuert mit je 350 Schuß


Panzerung: 11 mm Panzer – Kopfschutz und gesamte Sitz aus Panzermaterial im gleicher Stärke.


4 Kraftstoffbehälter: gegen 12,7 mm

Flugzeug hat geteilte Flächen.

Beurteilung:

Querruderkräfte sind hoch. Die Ruderwirksamkeit könnte etwas besser sein. Rollwendigkeit etwas geringer als bei Bf 109 G. Flugzeug kurvt sehr gut und eng. In der Mittellage (Schießflug) ist das Flugzeug etwas unruhig und fahrthängig. Abkippmöglichkeit zu einer bestimmten Seite konnte nicht festgestellt werden. Das Abkippverhalten ähnert der Spitfire. Sicht bei Start mäßig. Im Flug nach vorn oben beschränkt – nach der Seite und nach hinten gut. Start und Landung sehr einfach.

Flugzeug ist in Serie

Für Jabo-Einsatz mit Rumpfaufhängung nicht verwendbar, da Bauchkühler und Fahrwerk nach innen einziehbar. Kühler is groß genug und für Tropeneinsatz vorgesehen.

[Squeelig]

Graham said, "However, think what the German industry could produce in the time it would take to clear production lines and set up for the G.56 (about a year?). A casual ruling from on high rather ignores the practical problems. German industry will not have been set up to the same production methods and tolerances as the Italian: time would have been needed to create new drawings, new tools, new jigs requiring manufacture and assembly."

Did you read post #3?

"The interest in the G55 program was still high after the Armistice: in October 1943 Kurt Tank, who previously personally tested a G55 in Rechlin, was in Turin to discuss about the G55 production. However, war events and the not yet optimized production process were the reasons for which the G55 program was eventually abandoned by the Luftwaffe. Early produced G55's required about 15000 manhours; while there were estimations to reduce the effort to about 9000 manhours, the German factories were able to assemble a Bf109 in only 5000 manhours."

I have seen copies of some of the manufacturing/production reports and as you pointed out (and as pointed out in post #3 initially) the cost in man hours was unacceptably high.

[Graham Boak]

I accept the point about the greater production time, however my point above was the penalty/time taken to establish the design in production, rather than cost once in there.

The same or similar penalty would be true for any other new type, of course, which is why the preference was for modifications to established types. These could be brought on-stream with much less disruption. At some stage the penalty has to be paid, and it is no less true for the engine manufacturer than the airframe.

[Squeelig]

Graham, even if there was no penalty/time taken to establish the design in production, the production costs/time of 9,000 man hours for a G.55 would still have been unacceptably high compared to 5,000 man hours for a Bf-109. That's the point.