Yes, Lee's newest TCAS is just awsome!! Thanks a million for this toy.My question is, when is it proper to fly in RELATIVE mode, and when is it proper to fly in ABSOLUTE mode??? Just wondering what the real guys do..! Thanks :)Neil

"when is it proper to fly in RELATIVE mode, and when is it proper to fly in ABSOLUTE mode???"Don't really know the answer to this one, but I did see an aircraft the other day with a momentary pushbutton for absolute. That is, it wouldn't let you keep the TCAS in ABS unless you kept your finger on the button, so I'd say that most of the time, your aircraft should be REL. Perhaps ABS is only for comparing data, faultfinding, etc?Cheers.Ian.

One thing I am pretty certain I saw in the TCAS specs was that if own ABS altitude is not displayed that other ABS altitudes must be momentary. (I do display own ABS altitude in the lower right corner.)Lee Hetherington, PP-ASEL (KBED)

Hi,We use relative mode for 99.99% of the time (in B737NG). Altough you may alredy know this I will explain that if TFC is selected on EFIS, pressing the ABS/REL switch will display, while switch is pressed, the absolute traffic altitude (referenced to QNH or QNE). First two digits are thousands of feet, and third digit hundreds of feet (e.g. 073).

To Ian, AlekSandar, And LeeThanks for the replies! I appreciate it. And Lee, many thanks! :)Neil

Hi, Neil.A pilot on the PPRuNe forum tells me that he uses ABS for assessing available flight levels (for cruising). If there is not much traffic showing up on TCAS at the optimum altitude at which you wish to fly, I guess you could give ATC a call. If they say you can't,... hint that you can't see anything stopping you :(Cheers.Ian.