The highly critical “Butt Report”, published in 1941, concluded that a large percentage of RAF bombers and bombs were not reaching the actual target, despite crew’s claims to the contrary.
The government and the Air Ministry were extremely embarrassed about the findings and set about improving the situation.
Establishment of the Pathfinder Force
As part of the effort to improve accuracy, the Air Ministry agreed to form a specialised force, which became known as the Pathfinder Force (PFF).
PFF crews were trained to accurately follow the agreed navigational route, marking the “turning points” with coloured flares. Having reached the target area, they marked the start of the bombing run with flares and then dropped flares and/or coloured markers on the target.
Bombers in the main bomber stream were able to use these indicators to identify their turning points and bombing targets.
Pathfinder techniques changed considerably throughout the war as new technology became available.
- The “Parramatta” ground marking method, which was used when the weather forecast suggested good visibilty over the target area.
- The “Newhaven” ground marking method, which was used when the forecast suggested some visibility over the target area.
- The “Wanganui” sky marking method, which was used when the forecast suggested minimal visibility over the target area.
Each Pathfinder aircraft was assigned a specific role for each mission, based on their skills and experience. These roles were dependent on the method(s) being utilised for the mission.
Parramatta required “Blind Markers” and/or “Visual Markers” to drop coloured target indicators (TI) to identify the aiming point. “Blind Markers” utilised navigational aids to identify the target, “Visual Markers” utilised visual contact through the bombsight to identify the target.
Newhaven required “Blind Illuminators” and/or “Visual Illuminators” to drop flares to light up the target area. When the area had been lit up, “Visual Markers” would visually identify the target and drop their coloured target indicators (TI) to identify the aiming point.
Wanganui required “Blind Markers” to drop coloured parachute flares (skymarkers) to identify the aiming point. As well as being a standard method, it was used in an emergency if cloud cover, smoke screens etc obscured the target on arrival.
The following is an example of part of a 1944 briefing outlining the Pathfinder method(s) to be used:
As the flares and target indicators only burned for a short while (approximately three minutes), Pathfinder aircraft were spread throughout the main bomber stream to repeat the marking process. These were known as “Backers Up” or “Visual Centerers”.
To gain experience, new Pathfinder crew would be assigned the role of “Supporter”. They would fly as part of the initial wave of Pathfinders to “support” the markers.
The raid would be co-ordinated by a “Master Bomber”, circling above the target. He broadcast instructions to crews advising them on where to drop their flares, target indicators and bombs based on his view of where the target was in relation to the coloured indicators on the ground.
To perform their role, Pathfinder crews were provided with aircraft equipped with the latest navigational technology, including Gee, Oboe and H2S.
Their bomb loads were mission specific and, depending on their role, contained a mixture of bombs, flares and target indicators.
Target indicators were specially adapted 250lb bomb casings containing sixty coloured pyrotechnic candles (red, green, yellow). At the designated height, the casing would explode, releasing the ignited coloured candles which would float down to the ground. These would burn for about three minutes, providing a coloured “aiming point” for the main bomber stream.
Sky Markers consisted of an encased candle flare attached to a large parachute. When released it would float down to the ground, igniting at a designated height; pieces of the candle would full off, creating a vertical chain of light.