Posts Tagged 'Air traffic control'

Air Traffic Control, Bomber Command-style

Around the time that Jack Purcell and his crew were on active service with 467 Squadron (January – May 1944), Bomber Command was routinely sending forces numbering six or eight hundred aircraft on large-scale raids against German cities. Even the ‘smaller’ raids on French targets still involved a couple of hundred aircraft each. Landing everyone safely at their airfields after the operation, in the dark, with no lights or radar, and contending with fatigued aircrew, battle damage and the odd German intruder attack, required the development of some remarkably sophisticated and highly efficient systems, and thus laid the foundations for what we now know as air traffic control.

There were a number of local variations depending on which Group the airfield fell under, but the basic procedure was that incoming aircraft would call up the control tower as they approached their home airfield to identify themselves. Flying Control would respond with instructions to either land immediately if there was no-one in front of them, or to circle the airfield, stacked above earlier arrivals at 1,000’ intervals. As No. 1 was in the circuit at 1,000’ and preparing to land, No. 2 would be circling at 2,000’, No. 3 would be at 3,000’ and so on. No. 1 flew around the circuit, following the ‘Drem’ lights located around the airfield, and the pilot would report on the radio as he passed each position: ‘crosswind’ as he passed over the upwind end of the runway, perpendicular to it; ‘downwind’ as he passed the mid-point of the runway, flying parallel to it (which is also where he would begin a slow descent from 1,000’ to land), and ‘funnels’ as he made the final turn to line up with the runway, facing into wind. Then he would wait for the green light from the aerodrome controller (who was located in a caravan parked next to the landing end of the runway) before landing and taxying off the runway to dispersal. Meanwhile, No. 2 became No. 1 and would leave the stack. He would adjust his circuit spacing and speed to position himself one reporting position behind the aircraft in front. As each aircraft left the bottom of the stack, everyone else still circling above them could be stepped down a level until, in turn, they were at the bottom and next to land.

Arrival over base could be inside 10/10ths cloud. In this case, according to 49 Squadron veteran rear gunner Hugh McLeod, the navigator would use the ‘Gee’ navigation aid to home in to the airfield. He would be calling instructions to the pilot in much the same manner as the bomb aimer would while over the target: “Starboard a bit, Skipper… hold it there… should be coming into view now”. Hugh says it was accurate enough to take the aircraft all the way to ‘funnels’ – quite astounding accuracy for the time. In the event of an intruder alert (“this happened to me on three occasions,” Hugh said), an emergency call would come over the radio, lights everywhere would be turned off and the arriving bombers would all scatter until the all-clear sounded or they diverted to other ‘dromes.

It’s interesting to study how the ‘Quick Landing Scheme’ worked in practice on a typical operation. My interest was piqued by an entry in the 467 Squadron Operational Record Book, following a Berlin raid on 15/16 February 1944. Pilot Officer Clive Quartermaine, flying in Lancaster LM338, said this in his interrogation report:

Had to circle base for 40 minutes before landing. Quick Landing Scheme disappointing.

This was an intriguing comment, I thought, and warranted further investigation. Happily, the ORBs for both 463 and 467 Squadrons record landing times for each aircraft at Waddington. I plotted reported landing times in five-minute blocks, for all aircraft landing between midnight and 1 a.m. LM338 landed at 00.53 (in red). The resulting table looks like this:

Time Aircraft   Landing Times
0000-0004 0001 0001 0003 0004
0005-0009 0008
0010-0014 0010 0011 0012 0014
0015-0019 0015 0015 0015 0017 0019
0020-0024 0022 0023
0025-0029 0025 0029 0029
0030-0034 0032
0035-0039 0036 0039
0040-0044 0040 0041 0043
0045-0049 0045 0047 0048
0050-0054 0053
0055-0059 0056

During this hour, thirty aircraft landed at Waddington. The longest gap between arrivals is five minutes (it comes immediately before Quartermaine landed). Without a modern-day radar controller judging approach paths and in darkness, the odd ‘blow out’ of a few extra minutes in the landing sequence is quite understandable. Shorter intervals are far more common and, assuming the times recorded in the ORB are indeed accurate, there were an amazing three arrivals in a single minute at 00.15. Tellingly, this was about 40 minutes before Quartermaine landed, so was quite possibly about the time that LM338 arrived overhead – to find a large stack of aircraft already awaiting their turn to land.

In the next 40 minutes, as Quartermaine and his crew circled overhead the field, a total of 21 aircraft landed. At a rate better than one aircraft every two minutes, this is actually a reasonably efficient use of the runway given wartime conditions (blackout, no lights, no radar control, fatigued crews etc). There is insufficient evidence about the timing of when other aircraft arrived over the field, but there is a good chance that other captains faced similar waiting times.

So while P/O Quartermaine may well have felt a little hard-done-by having needed to wait for so long, it was a simple case of too many aircraft arriving at once and not enough runways for them to use. This basic cause of airborne delays is still a common occurrence in modern-day air traffic control. Nothing ever changes… someone still has to wait!

Descriptions of aerodrome control come from C07-014-123, The Trenches in the Sky by Dan Conway, and C07-050-023 Takeoff to Touchdown by Don Charlwood. Hugh’s recollections were related in a phone call in May 2013.

© 2013 Adam Purcell



I was talking to 463 Squadron veteran Don Southwell on ANZAC Day in April about his training to become a navigator in WWII. Among other things he spoke about life at Initial Training School at Bradfield Park. He said that days started with physical training and drill, and were then full of theory classes – and when the trainee aircrew had time off from formal classes, they were expected to study. He remembers some particularly challenging subjects keeping him working at his desk until one or two in the morning. “The blokes in my hut”, he told me on the phone recently, “used to say that they didn’t have to go to classes because they’d hear everything from me… while I was talking in my sleep!”

This got me thinking (as happens every so often). In some ways, I can draw some parallels with what I understand of Air Force training and what I’m currently experiencing as a trainee air traffic controller. For example, the eleven other lads in my group and I are known by the simple name ‘Course 44’. We are timetabled as a course and subsequently we do everything together. We’ve become a reasonably close-knit group, with friendships forged in the furnace of shared challenges. We’re all (mostly) young men. Many have travelled from all over the country, and some from overseas, to do this training. We are learning a highly technical discipline, and we’re under considerable time pressure. We work hard, and we have to. There is the ever-present threat of being ‘scrubbed’ and washout rates are not insignificant. In short, this course is by far the most intense thing that I’ve ever attempted.

But there are a few key differences. Most of us are in our late 20s or early 30s, which is older than an average Australian airman in training during WWII (Don celebrated his 21st birthday on a bombing raid over a German city). There’s no mandated physical exercise or drill to worry about. We don’t live on site. But most importantly, the end result of our training – if we actually get through it – is a high-pressure but ultimately civil job. Sure, we’ll be on shift at all hours of the day and night, we’ll be working some pretty tough days and nights and there is no ‘pause’ button in air traffic control. But we won’t be going into combat. We are not facing the prospect of half of our number going missing in action. We can be pretty sure that at the end of our shift we will get home safely.

Which is a lot more than could be said for the airmen of Bomber Command.

© 2011 Adam Purcell