Automatic Takeoff and Landing

 A description and analysis of some of the capabilities and limitations of two automated systems during the takeoff and landing operations and their effects on safe operations will be discussed in this paper.

First, I will outline some of the functionality of the autopilot uses for the manned Airplane Boeing 737 takeoff and landing. The performance is described below and this is done by the pilot manually flying the airplane or by the pilot through the autopilot. The pilot monitors   the system which allow the position of the plane before takeoff. If there is something wrong the pilot can des-engaged the autopilot at any time, during the takeoff or while landing the aircraft. Explanation on how the pilot or copilot operates the autopilot is described below:  

“The pilot can monitor the airplane using the auto pilot and for airplane performance and

While monitoring the system receives only an indication that, using maximum thrust, the airplane is still capable of achieving a desired result, using scheduled thrust. Further, it does not indicate where on the runway particular speeds are expected to occur or where the airplane can be stopped from current position and speed”.

The speeds are very important so at this level the pilot have to be aware of these need it speeds, before the airplane is airborne. Also David said in the report that; 

“The main future of the system is an airplane takeoff and landing performance monitoring system which utilizes runway, ambient condition, flap setting, and airplane loading characteristic information, input both manually and automatic maintain continuous communication with the transducers to a computer, to generate acceleration for predicting airplane performance during takeoff and landing”.

 There is not clear explanation on how the monitoring system controls the information with automatic control. Looking to the way the pilot monitors before the takeoff roll, David explain

“The take-off and landing performance monitoring system provides the pilot with graphic and metric information to assist in decisions related to achieving rotation speed (VR) within the safe zone of the runway or stopping the aircraft on the runway after landing or take-off abort. One-time inputs of ambient temperature, pressure altitude, runway wind, airplane gross weight, center of gravity, selected flap and stabilizers setting are utilized in generating a set of standard acceleration-performance data” (David B, september 1991).

 Continually supervision of this system is required by the pilot for complete verification of the information gather from the computer. All Know data is very important as the report said;

“We have to know Runway length available for rotation, run way length available for stopping, an estimated runway requirements of throttle position, engine pressure ratios, ground speed, calibrated air speed, along-track acceleration, are used in computing engine performance. A comparison of measured and predicted values is utilized in detecting performance deficiencies. These comparisons and the runway length computations lead to GO/ABORT signals. An important feature of the algorithm is that the estimated runway rolling friction is updated based on measured acceleration performance, resulting in more accurate predictions of future performance. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses.” (David B, september 1991)

This system is very reliable and demonstrates good performance in automation and reducing cockpit work load and increasing safety considerably. It is very important for the pilots to maintain the manual skill necessary for all stages of flight. It is important for pilots to learn well how to timely troubleshoot software or hardware problems. Such problems can degrade the system operations and integrity variables. Runway contamination and wind shear are not easy to be determined by the system and the pilots should exercise full awareness in this situation for the safety of the flight.

The second system to analyze is the UAV full Size Cypher UAV.  System can be used for law enforcement in the private sector. This UAV can be flown by using the conventional radio control hand set or automatic functionality with system manager right and left displays with supervision.

Operational characteristics of the system are described as:

“The System safety has been improved due to the shrouded blades. At the same time the design concept provides improved hover and precision maneuver characteristics. The flight control of the system is supervision, the operator directs the motion of the platform, but does not fly it”.

We know that the operator only act as an observer during this part. But the system

will be assisted by the ground operator. As is explain by the report;

                              “ Supervisory control allows the system to be operated by field personnel as a collateral duty and does not require a dedicated operator pilot. The on-board flight control system takes care of maintaining platform stability and coordinating the controls to respond to operator direction”.

 The sensor allow the UAV to fly to where the mission is planned as Douglas state;

                             “The air mobility platform was a shrouded rotor, VTOL UAV with a sensor suite mounted on top of it The platform would fly to target location where it would autonomously land and then conduct long term surveillance with its on board sensors. To reduce communication power and time of communication the sensor data was processed on-board the platform by automatic motion detection software”.

It is necessary to know previously how many more missions the system can

perform so the operator will performed the require activities. The report said;

                                                 “At the end of the mission or when surveillance was required in another location the system would be commanded to restart, takeoff and go to the new location or return to its launch point. In the ground control pilot interacts with the system thru the System Manager display that is split into two portions. The left side displays a digital map of the area of interest, and the right displays the payload sensor output to plan a mission the operator selects the route/destination way-points or areas to be searched using a mouse. Route planning software then plans a safe route to select the way-points or search areas”.

 These two displayed monitors help the operator to operate the UAV auto pilot for takeoff cruise and landing all is done through the system manager. Douglas is ending by saying;  

                                “The proposed route is displayed to the operator for acceptance. Soft buttons for control of aircraft functions, such as; auto takeoff, cruise, search, etc., are also displayed on the bottom portion of the System Manager screen. The right side of the System Manager display shows real-time data from the onboard sensor. This data includes full video or FLIR imagery. Data from the FUR can be analyzed by an Automatic Target Recognition system to detect targets and provides target location information back to the System Manager. Aircraft and target position along with track history are displayed on the digital map.” (Douglas Murphy, November 1998.)

 Some considerations are very important in this system. This system can be operated manually and automatically. The Cypher UAV can also be used for local missions and commercial applications. However, safety could be degraded in the event of software corruption during the takeoff or landing or during the mission. In the event that the operator made a mistake programming this system, there is no clear way to detect it. The problem would be that there is only one operator whom interacts directly with the UAV. The shrouded blades are a very important safety issue, therefore more simulation and fly hours are necessary to comply with the safe standards required from the FAA to gain public confidence for integration of this system in to NAS.

These two systems show the advance technology for operation of automatic systems with sophisticated autonomy. Only time and experience using these systems will let the manufactures and the engineering industry learn and correct any computer glitches software, hardware related problems and operational deficiencies of these systems.     

References

David B, R. S. (September 1991). Airplane Take Off and Landing Performance Monitoring Systems.

Douglas Murphy, J. C. (November 1998.). Applications for mini VTOL UAV for Law Enforcement.