Embracing Darkness

Björn Rüdén reports on a week of JAS 39 Gripen night flying with the Swedish Air Force.

There’s a light sleet falling when the pilot from the 171. stridsflygdivision (171st Fighter Squadron) signals for the start of the auxiliary power unit (APU) with one flash of the position light on his JAS 39C Gripen. The signal is quickly returned from the technician in charge of the aircraft, closely followed by the characteristic howl of the Gripen’s APU.

The sound drowns out all possibility of normal speech, but the technicians and mechanics wear hearing protection with a built-in communication system. The APU supplies the aircraft with power, hydraulic pressure and electronics cooling, ensuring the aircraft is self-sufficient until the RM12 engine is up and running.

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A technician checks the belly of JAS 39C serial 39230, which is sitting fully armed at its Ronneby base, ready for a night mission. All photos Björn Rüdén 

With the help of the APU, the aircraft performs an automated start-up self-test to identify any malfunctions while the pilot prepares the cockpit set-up. When ready, the pilot signals for engine start with two flashes. These are also returned by the technician and the RM12 start-up begins.

Soon after, the Gripen starts to taxi towards the runway in use, followed by a further three jets from the same squadron and another four from the 172. stridsflygdivision. One by one they disappear into the dark sky with afterburners roaring, while the technicians and mechanics returns to the warmth of the hangar building.


Ronneby Wing

Based at Ronneby in the southeast of Sweden, F 17 Blekinge flygflottilj (Blekinge Air Force Wing) is home to two Gripen squadrons, the 171. stridsflygdivision (callsign ‘Aquila’) and 172. stridsflygdivision (callsign ‘Gator’), as well as the two associated aircraft maintenance companies, the 21. and 22. Flygunderhållskompani (Fighter Support Company).

Due to F 17’s geographical proximity to the Baltic Sea, the wing plays a critical role protecting Swedish airspace and borders. The Flygvapnet (Swedish Air Force) quick reaction alert (QRA) is mainly based there. The usual peacetime set-up is a pair of JAS 39C Gripens on round-the-clock, 365-days-per-year readiness.

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The Gripen pilot performs a walkaround while a technician clears the aircraft for flight.

The Helikopterflottiljen (Armed Forces Helicopter Wing) also has its naval versions of the HKP 14 (NH90) and HKP 15 (AW109) aircraft based at F 17 and operated by the 3. Helikopterskvadron.


171. Stridsflygdivision

The squadron consists of around 30 pilots and mission support officers (intelligence, electronic warfare, planning) – a fairly typical mix for a Swedish Air Force Gripen squadron. The 171. uses both the JAS 39C and 39D, with the two-seat 39D primarily used for combat readiness training (CRT) of the younger non-combat-ready pilots. Major Joakim Rasmusson, commander of 171. Stridsflygdivision, explained: “The youngest pilots joining the squadron are around 25 years old and the oldest are around 50, giving them 20-25 years of experience flying fighters. This structure is important in order to spread the knowledge of tactics as well as flight safety to the younger ones and isn’t something that I would like to change.”

F 17’s location puts the squadron close to the military training areas over the Baltic. “Each pilot in the squadron flies roughly 120 operational hours a year. Our training areas are so close that we use minimal transition time to get there, meaning we are operative as soon as we take off,” said Rasmusson.

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The technician in charge of this Gripen is using red light sticks to indicate the spot where the pilot should stop the aircraft.

When asked about flying the Gripen, the CO said: “The aircraft today is one of the most competent in the world, constantly being upgraded. It has an extremely intuitive HMI [human-machine interface] and cockpit layout, making it a dream to fly. It feels that you strap on the aircraft, not strap into it.”

Sweden has chosen to organise the responsibilities of technicians and pilots in two units, which means the commanding officer of each can focus on one area. Rasmusson summed it up: “This grows a culture of integrity and pride in the work conducted. I’m constantly met by motivated technicians from the aircraft maintenance company that really want the Flygvapnet to have the best aircraft possible in the air.”


21. Flygunderhållskompani

The aircraft maintenance company consists of three platoons – two for aircraft maintenance and one for munitions and logistics – and roughly 70 personnel.

Aircraft maintenance platoons are responsible for the upkeep of the Gripens, be it scheduled work, calendar inspections or turnaround. Being split into two platoons enables the company to better support the Swedish concept of dispersing Gripens on wartime road bases.

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End of the shift. A technician parks Gripen serial 39273 in the hangar for the night.

The munitions and logistics platoon is responsible for the weapons used on the Gripens as well as the pilots’ equipment. It also conducts scheduled maintenance and calendar inspections of vehicles, power units and so on. The platoon handles all spare parts used by the aircraft maintenance platoons for the Gripens.

All the aforementioned responsibilities mean that the company’s employees have varied backgrounds and skill sets, with a mix of competences both broad and deep. The regulations covering Gripen maintenance are both civilian and military, which demands specific qualifications before anyone can work on the aircraft. This generally means a long time spent in the classroom before getting to work on the flight line. The Swedish Armed Forces have resumed the use of conscripts, who make a welcome contribution in the company and provide a good platform from which to recruit technicians.

The 21. Flygunderhållskompani commander, Major Christian Bertilsson, explained: “Even though the squadron and the aircraft maintenance company are split into two units, we try to work towards the same goal at all times – [getting the] effect on target. By joint planning, we optimise our resources and, in that way, become more lethal.”

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Lt Col Krznaric explained that the NVGs are useful both during beyond-visual-range combat and when flying close air support.

The company received the JAS 39A in 2002 and the last A-version was replaced by a JAS 39C in 2006. The aircraft currently operated are all modified to the MS20 software standard.


Gripen Stores

The Swedish Gripen fleet is equipped with the MBDA Meteor beyond-visual-range air-to-air missile (BVRAAM, Swedish designation Rb 101), AIM-120 AMRAAM (Advanced Medium-Range Air-to-Air Missile, Rb 99) and infrared-guided IRIS-T air-to-air missiles (Rb 98). Air-to-ground weapons include the GBU-12 Paveway II, GBU-39 Small Diameter Bomb (SDB) and GBU-49 Paveway II, as well as the RBS 15F (Rb 15F) air-to-surface missile.

Purchase of a replacement for the Spaningskapsel 39 (SPK 39 recce pod) is planned to maintain intelligence-gathering capabilities, while the Litening G-III laser designation pod (LDP) will be retained.

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JAS 39C serial 39230 carries a combination of IRIS-T (Rb 98) on the wingtip, plus AIM-120 AMRAAM (Rb 99) and air-to-surface RBS 15F (Rb 15F) missiles under the wing.



Balancing the long-term ‘health’ and availability of the Flygvapnet Gripen fleet, in order to have mission-capable jets on the flight line when needed, is centralised and scheduled from the Air Force Staff located in Uppsala. Major Bertilsson said: “At all times there are somewhere between ten and 20 JAS 39C and 39D Gripens under our care, all depending on scheduled maintenance, calendar inspections, modifications and exercises.”

The maintenance co-ordinator faces a constant challenge to keep the required airframes airworthy and able to conduct exercises, QRA and other events that result in wear and tear on the airframes and their components. In addition, the company doesn’t carry out all of the deep periodic maintenance on site and has to fly the aircraft to depots (currently at F 7 Såtenäs and F 21 Luleå) and sometimes to the manufacturer (Saab in Linköping). Bertilsson observed: “For me, aircraft maintenance is about keeping a high rate of mission-capable aircraft and still have a company with a high degree of endurance. In order to accomplish this, teamwork is of the essence. No matter your function in the company, your work strives towards the same goal. Regardless of our different support systems, it is all about the humans doing their jobs. Jobs that needs to be done no matter what time it is, indoors or outdoors, sun or snow, war or peace.”

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Gripen C serial 32281 returns to the Ronneby flight line following a sortie.


Flight Line Management

The week of AIR International’s visit, the 171. stridsflygdivision had been requested to provide four Gripens on the flight line for each of the four sorties pre-planned for the night, meaning that when the hangars were closed, 16 flights had to be undertaken without any major technical issues arising.

Maintaining the Gripens on the flight line in darkness is not much different to daytime, except that visual communication gets a bit trickier. Daytime hand signs are switched to flashes using position lights and torches or light sticks. And the week of night flying also means that the company switches to working two shifts. Bertilsson said: “It is usually not necessary for us to work two shifts, but we try to have a dynamic approach as our main mission is to have the aircraft available when needed, for example during an exercise like this. The rest of F 17 and the Flygvapnet works mainly during daytime, so in order not to be isolated, we split into two shifts this week.”

At the roll call, the duties of the shift are handed out to the maintainers and those who are working the flight line are split into pairs with one technician in charge. “Regardless of your function in the company, everyone is trained and qualified to be a launch assistant,” said Lieutenant Kenneth Nilsson, a technician on the Gripen. The aircraft are handed out randomly to the pairs, but the Flygvapnet doesn’t use a system with crew chiefs who have their ‘own’ aircraft.

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Serial 39281 is prepared for the next sortie. Note the specially painted drop tank.

The first pre-flight is most often conducted inside the shelter of the hangar. It is a formal affair and judges the aircraft’s airworthiness for the upcoming 24 hours. Among other things, the oxygen level of the backup emergency oxygen system bottle (BEOS, used if the pilot has to eject above 9,843ft/3,000m) is checked, fluid levels are monitored, checks are made for leakages and tyre pressures are verified.

Drop tanks, laser designation pods, reconnaissance pods and/or missiles or bombs are also hung before the aircraft are towed to the line. Chaff and flares are loaded when the aircraft are positioned on the line. Once there, the Gripens are connected to the ground-based communications system and hooked up to the refuelling system. Just above the refuelling point is the ground crew panel. This houses the controls for the technicians to run tests on the electrical, hydraulic and weapons systems, as well as to oversee the refuelling.

Overall, the aircraft is easy to handle, in order to keep turnaround time to a minimum. Nilsson observed: “The Gripen is designed around specific demands based on the Swedish Air Force’s operational requirements. For example, a very swift turnaround with re-arming and refuelling, on any road base, with only one technician and six conscript mechanics – very much like a pit stop in Formula One. On a normal day there is only one technician and one mechanic needed on the flight line to get a Gripen ready for another training flight.”

The pair on the flight line responsible for a Gripen reports the status of the aircraft to the turnaround co-ordinator who acts as liaison between the technicians, squadron operations and the maintenance co-ordinator. Should a malfunction arise or a late change of loadout, it’s up to the turnaround co-ordinator to solve the issue. He or she is also the person with an ear on the flight radios, to be able to give a heads-up to the technicians before the squadron recovers to the base after the sortie.

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A technician removes the chock from serial 39281 just prior to the pilot taxiing from the flight line.

One by one, the Gripens taxi towards the line, where the technician in charge of the specific aircraft receive it with a red light stick to indicate to the pilot that they are where they should be. A chock is placed in front of the right landing gear and the Gripen is once again connected to the ground-based communications system and hooked up to the refuelling system. When ready, the pilot hands over the aircraft to the technician in charge and highlights any malfunctions that developed during the sortie. Then the turnaround commences before the next sortie with another pilot.


Night Flying

The Flygvapnet has conducted organised night flying exercises between September and March since the 1950s. Thursday is normally the day when they are conducted, to relieve the burden on resources and ensure availability of air traffic control and command and control. The fighter squadrons at F 17 also use the opportunity to fly scenarios with other wings, on this occasion with squadrons from F 7 Skaraborgs flygflottilj based at Såtenäs.

When AIR International visited, F 17 wing was conducting a working week of night flying. Lieutenant Colonel Robert Krznaric, squadron commander of the 172. stridsflygdivision, explained: “The main reason for this is that the fighter squadrons get a concentrated amount of training in order to be operational and combat-ready 24/7 without restrictions, while at the same time keeping a high [level of] flight safety. During a night flying week with a high rate of aircraft availability, a squadron can get almost as far proficiency-wise as during a whole winter season flying only on Thursday nights. Concentrated night flying gives much better results than irregular flights. The squadrons in the north of Sweden [211. and 212. stridsflygdivision based at F 21 Norrbottens flygflottilj at Luleå] fly in the dark in winter, even during normal working hours, helping them to keep proficient without concentrated night flying weeks.”

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Technicians conducting scheduled maintenance on a Gripen. Note the spotlessly clean floor.

When asked about the challenges of flying at night, Krznaric said: “Flying low over the Baltic Sea at night, without night-vision goggles and without light sources can be really challenging when you can’t see the surface below you. It gets really dark and it is also much harder to visually detect other aircraft. Formation flying in these circumstances are challenging, even when using NVGs. Spatial disorientation is life threatening and the best cure is to trust your instruments, which can be really hard when your mind tells you something else. This can, for example, arise when flying over a calm sea, with no clouds and a starlit sky and the stars reflect in the sea. That makes it really hard to tell up from down.”

Air-to-air refuelling (AAR) is another challenge for a Swedish fighter pilot when flying during hours of darkness, partly because of the few available occasions to actually conduct nighttime AAR training – the Flygvapnet has only one dedicated tanker.

Swedish fighter squadrons follow a dedicated training syllabus before a pilot is considered combat-ready with NVGs. A Gripen pilot uses the NVGs purely to look outside the aircraft and handles the cockpit by looking under the goggles. Krznaric concluded: “The NVGs are useful, for example, during beyond-visual-range combat and when flying close air support. During BVR combat, NVGs enhance the ability to detect a missile launch from greater distances with your eyes. During a CAS mission, the NVGs help you to visually detect laser beams from aircraft or the ground.”