2007 Target Towing with Learjets
Updated: Feb 3, 2018
For over 40 years the German Air Force partners with civil companies in practising the air target simulation role. The biggest and most experienced of them is the GFD (Gesellschaft fűr Flugzieldarstellung = company for air target simulation), which operates from its home base Hohn for 20 odd years. Frank Visser and Ludo Mennes report from Hohn, Northern Germany, home base of the GFD.
Past en present
GFD’s target towing goes back to 1 October 1966. Condor Flugdienst, a subsidiary of Lufthansa, flew with Canadair CL.13B Sabre Mk. 6 from Westerland airfield at the peninsula of Sylt.
In 1974 the Sabres were replaced by Fiat G.91 “Ginas” and two years later Condor Flugdienst was relocated at Hohn.
Here a G.91R/3 can be seen on the ramp at Hohn Air Base in 1988. In 1989 the GFD started its activities and with the phasing out of the G.91 completed in 1992 all the activities were taken over by the GFD.
Its fleet was expanded and in those days Condor could dispose of 24 “Ginas” of the G.91R/3 and T/3 type. Since the military activities of a Lufthansa subsidiary had always been a very sensitive issue and with good economic prospects in mind it was decided to set up a separate, independently operating company. In 1989 the GFD was established next to Condor Flugdienst with four Learjets with a shared ownership between Condor Flugdienst and Aero-Dienst Nürnberg. In 2002 Aero-Dienst Nürnberg’s share was resold to EADS and with the phasing out of the Fiat G.91s from 1991 to 1992 Condor Flugdienst ended its target towing activities and lodged them entirely with GFD.
The entire fleet in one picture. Clearly visible is the Westinghouse AN/ALQ-119 GY pod on the D-CGFA used for the Electronic Warfare missions. Photo; GFD.
At present GFD disposes of 11 Learjet 35A and 36A; all of them bought second-hand. The aircraft are flown by 28 pilots, who all but one have a military background at the German Air Force or Navy. Mr Schweitzer, a former RF-4E pilot and now deputy Manager and Chief Operations said: ”We prefer pilots with a military training to a civil because they can assess the needs of the clients much better. Fortunately there was a large surplus of experienced pilots due to the reduction of the German Air Force. ” Each GFD pilot flying under the callsign “Kite” flies about 400-500 hours per year. GFD has a ground staff of some 60 people responsible for the planning, administration and a great part of the maintenance, which is carried out by their own highly qualified technical personnel. The more complex repair and replacement activities are done by Aero-Dienst Nürnberg.
Target simulation 1
The GFD has three main tasks. First Zieldarstellung 1 (Target simulation 1): the aircraft fly in a clean configuration.
During this mission the GFD Learjets simulate attacks on ground and sea targets, which have to be repelled by the air defence. Until recently the Learjets had under the wings pods with mirror reflectors, which could register hits by means of infra-red light. Meanwhile the GFD is busy replacing these pods by their own system mounted under the fuselage. At the moment only three aircraft are equipped with this system and more will follow. Then the hits can be recorded during the flight via a display on the ground as well as in the cockpit. In addition the planes are also engaged for the training of Ground Control Intercept (GCI) personnel of the Luftwaffe (German Air Force). The Learjets are then target as well as hunter. These missions, lasting two to three hours, are being flown in various Temporary Reserved Airspaces (TRA) at flight altitudes varying from 10,000 to 35,000 feet.
Target simulation 2
The actual towing of targets, so that ground troops can shoot at them is the main task of GFD and is part of Zieldarstellung 2. To tow these targets pods can be mounted under the wings of the Learjets. These pods of the MTR-101 type (Target Reeling Machine) have been developed by the Indian company CBAS Ltd.
The pod is equipped with a large reel of steel wire, which can be electrically unwound from the cockpit to a length of 30,000 feet. It is provided with a camera system to check the winding and unwinding of the system. For night missions the pod is equipped with a light. Either a dummy rocket or a metal tube with a bag is attached to the Target Reeling Machine.
For live firing with Sidewinders, Stingers and until recently Roland ground-to-air missiles the GFD uses a synthetic, carbon dummy Dornier DoSK (Schlepp Körper) 6-S11 rocket with a length of 2.5 metres and reinforced with fibreglass. These rockets and bags are towed behind the aircraft. A Learjet flies with the two bags hanging from the pods or with rockets. During take-off and landing the dummy rocket or steel tube are hung sideways in order to rotate 90 degrees downward by a mechanical arm so that the targets are straight under the system. The targets are towed behind the aircraft at a distance of 8,000 to 15,000 feet. Thus the German Air Force and Navy can shoot with their anti-aircraft artillery safely at the towed targets. The SETA-3 S1 synthetic bag is about six meters long and to both sides of the fabric an acoustic, battery-run recording system is mounted. This registers the (near) hits of the bullets at distances of 3, 6, 9 or 12 meters from the target. The hits are recorded by a Dornier Ground Control Unit of which there is one in the Learjet and one on the ground, so that both recording data can be compared.
Highly qualified GFD technical personnel do a great part of the maintenance. Here ground staff is working on one of the Learjets engine. The more complex repair and replacement activities are done by Aero-Dienst Nürnberg.
Besides target towing three of the eleven Learjets have been specially converted to an Electronic Warfare (EW) version. These aircraft can be equipped with two Westinghouse AN/ALQ-119 GY pods under the wings to enable them to interfere with the air defence and other means of communication on the ground or provide them with wrong or misleading information. The crew of these so-called Eloka flights (Elektronische Kampfung = EW) is then increased with a third member responsible for the operation of the interference equipment. Since the pods may have an effect on the interference of electronics and / or communication equipment of nearby ground and air traffic, these missions always have to be announced and can only be flown with permission of the German Ministry of Defence. EW missions generally last for three to four hours in a 100 km wide airspace. As there is only a limited number of competitors in Europe, namely the American Phoenix Air and the British FR Aviation Ltd, other airforces also make use of the GFD.
A new phenomenon for GFD are the seven or eight environmental flights carried out in cooperation with a number of German universities and research institutes. Thus scientists can carry out scientific research into the ozone layer, by which experiments are done at an altitude of 15 kilometres. There are three routes: to the north towards the polar circle and to the south in the direction of Crete or Morocco and the Canary Islands.
This Gates Learjet 35A is ready due to take off for a mission to train Ground Control Intercept (GCI) personnel of the German Air Force in intercepting unidentified aircraft. The Learjets are used as target as well as hunter.
A Gates Learjet 35A awaits her next mission on the ramp of Hohn Air Base. Clearly visible is the MTR-101 type pod under each wing. This particular aircraft has two white metal tubes mounted (seen under the left wing), which contain a sack attached to the Target Reeling Machine. These sacks are towed behind the aircraft.
The GFD is very content with the performance of the Learjet and as these aircraft are far from their maximum flying hours, they are not yet looking for a successor. Mr Schweitzer commented: “ The greatest advantage of the Learjet over her predecessor the Fiat G. 91 for any task carried out is her capacity to fly for a relatively long time. Besides the Learjet can simulate a QRA jet very well and is a much cheaper alternative than a real scramble of fighters.” During towing missions the Learjets can reel out two targets at different distances at the same time. Regularly missions are flown by two aircraft with four targets in the air. When the Luftwaffe phased out its Alpha Jet she was also be looked upon as a successor as this coincided with the final hours of the Fiat G.91, but she was rejected because of the just mentioned pros. The existence of the GFD is in the hands of a government authority, the Bundesamt für Wehrtechnik und Beschaffung (BWB). It is part of the German Ministry of Defence and its responsibility is the purchasing of materials and activities. This authority is the greatest client of the GFD and this carries a risk at the same time. Consequently further expansion of GFD’s business activities is being assessed. The Swiss Air Force has already shown interest in shooting with Sidewinders and there are also initial contact with the Finnish Air Force. Both are not concrete yet but do indicate that the GFD is opening up new horizons.