Many airlines are struggling with the need to upgrade relatively old flight management systems (FMS) to meet new NextGen capabilities such as ADS-B OUT and required navigation performance (RNP) procedures. These capabilities can shave minutes from a typical flight and enable arrivals in weather that earlier systems aren’t made to accommodate.
Innovative Solutions and Support (IS&S) has devised a simple solution that allows airlines to keep existing FMSs and gain the benefits of NextGen technology without expensive FMS and multi-mode receiver (MMR) upgrades. The solution is also available for business jets.
The IS&S solution simply builds RNP capability into displays that are easily retrofitted in the instrument panel. This includes an IS&S Beta 3 GPS sensor and RNP/LPV navigation capability. IS&S also offers this solution in its smaller and easy-to-install standby display for operators that don’t want or need a primary display upgrade.
The Beta 3 GPS adds another benefit; it meet the position-accuracy requirements for ADS-B OUT and thus can be wired to an ADS-B-compliant transponder to meet the upcoming 2020 ADS-B OUT mandate.
IS&S is certifying the new RNP solution in a launch customer’s Boeing 757, and FAA approval is expected in about six months, according to IS&S president Shahram Askarpour. EASA certification should occur about three months later.
RNP 1.0 Accuracy
Another benefit of this solution is that the Beta 3 GPS can deliver accurate position information to the FMS to provide RNP 1.0 accuracy for the entire flight. Older FMSs that use inertial reference unit and DME/DME for position can’t meet that level of RNP accuracy, Askarpour explained. “You can improve the performance of the existing FMS and don’t have to do an MMR upgrade.”
Older FMSs also have limited database sizes because of the types of processors and smaller amounts of memory found in these units. But newer types of RNP and LPV instrument approaches take up more space, and in any case some of these older FMSs didn’t contain approaches in their databases. “This essentially solves all the known issues with these FMSs,” he said.
The accuracy of the IS&S system can be better than RNP 0.1, but this could be limited by the capabilities of the systems in the airplane. “It’s question of whether the airplane and existing autopilot can deliver performance lower than RNP 0.3,” he explained. “Those are evaluated from airplane-to-airplane type. But the position accuracy of our system is less than 10 feet.”
Another benefit of IS&S’s RNP solution, which is patented, is that pilots don’t need to manipulate a bunch of line select keys on the FMS to select an RNP approach. The controls are all built into the IS&S display itself, whether it’s a primary flight display or the standby display. “The user interface is very simple and intuitive,” he said.