The History of Flight Inspection in Germany

by by Dieter Hielscher, DFS

Flight Inspection at the Federal Administration of Air Navigation Services (BFS) from 1953 to 1976

When the BFS was founded on 1 July 1953, one of its tasks was to ensure the operational readiness of the navigation systems. For this purpose, a flight calibration unit called the "Calibration and Test Unit" (MVS) was set up. The first experiments were conducted with equipment carried on a balloon; the measurements which could be executed with this configuration were costly and their scope was limited. The initial solution to this was to charter a light aircraft from a Swiss advertising company and to install measuring equipment in it.

In 1954 and 1955, two calibration aircraft were purchased: a four-engined propeller machine of the type Handley Page MARATHON and a two-engined propeller machine of the type De Havilland DOVE. Initially, these two aircraft were registered in Great Britain and had British crews. This situation lasted until Germany regained its air sovereignty, when the aircraft were taken over by the BFS and manned by German crews.

MARATHON: the first aircraft	DOVE: the workhorse of the 1960s

Now that these aircraft were owned by BFS, it was necessary to accommodate them at an airfield. For this reason, the unit was transferred in March 1955 to Frankfurt Airport, where it occupied a building close to today's Terminal 2 (PANAM Hall). Since no suitable measuring equipment for this rather exotic task was available on the market, the unit had its own development department for flight inspection equipment from the very start. This department modified standard on-board equipment to meet the accuracy requirements for measuring equipment and to permit recording of the measured values. Since this measuring equipment also had to be calibrated, and suitable calibration equipment was also not commercially available, the tasks of this special department were very demanding.

The MARATHON calibration aircraft was soon taken out of service; it is said that it lost so much oil from the engines that it always had to have oil trays below it when it was on the ground! Two further De Havilland DOVE aircraft were purchased in 1962 and 1963, resulting in a fleet of three calibration aircraft.

In the 1960s, the De Havilland DOVE was the workhorse of the flight calibration unit. The few radar flight inspections which had to be carried out (due to the small number of radar systems) were executed with jet aircraft of the German Armed Forces or with chartered business jets.

Also in the 1960s, the preparations for all-weather CAT II operations and, later, CAT III began to take shape. In addition to the comprehensive conversion work on the ground, it became necessary to meet the considerably increased requirements with respect to the accuracy of the measuring equipment. Since the DOVE calibration aircraft was already operating close to its maximum allowable useful load, a new, larger aircraft was needed. Furthermore, there was a trend towards more economical flight inspection of route navigation facilities. This was to be achieved by inspecting a large number of such systems in a single flight with new measuring methods, rather than inspecting each system individually. The FAA in the USA had adopted an extreme solution to this problem: they used a Boeing 707! The BFS did not want to go quite so far: they selected the Hawker Siddeley HS 748 and purchased two of these aircraft in the period 1969 to 1972. A consequence of this was that a larger hangar was needed for their maintenance; this was found on the South side of Frankfurt Airport, in the vicinity of the General Aviation building.

The Development of Flight Inspection in the German Armed Forces

The German Armed Forces (GAF) also possessed a number of ground-based navigation aids. The history of military flight inspection began in May 1958 with the formation of the Flight Inspection Squadron 612 in Kaufbeuren, which started operations in August 1958 with six Pembroke CMk 54 aircraft. Its task was the flight inspection of the navigation and landing aids for all services of the GAF and the execution of special tasks in the area of air traffic control and electronic warfare (Eloka).

The flight inspection squadron subsequently formed the core of the Communications Training and Test Regiment 61 which was formed on 23 March 1961 in Lechfeld and was transferred to its new location on 7 November 1961. New navigation systems and increased numbers of Eloka flights resulted in the continuous modification of the aircraft to meet the new technical requirements. After suitable modification, the squadron was gradually equipped with Do 27, C-47D Skytrain and N.2501D Noratlas aircraft.

The squadron was expanded in the years 1961 to 1965, finally reaching a total of 10 Pembroke CMk 54 aircraft and 13 Douglas C-47Ds. An additional task was assigned to the flight inspection squadron in June 1962 and was carried out until 1970: as part of the training for Starfighter pilots, four C-47Ds and one C-53DO aircraft were converted into NASARR (North American Search and Range Radar) trainers. This involved fitting them with the "radar nose" from the F-104 and several radar training positions, permitting them to be used as flying classrooms for radar navigation training.

After integration of the flight command of the Air Force Schools of Engineering on 1 April 1970, the Communications Training and Test Regiment 61 had two flying squadrons - the 4th squadron for flight inspection in Lechfeld and the 7th squadron as a flight operations unit in Kaufbeuren.

When the last C-47D was taken out of service on 14 April 1976, the 4th squadron shut down its flight inspection operations and the era of civil-military co-operation began. The squadron had logged a total of 44,251 flying hours by the time of its last operation on 26 March and had carried out about 4,700 flight inspections.

Pembroke CMk 54	C-47D Skytrain

The period after 1976 - the transition to civil-military co-operation in the flight inspection sector - the Joint Flight Inspection Unit (GFMS)

A widespread boom in air traffic in the 1970s presented the BFS with the problem of finding pilots for its new aircraft. The start of the civil-military co-operation was thus a pragmatic answer to this problem: the GAF promised DFS that they would, for the time being, provide pilots as an interdepartmental support. Military pilots were thus used from 1971 onwards.

Since the question of replacing the aircraft of the GAF by newer models was being discussed at that time, the possibility of joint execution of these tasks was also considered. On 30 June 1972, an agreement was reached between the Federal Minister of Transport and the Federal Minister of Defence which stated that the flight inspection operations should be carried out by one organisational unit. This was followed on 9 July 1976, by the ratification of an agreement between the above-mentioned ministries on the formation and operation of a Joint Flight Inspection Unit (GFMS).

This agreement stated that the main task of the GFMS would be the flight inspection of all civil and military air navigation facilities. It also stated that the BFS was the owner of the aircraft and that these were to be registered as civil aircraft, while the flight operations were the responsibility of the GAF and that these operations must therefore be carried out in accordance with a military flight operations manual. The responsibility of the BFS for the maintenance of the entire infrastructure was also defined. With respect to the financial aspects, the agreement stated that the outlay and operating costs were to be split proportionally in accordance with the actual utilisation of the flight inspection services by the two partners.

The construction of the new buildings for the service in Lechfeld was started in 1974. These comprised two aircraft hangars, workshops, laboratories and a power station. Although these buildings now seem far too large, it must be remembered that it was necessary to fight for every square metre of space when the buildings were being designed. Plans for stacking and nesting were tried out in order to keep the hangars as small as possible. At that time, it was also assumed that the aircraft, with their very temperature-sensitive measuring equipment, would be able to operate flexibly only if they were kept in hangars. Operations in Klosterlechfeld finally began on 1 November 1976.

Hangar with calibration aircraft at the Air Force Base Lagerlechfeld

The integration with the GAF also led to an increase in the number of aircraft in the years 1975 and 1976: five HS 748 were purchased, together with one Hawker Siddeley HS 125 to meet the increasing demand for the inspection of radar equipment.

The GFMS fleet thus reached a maximum size of seven HS 748 aircraft and one HS 125 jet. In addition, two DOVE aircraft were used until 1980 in order to bridge the gaps in the equipment with new aircraft.

The workhorse of BFS in the 1970s and 1980s - the HS 748

The HS 748 was the workhorse of the GFMS in the 1970s and 1980s, while the HS 125 jet was the pride of (not only) the pilots.

The pride of the pilots - the HS 125

The increasing miniaturisation of the electronic equipment led the unit to consider doing away with the existing flight inspection equipment and using a smaller aircraft which, if possible, could cover the flight inspection of both navigation and radar systems. After a comprehensive market analysis with the support of Lufthansa Consulting GmbH and Messrs. AERODATA, it was suggested that the 19-seater aircraft EMBRAER CBA 123 Vector would be suitable. This aircraft was inspected and flown in Brazil with respect to both its flight operations and its technology (aircraft and electronic equipment). Its performance and other features complied with the requirements. Unfortunately, series production of this aircraft was never started, and it therefore remained just a dream. One good result of this situation was that DFS still had a free hand in its decision as to how the flight inspection should be re-organised.

The flight inspection equipment

All of the measuring equipment was developed and adapted in BFS facilities. The equipment extended from the original, purely analogue measuring systems with recording of the data on board the aircraft to digital, computer-supported systems with which the evaluation could be carried out on the ground. In the meantime, the technology available today has led to a trend in the other direction, towards evaluation on board the aircraft again.

When the calibration aircraft HS 748 was put into service, inspections were carried out by two flight inspection engineers, since the aircraft provided a separate position from which its precise location could be determined with various technical aids.

In 1978, the digital flight inspection system for route navigation facilities was put into service, followed in 1991 by its use for the flight inspection of approach and landing aids. At the same time, the computer system for ground-based evaluation was extended to permit the evaluation, display and archiving of large amounts of measured data.

As part of the efficiency improvement measures, the measuring equipment was modified in 1982 to permit one-man operation.

As one of the suggestions for improving economic operation, the GFMS presented a proposal for the flight inspection system of the 1980s with which operations should become completely independent of the weather conditions. Suitable developments were started and were soon successful in the sectors of route navigation facilities and the military TACAN approach procedure. In the sector of ILS flight inspection, the most difficult part of this development work, the limits of feasibility were soon reached. After several delays, the development work was aborted in 1991 and an industrial solution was adopted in its place. This was the beginning of the end of in-house development and of the transition to the industrial products which are today available from several manufacturers. This new approach was accompanied by considerable conversion problems for the affected employees who, in the past, had contributed to a major degree to the progress in the development of new measuring systems.

In 1992, the first flight inspection system developed by Messrs. AERODATA was put into service and the installation in a second aircraft was started.

Efficiency improvement measures and the reduction of the fleet

The costs for flight hardware, including the flight inspection equipment, personnel and operation of the aircraft led, at the end of the 1970s, to increased efforts to make flight inspection more economical. For this purpose, activities were started in several areas and their results were presented in the following reports:

In the following years, these proposals were updated further, converted into suitable actions and rigorously implemented in the period up to 1990. They were the basis for the reduction in the number of aircraft, with its accompanying savings (personnel, material costs). This was all achieved in spite of the increasing demand for flight inspection capacity (additional systems, acceptance of responsibility for the new Federal States in East Germany and in Berlin).

The following results were achieved:

All of this was possible only with the active participation of the local employees, which, owing to the anticipated effects, was often difficult and in some cases incurred considerable stresses within BFS. Moreover, from the point of view of the civil side, the military flight operations also had to be modified - a task which was almost impossible due to the existing regulations of the GAF.

Combination of the flight inspection services of BFS and Interflug (GDR)

In the course of the Germany unification, first contacts were made in 1990 with the flight inspection institutions of the GDR, namely the Technical Testing and Flight Inspection (TPFS) of Interflug in Dresden, which operated an IL 18 calibration aircraft, and the Flight Measurement Service of the National People's Army of the GDR, also in Dresden, which operated an Antonow AN 26. The IL 18, the largest aircraft ever used in Germany for flight inspection, visited the GFMS in Klosterlechfeld. This was a special event because the aircraft needed landing permission on a NATO operational airfield! For economical reasons, this aircraft remained in service for only a restricted period.

In 1991, GFMS took over the responsibility for the flight inspection of all navigation and radar systems in the new Federal States and in Berlin and set up a "branch office" in Dresden. The An 26 was used for a further year by the GAF, since special navigation aids erected by the Soviet forces had to be inspected until the on-board equipment of the aircraft which had been taken over could be converted.

Germany's largest calibration aircraft - the Interflug IL 18

Summary of flight inspection under control of a state organisation BFS

By 1993, the GFMS had clocked up 100,000 flying hours since the foundation of the civil and military flight inspection services. By the time the HS 125 and HS 748 aircraft were sold, they had accumulated a total of almost 60,000 flying hours. During this period, there was only a single accident with material damage. This occurred in Düsseldorf and put the HS 125 out of action for three months. It was caused by the failure of both engines during an approach when the engine air inlets iced up and ice was drawn into the engines.

At GFMS, civil-military co-operation has been practised daily with success and little friction, starting at a time when such co-operation in other departments was still unmentionable.

The GFMS has won international acclaim by means of its innovative solutions in the area of flight inspection technology. Other organisations frequently asked for its advice on how to set up their own flight inspection activities.

Measures for the improvement of efficiency were nothing new for the GFMS. Just the opposite: in the 1980s, these measures resulted in many changes to the organisation, and many of these were extremely painful for the employees. All in all, the flight inspection organisation has produced a large number of changes. Last but not least, the integration with the TPFS was executed co-operatively and successfully, with consideration for the problems of the employees.

Flight inspection under control of DFS Deutsche Flugsicherung GmbH after corporatisation on 1 January 1993

On 1 January 1993, the air navigation services in Germany were corporatised. The responsibility for the provision of air navigation services passed from the Federal Administration of Air Navigation Services (BFS) to DFS Deutsche Flugsicherung GmbH. With this change, the conditions for flight inspection in Germany also changed.

The high speed of developments in the electronics sector, the sudden availability of commercial solutions, the need to switch to smaller aircraft due to the increased fuel prices which resulted from the new form of organisation (taxes), and the pressure resulting from the availability of similar services on the open market (although DFS enjoys legal protection for a certain period) all made it necessary to execute a radical reorganisation of the flight inspection service.

In April 1993, the DFS Board of Directors established a working group with the task of realising a German flight inspection organisation operating under market conditions. Within a very short time, proposals were developed for

In the summer 1994, two aircraft were bought (King Air 350), and a subsidiary was founded (DFMG Deutsche Flugmessgesellschaft mbH), office space was rented and equipped, DFMG flight operations were prepared and the move from Lechfeld to Braunschweig was planned in detail.

In 1996, the preparations for the certification according to ISO 9001 began with the objective to optimise the processes of the DFMG and, if required, to make them transparent to certification authorities and customers. The work began with

These initial activities will be completed in 1998.

A completely new task for the German flight inspection organisation was the marketing of flight inspection services. First positive results were achieved by providing flight inspection services in Switzerland and Austria, the Netherlands and Luxembourg, in Spain, Macedonia, Lithuania, Kiev, Sofia, Bucharest, Macau, Kuwait, Yemen, Sudan and Egypt, and, of course, in Germany.

On 1 October 1997, swisscontrol became a shareholder of the DFMG. At the same time, the company name was changed to FII Flight Inspection International GmbH. On 1 January 1998, Austro Control also became a shareholder of FII. With their accession, both countries gave up their own national flight inspection organisation.

So FII has three shareholders: AERODATA, swisscontrol and Austro Control. DFS has close connections to FII on the basis of a cooperation agreement and can thus be regarded as if it were, de facto, a shareholder.

The Super King Air 350, calibration aircraft of Flight Inspection International GmbH	The measuring equipment of the Super King Air 350