Gerry this is the very basic rule that governs visual and instrument (controlled) traffic http://www.access.gpo.gov/nara/cfr/cfrhtml_00/Title_14/14cfr91_00.html =A7 91.159 VFR cruising altitude or flight level. Except while holding in a holding pattern of 2 minutes or less, or while turning, each person operating an aircraft under VFR in level cruising flight more than 3,000 feet above the surface shall maintain the appropri= ate altitude or flight level prescribed below, unless otherwise authorized by ATC: (a) When operating below 18,000 feet MSL and -- (1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude +500 feet (such as 3,500, 5,500, or 7,500); or (2) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude +500 feet (such as 4,500, 6,500, or 8,500). (b) When operating above 18,000 feet MSL to flight level 290 (inclusive) and -- (1) On a magnetic course of zero degrees through 179 degrees, any odd fli= ght level +500 feet (such as 195, 215, or 235); or (2) On a magnetic course of 180 degrees through 359 degrees, any even fli= ght level +500 feet (such as 185, 205, or 225). (c) When operating above flight level 290 and -- (1) On a magnetic course of zero degrees through 179 degrees, any flight level, at 4,000-foot intervals, beginning at and including flight level 3= 00 (such as flight level 300, 340, or 380); or (2) On a magnetic course of 180 degrees through 359 degrees, any flight level, at 4,000-foot intervals, beginning at and including flight level 3= 20 (such as flight level 320, 360, or 400). http://www.access.gpo.gov/nara/cfr/cfrhtml_00/Title_14/14cfr91_00.html =A7 91.179 IFR cruising altitude or flight level. (a) In controlled airspace. Each person operating an aircraft under IFR i= n level cruising flight in controlled airspace shall maintain the altitude = or flight level assigned that aircraft by ATC. However, if the ATC clearance assigns "VFR conditions on-top," that person shall maintain an altitude o= r flight level as prescribed by =A7 91.159. (b) In uncontrolled airspace. Except while in a holding pattern of 2 minu= tes or less or while turning, each person operating an aircraft under IFR in level cruising flight in uncontrolled airspace shall maintain an appropri= ate altitude as follows: (1) When operating below 18,000 feet MSL and -- (i) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude (such as 3,000, 5,000, or 7,000); or (ii) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude (such as 2,000, 4,000, or 6,000). (2) When operating at or above 18,000 feet MSL but below flight level 290= , and -- (i) On a magnetic course of zero degrees through 179 degrees, any odd fli= ght level (such as 190, 210, or 230); or (ii) On a magnetic course of 180 degrees through 359 degrees, any even flight level (such as 180, 200, or 220). (3) When operating at flight level 290 and above, and -- (i) On a magnetic course of zero degrees through 179 degrees, any flight level, at 4,000-foot intervals, beginning at and including flight level 2= 90 (such as flight level 290, 330, or 370); or (ii) On a magnetic course of 180 degrees through 359 degrees, any flight level, at 4,000-foot intervals, beginning at and including flight level 3= 10 (such as flight level 310, 350, or 390). ----- Original Message ----- From: "Gerard M Foley" <gfoley@xxxxxxxxxxxxxxx> To: <AIRLINE@xxxxxxxxxxxxxxxxx> Sent: Thursday, September 25, 2003 11:10 AM Subject: Light aircraft use commercial airspace What's this about? Does FAA allow this? Australia's New Airspace Reforms May Compromise Safety Copyright =A9 2003, Dow Jones Newswires CANBERRA (AP)--The safety of thousands of commercial flights across Australia could be compromised by planned airspace reforms, air traffic controllers warned Thursday. Based on the U.S. Federal Aviation Administration's airspace model, the new National Airspace System (NAS) will allow light aircraft to use commercial airspace without having their flight plans approved by air traffic control. Gerry http://foley.ultinet.net/~gerry/aerial/aerial.html http://home.columbus.rr.com/gfoley http://members.fortunecity.com/gfoley/egypt/egypt.html