By Paolo Valpolini
Merging a series of data provided by Leonardo in an article published on its website, and the answers to a series of questions that we filed to the company, we are able to get a bit deeper in the evolution of the Spartan tactical transport aircraft, the company aiming at further improving its capabilities.
Looking at the aircraft from outside the mains distinctive feature is the presence of the winglets.
Their introduction allows increasing the Take-off Weight (TOW) of the aircraft whenever there are limitations on the climb gradient. For example, if in order to take off from a runway and due to certain altitude and temperature conditions (typical conditions in which a series of performance penalties are recorded for each aircraft), there are TOW limitations in order to respect the gradient minimum climb on the second segment in single-engine conditions, thanks the winglets presence it will be possible to increase the weight by 1,000 kg. This increase is always obtainable, regardless of the altitude and temperature at which the airport is located. This gain on TOW will therefore be available to the C-27J NG user, who will be able to exploit it either for increasing the payload or the fuel load. In the Next Generation version, structural changes have also been made to increase the Maximum Take-off Weight (MTOW) by 1 tonne and the maximum transportable payload by 3 tonnes.
In addition to this, the winglets allow the C-27J, at the same weight, to increase its operational ceiling in single-engine conditions by 500 ft. This last benefit is also independent of the temperature. Asked on beneficial effects on fuel consumption, Leonardo pointed out that the winglets have been developed and optimised to reduce the intensity of the extremity eddies at high angle of attack, thus further improving the climbing characteristics in single-engine conditions and increasing the availability of payload, as stated before. However there are also improvements in other areas of the aircraft’s flight envelope, i.e. aircraft controllability, in particular when flying at slow speed. No winglet retrofit kit has been developed, therefore these performance benefits will be available only to C-27J NG customers.
This is not true for the other main improvement adopted on the Next Generation Spartan, that is avionics. The new avionic suite can be installed on previous models, retrofit kits having been planned, and according to Leonardo some current customers have already shown some interest. The company is not ready at this stage to mention the subcontractors that provided the various elements of the new suite. The NG acronym does not mean only Next Generation in terms of aircraft, but also in terms of Air Traffic Control requirements. To improve ATC performances in civil airspace, where the Spartan often flies on deployment missions and even when operating downrange, new systems and regulations have been developed, and to comply with those new rules Leonardo fully evolved its tactical transport aircraft cockpit. Among those new systems the Spartan NG cockpit includes the Future Air Navigation System (FANS) 1/A+ data link that allows aircraft to be seen by ATC in areas where radar is not practical, the TCAS II 7.1 that resolves safety issues with the current TCAS II, a Cat. II Instrumental Landing System (ILS), and an enhanced video Terrain Awareness Warning System (TAWS). The new cockpit does not look only at navigation in civil airspace, but has it been fitted with state-of-the-art systems in place of legacy ones that can also facilitate the pilots task in tactical missions. Among those we find five new Colour Multipurpose Display Units, which feature new and enhanced LED lighting and panels that increase pilots’ efficiency, a dual redundant Flight Management System, and two Digital Autopilot-Flight Director Systems with auto-throttle capabilities. Leonardo’s Next Generation tactical transport aircraft has also been fitted with a new weather radar, new radio navigation, enhanced satellite communications and radio communication capabilities, a new intercommunication system, and the Mode 5 IFF/ADS-B (Identification Friend or Foe/Automatic Dependent Surveillance-Broadcast) with tactical VNAV (Vertical Navigational) and Search and Rescue modes. Moreover, former avionics and general systems interface boxes have been replaced with new equipment provided by Leonardo’s Electronics.
The C-27J assembly line at Torino Caselle will now produce only Next Generation aircraft, the NG being now the Spartan reference configuration. As for aircraft already in service, these might come back to their place of origin for upgrading their avionics, wholly or partly, to cope with new ATC regulations. The C-27J Spartan is currently flying in 14 countries which ordered nearly 90 aircraft.
Photo courtesy Leonardo