RE: AVIATION: Altimeter settings

Randy Black said: All aircraft operating in controlled airspacewhich, for instance includes approximately anything within about 50 miles of Dallas/Fort Worth International Airport, must have working transponders.

Mike Sullivan comments: Randy is correct if your operating in controlled airspace you must have an operating transponder but controlled airspace is normally designated in high density, air traffic control areas around major metropolitan areas or military operating areas.  

The altitudes below FL 290 are assigned odd and even  altitudes in 2,000 ft separation levels using the same heading requirements as aircraft operating in the high altitude route structure.  So there is always 1,000 ft separation for aircraft converging on instrument flight plans (IFR) below FL 290.  Above 18,000 ft you must be on an instrument flight plan and  visual flight rules are not permitted.

Problems can arise below 18,000 ft where most light, civil aircraft, like Cessnas 172s, fly as they are on visual flight plans. They are required to conform to the same east-west, north-south altitude rules as IFR flight plans plus they add 500 ft.   If they are not conforming to these altitude rules they can cause near misses or mid air collisions with other aircraft.   Operating without a transponder makes it very difficult for air traffic controllers to see the aircraft or know its altitude to warn other aircraft in the vicinity.  It is recommended that all aircraft have transponders, and they are required, as Randy says, in controlled airspace, but they are realitively expensive so many light aircraft owners don't have them.  I predict that in the not too distant future all aircraft flying in US airspace will be required to have an operating transponder.

Randy Black writes:General Sullivan is obviously a veteran professional pilot. I am not. I‚m just a low timer with enough experience and training to stay alive in Cessna and Beechcraft single engine, fixed gear puddle jumpers and the occasional retractable aircraft. But in my few hundred flights over 25 years as pilot in command of various small planes, I have found that is darn near impossible to fly anywhere any more without entering controlled airspace. Heck, just filing a flight plan (generally required) means that for all practical purposes you‚re in controlled airspace beginning from when you report in after takeoff that you want to activate your flight plan, to flight following (when the various Centers follow your flight path on their radars as you go from A to B, when you are above 6,000 above sea level, which I always am, and so forth.

While Mike is correct that while most small aircraft operate under Visual Flight Rules (VFR) at the lower altitudes, many others fly Instrument Flight Rules, which I have on numerous occasions. On those occasions, I was flight followed by one or more of the 21 terminal radar approach facilities (TRACONs). When flying VFR, however, I utilized one of the 74 flight Service Stations which provide pilot weather briefings and also handle en route communications and initiate search and rescue procedures for overdue aircraft operating under visual flight rules

Interesting stat: There are more than 260 FAA airport control towers in the United States.
Pilot humor: Question: What are the three most useless things to a pilot? Answer: Runway behind you, altitude above you and fuel you don't have.
's Proverb: There are old pilots and bold pilots, but there are no old, bold pilots. General Sullivan must be the exception if his online biography is an indicator.

Ronald Hilton 2004


last updated: February 2, 2005