A growing share of Brazilian business aviation and air taxi flies in turboprops and light jets certified for single-pilot operation. They are pressurized aircraft, with integrated avionics, a three-axis autopilot, and jet performance, operated by one person who at the same time flies, navigates, communicates, manages systems, makes decisions, and, in air taxi, looks after the passenger.
The rule recognizes the operation. What it does not do is divide the workload.
What RBAC 135 allows, and under what conditions
Section 135.105 of RBAC 135 is the exception to the second-in-command requirement. One person may operate the aircraft without a second in command provided it is equipped with an approved autopilot system, in working order, and that its use is authorized in the operations specifications of the company. ANAC only issues the authorization if the autopilot is capable of maintaining and maneuvering the aircraft in all three axes and if the operator demonstrates that the operation can be conducted safely. In scheduled operations, the pilot must have at least 100 hours as pilot in command in the same make and model.
Read the logic of the rule: the autopilot is treated as the substitute for the second pilot. It keeps the aircraft on the flight path while the pilot does everything else. The premise works when everything goes well. The human factors question is what happens when it does not.
The cockpit with a single brain
The FAA's Risk Management Handbook defines single-pilot resource management (SRM) as the proper management of all resources available to the pilot flying alone, inside and outside the aircraft. The competencies listed are the same as CRM's, only without the other crewmember: situational awareness, communication, task allocation, decision making, risk management, CFIT awareness, and automation management. The handbook adds a condition that CRM does not need to state: before using a resource, the single pilot must assess whether there is time to use it. The controller can help a pilot who is lost; in an emergency, there may be no time to call.
This is where the snowballing workload comes in, described by the NASA study of 19 airline accidents: small demands that pile up in the descent and the approach, each asking for a little attention, until the pilot falls behind the airplane. In a two-pilot cockpit, the monitoring pilot absorbs part of this. In a one-pilot cockpit, the snowball falls entirely on the same person, and the autopilot, which should be the relief, becomes one more system to be managed.
What the FAA automation report found
In 2013, a joint working group of the FAA, the PARC committee, and CAST published the report Operational Use of Flight Path Management Systems, with 29 findings and 18 recommendations on how crews use flight path management systems. Three of them matter directly to the single pilot:
- Manual flying. The group identified vulnerabilities in pilots' knowledge and skill for manual flight: prevention of and recovery from abnormal attitudes, transition from automatic to manual control, energy management, and inappropriate control inputs. More than 60% of the accident reports reviewed cited manual flying error as a factor.
- Mode confusion. Autopilot mode awareness errors continue to occur. The pilot believes the system is doing one thing, and it is doing another.
- Responsibility. The recommendation on operator policy is direct: responsibility for flight path management remains with the pilots at all times, regardless of the level of automation.
For the single pilot, these three findings combine uncomfortably. The rule authorizes the operation because the autopilot is on. The skill that degrades most is precisely that of taking the airplane back when the autopilot disconnects, or does something the pilot did not expect, at the moment of highest workload, with no one alongside to notice first.
What must be ready before the airplane leaves
The principle of SRM is to move work out of the cockpit. Everything that can be decided, calculated, and organized on the ground should not compete for the pilot's attention in the descent. In practice:
- Planning closed on the ground. Route, fuel, weight and balance, runways at the destination and alternate, weather and NOTAMs read and annotated, with the numbers already extracted: the single pilot should not open a 40-page PDF at 200 knots.
- Risk assessment done and decided. Night flight, over-water segment, terrain, forecast icing, short runway, experience on type. If the risk is high, the decision to go belongs to someone who has the time to make it, not to the pilot at the threshold.
- Approach briefing before top of descent, with the diversion and the go-around already built into the plan, not improvised.
- Written automation policy. When to use it, when to turn it off, which modes are acceptable in each phase. The FAA report asks the operator to have one, and that it emphasize the pilot's responsibility for the flight path.
- Recurrent manual flying. The skill that degrades most is the one that needs the most training, in the simulator and in flight, under conditions that allow it.
- "I am behind the airplane" criteria. The single pilot needs defined triggers to ask for a vector, ask for a hold, declare that more time is needed. Asking is a resource, not a weakness.
Where Alis comes in
Alis works on the part of SRM that happens on the ground. The Flight Kit brings together, in a single document, what the single pilot needs to have resolved before boarding: the route with terrain elevations, the runway dimensions and aerodrome elevation, the weather and NOTAMs ordered by relevance, the weight and balance with takeoff and landing weight and the MTOW exceedance warning. The FRAT assesses the dispatch factors, including night flight, over-water segments, mountainous terrain, icing conditions, and the threats reported by other operators at the aerodrome, and returns the decision authority: at high risk, approval from the operations manager is required before the flight. All of this is filled in on the web, with time to spare, and followed in the pilot's app, which works without a network.
After the flight, the digital logbook records the hours and landings and feeds maintenance tracking, and scheduling shows the manager the sequence of flights for each pilot, so that the workload of the whole day, and not just of one leg, is management information.
For risk assessment, the article on FRAT and PAVE describes the method; the one on duty and rostering in air taxi covers the other side of workload: fatigue.
Want to see the Flight Kit and the FRAT prepared on the ground and in the pilot's pocket? Book a demo.
This article is informational. Section 135.105 is cited according to RBAC 135, Amendment 07; the SRM concept is that of the FAA's Risk Management Handbook (FAA-H-8083-2A); the findings on automation are those of the report Operational Use of Flight Path Management Systems (FAA/PARC/CAST, 2013); the snowballing workload is described by Berman and Dismukes (NASA Ames, 2006). The text does not replace consulting the regulation, the operator's operations specifications, or the guidance of the person responsible for operations.