Aircraft Bomb Sight (Germany)

German aircraft bomb sight removed from the first German two seater to be shot down in British lines, Palestine 1917.
The instrument comprises two triangles with their peaks truncated, the smaller being attached to the aircraft fuselage, the larger (outer) being able to slide over the smaller (inner) to allow the bomb aimer to adjust the sight for level. The whole instrument is constructed of wood, with metal plates, slide and sighting apparatus. The wood and metal parts (where painted) are painted a light grey-green, corresponding closely to Munsell 10GY 6/1. The triangles are mounted upside down on the side of the fuselage. The ends of the triangular structure are rounded.

The smaller triangle has a base approx. 205 mm in length. The vertical (to the base) side is 235 mm in length. The third side measures 270 mm in length. The top where the peak of the triangle is cut off is 80 mm wide. The two legs of the triangle are 25 mm wide and 15 mm thick. The base is 45 mm wide and 15 mm thick. A metal plate holds the two sides apart and is attached by two screws in each side. This plate is 60 mm deep on the vertical. It has a keyhole where it is attached to the fuselage. The keyhole circle is 9 mm in diameter. The “key” is 16 mm in depth. Two metal plates secure the base to the sides. Each has four screws and a key hole for attachment to the fuselage. These two plates are the same and are mounted as mirror images. They are 50 mm x 75 mm in size with the top cut approx 6 mm at each side to form a hexagon.

The larger outer triangle has a base approx 280 mm in length. The vertical side is 285 mm in length. While the slopping side in 330 mm in length to the truncated top of the triangle. The top where the peak of the triangle is cut off is 105 mm wide. The sides of the triangle are 25 mm wide and 15 mm thick. The base is 35 mm wide and 30 mm thick. There is a bolt in the base of the smaller inner triangle approx 65 mm from the vertical side. This bolt had a wing-nut and compression washer attached that passes through a 50 mm wide metal slide that is attached to the larger outer triangle 100 mm from the base of the triangle to the top of the metal slide. By adjusting the tension on the washer the outer triangle may be slid over the inner triangle through a curved slot in the metal slide. There is impressed into the wood on the vertical side of the triangle a black logo that appears to be a stylised bird in a circle with a lightning bolt underneath and the “Nr.28410”. This is located approx 145 mm from the base.

At the base of the pyramid is attached the bomb sighting apparatus. It comprises a slide with a spirit bubble attached approx 90 mm overall in length. This slide runs for the complete length of the base in a modified C-section channel 34 mm wide with a 20 mm slot over which the sighting apparatus slides. A release is attached to the end of the sighting apparatus, and there is a small periscopic instrument in a tube 55 mm long that is attached to the other end of the slide so that it is vertical when the whole instrument is mounted on the fuselage. The tube is threaded on its interior. This would originally have allowed the attachment of an electric torch bulb, which would have alloewed the use of the device at night. (see RELAWM03828 for an extant example). The left side of the slide is inscribed with 'Hohe' (height) and the right side with Gest. Zeit. ([unknown] Time). Projecting vertically from the slide is a metal bar approx. 10 mm wide and 40 mm in height. To this is a tapered metal piece that holds at its end a rectangle with a half circle cut in to the plate at its middle. This is the rear sight for the bomb aimer. The fore sight is missing - it would have been a metal rectangle attached to the bottom of the triangle, and bisected with a thin wire. This sight slides up and down a series of scales inscribed into a black metal plate with white painted letters.

The outside scale measures from 16 to 20 in units of “2”, thence in units of “5” to 40, then in units of “10” to 70. The scale is graduated and the lower numbers are further apart. This scale might represent freefall time from release of bomb to impact, or horizontal distance covered by the bomb. On the inside side of the scale is similarly inscribed another series of units, measuring height from 600. From 600 to 1200 is in units of “100”, then to 2000 in units of “200”; then 2500, 3000, 4000, 5000 and 6000. Again the units are closer together the higher up the scale one goes. A hollow metal rectangle that is attached to the sighting apparatus is marked at its centre with two white arrow heads directly opposite each other that read the two scales. The two are read together. There is no means of adjusting the instrument such that a different reading may be made.

When attached to an aircraft the base of the instrument with the scale becomes the top of the instrument with the sighting apparatus on the outside side, as is the adjusting wing-nut.

This bomb sight would have been mounted onto the side of a light reconnaisance or bombing aircraft, and would have given the bomb aimer the ability to place his bomb on target using the aircraft's height and wind speed as the main variables. (The aircraft speed would be considered to be constant). The manufacturer is also not yet established.

The item is associated with the service of Lieutenant Leslie William Sutherland MC DCM MID. Sutherland was born in Murrumbeena, Victoria on 17 December 1892. He enlisted as a Private in 1 Signal Troop, ANZAC Mounted Division on 19 August 1914 but was a Corporal on embarkation on 20 October 1914. Sutherland was promoted to Sergeant on 22 May 1916 and was awarded the Distinguished Conduct Medal for conspicuous gallantry in action on 31 August. He was promoted to Second Lieutenant and transferred to 1 Light Horse Regiment on 6 September and was promoted to Lieutenant on 21 December. On 15 June 1917 Sutherland was transferred from Base Signals Depot to Royal Flying Corps Rafa for duty. He was then attached to No. 67 (Aust) Squadron RFC (officially titled No. 1 Squadron AFC from 19 January 1918) on 13 July 1917 before being formally taken on strength on 14 August as a Flying Officer (observer). Sutherland was awarded the Military Cross for gallantry and devotion to duty in the field on 1 December 1917. On 1 November 1917 Sutherland relinquished his appointment as a Flying Officer to be the Squadron’s Recording Officer. He resumed duty as a Flying Officer on 13 July 1918 but trained to become a Flying Officer (pilot) during the latter half of 1918. By the end of the war, he had 8 kills to his credit. Sutherland graduated as a Flying Officer (pilot) on 20 January 1919. He returned to Australia on 5 March 1919 aboard the Port Sydney and had his military appointment terminated on 16 June 1919.