Centauro fighter

[Shortround6]

I agree that excess power affects the ability to stay in a horizontal turn, but do not think it affect general maneuverability. The pilot is free to descend if he wants to turn tighter than his excess power will allow, right up until he gets to ground level. Of course, descending takes you out of the fight, but maybe you would rather live than remain with an opponent who is out-turning you.

The extra weight might well affect the ability to stay in formation near the service ceiling, but people generally don't stay in formation at the service ceiling anyway. Since the planes we are generally talking about are Me 109's, their service ceiling varies considerably, but let's say they have a general service ceiling of 36,000 feet. If so, and if they have the wing gondolas, then I think they could afford to fly at 32,000 feet instead since the bombers were generally not that high.

I think we are getting to a point where we are not that far apart. Think of pilots perception of an aircraft, Say for instance the 3 gun 109 can turn at 1 1/2 Gs at a certain speed at a certain altitude and climb at 1 m/s. A some what gentile turn to position the formation in an attack position? or to meet a threat? in any case the 5 gun machine, while doing the same turn at the same speed and altitude would be descending at 1m/s or more. Now if takes 20 seconds to execute a 180 degree turn at this speed and altitude the 5 gun machine is going to be 80 meters or more below the 3 gun airplane. Now are the German pilots going to think the 5 gun is "sluggish" or doesn't turn well compared to the 3 gun? If both are pulling 5 "G"s both are loosing 15-20m/s and a 2-3m/s difference is not going to be real noticeable The British seemed to think that 500fps climb was needed for formation or "operational" ceiling. so operational ceiling is around 2-3000ft lower than Service ceiling for ALL fighter aircraft. 400-500fpm climb is about what 40hp J-3 cub can do down low however. Anybody think you can fight (aside from a diving attack) with only 400-500fpm worth of climb in hand?

So, I think the effect of the gondolas on dogfight maneuverability was definitely there and definitely bad, but the effect on maneuverability when not in a dogfight was almost nothing. That is, if they were attacking from ambush, there was no effect. Most kills did not happen in a dogfight, they were made from a blind spot.

So, I think the Germans dropped the gondolas due to pilot preference and lack of demonstrable superiority to the fuselage-only configuration. The gondolas would have been a good idea if strafing beaches or troops columns, so they would have retained the gondolas and the mounts on the aircraft.

I will freely admit the gondolas were a good idea against bombers too. They may have worked OK against some Russian fighters at low altitude. If the 109 with gondolas can out climb the Russian fighter it was opposed by then then there may not have been a problem. The Problem in the west was the the "combat" height for the German fighters was about on the edge of what the "standard" 109 with a DB605 could operate at. Depending on whose chart you look at a P-51B could climb at 2000fpm at 30,000ft A P-47 at 1400-1650fpm, a P-38J at 1830fpm and the 3 gun 109G-1 was supposed to do 1640-1650fpm. Cutting the climb rate of the 109 by 400-600fpm at 30,000ft by hanging the gondolas on it was not a good idea once the escort fighters started showing up.

I doubt seriously that the gondolas would have adversely affected an E or F model, though they WOULD be noticeable and high altitude, but by the time the G-model came along, it had porked up considerably and was quite a bit heavier than an E or F model. Any extra weight would definitely have an effect on a G or later model Me 109.

Well, I would note that the engine power did increase for about 1100hp to 1475hp from the E to the early G so it's ability to carry the extra weight did go up. Also the critical height of the engine went from around 4000meters to 5800 meters even before the later models with the 605 supercharger. The better streamlining of the "F" and early "G" would help climb also. I will try to give credit where I think credit is due. Pods under an "E" might have been a disaster. But then 20mm Hispanos in pods underneath a Spitfire MK I wings (and keeping the machine guns in the wing) would have been a disaster too.

 

[Juha]

...Well, I would note that the engine power did increase for about 1100hp to 1475hp from the E to the early G ...

Hello Shortround6
I'd say that the power went from 1100hp to 1310hp because the 1.42ata Start- und Not -power was banned for 605A most of the time early 109 Gs were in widespread service.

Juha

 

[Juha]

...So, I think the Germans dropped the gondolas due to pilot preference and lack of demonstrable superiority to the fuselage-only configuration. The gondolas would have been a good idea if strafing beaches or troops columns, so they would have retained the gondolas and the mounts on the aircraft...

Hello Greg
The main reason of introduction of gun gondolas was the demostrated difficulties to down US heavy bombers and Soviet Il-2s with the standard 109 F and early G armament. And that was a big question to LW and Germany.

Juha

 

[GregP]

I agree, Juha, and mostly agree with Shortround, too. The differences we have aren't worth arguing about at all, and in the end, we may well agree all the way down the line but might be expressing it differently from one another.

Elmas, there was no fighter ever buiilt that rolled fast enough for the rotational mass to exhbit gyroscopic effects, even the Lockheed F-104 couldn't roll fast enough for that! Most of them never exceeded about 115° per second and many were slower. To exhibit gyroscopic effects, you'd have to spinning and many revolutions per second, not fractions of a revolution per second. Now the mass of outer-wing stores, be they gondolas or fuel tanks, might well produce some roll intertia that made a roll difficult to stop at a certain point, but it would not throw off the nose as a gyroscopic effect would.

If you look up gyroscopes and look at the speeds required for gyroscopic effects, youll see the rotational velocity for a gyro is WAY faster than any fighter rolls. There are only very slight gyroscopic effects on the propeller and they can be countered by rudder, and the prop turns well more than 1,500 times as fast as a fighter rolls.

No sarcasm or anything else imtended, so please don't take it that way. Just my take on gyroscopic effects of rolling an aircraft. The only reason an aerobatic aircraft tumbles in a Lomcevak is due to the elevator input required to initiate the snap (flick) roll to start with.

 

[krieghund]

If the Luftwaffe had LOTS of Fiat G55 Centauro fighters (as well as FW's and 109's) to defend Germany against the 8th A.F. bombers what effect would they have? :druid

Have we answered his question yet? I think one must compare the G55 to the Fw and 109 to determine how effective it may or may not have been to have replaced them.

One source is;
The German tactical trials comparing the Luftwaffe`s Bf 109G-4 and FW 190A-5 to contemporary Italian types Macchi 205 V, Macchi205 N, Reggiane 2005 and Fiat G 55.

http://www.ww2aircraft.net/forum/aviation/fli...tml#post907715 (Report on fighter aircraft comparisons at the Italian Guidonia Test Centre)

Summary of report on German tests at Guidonia


The G-55 was seen as most favorable of the tested Italian planes

G-55:
- Armament: 1 MG-151/20 and 4 12.7 mm MG.
- High forces on the aileron.
- Effect of rudder could be better.
- Plane curves very good and narrow.
- Slightly uneasy in "mid position" (shooting position).
- Pitch to any side could not be noticed, similar to Spitfire.
- Moderate pilot view on takeoff, during flight limit to front above, good to sides and backwards.
- Worse pilot view than the German planes.
- Aeronautical not as good as German planes.
- Not useable as fighter-bomber with bomb under fuselage.
- Equal to German planes in climb and high altitude performance.
- Inferior in speed by 25 km/h, but Italian produced DB 605 delivered 100 PS less than the German.
- Superior in armament and range to the German planes.
- Ability to install DB 603 without bigger modifications.
- Was evaluated as best Italian plane in the trials.

Macchi 205 V:
- Armament: 4 12.7 mm MG.
- Unstable in lateral axis.
- Very high effect of rudder.
- Tendency to "Überziehen" (stall ?).
- Forces on aileron and rolling good.
- Moderate pilot view on take-off, during flight limit to front above, good to sides and backwards.
- Will be only produced in small numbers since it is a temporary solution.

Macchi 205 N:
- Armament: 1 MG-151/20 and 4 12.7 mm MG.
- Mass production variant of DB 605.
- Good rudder effect.
- Was smoothly in "mid position" (shooting position).
- Rolling good.
- Rudder forces a little smaller than for Bf 109 G-4.
- Cooler too small for constant climbing and use in tropical environment.
- Moderate pilot view on take-off, during flight limit to front above, good to sides and backwards.
- Wing not solid but made of three parts, plane not suited for fighter-bomber use.

Reggiane 2005:
- Armament: 3 MG-151/20 and 2 12.7 mm MG.
- Aeronautical attributes were sufficient.
- Curves well, rolling like Bf 109 G-4 with rudder forces a little less.
- Take-offs and landings easy.
- Pilot seat a little too far away from control stick.
- Not suited as fighter-bomber due to size and location of cooler.
- Moderate pilot view on take-off, during flight limit to front above, good to sides and backwards.

All Italian planes had an armored pilot seat with 11 mm armor thickness and an 11 mm thick headrest armor.

I also found this on a site a while back about the G55:

"I can refer about the opinions of some pilots who drove them in battle: dad drove only Fiat G-55, probably not the exploiter among those but probably the most advanced and easy to ride. As macchi 205 it was produced also after the end of the war and serviced as Fiat G-59, a nice evolution powered with a Merlin. Dad said that the pitch roll rate were higher than Spits and Mustangs, in the while the DB605 engine provided an extra kinetic energy boost after sudden dives than the Merlin equipped versions. G55 (G= ing.Gabrielli the father of G91 and G222) was a masterwork: easy to ride, extremely reactive, highly aerobatic was really tough to die. Dad was wounded while attacking a B-24 box in summer 1944: the wind shear hit by a .50 round exploded punching his face with a lot of glass-shrapnel and the hot oil blowed out the DB engine suctioned deeply all those tiny wounds on his face. When he landed there were more holes in his own wings than a Swiss gruviere, at least 50.50 rounds drilled his G55. The day after the FIAT was combat ready another time, dad not at all."


This was cut and pasted from a web source on another site about the Series 5 fighters:
------------------------------------------------------------------------

In December 1942 a technical commission of the Regia Aeronautica was invited by Luftwaffe to test some German aircrafts in Rechlin. The visit was part of a joint plan for the standardization of the Axis aircraft production. In the same time some Luftwaffe officers visited Guidonia where they were particularly interested in the performances promised by the Series 5's. On December 9 these impressions were discussed in a Luftwaffe staff meeting and raised the interest of Goering itself.

In February 1943 a German test commission was sent in Italy to evaluate the new Italian fighters. The commission was led by Obverts Petersen and was formed by Luftwaffe officiers and pilots nad by technical personnel, among them the Flugbaumeister Malz. The Germans carried with them also several aircrafts included a Fw190A and a Me109G for direct comparison tests in simulated dogfights.

The tests began February 20. The German commission, not without a certain surprise, was very impressed by the Italian aircraft, the G55 in particular. In general, all the Series 5's were very good at low altitudes, but the G55 was competitive with its German opponents also in term of speed and climb rate at high altitudes still maintaining superior handling characteristics. The definitive evaluation by the German commission was "excellent" for the G55, "good" for the Re2005 and "average" for the MC205. Oberst Petersen defined the G55 "the best fighter in the Axis" and immediately telegraphed his impressions to Goering. After listening the recommendations of Petersen, Milch and Galland, a meeting held by Goering on February 22 voted to produce the G55 in Germany.

The interest of the Germans, apart from the good test results, derived also from the development possibilities they was able to see in the G55 and in the Re2005. For the Re2005 the German interest resulted in the provision of an original DB605 with the new WM injection. This engine and a VDM propeller were installed on the MM495 prototype that was acquired by Luftwaffe and tested in Rechlin. The aircraft reached 700 km/h during a test with a German pilot, but the airframe was not judged sufficiently strong for these performances.

The G55 was bigger and heavier and was considered a very good candidate for the new DB603 engine. Other visits were organized in Germany during March and May 1943 in Rechlin and Berlin. The G55 was again tested at Rechlin at the presence of Milch. Gabrielli and other FIAT personalities were invited to visit German factories and to discuss the evolution of the aircraft. The specifications of the German G55/II included the DB603 engine, five 20 mm guns and a pressurized cockpit. The suggestion of weapons in the wings, limited to one 20 mm gun for each wing, originated the final configuration of the Serie I, while the 603 engine was successfully installed in the G56 prototypes.

As a concrete results of the German interest in the G55, the Luftwaffe acquired three complete G55 Sottoserie 0 airframes (MM91064-65-66) for evaluations and experiments giving in change three DB603 engines and original machinery for the setup of other production lines of the DB605/RA1050 RC58 I. Two of the Luftwaffe G55's remained in Turin, at the Aeritalia plants, where they were used by German and Italian engineers to study the planned modifications and the possible optimizations to the production process. Later these two were converted to Serie I and delivered to the ANR. The third one was transferred to Rechlin for tests and experiments in Germany. The DB603 engines were used to build the G56 prototypes.

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.

 

[GregP]

Noting Italian goes together quickly and isusually a bit overly complex, but their machines are usually very good performers, and oftentimes the best.

I think the "5" series fighters were very good relative to the compeition, if not too numerous.

 

[davparlr]

I had a visit from Davparlr today at the museum and asked him to get under our Ha.1112 (on jacks) and lift the gear into the wells. Not surprisingly, he could not, and the weight IS concentrated out near the gondola attach point which, conicidentally is almost exactly where the wing-mounted armement of ah Ha.1112 Buchon is mounted (and weighs about what a gondola weighs or more). And THEY don't roll any slower than an Me 109G, so while your point may be interesting from an academic standpoint, it just doesn't actually FLY that way in real, live experience.

In case anyone in here forgot, the Hispano Ha.1112 is identical to an Me 109G from the firewall aft, but has a Merlin in it and wing-mounted armament since there is no palce for a nose cannon to shoot through a Merlin. It just happened to be up on jacks today. The pilots don't notice any roll problems ...

What Greg failed to say was that when I tried to lift the gear, I lifted the entire aircraft! Just kidding, of course. The gear is quite heavy. I had a great time visiting with Greg at the Chino museum. They have really neat aircraft that actually fly. Also, they have an abundance of aircraft dearly in need of rebuild. Since I love old aircraft and junk yards, I was in, as my wife said, hog-heaven. Here is a pix of the Spanish Bf-109. What a thrill just to touch it!

 

[GregP]

Nice pic, Dave. Glad you enjoyed it, and I enjoyed meeting you, too.

In case some of you don't know, Dave went through USAF pilot training and flew the T-37 and T-38, amiong other planes. So maybe we could take some advice from Dave! I know I could, anyway.

Cheers, Dave! Come see us again anytime.

 

[vikingBerserker]

Way cool!

 

[GregP]

The Ha.1112 was sitting forlornly on a cart in 2007 with no landing gear and no wings, and another volunteer and I decided to get it back on the gear. We asked for the parts to attach and repair the gear and started replacing the gear mounts. It was pretty comical.

I was in the cockpit, head first with my feet sticking out of the canopy, with nuts, washers, and wrenches and my friend was outside with the gear attach points. We collectively managed to get the gear attach points bolted in, which is no mean feat. The Germans managed to get the holes exactly apart from each other, so bolts that were 90° apart were at the same level and each had to be inserted and the nut started before the bolt was seated. When tightened, the bolts were touching and you could never get a nut on if both were seated. VERY frustrating when you are upside down with a wrench and bolt in your face, trying not to slide your nose down onto the bolt!

Of course, when the Germans built them, the firewall had openings to work through. Unfortunately, once finished, the access was awful. Once we got the gear on, the project took off and a team was formed to continue the restoration. I went to the Bell YP-59A Airacomet team, but still put some time in on the Ha.1112 once in awhile and also on the North American O-47 project.

All in all a very neat setup for me. I also got to be on a team of 3 who restored a WWII pulsejet to running order. If you Google "Chino Pulsetjet run" you can see our WWII pulsejet running. In one video, we pushed my pickup down the runway on Saturday and down a taxiway on Sunday during the 2009 Chino Airshow. You can hear it run for 10 miles! The sound is very low frequency (about 44 Hz) and carries a LONG way! When we first fired it up, the fire department came over with lights on to see what was exploding continuously …

Anyway, if any of you get around Southern California, come see us and I'll be glad to show you around, get acquainted, and have lunch. If nothing else, we DO have a pretty good museum.

 

[Elmas]

A – When there's 1) a mass and 2) a centripetal acceleration, there's always (always) a gyroscopic effect. Of course, more the speed, more the effects.

B – Here what Adolf Galland says about the gondolas or "bathtubs" under the wings of the Me 109......
"Die Ersten und die Letzen", Italian edition, "Il primo e l'ultimo", 1959

Just the translation of the phrase between black lines:

"These "gondolas" or "bathtubs" as we called them, quite naturally impaired a lot the flying qualities of the aeroplanes (Me 109), as they became so deformed to render them unfit for combat between fighters. However, with their three guns, they had a firepower with which they did something good in fighting the four-engined bombers. When the American escort fighters became more and more strong, we had to dismantle the "bathtubs".

I will be glad if someone is in possession of the original edition in German, as I would like to compare the translation with the original one. But I don't think that it will be much different.

 

[GregP]

Nope, no gyroscpic effects at the roll rates of any aircraft I know of. If the gondolas were heavy enough to deform the wings, then that is why they were abandoned.

If there was mention of the nose snaking around, then I'd say it is dutch roll, which most aircraft have in some form due to aileron drag, no gyroscopic effects. Dutch roll practice is required in basic pilot training, as you no doubt know. I rather enjoy playing with them, even in Cessnas.

 

[Elmas]

During my examination of "Rational mechanics", that I studied almost forty years ago for my PhD degree, but that I remember extremely well as it was the most difficult examination with the exception of "Mathematical analysis II", I was compelled to tell my Professor what, in an extremely rough manner, I tried very badly not to explain but only to suggest here.
Youth errors, maybe.

Even a lesser source as Wikipedia ( even there with a little bit of an error: pendulum, as an objetc with a mass + centripetal acceleration is subject to the law of angular momentum conservation, but a pendulum is a little bit different thing) tries to explain:

"In place of internal wing armament, additional firepower was provided through a pair of 20 mm MG 151/20 cannons installed in conformal gun pods under the wings. Although the additional armament increased the fighter's potency as a bomber destroyer, it had an adverse effect on the handling qualities, reducing its performance in fighter-versus-fighter combat and accentuating the tendency of the fighter to swing pendulum-fashion in flight.[34]. The conformal gun pods, exclusive of ammunition, weighed 135 kg (298 lb);[35] and 135 to 145 rounds were provided per gun.
The total weight, including ammunition, was 215 kg.[35] Installation of the under-wing gun pods was a simple task that could be quickly performed by the unit's armourers, and imposed a reduction of speed of only 8 km/h (5 mph).[35]

References:

34) Green, William. Messerschmitt Bf 109: The Augsburg Eagle; A Documentary History. London: Macdonald and Jane's Publishing Group Ltd., 1980. ISBN 0-7106-0005-4. Page 88.

35) Randinger Otto, Radinger, Willy and Wolgang Otto. Messerschmitt Bf 109 F-K – Development, testing, production. Atglen, PA: Schiffer Publishing Ltd., 1999, p. 21. ISBN 0-7643-1023-2"

Messerschmitt Bf 109 - Wikipedia, the free encyclopedia

All my compliments for your pilot skills: but Pilots and Engineers are a quite different sort of a thing......
Ing. Mario Castoldi

the designer of MC 72 and Macchi 205, is said never put a single feet inside a flying aeroplane, affirming that he was "too fat and too heavy to go inside an aeroplane"......
I don't think that the designer of the Cessna 172 will be too pleased if you will attach a weight of, say, 100 Kg ( two passengers) under each wing and with them to attempt a dutch roll......
And, finally, I don't think either that the Luftwaffe Pilots had particular problems flying the "bathtubs" Me 109s, even if I think that 200 kg plus certainly did not improve, say, the landing characteristics: but one thing is to fly an aeroplane, another thing is to fly an aeroplane trying to nail some other Pilots, and in the same time carefully avoiding to be nailed.....

 

[Altea]

"In place of internal wing armament, additional firepower was provided through a pair of 20 mm MG 151/20 cannons installed in conformal gun pods under the wings. Although the additional armament increased the fighter's potency as a bomber destroyer, it had an adverse effect on the handling qualities, reducing its performance in fighter-versus-fighter combat and accentuating the tendency of the fighter to swing pendulum-fashion in flight.[34]. The conformal gun pods, exclusive of ammunition, weighed 135 kg (298 lb);[35] and 135 to 145 rounds were provided per gun.
The total weight, including ammunition, was 215 kg.[35] Installation of the under-wing gun pods was a simple task that could be quickly performed by the unit's armourers, and imposed a reduction of speed of only 8 km/h (5 mph).[35]

Elmas, you talk about 8 km/h, but from TsAGI tests, the same captured Me-109G-2 with 3 x20 guns gained 213 kg,

lost 666-650 = 16 km/h at hight 19 km/h at SL.
0.7min (4.4 to 5.1) to climb 5000m (16%)
about two secunds (10 %) for a 360° turn @ 1km hight
I only can imagine roll acceleration loss.

I think it was a quite considerable degradation, specially on the eastern front when Me-109 was confrontated to nimble fighters.
Considering Artiom Drabkin works ("I faught on an Airacobra", etc...) with soviet vets, 3 canon Me-109G disappeared (hier und zuruck they said from german expression) as fast as they appeard.

So its dogfighter capability was considerabily affected. But Me-109 was a small plane with high wing loading. I bet P-47or Tempest would not be such affected (all is relative) by 2 extra 20mm canons

 

[GregP]

What he is describing is roll-inertia. Any aircraft with weight out on the wings will have it, even a Cessna 310 with full tip tanks, or a T-33 with same.

It may well feel like a pendulum to a fighter pilot not used to flying aircraft with roll intertia, but all that is really happening is the mass on the outer wings having to be stopped with opposite stick instead of just centering the stick as in normal fighter operations and having the roll stop right away. Pilots got used to it or complained until the gondolas were removed.

The F-86 flies much better wiothout feull driop tanks and so does the MiG-15-bis we fly ... same reason, roll-inertia and a bit of extra weight combined with relatively weak early jet engines makes a clean Sabre or MiG-15 fly better, too.

 

[Altea]

I'd prefer the Re-2005 to a Centauro. It's beautiful.

Subjective? No, as René Caudron and Emile Dewoitine said, a nice plane alwas fly well.

Regards


PS Why not a Fiat, then?

-Ah no! Condisering my experience with Fiat Panda and Fiat 500 mid 80ies of the last century, NO, never again ! Thanks...

 

[Ascent]

Something that's not been mentioned, what with all the figures and numbers flying around, is that unquantifiable 'feel' of an aircraft.

Sticking the extra weight on the wings may or may not make a significant difference to the performance of the aircraft when using objective measurment but it may effect how it feels to the pilot which is purely subjective. If the the aircraft 'feels' wrong to the pilot then it may effect his confidence in the aircraft and his subsequent performance in it. Measured in numbers you wouldn't see that but it could make a difference all the same.

Numbers aren't everything.

 

[GregP]

For rate of climb, rate of roll, rate of pitch, rate of yaw, top speed, and similar things, numbers ARE everything.

For things like aircraft feel, apparent pre-stall buffet, etc., then number aren't a very good measure, as you pointed out. For, say, ease of tracking a target, nunbers are meaningless. What you need to do is try out the fighter in question and see which one is easier to track with, I agree.

 

[Elmas]

Certainly, I agree, numbers aren't everything.
But the Physical Laws that act on an aeroplane in flight are there, always.

 

[Ascent]

I certainly don't mean to imply that numbers aren't important and comparing different aircraft types or even MK's in a single type it will give you an idea of where your advantages are and what tactics you should be adopting, no argument.

But when comparing the same aircraft in different fits, which we are effectivly doing here for the 109, the numbers might not tell the whole story.