Just one Swiss Air Force squadron flies the rugged Pilatus PC-6 Turbo Porter, and it puts its militia pilots to the test with demanding rough-field operations. In the March issue of AFM, Peter Lewis finds out what makes Air Transport Squadron 7 a unique unit within the Swiss armed forces.
LT St 7 (previously Leichte Fliegerstaffel 7, Light Squadron 7) is the service’s only squadron to have continuously operated the same aircraft type – the PC-6 Porter. It is also the only Swiss Air Force unit operating the type, which it has now flown for 50 years.
The robust Porter was first adopted by the Swiss Air Force in 1967 when 12 units were acquired from the Buochs-based manufacturer. Initially piston-powered, the PC-6/H2M Porters were modified with turboprop powerplants in 1980-81, becoming PC-6/B2-H2M aircraft. A second batch of six aircraft had been acquired in 1976, again with the Pratt & Whitney Canada PT6A-27 turboprop. As a result of weight changes, the Turbo Porters had their nose sections lengthened to accommodate the new engine and to keep the airframe balanced. This became the standard configuration for all PT6-engined Turbo Porters leaving the production line. Delivering some 680shp (507kW), the PT6A-27 is also the standard powerplant for the DHC-6 Twin Otter, EMB-110 Bandeirante and L-410 Turbolet.
In previous years, the light squadrons also used to perform snow and glacial landings and were accordingly equipped with skis. With the Super Puma/Cougar and EC635 helicopter fleet now complete, this task is no longer performed.
The Turbo Porter’s avionics and instrument upgrade programme (known as AEB 2015) is now complete across the Swiss Air Force’s fleet. Gone is the 1970s-era mechanical instrumentation, replaced by large display screens from both Garmin and EI Electronics (MVP-50). The aircraft is now comparable with current production PC-6s leaving the factory. With the addition of Garmin VHF radios, plus existing VHF/UHF and FM transceivers, the Swiss PC-6s have an abundance of radios. Thanks to a new autopilot system, the Porters are fully cleared for instrument flight rules (IFR) weather conditions, which is critical in a small mountainous nation where weather can be different from valley to valley. With the upgrade finished, the PC-6 fleet is expected to continue flying until at least the early 2030s.
The March issue of AFM is out now, and is also available as an app.