Monthly Archives: January 2014

Ha! I now have a trivial python program the works interactively! momdad.py:


“””
“””

import os

print “os.listdir(os.getcwd())”
print os.listdir(os.getcwd())

for fname in os.listdir(os.getcwd()):
print fname
text=open(fname).read()
print “text.count( hi mom )”
print text.count(‘hi mom’)

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A philosophic reason to sets pointers to NULL after free’ing them.


A philosophic reason to sets pointers to NULL after free’ing them.

On reflection, I think I got this one right, and I kinda like it! I have experienced other people’s double-free errors, surprisingly, but the value of crashing-on-access-via-null is persuasive to me. Making double-free happen silently and without error is a small cost for positively crashing on a rogue access through a freed pointer.

Hawker Hurricane Mk I, 4/27/1939-6/5/1940 dH 2-position prop, “B” pattern camo, starboard profile, 1/2 white underside, v.10


<Hawker Hurricane Mk I, 4/27/1939-6/5/1940 dH 2-position prop, "B" pattern camo, starboard profile, 1/2 white underside, v.10

Mid-production Hawker Hurricane, Mk I, with Rotol constant-speed prop and a Spitfire spinner (the dedicated Hurricane spinner arrived in late 1940). This is what one would look like if it was painted all together, and they stopped before applying the national and service markings. Just “B” pattern camouflage on top, Dark Green and Dark Earth. Starboard side white, port side black, underneath, meeting at the centerline. Nothing of the original “Aluminum” finish remains outside, but the wheel wells and inside of the undercarriage doors might well be “Aluminum”, still.

The “A” and “B” camouflage patterns were mirror images, so this starboard, “B” scheme, is the same as a port-side “A” scheme, except reversed left to right
The black/white underside recognition features was ordered in August 1938. While the requirement for black under the port wing was made known fairly readily, how to treat the starboard wing, horizontal stabilizers and fuselage underside was somewhat to very unclear between 8/38 and 4/39. The intent was to have the port side black up to the center of the fuselage, and the starboard side white, up to the center of the fuselage, as this drawing and its companion show.

Hawker Hurricane, 1939, dH 2 position prop, “B” scheme camo, port profile. Black and White meet halfway under the wing. v.11


<Hawker Hurricane, 1939, dH 2 position prop, "B" scheme camo, port profile. Black and White meet halfway under the wing. v.11

Another mid-period Hurricane. Between Munich (August, 1938) and the invasion of Poland (September, 1939), the, still, “peacetime” RAF expanded dramatically and was flooded with new technology. While everyone more or less understood the written instructions to paint the underside of the port wing black, for recognition when airborne, what to do with the rest of the plane was not always grasped. Black and white across the undersurface of the wing, meeting at the center line, was a durable interpretation, frequently seen, with the rest left as built, in Aluminum finish. Here’s what that would look like with no national or service markings.

Note, the “B” scheme camouflage is the mirror image of the “A”, same blobs of color, but on the other side. So that a row of airplanes would not stand-out by looking identical.

Hawker Hurricane, 1939, port profile, “A” pattern camo, de Havilland 2 position prop, Blk Wht Alu under v.12


Hawker Hurricane, 1939, dH 2speed, "A" pattern camo, Port profile, Blk Wht Alu under v.12

(Click on image for all size access)

A mid-production Hurricane Mk I. “A” pattern camouflage. Underside finished in Aluminum but outer wing panels are black on port side and white on starboard. De Havilland 2 position prop (their build of the Ham.-Std patent), ejector exhausts, anti-spin strake and rudder extension. Port profile.

de Havilland’s metal prop and related hydraulics weighed 350lb more than the Watts wooden prop, but offered a fine (for acceleration from low speed) and coarse (for high speed) settings. With a takeoff speed under 100mph and a maximum speed above 300mph, the Hurricane with a fixed pitch prop was like an automobile with one gear from 20mph to 60. Unresponsive and twitchy at low speed, screaming like a banshee, unnecessarily, at top speed.

The camouflage pattern looked quite different from port side than from starboard, intended to disrupt the outlines of multiple planes parked on the ground.  The “B” scheme was the mirror image of the “A” scheme, so that a line of planes parked in a single direction wouldn’t all look exactly the same.

At the beginning of the war, the “Dark Green” area was always painted Dark Green and the “Dark Earth” always painted Dark Earth, but in the later part of the war, colors were sometimes seen reversed, particularly if re-applied or revised in the field.

Hawker Hurricane Mk I, digital image, by me, “A” pattern camo, Watts prop, no strake, tube mast, Aluminum finish under


Hawker Hurricane Mk I, 1938, digital image, by me, "A" pattern camo, Watts prop, no strake, tube mast, alu. finish under.

Hawker Hurricane Mk I, early production, one of the first 50 built, in 1938, before the anti-spin strake and rudder extension were added. It should have the “kidney” style exhausts, and I’ll change it. This shows the complete external finish, with no national or service markings, yet.  Much like a painted model airplane, before the decals…

Hawker Hurricane Camouflage and exterior / interior colors.


I’ve just completed a series of color profiles of Hurricanes and I’m going to explain them here, with links to click on to show the images. I can’t seem to imbed them in this page without making a literal copy, which seems like a bad idea. So here’s literal copy to show what kind of image we’re talking about, and then descriptions and links:

Hurri Mk I, A patt

Hawker Hurricane, 1939; port profile,”A” pattern camouflage; 2 speed de Havilland prop; black, white, aluminum under v.12

Here’s the first plane, chronologically by subject:

Hawker Hurricane Mk I, 1938, digital image, by me, "A" pattern camo, Watts prop, no strake, tube mast, alu. finish under.

There are four parallel histories here, one, of the exterior colors and camouflage the RAF and RN used on all their airplanes, from 1937 to 1946. Second, the evolution of Hurricanes as a new-build manufactured item from Hawkers, Gloster, etc., in the UK, and Canadian Car and Foundry in Canada. Third, the evolution of Hurricanes in service, as operated, maintained, and repaired in the RAF, RN and Empire Air Forces. Fourth, the colors and markings specific to Hurricanes in the RAF, RN and Empire.

RAF camouflage and exterior colors  evolved in this sequence:

  • Overall Aluminium
  • Dark Earth and Dark Green upper surfaces, Temperate Land Scheme; black propeller blades
  • Aluminium undersurfaces
  • Black and white undersurface identification marking
  • Black spinner, yellow propeller tips
  • Sky undersurfaces (Sky type ‘S’)
  • Black starboard wing underside returns, departs
  • Sky spinner and aft fuselage band
  • Black overall night fighters
    • Special Night, ultra-flat black
    • Smooth Night, matte black.
  • Dark Earth and Mid-Stone, over Azure Blue
  • Dark Green and Ocean Gray, over Medium Sea Gray
  • Dark Green and “Mixed Gray”, over Medium Sea Gray
  • Black undersides for night intruders
  • Dark Earth and Dark Green, over Medium Sea Gray

 

RN camouflage and exterior colors evolved in this sequence:

  • Overall Aluminium
  • Slate Gray and Extra-Dark Sea Gray upper surfaces, Temperate Sea Scheme; black propeller blades
  • Aluminium undersurfaces
  • Black and white undersurface identification marking
  • Black spinner, yellow propeller tips
  • Sky undersurfaces (Sky type ‘S’)
  • Black starboard wing underside returns, departs ?
  • Sky spinner and aft fuselage band
  • All white lower surfaces, gloss below, matte above

 

Hurricanes as manufactured: The original Hurricane production line followed Hawker’s usual practices of the mid 1930s, building up the fuselage truss and wing center section spars from tubing and rolled sheet metal. A family of joints between multiple tubes had been designed at Hawker, with tools to form the tubing into flat-sided, readily joined pieces, brackets to allow the formed pieces to be bolted together securely, and fittings to anchor the joints to internal tension wires. The fuselage girder was internally wire braced from the engine bearers to the rudder pivot.

The first 500 airplane’s wings were also fabric over metal frames and featured high strength sheet steel spars, rolled from single sheets into avertical web and top and bottom octagonal tubes, fore and aft. Ribs zig-zagged between the spars (/\/ww.\/\) forming a light, strong, stiff structure. The wide-track, retractable, landing gear was attached at the outside of the inner wing stubs. Ribs attached to the spars, front and back, to give an airfoil shape to the linen that was stretched over the whole structure and then doped.

Photographs clearly show the tube frames were painted a light color, almost certainly the familiar Aluminium lacquer or enamel, as were the interiors of wheel wells, spars, ribs, etc. The cockpit walls, outside the tube frame, were, in production, painted with the RAF’s standard, gray-green, fuel-proof, coating. (Lacquer? Enamel? something else?)

The heel-boards leading from under the seat to under the rudder pedals were unpainted aluminium or possibly painted Aluminium colour. Cockpit seats also appear to be unpainted aluminium, but Aluminium colour is again possible. There aren’t any contemporary color photographs and few Hurricanes led a sheltered life. Forensic sanding, as the Smithsonian did on the rudder counterweight of the Mustang “Excalibur” would be interesting. Presumably, this is what leads to the schemes used by Hurricane Restoration and other professionals.

While those were being built, Hawker designed an all-metal wing of monocoque construction. It was lighter, cheaper and easier to build than the traditional form, but required Hawker’s technology to evolve, while the original form poured off the production line and into RAF service.

It was painfully clear that centralized manufacture of anything in war-time was an invitation to disaster. Hurricane production, like everything else, was dispersed to many locations, each building as much value into their piece as possible, before having to send it to another workshop to integrate into the next step.

 

Other operators: Hurricanes in the Belgian, Dutch East-Indies, Royal Egyptian, Finnish, Imperial Iranian, Irish, Portuguese, Soviet, Turkish, and the Kingdom of Yugoslavia Air Forces started out in RAF/RN colors, and if they survived, further evolved locally. A single Hurricane shipped to Australia during the war, a single example shipped to Argentina after the war and three that were transferred to the Belgian AF after the war had similar histories. The RAF identified many of its own squadrons by the country of origin of most of their pilots, for example, Royal Australian, Royal Canadian, Czechoslovak in exile, Danish in exile, Free French, Royal Indian, Royal Hellenic. Royal New Zealand, Royal Norwegian, Polish, and South African. All operated within the RAF and their equipment was the same as near-by RAF units.

I do not attempt to describe what camouflage was carried by the 20 Hurricanes built by the Zmaj factory in Yugoslavia or the two built in Belgium. More than one Zmaj-built example fell into Italian hands, two Mk IIb Trop models fell into Japanese hands and a number of working or repairable examples came into German hands.

The RAF and RN standard, when Hurricane production began, was overall Aluminium (note spelling) dope, lacquer or enamel, depending on substrate. Fabric surfaces of Hurricanes were Irish linen, with a dark red dope applied to tighten it, then the Aluminium top coat. Aluminium dope is a excellent finish for fabric covered airplanes, because it blocks all Ultra-Violet light, which would otherwise bleach and degrade the underlying dope and fabric. A trained worker can get a satisfactory finish using standard tools and techniques.

Before the Munich Crisis, someone in the RAF realized it was time to hide the airplanes, and the familiar Dark Green and Dark Earth were applied. These were not repeats from WWI practice. There must be a history, but I don’t know it. They were collectively named “Temperate Land Scheme”. The Royal Navy soon had both a Temperate Sea Scheme, and a Tropical Sea Scheme. Eventually there was a Desert scheme for the RAF. All of these camouflage schemes applied only to the upper surface of the airplane. The underside finish was the previous, non-camouflage, standard, Aluminum, dope, lacquer or enamel.

Yes, these rabbit holes go very deep. See, for example,
http://www.britmodeller.com/forums/index.php?/topic/66903-raf-hurricanes-in-desert-camo/

The prototype Hurricane had its exterior metal panels polished, the very first production planes might have had Aluminium lacquer over gray primer. The green and brown finish became the factory standard, quickly, and the Maintenance Units would have updated any early production.

All this first set use the Temperate Land Scheme and the Desert scheme. (Capitalized? “S”cheme? There is no end to this stuff.)

Temperate Land colors are Dark Earth, a golden brown, much like a freshly plowed field in UK, and Dark Green, a nice, mature foliage color. On my first visit to the UK, looking out of the airplane window, I saw these same colors spread out in the countryside, and I realize this is precisely what this camouflage was intended to blend in to.

Here are relevant examples:

Captured Hawker Hurricane

Color photo of captured RAF Hawker Hurricane undergoing testing in German hands. Note Luftwaffe markings, worn appearance of finish.

Canadian Hurricane

Contemporary color photo of Canadian Hurricane in flight

Preserved Hurricane

British Science Museum’s Mk 1 Hawker Hurricane and Supermarine Spitfire. Hawker Siddley overhauled the Hurricane in 1963, the finish may not be original.

 

 

Contemporary WWII photo of Hurricane production, in Desert scheme

 

When Hurricanes went to Crete, Malta, Palestine, the Suez Canal Zone, and Egypt, they went wearing the standard green and brown. An Azure Blue for undersides to match the deep, dark, blue of a drier sky, appeared. A yellow-brown named “Mid Stone” replaced Dark Green and that was enough. Night bombers and intruders got black undersides, sometimes, but I’ve never seen evidence of all-black night flyers in the Mediterranean.

Undersides are a different kettle of fish. Originally left Aluminium, they were then intended to be painted half black and half white, divided down the middle of the underside. with the black on the left or port underside and the white on the right or starboard underside. This would make it very easy to recognize RAF airplanes compared to any others. The tersely worded official telegram instruction was open to more than one interpretation, however, resulting in airplanes with the wings painted white and black underneath, but the fuselage and tail left all Aluminium. In other cases, the black and white on the wings extended to the centerline under the fuselage, but the fuselage, fore and aft of the wings, remained Aluminium.

During the Battle of Britain, providing easy identification of British planes was reconsidered, and a new underside color, named Sky, was required, from sunrise on May, 1940. Also referred to as “duck egg blue”, Sky was a light, slightly greenish, blue. It had been worked out as the overall color for a notionally civilian Lockheed owned by a man named Cotton. As war became more and more likely, it became clear that accurate maps of Germany might be valuable and hard to get. Mr Cotton’s twin-engined Lockheed had a hidden camera installed, with a remote controlled cover that could open in flight,

Some experimentation revealed the light greenish blue concealed it best from ground observers. Thus painted, it ranged far and wide in European skies, in the fading years of peace, building a foundation for British aerial mapping throughout the war.

 

Additional reading:

https://en.wikipedia.org/wiki/List_of_Hawker_Hurricane_operators

“Duel of Eagles” – Peter Townsend

Camouflage & Markings: R.A.F. Fighter Command, Northern Europe, 1936-1945 
by James Goulding

http://www.britmodeller.com/forums/index.php?/topic/66903-raf-hurricanes-in-desert-camo/

Explore Hawker Hurricane and more!