In this context, the Cougar helicopter was test-loaded onto the C-17 strategic transport aircraft in mid-September at the Cerklje ob Krki Airfield.
This was a major organizational task, requiring the coordination of members of the SAF’s 15th Wing, members of the Strategic Airlift Capability (SAC) with the C-17 Globemaster III aircraft from the Papa Air Base in Hungary, and staff from the Air Transportability Test Loading Agency (ATTLA) from the US, which will also issue the appropriate certificate.
Helicopter and ramp preparation
“During the preparation of the helicopter, two conflicting factors have to be taken into account. The smaller the helicopter’s dimensions, the easier it is to load it; however, maintenance must be as simple as possible so that the preparation and the subsequent return of the helicopter to flight readiness does not take too long,” said the project leader responsible for the preparation of the Cougar airlift, Captain Benjamin Škrinjar of the 15th Wing, and added: “It took a lot of calculating and determining the appropriate configuration and possible ways of loading the helicopter. We also had to calculate the dimensions of the ramps and tools needed to mount the helicopter on the aircraft. After the manufacture of the tools, their strength had to be tested. Also, we had to try several different ways of towing the helicopter, all of which were new to us, as the nose leg would most likely not be able to withstand the load. We decided to attach a tow rope to the main landing gear legs, which required the manufacture of additional tools and devices. It was important to find a helicopter configuration that would not require major maintenance, yet would allow the helicopter to be loaded onto the C-17 aircraft. What we did was remove the main and tail rotor blades as well as the rotor head, thus allowing the helicopter to be ready for airlift in one day and returned to flight readiness within two days.”
The SAF has been using Cougar helicopters for more than ten years, which makes the disassembly and reassembly of a helicopter a fairly routine task. However, the building of the ramps required for the smooth loading of the helicopter was completely new. The ramps’ dimensions were calculated by flight engineers of the 15th Wing, under the organization of the ATTLA. “We are familiar with the dimensions and features of the Cougar helicopter, while the ATTLA engineers are familiar with the dimensions and features of the C-17 aircraft. In addition to the dimensions, the permissible load and possible towing methods also have to be taken into account. The final ramp dimensions are only determined during the certification, as temporary dimensions are produced for the test. But even though they are only temporary, they still need to be of good quality in order to withstand the helicopter’s weight,” said Captain Škrinjar. To avoid the relatively high costs of producing temporary ramps which would not be used again after the testing, members of the 15th Wing decided to try to produce them themselves. In doing so, the experience and knowledge of two members of the 107th Air Base, Roman Jakše and Robert Šoško, who produced the ramps, were essential. The ramps, made of wood, had to be of the appropriate size and weight in order to be safely placed under the helicopter by the available team. During the loading, additional measurements, calculations and adjustments were performed in order for the standard ramps to meet the actual demands.
The C-17 cargo space is 26.8 metres long, 4.5 metres high and 5.5 metres wide. This may appear to be plenty of space, but it is not when trying to load a helicopter 15.5 metres long and 3.5 metres high onto the aircraft. The C-17 aircraft cargo door opens upwards and inwards and is 5.5 metres wide; the height between the ramp and the open cargo door is 4.5 metres; and the cargo space level is 1.6 metres above ground. The ramp has a 9 degree incline, and its back section a 15 degree incline. These are the properties that make the loading of exceptional cargo, such as the Cougar helicopter, very demanding. Additional stress was posed by the fact that there were only five hours and two attempts available to load the helicopter, determine all the ramp procedures and dimensions, lay the ramps, confirm the helicopter configuration, and anchor and disassemble the helicopter.
During the planning, the ATTLA engineers decided to first try and load the helicopter tail-first and then cabin-first. “Loading the helicopter tail-first was our first choice as the method of towing the helicopter over the main legs is thus simpler. Before removing the helicopter parts it was difficult to determine how much the tail would lift due to the reduced weight, which made it impossible to accurately determine the ramps. When we measured the height of the tail section after having prepared the helicopter, we knew it would be a close call, as the extra space was minimal,” said Captain Škrinjar. At certain times, the helicopter tail was less than five centimetres away from the fuselage, and continuing the loading procedure would have been both pointless and dangerous. It was established that such a loading method would require the removal of additional tail components or increasing the ramp incline. Because the time was limited, Captain Škrinjar decided to continue with a different loading method.
The main landing legs were attached to the aircraft’s wire rope and winch, and the helicopter was pulled to the ramp. In the meantime, the technicians laid the prepared ramps and soon the helicopter’s cabin was in the middle of the ramp. The winch was operated by a member of the US Air Force responsible for cargo, loadmaster Staff Sergeant Kevin Banas, who said they had enough knowledge and experience to carry out the task, although it was the first time for such cargo to be loaded onto the C-17 aircraft. He stressed the importance of safety, which always comes first. When loading a helicopter, the security risk is very high, as the focus needs to be on the winching of the helicopter as well as on the team and the distances between the helicopter and the aircraft. In order for the helicopter not to shift uncontrollably, there was a technician in the cockpit operating the helicopter brakes; moreover, for safety reasons, the helicopter was additionally anchored to the bottom of the aircraft during the laying of the ramps. While the helicopter was stationary, other team members were moving the ramps as directed by the ATTLA engineer, in order to successfully load the helicopter onto the aircraft. The procedure was repeated several times, with the helicopter being ever closer to its final position inside the aircraft. “In both cases, in addition to the aforementioned technician in the cockpit and two technicians or loadmasters of the C-17 aircraft operating the aircraft ramp and the winch, at least seven other team members had to be present for the loading of the helicopter,” said Captain Škrinjar and added: “Five members are the ‘observers’, who watch the distances between the helicopter and the aircraft and stop the loading process if necessary. One or two members manage the drawbar, thus controlling the helicopter, while one member coordinates the entire loading process.”
The ramps are laid while the helicopter is secured, which allows the entire team to participate in the work. The commander of the 151st Rotary Wing Squadron, Lieutenant Colonel Igor Lanišnik, also participated in the transporting of the ramps, and he commented: “It has once again been shown that, in aviation, teamwork is essential for success. Missions and exercises prove that it is not rank that is most important, but the task dynamics that determine the activities. In searching for the best solution we tried to load the helicopter both tail-first and cabin-first. Both solutions are possible, but we opted for the cabin-first method, as it facilitated the preparation of the helicopter for transport.” Lanišnik’s statements were supported by Captain Škrinjar, who said that without the excellent cooperation and high motivation of all those involved in the preparation and testing of the helicopter loading, it would have been impossible to perform such a complex task. The cabin-first method worked much better, and the satisfaction of the team, once the helicopter was safely inside the aircraft, was enormous.
Due to the small distances between the aircraft and the helicopter, the helicopter must be firmly anchored to the bottom of the aircraft. Wooden blocks are put in appropriate places under the helicopter to eliminate the influence of landing gear shock absorbers, and then the helicopter is strapped to the aircraft floor at eleven different places. Parts removed from the helicopter during its preparation must also be prepared for transport and subsequently affixed to the bottom of the aircraft. The loadmaster, Staff Sgt. Kevin Banas, said it was most important for the load to be properly positioned, secured and loaded in accordance with the procedures.
“This was the first time for the Cougar helicopter to be loaded onto the C-17 aircraft, which was a learning opportunity for everybody,” said Captain Škrinjar. He added that the time needed for loading will be much shorter once the procedures have been specified, and finished by saying: “I suppose that loading a helicopter could take less than an hour; however, after the loading, the helicopter also needs to be appropriately attached and the removed parts loaded. Once the helicopter was loaded, I was very pleased, yet real relief only came after it was once again safely outside the aircraft, as so many things could have gone wrong during the process. Even when the helicopter is loaded, the distance between the helicopter and the part of the aircraft under the wings is less than ten centimetres, which makes it very important for the helicopter to be firmly secured to the bottom of the aircraft. Any damage to the aircraft or the helicopter could have significant financial implications.”
Successful task implementation will be followed by recording the process of loading the Cougar helicopter onto the C-17 aircraft in writing, which will be done by the ATTLA organization. The process will serve both the organization performing the C-17 airlift as well as the organization requesting a helicopter airlift. The process description must serve and enable both the C-17 aircraft technician in charge of the cargo and the Cougar helicopter technician to properly carry out everything required to guarantee the safe loading of a helicopter onto an aircraft. Aside from the processes, the loading and unloading tools and equipment must also be carefully defined and described.
The certificate will enable the 151st Rotary Wing Squadron to ensure, in accordance with the NATO declared forces, the shortest possible response time when activated, said Lt. Col. Igor Lanišnik, and added: “We are aware of the importance of the task and shortly expect to acquire a certificate for the strategic airlift of the AS532AL Cougar helicopter. We already have a certificate for the airlift of the Bell-412 helicopter. Regular crew conditioning, equipment inspection, and cooperation with members of other countries in international military exercises are the basics of a solid foundation of the helicopter team’s readiness.”
Photography: Borut Podgoršek