Tuesday, February 17, 2015

Boeing 787 and MQ-1C ATLS Systems



Boeing 787

The Boeing 787 has a full Autoland capability where the aircraft is able to land using its redundant autopilot systems, GPS/INS systems, and FAA certified approach plate database.  The pilot of the aircraft selects the approach that is required and then selects the Autoland system for the approach.  The pilot is capable of taking control and landing manually or aborting the approach at any time.  This system has full control of the aircraft and will even keep the aircraft on the centerline of the runway, slow down, brake, and stop the aircraft without input from the pilot.  Once the plane stops the pilot must then take control of the airplane to taxi off the runway and to the terminal.  The crew of the aircraft is required to keep current on this system and must do an Autoland approach on a regular basis to keep proficient with this system.

The only downside to this system like any automated system is the risk of complacency and putting too much trust into the system.  Because the pilots are not actively engaged in the landing other than as a system monitor there is a higher chance of distractions and inattention.  This must be overcome with training and discipline.  I don’t see any other limitations to this system since the plane can be reverted to fully manual control at any time.  Future improvements will likely involve more automated aborts if approach limitations are exceeded and more accurate navigation equipment.

MQ-1C Gray Eagle

The MQ-1C Gray Eagle has a very extensive Automatic Takeoff and Landing System (ATLS) which utilizes GPS/INS/DGPS systems as well as a backup system call Tactical Automated Landing System (TALS) which uses a ground based navigation system to takeoff and land the aircraft.  The GPS/INS/DGPS system on this aircraft is very accurate with an accuracy of less than 1 meter and the TALS system has similar accuracy.  The runway is surveyed using the aircraft GPS and the GCS is surveyed as well for DGPS capability and the ATLS mission is then loaded to the aircraft.  When the operator is ready for takeoff or landing he selects the desired runway, puts the aircraft within the required parameters and then selects land or take off.  For takeoff the aircraft accelerates and becomes airborne with the system capable of automatic aborts for system, emergency, or environmental (winds) conditions or it can be aborted manually by the operator prior to rotation of the aircraft.  After lift off the pilot is able to command heading changes at 50’ AGL and full control at 300’ AGL.  For landing the auto aborts are the same and the operator can manually abort all the way until touchdown.  After touchdown the aircraft tracks the runway and brakes to a stop without input from the operator.  After the aircraft stops the operator takes manual control of the aircraft to taxi off the runway.  The aircraft does have the capability of being configured to have a backup GCS with full manual control as with other Predator aircraft however this capability will be going away shortly because the Army does not want full manual control of the aircraft.  The operator can override all automatic aborts to force the aircraft to land but this can lead to a crash if too far outside system capabilities.

The TALS works in a similar manner to the normal ATLS system but works with a ground based navigation unit that has its own TALS GDT like antenna that takes control of the aircraft and lands it when selected.  The primary purpose of the TALS system is as a backup in case GPS capability is degraded or lost for any reason.

There are negatives to this system.  Because the runway has to be surveyed prior to being able to takeoff or land from it the aircraft is unable to land at another runway if it is unable to land at its home field.  Future capabilities may allow the aircraft to land at alternate fields but this is not available at this time.  Because there will be no full manual control if the aircraft is unable to land for any reason the only option is to ditch the aircraft in a safe area.  This would be a major problem if the aircraft was attempting to land in a large metropolitan area with few or no safe ditching areas which is a hindrance to this aircraft flying in the NAS.  More flexibility and is going to be required of this system to allow full integration into the NAS.


References

JustPlanes. (2014, June 15). PilotCAM 787 Autoland into Brussels Rwy 01 [Video file]. Retrieved from https://www.youtube.com/watch?v=2zllukY-

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