Summary of the First Meeting Special Committee 227 ... - RTCA
Summary of the First Meeting Special Committee 227 ... - RTCA
Summary of the First Meeting Special Committee 227 ... - RTCA
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Q: what is <strong>the</strong> impact on economy <strong>of</strong> flight with <strong>the</strong>se speed constraint changes<br />
Mike: There is 3D-PAM study on this. If procedure is done well <strong>the</strong>re is not much impact.<br />
Issue Lateral Offset Operation<br />
Ref: “FMS Standardization <strong>of</strong> Lateral Offset Operation FINAL RECOMMENDATION.pdf and<br />
FMS Standardization - Lateral Offset and FRT.pdf”<br />
The first paper indicates that FMS treatment <strong>of</strong> lateral <strong>of</strong>fsets differ to <strong>the</strong> point that ATC cannot easily<br />
use it as a tool. Entry and exit treated as a straight path, but <strong>the</strong> intercept angle varies between 30 and 45<br />
degrees, but some aircraft allow specification <strong>of</strong> <strong>the</strong> angle in <strong>the</strong> AMI and some systems allow <strong>the</strong> pilot to<br />
enter <strong>the</strong> angle. Most perform a flyby transition from parent path to intercept path. Some systems display<br />
<strong>of</strong>fset path and intercept track, o<strong>the</strong>rs don’t. Some systems allow 0.1nm increments, o<strong>the</strong>rs only 1.0nm.<br />
Some systems allow specification <strong>of</strong> <strong>the</strong> lateral <strong>of</strong>fset start and end points, some don’t – <strong>the</strong>y only allow<br />
immediate engagement and disengagement <strong>of</strong> <strong>the</strong> <strong>of</strong>fset.<br />
This variation makes it difficult for ATC to use it because <strong>the</strong> result <strong>of</strong> <strong>the</strong> clearance varies. ATC use <strong>of</strong><br />
this is desired, and ATC automation tools are being developed that could make use <strong>of</strong> this capability if its<br />
response were consistent.<br />
Desired operations:<br />
1. all aircraft should respond in a consistent and predicable manner to lateral <strong>of</strong>fset clearances.<br />
2. all aircraft should be capable <strong>of</strong> <strong>of</strong>fsets up to 99nm in 0.1nm increments.<br />
3. <strong>of</strong>fset types should handle optional specification <strong>of</strong> begin and end fixes.<br />
Recommendations:<br />
1. intercept angle default is 30 degrees.<br />
2. flight deck selectable intercept angle from 10-50 degrees to use as needed<br />
3. start and end waypoints should be specifiable<br />
a. automatic initiation and cessation at <strong>the</strong>se points<br />
b. <strong>the</strong> intercepts should be flown with fly-by transitions<br />
4. <strong>of</strong>fset distances specifiable by 0.1nm<br />
5. common requirement for which ARINC path terminator types that should be <strong>of</strong>fsetable.<br />
a. Fixed radius transitions should be preserved for <strong>the</strong> <strong>of</strong>fset by <strong>of</strong>fsetting <strong>the</strong> turn center<br />
along <strong>the</strong> bisector<br />
b. For RF path terminators <strong>the</strong> radius should be changed by <strong>the</strong> amount <strong>of</strong> <strong>the</strong> <strong>of</strong>fset<br />
6. terminators that automatically terminate<br />
a. no system should allow <strong>of</strong>fsets to be applied in approach or missed approach segments<br />
i. <strong>of</strong>fsets should automatically terminate at first approach waypoint<br />
ii. do not propagate across route discontinuities or unreasonable geometries.<br />
7. provide data to support <strong>the</strong> map display<br />
8. do not need to support multiple pre-planned <strong>of</strong>fsets<br />
9. provide output <strong>of</strong> intent on ADS-B and ADS-C<br />
A table <strong>of</strong> current behavior across different FMSs was also presented in <strong>the</strong> second paper.<br />
From a timetable standpoint, ATC automation tools will start coming along around 2015.<br />
Frank: concern about lateral <strong>of</strong>fset terminating at FAF.<br />
Mark: a clearance like this should not be issued.<br />
There was general agreement that it should still be fixed in <strong>the</strong> document<br />
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