The Portuguese Air Force helicopter fleet is made up of the Leonardo EH101 Merlin, a 15-ton multi-purpose helicopter mainly used for the search-and-rescue (SAR) mission over the ocean and islands, and the Leonardo AW119Kx Koala, a three-ton, eight-seat helicopter that replaced the older Aerospatiale SA.316 Alouette III that was in service for about 60 years.
The Alouette III was first delivered in April 1963 to the Esquadra (Squadron) 94 on Air Base 9 (BA9) at Luanda, Angola, the first Portuguese unit to receive the type. In the following months, 33 Squadron on BA3 got its new helicopter, and on Nov. 24, 1978, the squadron changed denomination to 552 Squadron.
552 Squadron “Zangões” (Drones) received its first Koala in 2019. Today, the squadron operates five machines from BA11 at Beja, about two hours from Lisbon. The €20-million (US$22-million) contract between the Portuguese Ministry of National Defence and Leonardo included five helicopters with an option for two additional units.
The Koala is derived from the bestseller AW109. Powered by a single Pratt & Whitney Canada PT6B-37A turboshaft engine delivering 1,002 horsepower, the helicopter has a cruise speed of more than 130 knots. It can fly more than five hours without interruption, with a service ceiling of 15,000 feet (4,500 meters), although during tests run in Nepal, the helicopter reached 22,000 ft. (6,700 m).
The helicopters are equipped with a Garmin G1000H glass cockpit with a primary flight display and a multi-function display that presents engine and basic flight information beside a digital map with flight plan data. The cockpit is compatible with night vision goggles to perform night operations.
The aircraft is equipped with fixed skids instead of retractable wheels, supporting the installation of an emergency float system for over-water missions. For cargo missions, the aircraft is fitted with a cargo hook under the fuselage that can support up to 1,400 kilograms (3,000 pounds) of external load.
A 204-kg (500-lb.) capable door winch is used for SAR missions and can hold two people. All the equipment can be mounted or unmounted depending on the need. For example, if the helicopter is used to support ground troops, removing the hook, winch and float system can save weight at takeoff and improve performance.
Transporting troops
552 Squadron’s primary role is troop transportation. The Koala can accommodate up to six people in the rear cabin, or four to five fully equipped soldiers. Reducing the number of fully equipped soldiers helps preserve the agility of the helicopter, allowing it to perform well at low altitudes and over different terrain. When crews train in a simulated environment over enemy territory, they need to fly low level tactical.
In order to strengthen the synergy between pilots and troops, the teams take part in exercises such as the Real Thaw and the Hot Blade — both are operated in Portugal with the first exercise planned by the Portuguese Air Force and the latter supported by the European Defence Agency.
During these exercises, the Koalas bring troops to the landing zones or exfiltrate them after they have completed their objectives. The helicopters also support troops with their heli-sniping technique where one or two skilled operators cover the troops from the rear cabin, deploying sniper rifles aimed at possible enemy. This technique is also used when the Zangões support the Merlin from 751 Squadron during combat search-and-rescue missions.
Pilot training
552 Squadron is also in charge of helicopter pilot training. This will later be assigned to 751 Squadron and its Merlin or the Navy Helicopter Squadron and its recently upgraded Westland Lynx Mk.95. 552 Squadron will also like be in charge of the formation of pilots that will be assigned to the newly acquired fleet of six UH-60 Black Hawks that will provide firefighting services around the mainland.
Pilot training follows a syllabus common to all the pilots of the final approach point. After an initial course where cadets fly the 802 Squadron de Havilland Canada DHC-1 Chipmunk and the 101 Squadron Socata TB-30 Epsilon for a total of about 200 hours, the ones who will join the helicopter squadrons are assigned to the instructors in 552 Squadron.
Once cadets arrive at Beja, they start with lectures while performing instruction flights. Cadets fly solo while the instructor remains on the ground in contact with the cadets via radio. This phase lasts about 100 flight hours, after which, cadets fly supervised with an instructor or an experienced pilot, performing flights in a simulated scenarios they will face in the future.
Cadets are evaluated during this second phase, and only those able to accomplish all simulated situations are qualified to fly a helicopter. The duration of this phase varies depending on the skills that each cadet is able to achieve. The best pilots can choose between remaining at the squadron to become an instructor themselves or reaching the operational squadrons. Every year, an average of four cadets reach the operational squadrons and two of them are asked to remain.
SAR and firefighting
552 Squadron is also called to support civilians through SAR and firefighting coordination. Due to the Koala’s single-engine helicopter design, SAR is mainly conducted on the mainland but can also be carried out over the ocean within a range of five miles (eight kilometers) from the coastline.
The squadron also provides 24-hour service from BA8 at Ovar. Thanks to the service ceiling and the presence of a door winch, the Koala can rescue people in the mountains. A stretcher can be placed in the rear cabin, and medical personnel have enough space to support the rescued person.
A standard SAR mission over the land, in the mountains, or at sea includes a pilot, winch operator, and rescue swimmer. If the call comes from the mountains, 552 Squadron operates with specialized National Guard operators, specially trained for rescues in that area. They train together to coordinate their efforts, although 552 Squadron is able to perform rescue missions on its own.
When 552 Squadron operates over the ocean, efforts are coordinated with the Portuguese Coast Guard. Methods are different depending on the environment where they are called to intervene.
With regard to firefighting, 552 Squadron will dispatch two Koalas to Lousã to support firefighters by coordinating ground crews and vehicles, as well as other helicopters and airplanes.
The Koala acts as a command and control center, providing a better aerial view of the scene and improving situational awareness for the crews involved in extinguishing the fires. One or two experienced firefighters are on board the helicopter to maintain live communication with the ground crews or pilots.
The Koala will maintain this role even after the Black Hawks arrive. These helicopters will be able to carry 12 firefighters onboard and will be modified with a under-fuselage tank that can drop more than 2,800 liters (740 US gallons) of water directly over the fires.
Koala pilots undergo two to three years of training to be qualified to fly a solo firefighting coordination mission. The Zangões is made up of 14 pilots, including three instructors and two supervisors. Some of them have flown on the Alouette III before its withdrawal.
Improved technology
Pilots said the Koala’s new avionics improves performance and reduces workload, and the flight characteristics of the new helicopter are a leap forward in comparison to the 70-year-old predecessor. The Koala has digital displays that concentrate all the information in one place, giving very precise information to the pilot. It also has an integrated GPS antenna that indicates the position of the helicopter — a valuable tool when the Zangões are called to operate in adverse weather conditions.
In terms of mechanics, the engine of the Koala exceeds the Alouette III by more than 200 hp, and its four-blade main rotor delivers more energy compared to the Alouette III’s three blades. Both have a mechanical transmission, so the pilot “feels” the helicopters, but the Koala has a flight control system that helps to stabilize the helicopter on the three axis.
It also has autopilot that keeps the helicopter flying in a straight path. However, the Koala doesn’t have the ability to perform an automatic hover on a point like the Merlin, which means significant training is needed to stabilize the helicopter and fly it smoothly to let the rescue swimmer and winch operator operate at their best.
In 2020, the Minister of Defence indicated that the government was considering buying another two Koalas in order to extend the firefighting support around the nation, but a decision has not been made. It is unclear whether the contract to purchase six UH-60 Black Hawks for firefighting canceled the option for the Koalas or if it is delayed, although the roles of these two types are complementary.
During the first months of 2023, the AW119Kx Koala fleet reached an important milestone of 5,000 flight hours, performed during their continuous training activities and in support of the Portuguese population.