Appendix A: Glossary of Communication Terms -Cont.

APPENDIX A

T-34C INSTRUMENT NAVIGATION WORKBOOK

CORRECTION - An error has been made in the transmission, and the correct version follows.

CROSS (FIX) AT (ALTITUDE) - Used by ATC when a specific altitude restriction at a

specific fix is required.

CROSS (FIX) AT OR ABOVE (ALTITUDE) - Used by ATC when an altitude restriction at a

specified fix is required. It does not prohibit the aircraft from crossing the fix at a higher altitude

than specified; however, the higher altitude may not be one that will violate a succeeding altitude

restriction or altitude assignment.

CROSS (FIX) AT OR BELOW (ALTITUDE) - Used by ATC when a maximum crossing

altitude at a specific fix is required. It does not prohibit the aircraft from crossing the fix at a

lower altitude; however, the aircraft must remain at or above the minimum IFR altitude.

DISCRETE FREQUENCY - A separate radio frequency for use in direct aircrew-controller

communications in which ATC reduces frequency congestion by limiting the number of aircraft

operating on a particular frequency at one time. Discrete frequencies are normally designated for

each control sector in enroute/terminal ATC facilities. Discrete frequencies are listed in the

Airport/Facility Directory and IFR Enroute Supplement.

DISREGARD - Cancel my last message.

EXECUTE MISSED APPROACH - Instructions issued to an aircrew making an instrument

approach that mean continue inbound to the missed approach point and execute the missed

approach procedure as described on the Instrument Approach Procedure Chart, or as previously

assigned by ATC. The aircrew may climb immediately to the altitude specified in the missed

approach procedure upon making a missed approach. No turns should be initiated prior to

reaching the missed approach point. When conducting an ASR or PAR approach, execute the

assigned missed approach procedures immediately upon receiving instruction to "execute missed

approach."

EXPECT (ALTITUDE) AT (TIME) OR (FIX) - Used under certain conditions to provide the

aircrew with an altitude to be used in the event of two-way communications failure. It also

provides altitude information to assist the aircrew in planning.

EXPECT FURTHER CLEARANCE (TIME)/EFC - The time an aircrew can expect to

receive clearance beyond a clearance limit.

EXPEDITE - Used by ATC when prompt compliance is required to avoid development of an

imminent situation.

FIX - A geographical position determined by a visual reference to the surface, by reference to

one or more radio NAVAIDs, by celestial plotting, or by another navigational device.

A-2 GLOSSARY OF COMMUNICATION TERMS