SQUADRON REPAIRS TO WOODEN PROPELLER BLADES [Main Title]

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  • Title: SQUADRON REPAIRS TO WOODEN PROPELLER BLADES [Main Title]
  • Film Number: AMY 52
  • Other titles:
  • Summary: Detailed instructional film focusing on repairing damaged wooden propeller blades.
  • Description: PART ONE: COMPOSITION OF THE BLADES: Reel one: Description of wooden propellers, fixed pitch, veneer construction. Spitfire crash landing on aircraft carrier and damaging prop. Repairs in squadron workshops can be classed as minor or major. Major requires prop sending away for specialist repairs and damaged areas treated with cellulose to seal exposed wood and prevent further damage by moisture. Minor damage such as tips can be repaired in squadron workshops. Prop removed from aircraft. Description of construction of wooden props. Rotol props made from Hydulignum Board, Spruce or Fir Board or Jablo Board. Jablo Board - Method of layering wood veneer and resin impregnated paper and compression of layers to achieve strength. Hydulignum Board is coated on both sides with thermoplastic resin and dried. Boards compressed. Softwood board construction explained using hardwood “scarfed” into the spruce or fir to strengthen the root of the prop. Wooden veneer placed on lathe to cut to shape and hand finished. Reel two: Various methods of finishing/covering wooden propeller blades and testing balance of completed blades. Completed blades are marked to indicate covering, balance and type of wood. PART TWO: EMERGENCY AND TIMBER REPAIRS: Reel three: Temporary repairs to slightly damage blades. Must not be painted black – repaired area must be obvious. Damaged tips can be cropped to within 3% of the propellor diameter but only in an emergency to keep the aircraft in service. If ground running exposes any vibration the other tips may also be cropped by same amount. All repairs must be sealed. Blade should be marked with repair type e.g. “Cropped 3/4”” Bullet holes can be repaired temporarily and later in station workshops but not if within 12” of propellor root. Repairs covered with doped linen overpainted red. Worn edges are cleaned and repaired with dope linen cloth. Small stone chips can be cleaned and sealed. Reel four: A.P. 1538C/E/F Vol 2 covers limits of repairs permitted at station/squadron level. Mixing of Casein cement explained in A.P. Stores reference numbers for all materials given. Timber repairs covered first. Repairing a propellor trailing edge with a wooden insert. Tip repairs are carried out in a similar way. Repairing a bullet hole that had been previously repaired under 'emergency' conditions. Limits explained regarding repairs to holes on various parts of blade. PART THREE: COVERING REPAIRS: Reel five: Five types of covering used in Rotol Propellers. Each easily identified. Covering repairs can be made at squadron level and usually done with the blade in the hub but in the film they have been removed. The small information discs at the root of the blade state which covering is used (Cellulose Sheeting in this example). Once timber repaired the old covering is bevelled back to allow new covering to be blended in. Cellulose primer applied. Cellulose nitrate sheet softened prior to application. Once dried smoothed down and painted. Repairs to damaged tips. Removal of leading edge armour sheath. Once tip repaired replacing armour sheath strip and riveting in place. Reel six: Repairs to brushed on type of coverings. (Cristofin covering with simple metal sheath in this example). Repairs to damaged edge. Old covering removed and rivet screw holes filled in. Rivetted/screwed then soldered and filed down and reprimed/painted. Repairs to the flat portions using Cristofin patch.Trailing edge repairs using Cristofin patches. Reel seven: Jablo covered blade with brass sheath understrip repair – leading edge damage. Removal of the sheath and understrip. Jablo gauze under covering removed. Timber damage repaired and the replacement of the Jablo covering. Mixing Jablo enamel. New piece of gauze measured and fixed over repaired area. Patch clamped to ensure gauze fixes. New leading edge strip measured and fitted. Sanding down of repair patch and finishing off with grey primer and painted black. Repair of Schwartz reinforced fabric covered blade.
  • Alternative Title:
  • Colour: B&W
  • Digitised:
  • Object_Number: AMY 52
  • Sound: Silent
  • Access Conditions:
  • Featured Period: 1939-1945
  • Production Date: 1943
  • Production Country: GB
  • Production Details: ROYAL AIR FORCE (Production sponsor) Signet Pictures Corporation Ltd (Production company)
  • Personalities, Units and Organisations:
  • Keywords:
  • Physical Characteristics: Colour format: B&W Sound format: Silent
  • Technical Details: Format: 35mm Number of items/reels/tapes: 7 Length: 5231ft
  • HD Media:
  • Link to IWM Collections page:

    AMY 52

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