Considering the unwise decision of the German Ministry of Transport and the German Federal Administration for Air Navigation Services (BFS) to abandon the concept of providing air traffic control service (ATC) to all flights above 20.000 feet MSL, whether civil or military, and to reduce the upper limit of controlled airspace to 25.000 feet MSL as of 1 January 1960 caused many negative effects to both pilots and controllers and reduced flying safety considerably.
With the RHEIN (formerly Frankfurt) upper flight information region (UIR) covering all airspace above 19.500 feet with the lateral limits of the underlying Frankfurt and Munich FIRs, a distinct difference existed. Whereas in the lower airspace, the FIRs, general air traffic (GAT) on instrument flight rules (IFR) flight plans was restricted to airway (AWY) and advisory route (ADR) corridors of generally 10 NM width together with the civil and military terminal control areas (TMAs) constituting the Control Area (CTA); the upper control area (UTA) however, an area of about 100.000 sq/km, encompassed all of the airspace within the lateral limits of the UIR. This allowed controllers to clear flights along published routes and also from any one point within the UTA direct to any other point off published routes within the UTA above 19.500 up to and including 25.000 feet. Civil and military GAT in accordance with ICAO rules was obliged to file flight plans along the published predetermined routes (PDRs). Operational air traffic (OAT), not having to follow ICAO rules, could file flight plans along and off published routes.
With conventional, procedural non-radar air traffic control service being provided only by RHEIN UAC until 1964 and some 20 high altitude initial approach fixes (IAF) and associated holding pattern airspace areas (HPAA) situated in the UIR at 20.000 feet (FL 200) and above, many of them covering an airspace area of at least 14 x 24 NM at FL 250, controllers all to often had to take overflying traffic off the filed route and to reroute flights around these holding patterns. And with one VHF and one UHF radio channel each per sector, being operated simultaneously, however without a VHF/UHF frequency link, many critical situations arose for pilots and controllers. With military and civil aircraft transmitting at the same time, controllers had a hard time to distinguish between messages from civil and military aircraft, because both came out of one and the same loudspeaker or headset. And military pilots could not hear the civil pilots transmissions and vice versa, despite both traffic categories operating in close proximity within one and the same portion of the airspace.
The 60-minute live traffic radiotelephony example of RHEIN CONTROL's North Sector of 1962 on the CD will give the reader / listener a good impression of the then prevailing daily working conditions for pilots and controllers.
But, not enough, the situation above flight level 250 in the uncontrolled airspace above the UTA was even more complicated and considered dangerous, proven by hundreds of near-misses between flights over the years, as far as flying safety was concerned. ACAS / TCAS did not exist as yet. Here, almost everyone could do what he wanted to do, no matter if visual (VMC) or instrument (IMC) weather conditions prevailed. Conditions to be met by aircraft operators were minimal. GAT flights had to file ICAO type flight plans along the published PDRs, establish radio contact and maintain listening watch on RHEIN INFORMATION's frequencies. The same applied to OAT flights wishing to fly under IFR. All of them and some additional VFR flights were dependent on traffic information provided by RHEIN UIC.
During IMC, when clouds often reached up to 30.000 or 35.000 feet and sometimes even higher with thunderstorms embedded and turbulence adding to the pilot's problems, this situation reached intolerable levels of unsafe operations. In extraordinary cases up to eight flights passed one and the same navigation aid location in clouds at almost the same time (within one minute) and at almost the same altitude in level, descending and/or climbing flight, i.e. for instance six civil airliners and two military fighter aircraft. As a controller working the flight information service (FIS) working position one was only allowed to provide traffic, weather, navigation aid status and airport information or navigation warnings. All other pilot intentions were left to the participating pilots discretion with the controller desperately waiting to receive their decision so that he could comment to them on the resulting consequences. For the pilots to reach a meaningful decision was difficult, because VHF aircraft could not listen to UHF aircraft and vice versa. Under extraordinary situations, such as IMC prevailing and Air Defence unit breakdown, RHEIN INFORMATION hat up to 70 flights on the two frequencies at the same time, with such situations sometimes lasting for up to one hour. This situation was tolerated by the German air navigation authorities from 1 January 1960 until 1 June 1967! But despite the given situation only one midair collision took place between two military jet trainers at FL 295 in 1963.
Regarding the operations set-up on the ground, every C-Controller (the man responsible for the provision of standard separation in the UTA and for meaningful traffic information to flights above the UTA and operating the radios) had one assistant controller assigned to him to help point out conflicts, correct flight progress data and perform all telephone coordination in passing on CPL "Estimates" and revisions, etc. With the two UTA sectors, the UIC (FIS) working position and the adjacent units the assistant had to coordinate with a minimum of 20 partners. Therefore, the job of the C- and A-Controllers often turned out to be a rat-race in chasing for seconds to reach the required coordination partner with some of them only to be reached through telephone switchboards, which added to the delay. Lacking frequency coverage in the south of the Rhein UIR, such as over Kempten and south of Munich only added to the existing problems. Landline and radio outages, missing or wrong flight plans and uncoordinated entries into the Rhein UIR were standard daily routine.
Already towards the end of 1960 the traffic amount above FL 250 had reached such a level that a multiple flight progress strip display system could no longer be applied because the flight progress boards could not hold all the required strips, i.e. one strip per flight per route conflict / waypoint, and could not be handled by one C- and one A-Controller working there. Flight progress boards were equipped with six bays, each holding about 25 strips. Instead, a so-called "Single Strip System" was introduced, i.e. one strip only per flight throughout the whole flight in the UIR above FL 250.
Proper staffing levels were never reached. About 20 to 30 % of all official working positions could not be manned for a period of 15 years! Both organizations, BFS and GAF, being responsible for ATS operations could not manage to provide for the required numbers of ATS staff due to the existing bad working conditions, employment tariffs and low remuneration offered under government pay scales.