For the Amateur Constructor

1. Techni cal Data Circulars, by which means our constructor members receive details of airworthi_ ness procedure, modifications and recommendations are sent out from Londonderry House.

2. Technical Data Circular No. 1 refers to material equivalents and bolt sizes for Turbulen t aircraft. Issue I of this circular contains certain ad_ ditional notes which refer only to Turbulents with Constructors Numbers below 400.

3. Technical Data Circular No. 2 lists certain stages of inspection which should be recorded in respect of structural inspection before spars and leading edges, etc., are boxed up.

4. Technical Data Circular No. 3 is similar in content to Circular No. 1 but concerns Turbi arrcraft.

5. Technical Data Circular No. 4 refers to essential registration requirements for both Turbulent and Turbi aircraft.

TncsNrcar, Darl CrRcuren No. I - Turbi

Conversion Chart x 14 l"x15t"x16 1"x19 *L" x 12

Note 1: British bolts are BSS. 6 Al. Low Tensile steel 35_45 tons sq. in. 5530-7110 kgs. sq. in. On sheet steel fittings: Mark off radii as shown on plans, except for 6 mm. and 7 m1n. bolts, where mark off radii as shown on plans plus 0.010 in. and 0.020 in. respectively.

Sheet steel Spec. 3.S.3. 28 tons sq. in.14424 kgs. sq. cm. Steel tube: Specification T.45. 45 tons sq. in.i77l0 kgs. sq. cm.

1. Plunger marked 23 mm.on plan make 23.4 mm.

Pedal tube (4)

Main axle

Radius rods

Silentbloc housings (2) u/c leg & control column (l)

Axle ends (3)

2. Ream out to $" for Silentbloc bush $,, centre hole.

3. Ream out to suit outside diameter of bush g3.

4. Rudder pedal hinge to suit and pack under one side with 1 mm. ply.

Where bushes are welded on to fittings do not open out holes without making allowance on outside diameter. e.g. Control Column -ioint to floor is 12 mm. tube reamed 7 mm. hole, therefore increase outside diameter to *,, to allow for reaming hole to *s".