Excerpted from Cobham’s Connectivity White Paper Series

Out of the Shadows: The Dawn of a New Day for Rotorcraft Connectivity

How a Technology Breakthrough called SB-Helo X-Stream Overcame the Rotor Shadowing Challenge

INTRODUCTION

An ongoing complaint from the helicopter community is the lack of suitable connectivity solutions. That’s a fact. The problem has to do with the way satellite technologies are architected, the unique nature of rotary-wing aircraft, and the physics of rotating blades. Since you can’t take the rotor out of the rotorcraft, many operators have been stuck with partial performance and relatively few choices. With the recent debut of a new service called SB-Helo X-Stream, the age-old problem of rotor shadowing has finally been solved – once and for all. In this whitepaper, we take an educational look at the state of the art in helicopter connectivity, where the market has been, and how past issues have been addressed.

THE CHALLENGE OF ROTOR SHADOWING

Satellite-based connectivity depends on having an uninterrupted signal between the aircraft’s antenna and satellites orbiting in space. In helicopters, rotor blades interrupt that signal as many as 33 times per second, or more. Those constant interruptions to the signal produce degradation in the data connection (called packet loss), which reduces reliability and throughput.

In larger aircraft, performance degradation is significant – rotating blades become a connectivity shredder. It’s a critical issue for missions like ISR, where streaming service is virtually always required. And unfortunately, streaming is where performance degradation from packet loss is most pronounced.

SOLVING THE ROTOR SHADOWING ISSUE

Rotor shadowing is a problem that has existed for as long as there’s been satellite connectivity – and the industry has been searching for a solution ever since. For larger aircraft, the traditional way of solving the rotor shadowing issue has been with a service from Inmarsat called HDR (High Data Rate), which enables reasonably good performance and reliability. But HDR comes at a price. Not only is HDR-compatible equipment less prolific and more expensive to purchase, it can cost more to operate on a per-minute basis.

Following years of industry effort, the team at Cobham has finally cracked the code on helicopter connectivity. Now, there’s a new way to solve the rotor shadowing issue – a new service from Inmarsat and Cobham called SB-Helo X-Stream. With SB-Helo X-Stream, helicopters can now get virtually the same level of streaming connectivity as one finds in a fixed-wing aircraft.

SB-HELO X-STREAM: A NEW APPROACH TO HELICOPTER CONNECTIVITY

HOW DOES IT WORK?

When an SB-Helo X-Stream-equipped connectivity system signs on to the network, the network automatically recognizes it as a helicopter – activating new algorithms, modulation schemes and QoS calculations specifically designed for the unique operating characteristics of rotary-wing aircraft.

WHAT IMPROVEMENTS DOES IT MAKE?

A standard SB X-Stream connection promises theoretical throughput of up to 432 Kbps – but rotor shadowing means real-world performance in larger aircraft is typically only in the range of 200-250 Kbps. The new SB-Helo X-Stream service is a proven solution backed by many years of development and real-world test result data. In fact, during 2019 field tests conducted on a Mi-8 platform in Hungary, a Class 6 terminal performed exceptionally well – achieving a speed over 430 Kbps with minimal packet loss using just a single channel of SwiftBroadband.

CLOSING

For many rotorcraft operators, connectivity has always been a must-have – but up to now, available solutions just didn’t meet the need or may have simply been too risky from a functional perspective. Technology has improved dramatically in recent years, and the new SB-Helo X-Stream service opens a whole new world of BVLOS SATCOM capabilities for the helicopter community. The true impact of the service starts with a faster, more reliable connection. But more significantly, it gives you more options throughout the entire helicopter connectivity ecosystem – SB-Helo X-Stream gives you more hardware packages to choose from, along with more opportunities to reduce certification costs, activation fees and ongoing airtime expenses.

If you looked at connectivity in the past but the available solutions didn’t meet your needs, recent technology breakthroughs make it a great time to take a fresh look – especially if it’s been a while. We encourage you to take the knowledge and insight from this whitepaper and talk to Cobham, your OEM and/or the various MROs, hardware manufacturers and airtime providers – to see what opportunities are available.

Available for free download here, the unabridged version of Cobham’s Heli Connectivity whitepaper includes expanded content, including:

  • Real-world flight test data with actual SB-Helo X-Stream performance figures
  • Connectivity terms, explained – packet loss, jitter, throughput
  • How-to insights – sorting out your coverage and feature needs, choosing the best network, pitfalls, tips & tricks
  • High-level round-up of all current heli connectivity technologies – SATCOM (L-, Ku- and Ka-band), ATG, microwave and ground cellular
  • Charts, graphs and educational sidebars

Cobham has created a dedicated digital resource for SB-Helo X-Stream information and education – outoftheshadows.aero. Heli operators with BVLOS connectivity needs can access useful resources including a white paper, video, podcast, literature and more – all at no cost, with no registration required.

For more information and assistance, please contact your Cobham regional sales representative, or Jeff Saucedo at +1.925.348.5351 or jeff.saucedo@cobham.com