Take Five: PIREP
"Long River radio, this is Birdman 621. I'm on a VFR flight plan between Centreville and Blanktown. I've got a PIREP for you. Turbulence is pretty bad, the visibility is dropping quite a bit and clouds are low in places. Looks like I'll be a little late on my ETA."
What is this pilot trying to say? It is obvious that he gave little useful information, even with all his good intentions. Where is he? What's his altitude? How much turbulence is there? What's the vis and cloud base? Why is his ETA off?
PIREPs are the only direct source of information on cloud heights, turbulence, visibility, winds, icing, etc., between weather reporting stations and at some airports. They are particularly important on flights below 10 000 ft. If they contain reasonably precise information, they are valuable to flight service specialists, controllers, weather briefers and forecasters—and of course, to other pilots.
There are several observation items which are valuable, such as outside air temperature, cloud types, bases and tops, thunderstorm activity and visibility restrictions. But even more important are conditions which are worse than forecast, and you should be able to describe them adequately. Here are some definitions relating to turbulence and icing, to demonstrate what we mean.
Light—Turbulence that momentarily causes slight, erratic changes in altitude and/or attitude. Occupants may feel a slight strain against seat-belts or shoulder straps.
Moderate—Turbulence that is similar to Light Turbulence but of greater intensity. Changes in altitude and/or attitude occur but the aircraft remains in positive control at all times. Occupants feel definite strains against seat-belts.
Severe—Turbulence that causes large, abrupt changes in altitude and/or attitude. It usually causes large variations in indicated airspeed. Occupants are forced violently against seat-belts or shoulder straps.
Light—The rate of accumulation may create a problem if flight is prolonged in this environment.
Moderate—The rate of accumulation is such that even short encounters become potentially hazardous, and use of de-icing equipment or diversion is required.
Severe—The rate of accumulation is such that de-icing or anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary.
Take a few more minutes to review the following sections of the TC AIM: MET 1.1.6, MET 2.0 and MET 3.17. For in-flight guidance, remember that the recommended contents of a PIREP are listed on the back cover of your Canada Flight Supplement (CFS).
One day, your PIREP could save someone else's life…
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