Section 171.315 14 CFR Ch. I (1-1-19 Edition) (m) False guidance. False courses which can be acquired and tracked by an aircraft shall not exist anywhere either inside or outside of the MLS coverage sector. False courses which exist outside of the minimum coverage sector may be suppressed by the use of OCI. equivalent of Section10 ft. at the approach reference datum. This will limit the electrical component of the mean course error to Section10 ft. The field monitor alarm limit should be set such that with the mean course error at the alarm limit the total allowed PFE is not exceeded on any commissioned approach course from the limit of coverage to an altitude of 100 feet. NOTE: False courses may be due to (but not limited to) MLS airborne receiver acquisition of the following types of false guidance: reflections of the scanning beam, scanning beam antenna sidelobes and grating lobes, and incorrect clearance. (2) There are errors in two consecutive transmissions of Basic Data Words 1, 2, 4 or 5. (3) There is a reduction in the radiated power to a level not less than that specified in SectionSection 171.313(a)(4) or 171.313(g)(4) for a period of more than one second. (4) There is an error in the preamble DPSK transmissions which occurs more than once in any one second period. (5) There is an error in the time division multiplex synchronization of a particular azimuth function that the requirement specified in Section 171.311(e) is not satisfied and if this condition persists for more than one second. (6) A failure of the monitor is detected. (b) Radiation of the following fuctions must cease and a warning provided at the designated control point if there are errors in 2 consecutive transmissions: (1) Morse Code Identification, (2) Basic Data Words 3 and 6, (3) Auxiliary Data Words. Section 171.315 Azimuth monitor system requirements. (a) The approach azimuth or back azimuth monitor system must cause the radiation to cease and a warning must be provided at the designated control point if any of the following conditions persist for longer than the periods specified: (1) There is a change in the ground equipment contribution to the mean course error component such that the path following error at the reference datum or in the direction of any azimuth radial, exceeds the limits specified in SectionSection 171.313(e)(1) or 171.313(j) for a period of more than one second. NOTE: The above requirement and the requirement to limit the ground equipment mean error to Section10 ft. can be satisfied by the following procedure. The integral monitor alarm limit should be set to the angular VerDate Sep<11>2014 08:20 May 17, 2019 Jkt 247048 PO 00000 Frm 00884 Fmt 8010 Sfmt 8010 Y:\SGML\247048.XXX 247048 EC15SE91.019 874