[bearoutwest]

Am I sure? Well, I’ll tell you what I know, and let you decide.

1. Apparent sizes of target:

In Alfred Price’s “Spitfire at War” (I assume Volume 1, as there is no number mentioned), on page 63, is a photo of a Spitfire at 600 yards distance. The instructions in the caption are to hold the page 18 inches away from your face. The Spitfire’s wingspan measures an apparent 1cm (or approximately one fingernail space).
Look up “Mil-Dot Range Estimation” in Google or Wiki for a more scientific calculable range estimation method.

2. Opening fire at 600m or 400m or closer:

The RAF had their Hurricane and Spitfire wing guns harmonised to 450yards range. The average pilot couldn’t hit the side of a barn at that range. Through operational experience, this was lowered to 250 yards. It was shown to be far more effective range to cause damage.
The Luftwaffe Bf109G would have centreline 20mm or 30mm cannon and nose (close to centreline) heavy machine guns. Longer ranging and more hitting power than the early RAF 0.303-in Brownings. Centreline weapons also simplified the ballistic trajectory for aiming. However, I suggest you want to get close to be able to hit a jinking target effectively. I would also suggest 400m is a reasonable compromise between weapon range versus hitting power (i.e. longer range is possible but likely to result in less hits). Hartmann was noted as liking to get really (almost collision) close to effectively hit targets like IL-2s.

3. Estimated closing speed:

100 km/hr closing speed; i.e. 100,000 m/60min
400m distance is covered in 0.24 min (approx. 14 seconds)
I rounded to 10 seconds for the discussion, so OK, you have 4 more seconds to make up your mind to fire or not.

4. What sort or detail can you see (colours or markings, etc) at 150m or at 400m:

1m = 1.09 yards, so not much change from using either.
I base my observations from my own flight training. I flew from a General Aviation airfield at Moorabbin in Melbourne. Twin parallel runways, and quite busy at times. Saturday mornings in Spring or Summer, not unusual to have 12 aircraft (Cessna 170s, or 180s, Piper PA-28s and some light twins) in the dual circuits. Head constantly swivelling and eyeballs on stalks to keep track of aircraft. Only thing different to war was that no one was shooting at me…..though some would say the “bark” of the Air Traffic Controllers was sometimes worse! I know I could make out the colours and details of aircraft flight school or charter company logos from across the flight circuit (so approx. 100-150m). From forward or rearward direction, I could tell you it was a blue aeroplane or a white aeroplane or maybe white with red fin. From 400m away, I could tell you it was a dark shadow on a blue sky or a white shape on a grey sky. If they turned to join in the circuit, and you could see the plan shape then you could make out what colour the fuselage was, but not much of the logo.
Try the exercise yourself with trucks on the road. Hopefully from the safety of a house window….see how much of the truck company logo you can see at 100m or approx. 400m or more.

5. How effective were aircraft markings:

I would say next to useless!

I don’t think they were much use for identification in flight combat. If they were so good, ask yourself, why the Luftwaffe needed yellow nose theatre markings on the Bf109E and F models during the Channel Front operations 1940-41. With the huge difference between a Black Balkenkreuz and the oversized RAF Red/Blue upper wing roundels, why were so many RAF Mustangs and Typhoons bounced and attacked by friendlies? Why did markings shrink in size with the passage of time?
Why would the Swedish AF remove the yellow crowns from the top of the wings on these Capronis? Perhaps to make the dark camouflage more effective against the dark sea. If they were to make their neutrality obvious, why not go high-viz with yellow upper-wings with blue crowns? I suggest because the markings were not going to be obvious enough at 400 km/hr speeds at 400-600m ranges, when a likely attack would be initiated. So far better to hide in the background to enhance survivability.

Like I said, just my thoughts.
…geoff


Additional (noticed sveahk's last comments):
I have no problem believing Schalk saw and recognized the markings, but he was being interviewed some time after the event. How close was he when he realized they were Swedish markings? How low were the Ca 313s flying? How low was Schalk? Did he attack the second Ca 313 a day later because he had convinced himself they were Russians flying with Swedish markings?


Juha, 1.5m diameter marking is not very big from 600m away. Spitfire has 11m wingspan and has an apparent size of about 1cm at 600 yards (say 590m). Do the truck test, and you will see what I mean.