The best Soviet fighter had the same wing loading as Fw 190A-8 (240 kg/m2)
Small wings/high wing loading of German fighters
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Shortround6
Major General
In the early/mid 30s there was a lot of transition. It there was also a lot scheming to get around patents.
There is an awful lot of confusion (at best) or dishonesty (at worst) about the slats on the 109.
Slats do several things, what the major effect is depends on size (amount of span) of the slats which affects the area of the wing the airflow from the slats act on. Handley Page obviously knew a lot about slats and stuck them on just about anything the company made during the 20s and most of the 30s.
The original goal was to increase aileron effectiveness at low speed/high angles of attack. Planes going into spins was a very common accurance in early flight with often fatal results.
Slats (and slots) showed up before the common use of Flaps and even flaps changed quite a bit is just a few years in the mid 30s. Early flaps did very little to increase lift at low speeds.
What they did was increase drag (air brake) and increased the glide slope. They shortened the approach or cut down the amount of time/distance the plane 'floated' over the runway.
However small changes in pitch could affect how the airflow over the wings flowed over the ailerons and while the wing overall might still be providing lift (not stalled just yet) the rear part of the wing where the ailerons were had disturbed airflow and might be stalling. Loosing lateral control at low speed and low altitude usually meant a crash as there was no time/altitude to recover.
Getting back to the slats.
Handley Page Gugnunc 1929.
Notice the almost full span slot/s. Which were not used on many aircraft. Like the HP. 42
The slots pretty much affect only the airflow on the outer portion of the upper wing where the alerions are.
Grumman TBFs used fixed slots to maintain alerion control at low speeds.
Willy and the boys could use short span slots to maintain aileron control low speeds (and in high speed turns) and use a smaller wing because they didn't need quite as much safety margin above the stall to keep control. Willy and boys were also using a different flap set up than Mitchell.
Jumo powered version with radiator under the engine. The wing flap may have gone lower, I don't know but it obviously could use less angle than the Spitfire. Spitfires had a choice of no flap or full flap which was 85 degree drop from the wing. The Spitfire flap was an airbrake. The 109 Flap was changing the camber of the wing/airflow. The Spitfire?
That will slow the plane down and change the glide ratio (rate of sink) but it doesn't do much for lift.
And yet the 109 slats, that affect a bit under 1/2 the overall span of the wing and well under 1/2 the wing area get all the credit?
Mitchell and his boys used washout
so that the wing roots stalled before the wing tips and helped maintain aileron control at/just above stall (and they didn't have to pay royalties to HP)
Willy and the boys had a pretty good idea how the 109 wing would act.
Bf 108 first flown in 1934. Willy and the boys were using very modern developments and were ahead of much of the competition.
But short span slats are not magic and the Willy and the boys were not using them as magic. They were using them in combination with the flaps to get desired results.
Let's not short-sell the Bf 109.
It won the contest because it was a better fighter when tested, despite (because?) Willy risking it with going on with the small wing and the resulting higher wing loading that LW wanted initially.
He 112 was a worse fighter when tested (so no contract to Heinkel to make the 112s for LW), prompting Heinkel to make the ever-smaller and sleeker versions of the He 112, culminating with the 112B and with the bespoke He 100 type.
Bf 109F introduced a new wing, whose main visible differences were the wider volume for the radiators, new flaps system, and the rounded wing tip.
What the 109 didn't gotten were the wing-mounted fuel tanks, the only stablemate with wing fuel tanks being the 2-seater Buchon (so the drop tanks must not be used since the fuselage tank was of reduced capacity due to the second cockpit).
109F also introduced a new tail and nose, yet the 109s were still manufactured at a high rate.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Informative post and the Gugnunc is a really pretty little thing.
In 1942, one of the leading aerodynamicists of the Central Aerohydrodynamic Institute (TsAGI) Kolosov published an article "On the choice of the wing loading" in the journal "Aircraft Technics" ("Tekhnika vozdooshnogo flota", pdf-version is available). In this paper, he convincingly argued that the increase in wing loading over 170 kg/m^2 makes no sense, as the gain in maximum speed is too small to justify the reduction in maneuverability and deterioration of take-off and landing characteristics. But at this time the I-185 with a wing loading of 230-240 kg/m^2 already flew, and it was superior to ALL the Soviet fighters with a much lower wing loading almost in all characteristics (max. speed, climb, roll, armament, etc.). OK, the turn time was slightly longer than that of the Yaks (22-23 s vs. 18-20 s), but it was already clear to everyone (except for TsAGI specialists, apparently) that the vertical maneuverability was much more important for fighters than the horizontal one. Moreover, the post-war development of Lavochkin's fighters with piston engines demonstrates a clear tendency for increasing of the wing loading towards values close to those of the I-185. I suspect that the article was written only to discredite Polikarpov's ideas, but perhaps it was Kolosov's sincere misconception.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Okay, I think you've had enough to drink.
NZTyphoon
Airman 1st Class
Another German fighter waiting in the wings (so to speak) was the Heinkel He 100 that, if it wasn't for a combination of factors, could have gotten into production as a supplement to the Bf 109:
the He 100 was even smaller than the 109, with a wing span of 9.4 metres (30 ft 10 in), a wing area of 14.60 m² (157.2 sq ft) and a loaded weight of 2,500 kg (5,512 lb) [fuel capacity =300 kg (660 lb) ]*. The wing loading was 171.2 kg/m² (35 lbs/ft²).
AFAIK, the only comparable fighter to get into large scale production was the Yak-3, with a wingspan of 9.2 m (30 ft 2 in); wing area 14.85 m² (159.8 sq ft); loaded weight 2,697 kg (5,946 lb)* and a wing loading of 181.6 kg/m² (37.2 /ft²).
Because the He 100 never got into operational service in front-line units, it's difficult to know how it would have performed in combat over the long term: there wasn't much room to expand either the fuel capacity, or the armament. In the short term it would have undoubtedly been a nasty shock to the RAF fighters and may well have changed the course of the Battle of Britain, but that's purely hypothetical.
*Wikipedia data
the He 100 was even smaller than the 109, with a wing span of 9.4 metres (30 ft 10 in), a wing area of 14.60 m² (157.2 sq ft) and a loaded weight of 2,500 kg (5,512 lb) [fuel capacity =300 kg (660 lb) ]*. The wing loading was 171.2 kg/m² (35 lbs/ft²).
AFAIK, the only comparable fighter to get into large scale production was the Yak-3, with a wingspan of 9.2 m (30 ft 2 in); wing area 14.85 m² (159.8 sq ft); loaded weight 2,697 kg (5,946 lb)* and a wing loading of 181.6 kg/m² (37.2 /ft²).
Because the He 100 never got into operational service in front-line units, it's difficult to know how it would have performed in combat over the long term: there wasn't much room to expand either the fuel capacity, or the armament. In the short term it would have undoubtedly been a nasty shock to the RAF fighters and may well have changed the course of the Battle of Britain, but that's purely hypothetical.
*Wikipedia data
The He 100 was a speed record plane. It could not be a fully operational fighter, and that was quickly realized by everyone who had the opportunity to examine it thoroughly (the Japanese and the Soviets). The He 100 was no real threat to the RAF - it was too vulnerable (especially, its oil cooling system) even taking into account its high flight performance.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
It's oil cooling system was unusual but a single bullet through a P-51D's radiator was just as damaging.
And the Japanese thought well enough of the He100 to purchase several.
The Soviets were impressed too and purchased several copies of He 100. But after a thorough examination they came to the conclusion that it was not an airplane for a real air combat. The cooling system was not only vulnerable, but also suffered from vibrations. Therefore, the installation of a 20mm motor-gun was considered as unlikely by the Soviets, moreover, they believed that even a rifle-caliber motor-gun was already too heavy for the plane.
Every airplane with a water-cooled engine is vulnerable. But even when the radiator is damaged, it takes time for the water to evaporate - the same concerns the vapor condensers in the wing à la He 100, but the _oil_ was cooled by _alcohol_, which evaporates much faster, and the system itself was located where a hit was most likely.
The Soviets discontinued all experiments with evaporative cooling after studying the He 100, where this system had been developed to a high level of perfection.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
The Soviets toyed with evaporative cooling before purchasing the He100.
The Ilyushin IL-21 predated their acquisition of the He100 by three years and were more interested in the aircraft design than the various cooling systems in the "V" series prototypes they recieved.
Before the war, evap. cooling was tried by the French, British and other nations and it was found to be too complex for.the desired results.
However, the technology is still in use today by air-racers.
I know in detail about Soviet experiments with evaporative cooling - and not only Ilyushin's. Thus, the Stal'-6 of Bartini's design was flying already in 1933. But the I-21 was probably the most unsuccessful project of Ilyushin, who did not like to mention this airplane at all.
Nevertheless, the He 100 demonstrated to the Soviets that even a very perfect evaporative cooling system was not sufficiently resistant to combat damage. In addition, they noted a number of fundamental design flaws - such as the engine mount.
cherry blossom
Senior Airman
- 513
- Apr 23, 2007
There was a thread some years ago arguing that the Ki 61 engine mount was a copy of the He 100 design Ki-61 and He-100 related?.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
I thought it was a design copied by NAA from Fokker whose sales rep left the plans on a sight seeing bus on Oahu.
Shortround6
Major General
Plane....................weight/lbs...............................wing area..........................lbs/sq/ft
P-26..........................2955........................................150.....................................19.7
D.510........................4253........................................178.....................................23.9
PZ-11........................3594........................................193.....................................18.6
I-16 type 5..............3378........................................156.....................................21.6
109B..........................4180........................................172.....................................24.3
P-35..........................5599.........................................220....................................22.45
Weights may vary with source.
The 109 was in the high side of the range but not by that much and the table shows what direction many countries were heading in.
The I-16 numbers are for a plane with just over 700 hp radial and two 7.62mm machine guns.
First 3 planes had fixed landing gear and external bracing.
GregP
Major
A few years back there was a question about the slats and we were working on an Ha.1112 (still are ... actually, it is sitting just now not being worked on). I measured them and they take up about almost exactly 1/3 span if you include the fuselage width and are placed to keep the airflow improvement more or less mostly over the ailerons. This helps maintain aileron control during a stall, but also causes directional snaking if they deploy asymmetrically. Since there is no rudder trim, they usually deploy a bit asymmetrically.
Moral of the story is to stay away from a stall if you are attacking something. If you do that, your aim will not be affected. There weren't very many times in a WWII fighter when hanging on the prop while firing at an enemy going around in a circle in front of you arose as a tactical concern but, if it DID come up, the Bf 109 could do it better than some other WWII fighters could.
Thanks for the link to an interesting topic!
As far as I understand, the Soviets' main criticisms of the motor mount on the He 100 were insufficient rigidity to fit a motor cannon and the necessity of considerable changes in the fuselage structure when installing new engine modifications. The Ki.61 was not fitted with a motor-cannon (at least I have not heard of any attempts or plans), so the Japanese engineers did not consider this flaw to be serious. The Soviets' opinion often reflected only the peculiarities of the Soviet approach to the aircraft design.
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Tony Kambic
Airman 1st Class
I did not read through all of these posts, but I did read Willy Messerschmitt's biography years ago. I was surprised to learn his design philosophy was a single main spar. The 109 is clear evidence of that. Maybe a smaller wing because of that?
GregP
Major
The 109 is a pretty neat little fighter, but no place to be if you're claustrophobic; the cockpit is small and cramped. But, the view out isn't as bad as some people suggest it is.
The cockpit bracing is way bigger than it needs to be, but the rest is at least a decent-quality enclosure. It was easy to bail out of as the entire canopy departed when the bail-out lever was pulled but, it you went out the starboard side, you might hit the tail support strut ... before it was deleted.
Altogether, it needed to have only a few things fixed that never were fixed. We have enumerated them before, so I needn't rewrite them here. Right up there in importance were rudder trim and re-gearing the roll and pitch authority to make it easier at higher speeds.
The cockpit bracing is way bigger than it needs to be, but the rest is at least a decent-quality enclosure. It was easy to bail out of as the entire canopy departed when the bail-out lever was pulled but, it you went out the starboard side, you might hit the tail support strut ... before it was deleted.
Altogether, it needed to have only a few things fixed that never were fixed. We have enumerated them before, so I needn't rewrite them here. Right up there in importance were rudder trim and re-gearing the roll and pitch authority to make it easier at higher speeds.
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