Airbus Helicopters did more than create a new aerodynamic design for the H160 medium twin-engine helicopter; it also changed how pilots fly the unique new machine. While Airbus didnât opt for costly and complex fly-by-wire, the H160âs full-time autopilot (or automatic flight control system or AFCS) offers many similar benefits to fly-by-wire flight controls.
Airbus calls the new design âaccrued pilot assistanceâ and it includes flight envelope protection, all with the goal of helping pilots stay out of trouble orâif they do get into troubleâfix the problem before loss of control results in an accident.
That isnât to say that the pilot doesnât have full control over the H160 at all times. But the automation is there for a reason and also carefully thought out from the perspective of a human-machine interface.
Olivier Gensse, Airbusâs H160 experimental flight test pilot, was instrumental in the design and testing of the H160âs AFCS. âI hope it will be a big step for us too,â he said. âWe spent a lot of energy to find a new answer for incidents and accidents. Most are linked to human factors, and it was a big part of our innovation to try to develop automation that is more simple and intuitive for pilots with less experience.â
The H160, which is equipped with Airbusâs Helionix avionics package with weather radar, synthetic vision, moving map, TCAS II, and HTAWS, builds on the H175âs automatic airspeed and flight path stability. That makes flying the H160 much easier and allows the pilot to attend to other tasks without worrying about ending up in an unusual attitude. Also known as a fly-through autopilot, the AFCS remains on all the time in the H160. In hands-on mode, the pilot can make the H160 do anything the helicopter can do, but the autopilot is still on. With hands off the controls, that just results in the helicopter maintaining the same flight path and airspeed.
This key feature fits with Airbusâs philosophy of making its helicopters easier to fly and requiring less training. But at the same time, Airbus designers paid a lot of attention to the flight deck design. The goal was to remove and simplify the controls, switches, and knobs, Gensse explained. That allowed designers to improve the pilotâs field of view for looking outside but also helps lower the number of pilot actions required, which benefits training and safety. âWith less actions, there are less mistakes, but you also save time,â he said.
Gensse likes to demonstrate how the design improves the pilot and passenger experience, going from dark cockpit to engine startup and ready for takeoff in less than two minutes. âEverything is automatic,â he said. âItâs positive automation. You can follow everything, and itâs easy to understand. But if there is any discrepancy, you have feedback or an alert.â If there is nothing wrong, then the system doesnât bother the pilot with unnecessary information.
The design further helped expand the pilotâs outside view, by reducing the space needed for instrumentation and displays. âBecause we donât have oil pressure [and] temperature showing all the time, we have space to present safety information like TCAS, nav, etcetera,â he said. âFor the internal part, you have all the information that you need and a very large field of view from your feet to the roof to have an opportunity to see the external view. This is a very new concept philosophy and hard to build. It cost a lot in terms of design.â
Although engine instruments arenât always front and center, the system manages any applicable limitations and alerts the pilot if there is an issue. âYou can fly the H160 with no engine instruments in front of you,â he said. âIf you have a discrepancy, you have an alert and have time to manage that.â
If there is a failure, the H160 automatically reconfigures the system appropriately instead of waiting for the pilot to run through steps in a checklist. The pilot still has full control of the systems, if preferable. But the workload is much lower when the helicopter automatically takes care of the problem. âIt takes five to ten seconds to achieve every procedure,â he said. âItâs very efficient and easy.â
Although touchscreens are becoming widespread in aircraft, the H160 sticks with traditional displays surrounded by configurable keys. Helicopter vibration has always been an issue for touchscreens, but the H160âs lower vibration levels would easily allow touchscreens, Gensse said. âI think we will [eventually] have touchscreens,â he added.
During takeoff, the dual-autopilot AFCS provides an automatic assisted takeoff function, which can be done with hands off the controls. While it can be a lot of work to calculate the safest trajectory for takeoff, the automatic system monitors rotor rpm and the flight path to ensure a safe outcome in case of failure of one of the H160âs two Safran Arrano engines. The system can even help land the H160 safely after engine failure while in a hover, automatically selecting the power needed on the remaining engine.
In cruise, if an engine fails, the H160 AFCS reduces speed to maintain the flight path, giving the pilot plenty of time to evaluate the situation, brief passengers, plan a diversion, or try a restart. âEverything is managed,â Gensse said, âand the workload is very low.â
Although demonstrated during certification testing, a dual engine failure is a very low probability event, he explained. âWhat is good about that compared to other helicopters is that it is easy to manage rpm, there is a lot of inertia in the rotor system. This is good because you have time to manage the trajectory.â Due to the low probability of dual engine failure, Airbus didnât automate the autorotation processâalthough that could be doneâso the pilot still has to manage rotor rpm.
Like other modern helicopter autopilots, the H160 has a recovery mode. This is activated by double-clicking a button on the cyclic and automatically brings the H160 to straight-and-level configuration. If flying close to the ground and experiencing a visibility-reducing phenomenon like a dusty brownout or snowy whiteout, the pilot can simply double-click the button and the H160 will revert to a safe hover.
With a full-time AFCS, there is no so-called âwet noodleâ mode where the pilot can opt to fly fully manually, although Airbus has demonstrated what happens if the AFCS isnât operating. âThe autopilot is always on,â Gensse said. âItâs part of our design philosophy, to try to build the most stable aircraft we could, with the best handling qualities. But with two autopilots, that failure never happens.â
Airbus added a significant new safety feature that is unique to the H160, a vortex pre-alerting system designed to give pilots advance notice that the helicopter is about to enter a dangerous vortex ring state. âThis gives a five- to seven-second warning,â he said, âenough time to change the condition.â
Vortex ring state, also known as settling with power, is not only hard to detect when it is happening, itâs impossible to demonstrate safely. âWe expect this will change the point of view to vortex ring state,â Gensse said.
The system provides both an audible and visual alert to âcheck power.â The pilot can either add power, if sufficient margins are available, or if already at maximum power, try to fly out of the condition. Another option is to push the go-around button on the collective, which will fly the H160 out of the vortex ring state in the most efficient way possible.
âVortex ring state is not so big an issue to manage if you have altitude,â he explained. âWhen we did the tests, we were at high altitude with lots of time to recover. The problem in operational life is that most time is spent close to the ground. Vortex ring state might have a descent rate of 3,000 feet per minute, and thatâs not enough time to get out. Itâs important to have pre-alerting.â
The pre-alerting system âis quite a complex equation,â he said, âbut it takes into account deceleration, the level of power, and the total energy picture.â A high rate of deceleration without extra energy available from the engine signals likelihood of vortex ring state, for example. A challenge in developing this system was to eliminate a high rate of false alerts. âThe secret is to have the alert only when you will encounter it,â he said. âFor a long time, weâve wanted to implement it, and weâre happy to have certified that.â
The design philosophy of the H160 AFCS is that the autopilot is always on and will always try to assist. âWhatever the condition, the autopilot will be on and will try to help you,â Gensse said. âIf you are out of the normal flight envelope, the autopilot will try to recover to go inside the envelope. For the pilot, he doesnât have to think, âcan I use it?â Donât ask questions, just use it.â
For that reason, there are no limitations beyond which the autopilot will just give up flying and hand an out-of-control helicopter back to the pilot. It will take longer to recover from more extreme conditions, Gensse explained, âbut the aircraft is recovering in the most efficient way. If itâs close to the ground and nose down and full speed, the limit is physics; if the aircraft is able to recover, it will. If itâs too extreme an attitude, it will try, but if not possible, then it canât do it. We didnât want to put limits for recovery because every time you can use it, the autopilot will do its best.â
The H160 isnât designed to eliminate the need for piloting skill, but to enhance the pilotâs skills without adding to the workload. If an unexpected event happens, pilots typically arenât ready, but as Gensse explained, âyou have a lot of direct access to help you. Itâs easy to use in a normal way and easy during an event.
âYou can train a lot and use a simulator to become the best pilot,â he added, âbut we prefer to have not much training required to achieve the best level. Safety is the first priority. Each time we can improve safety, itâs better.â
That said, Airbus doesnât intend to lower the training requirements for such a capable helicopter. âMy philosophy is to keep the same volume of training because of innovation,â he explained. âWe want to be sure the customer is comfortable with all that automation. Automation is good if you understand it.â
H160 pilot training will take place at Airbusâs Marignane facility in France, where the first H160 simulator was certified by EASA in August. FAA certification of the simulator is expected at the end of this year. A second simulator is planned for the U.S.
Helionix and the dark cockpit concept are not new for Airbus Helicopters; these are also implemented on the H175 and H145. Some of the H160 features will likely be made available on other helicopters, such as the vortex pre-alerting and assisted takeoff. The family concept will already help because H175 pilots will need just two flights to transition into the H160.
âWhat is impressive for the new H160 pilot is the external visibility,â he said. âThis is the first time in that size helicopter that you can have such visibility...and comfort. There is no vibration; itâs a really pleasant aircraft.â
When pilots fly the H160 for the first time, Gensse said, âeverybody can understand itâs really an improvement. When we see the pilotâs smile at the end of the flight, itâs really nice for the team. We all worked for one thing: that smile.â