Death in the darkness

On a wing and a prayer...and an instrument gauge.
 

0450hrs and you're returning from a nightmare bombing raid over Bremen.

Outer starboard engine - feathered; no response from your tail gunner or wireless operator and there are gaping holes in both wings as oil streams from two of the aircraft's three remaining Rolls-Royce engines.

Somewhere below, approaching you at over 140 mph is your airfield - blacked out and shrouded in dense fog.

In front of your control column, just left of the airspeed indictor, you cast nervous glances at the intermittent flashing lights coming from your Lancaster's Beam Approach Indicator as you struggle to manoeuver 17 tonnes of labouring aircraft just enough to get a single, uninterupted signal.

Hopefully that signal will indicate your correct height and alignment to your runway - somewhere out there in the darkness.

Wheels down, flaps extended and heart racing - you say a prayer...

Floundering in the dark...

For the hundreds of returning Lancasters, Wellington and Halifax heavy bombers of Britain's Bomber Command, successfully evading anti aircrfat fire and Luftwaffe nightfighters over the target did not guarantee your mission survival.

Most found themselves returning under darkness to airfields completely blacked out. Even worse, those same airfields would often be shrouded in a thick blanket of fog - rendering any ground-based visual signalling next to useless.

Technical aids for landing assistance were still in their infancy with only two basic systems available to the pilots. One, GEE was a radio navigational aid which transmitted a homing signal to the aircraft’s Marconi R1155 Radio Receiver’s directional finding antenna which would then display a visual aid to the pilot via the Left/Right Beam Approach Indicator.  

Unfortunately, GEE could only guide the aircraft back to the airfield. It could do nothing to assist with landing safely in the dead of night, on a runway shrouded in fog.

This left only one other alternative, the SBA or Standard Beam Approach. Similar to today’s modern Beam Approach Beacon System – BABS, the original Standard Beam Approach System was a basic homing device where radio beacons on the airfield transmitted a continuous stream of signals to the approaching aircraft in a form of a narrow beam. 

The SBA system consisted of two main elements - one placed horizontally and one vertically and featured two neon lamps which would light up when passing directly over the appropriate marker beacon and a speaker output to receive the audio signal. The pilot would then check his altimeter and adjust his angle of approach to the runway.

When the pilot was lined up correctly, the signal received was steady and he knew he was aligned with the runway. If too far to the left or right, the signal became a stream of dots or dashes and he corrected his course until the signal changed to a steady pulse.

Unfortunately the poor accuracy of existing altimeters at such low altitude rendered the system somewhat unreliable with often catastrophic results.

This was never more disastrously demonstrated than on the night of 16th - 17th December 1943 - the RAF’s infamous, ’Black Thursday’, when 483 Lancasters and 15 Mosquito 'pathfinders' turned for home after a major raid on Belin's industrial center.

Dropping out of the sky...

RAF 97 Sqn were expecting 21 Lancaster to land within a space of just twenty minutes that night, but with the airfield blanketed in thick fog, controllers could only instruct each returning aircraft to join the stack already circling overhead and wait for it to clear. 

With each returning aircraft allocated a position some 500 ft higher than the previous, crews were forced to circle in the darkness waiting for their turn to descend. As more and more aircraft joined the stacks, all with ever decreasing fuel levels - the first of a number of midair collisions began to occur.

Many crews, with fuel tanks now empty were forced to bail out over the English countryside whilst others tried to bring their aircraft in by using the glow of crashed aircraft as a guide. 

It was a terrifying night for those in the air and on the ground and by first light, a total of 70 of the returning 483 Lancasters had been lost to the appalling weather. Nine of those Lancasters were from 97 Squadron and were their heaviest single loss of the entire war.