I’m sure you’ve heard the old helicopter pilot adage that says flying a helicopter is like trying to pat your head while rubbing your stomach while standing on a beach ball. Well, maybe that’s not exactly how it goes, but you get my drift, and the comparison is pretty close to accurate. Also, if you want to ratchet the difficulty up a few notches, flying a helicopter on instruments is doing all that while turning in a circle blindfolded.
Of course, like with a fixed-wing airplane, having the right IFR certified autopilot and EFIS displays on board makes the whole process that much easier, especially in single-pilot operations. However, knowing how much skill and coordination it takes for a qualified pilot to fly a helicopter on a nice day, we’re often asked just what does it take to certify avionics for single-pilot helicopter IFR operations?
The short answer is it takes a lot more time and effort to get an autopilot IFR certified in a single-engine single pilot helicopter than it does in an airplane. Also, because of some mechanical system requirements, not all VFR helicopters can get an IFR certification.
Since the Genesys Aerosystems certification team just completed a program to earn an STC (Supplemental Type Certificate) for Single Pilot IFR Operations (SPIFR) using our IDU 680 displays in the Leonardo TH-119 single-engine turbine helicopter, I figure we have some of the most knowledgeable experts in the industry to educate us on just what it takes to get avionics certified for single-pilot IFR operations in a single-engine helicopter.
#1: Helicopters require a Stability Augmentation System and hydraulically boosted controls.
As a result, the reliability of the hydraulically-boosted controls must exceed the minimum reliability required for the SAS, since the failure of the hydraulic boost will generally also result in the loss of SAS capability. This often requires dual-boosted controls for IFR certification, where a VFR only helicopter requires only a single boost system.
#2: Helicopters require back-up electrical power.
This requirement has traditionally constituted the installation of dual generators in IFR rotorcraft. In some instances, the single-engine helicopter can be outfitted with an increased capacity battery in lieu of the back-up generator if other requirements are met.
#3: Helicopters can require a second pitot-static source.
According to the FAA regulations, if a stability augmentation system, like the Genesys Aerosystems HeliSAS, is used to achieve the required stability performance and it is dependent on air data information, the system’s basic SAS’s capabilities must not be dependent on the same pitot-static system as the primary instruments.
#4: Helicopters require additional primary and back-up instruments and systems.
The typical IFR certification has a non-stabilized magnetic compass to back-up the required magnetic gyro-stabilized direction indicator. It also has dual, independent attitude indicators. Electronic integrated displays like the Genesys IDU-680 displays and related sensors in the Leonardo TH-119, which use a common air data computer, also require a redundant indication of airspeed and altitude, which may use the common pitot-static system.
Of course, all these are just the basic requirements for earning the IFR approval for the helicopter and autopilot combination. There’s still seemingly countless hours of system design and engineering time, followed by installation, ground testing, and developing the certification flight plan. With regards to our recent program with the Leonardo TH-119, pilots logged many, many hours putting the helicopter and its new Genesys Aerosystems avionics through their paces.
How long did the program take? Well, all totaled, if you started your helicopter IFR flight training and the autopilot STC program on the same day, I figure you’d have your rating a while before the helicopter was certified. That being said, we still won the race to be the first to achieve IFR certification on a single-engine helicopter in over 18 years.
At the end of it all though, you'd have a helicopter that is well equipped to provide low-cost IFR training to pilots, allowing for safely and comfortably tackling the challenges of operating a helicopter in reduced visibility conditions.
Until next time, fly safely,