Flight envelope

However, a change in the flight speed and/or the flight alhtude alters the airflow rate. Then, the air-to-fuel ratio in the combushon chamber is also altered, and the thrust produced by the ducted rocket is altered. Consequenhy the flight envelope of the projechle becomes highly limited. These operahonal characteristics of the fixed fuel-flow ducted rocket reshict its application as a propulsion system. 

Aircraft inevitably have to mix up control systems and protection systems, at least to some extent, whereas in both NPPs and in oil and gas facilities it is possible (and desirable) to separate control and protection. Modem digital aircraft systems have tended to become more integrated - which means the separation between control systems, pilot display systems, and protection systems (which act to limit the flight envelope to safe areas) has become more diminished. 

EXTENDING THE FLIGHT ENVELOPE TO MINIMIZE THE RISK OF LOSS-OF-CONTROL... 

To ensure the safe operation of UAS and to prove that autonomous system performance is reliable, an FMS for autonomous aircraft capable of provably avoiding loss-of-control in all situations where avoidance is possible will be essential. This will require that the autonomous system understand its flight envelope sufficiently to ensure that its future path only traverses stabilizable flight states (i.e., states the autonomous controller can achieve or maintain without risking loss-of-control). 

Researchers are beginning to develop nonlinear system-identification and feedback control algorithms that offer stable, controlled flight some distance beyond the nominal steady flight envelope (Tang et al., 2009). Such systems could make it feasible for an autonomous system to discover this more expansive envelope (Choi et al., 2010) and continue stable operation despite anomalies... 

FIGURE 2 Examples of steady-level (left) and 3-D (right) traditional flight envelopes. Source McClamroch, in press. 

It is noteworthy that the laws are robust due to their design incorporating a sufficient margin of stability pUP 04 FAR 89 FAV 94 KUB 95 LAV 05 LIV 95]. In addition, if the input vector of the system is largely outside the certified maximum flight envelope, only a simple law, using the position of the controller and of the control surfaces, is enabled (this law is similar to the type of command available on a conventional aircraft). 

Laws must be reconfigured in case of loss of some sensors (especially the ADIRU). The crew is made clearly aware of die status of the control law. If the three ADIRU are available (normal case), the pilot has fiill authority within a safe flight envelope. This flight envelope is provided by the protections built into the eontrol laws, by adding levels of protection to die pilot orders. The flight mode is then in a load factor mode. 

If only one ADIRU is available, it is partly monitored by comparison with other independent sources of information (in particular, rate-gyro or accelerometer). In this case, the safety of the flight envelope is provided by alarms, as in conventional aircraft. The pilot is still in load factor mode. In case of loss of all ADIRU, the protections of die flight envelope are also lost, and the control law finds itself in... 

The functional specification and, therefore, the software ate also different the ELAC and PRIM execute complex functions, while the SEC is simpler (fewer functions, such as flight envelope protection, autopilot on A380/A400M, passenger comfort requirements are less stringent) and, therefore, more robust. 

The flight control system of the Airbus offers the pilot aids, such as flight envelope protection, some of which are available on non-FBW aircraft, whereas others are specific, as well as assistive devices for maintainability. Note that the errors introduced by the designers are covered in section 6.3. 

Several pieces of avionics equipment, already dedicated to the flight envelope protection, enhance situational awareness of the crew through ... 

The protection afforded by the flight envelope is an extra layer of safety and may be semi-automatic or fully automated. 

Neutral control column - the aircraft remains in a normal flight envelope... 

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