First Astronautics RoadRunner EFIS Installation in Sikorsky S61

1974 Sikorsky S-61N

New Equipment Being Powered Up for a Test Flight
New Equipment Being Powered Up for a Test Flight

Aircraft and Owner

Canadian Helicopters is the largest helicopter transportation services company in Canada with 25 bases and a fleet of over 90 light, medium, and heavy lift helicopters. The Sikorsky S-61N is the civilian version of the Sea King military helicopter. The N model is amphibious and designed for passenger transportation. This helicopter is impressive in size at over 58 feet in length, with five 31 feet long rotor blades.


This aircraft was due for a 9000-hour inspection making this an ideal time for a substantial avionics overhaul, which was an excellent way to minimize downtime. With most of its original steam gauges, it was clearly time for some upgrades. A modern primary flight display (PFD) was the most pressing matter for this project. The PFD also had to tie into a modern GPS which would provide LPV approach capability. Additionally, they required an ADS-B transponder for operations in US airspace. Complete IFR capabilities, including localizer performance with vertical guidance (LPV) approaches was a must as this aircraft will be operating in a wide variety of conditions and environments. A modern weather radar system will help the flight crew operate in harshest instrument meteorological conditions possible.

New Paint
New Paint



Dual AFI4700 RoadRunner

GTN750H Xi (dual)



STC SH20-33

STC SH20-32

STC SH20-31

STC SH20-30

Electronic Flight Instrument System (Astronautics)


Weather Radar (Garmin)

Transponder (Garmin)

Garmin Helicopter Terrain Awareness System STC (Maxcraft)

Garmin GWX Weather Radar STC (Maxcraft)

Garmin GTX ADS-B Transponder STC (Maxcraft)

Astronautics AFI4700 PFD with Garmin GTN750 GPS STC (Maxcraft)

The Old Dated Panel
The Old Dated Panel

Maxcraft Solution

The mechanical instruments on this aircraft were showing their age. The Astronautics RoadRunner AFI7400 primary flight display will act as the hub connecting the many internal systems and providing the pilots with vital information in one place. The GTN750H combines the many functions of a GPS, radio navigational aid receiver, and radio transceiver while also feeding information to the RoadRunner. We also opted to add on the Helicopter Terrain Awareness and Warning System (HTAWS) enablement to the GTN750H which provides flight crews both audio and visual warnings when possible conflicts with terrain exist. As this helicopter will need to be able to fly in any condition and navigate even the harshest of storms the Garmin GWX75H will provide the pilots a much better view of weather ahead even in total instrument meteorological conditions allowing them to dodge bad weather cells. The GTX335R is a versatile transponder giving ABS-B capability and interfacing with the GTN750H.

Instrument Panel Removed to Facilitate Upgrades
Instrument Panel Removed to Facilitate Upgrades

The Story

Most work for this project was completed remotely at Heliwelders Ltd (a division of Canadian Helicopters) where it was also undergoing a major 9000-hour inspection, major structural and airframe overhauls, and new paint. This was the perfect time to perform upgrades making a single block of downtime for all maintenance. While new paint was being sprayed, we were able to prefabricate wire harnesses, and prepare everything for installation at the same time. As this was the very first time many of these systems were installed in the Sikorsky S61 Supplemental Type Certificates (STCs) were required from Transport Canada. Maxcraft utilized our in-house Design Approval Organization (DAO) to develop four approvals for this project to allow installation of the GTN750H, GWX75H, GTX335R, and most notably the AFI4700 RoadRunner in the S61. This certification can now be used for similar installations by us, or potentially by other qualified avionics facilities.

Instrument Panel Wiring Being Prefabricated at Maxcraft
Instrument Panel Wiring Being Prefabricated at Maxcraft

Press Release:

Maxcraft Version:

Customer Comments“Maxcraft has been a long-standing supplier of Canadian Helicopters. We anticipate significant benefit with this retrofit and are pleased to partner with Maxcraft on this initiative.”

Don Wall

President & CEO
Canadian Helicopters Ltd