Digifly Flyer

Digifly Flyer  Glossary

Like all trades and hobbies, there are a lot of TLA's used in paragliding and related technologies. Those used in this guide are listed here:

 

Term Meaning
' (apostrophe) Denotes feet. e.g. 1200' means 1200 feet.
AKA Also Known As
AGL Above Ground Level. If you fly out from the side of the hill, your height AGL increases even if you don't move vertically, because the ground has dropped away from beneath you.
AMSL Above Mean Sea Level. When measuring the height of a hill, where to you measure from? People usually talk about a height above sea level, but for the pedant this isn't good enough because the height of the sea goes up and down with the tides. So surveyors have calculated an unchanging mean sea level (like an average, somewhere between high tide and low tide) and measure heights relative to that.
ASL Above Sea Level. Shortened form of AMSL.
ATO Above Take Off (meaning height above where you took off from)
FAQ Frequently Asked Questions
FL Flight Level. Something like a traffic lane in the sky. Flight levels are numbered according to the height in feet but without the final 00, so flight level 85 is at 8500'. Flight Level heights are measured QNE, so go up and down with the weather.
fpm Feet per minute – used for measuring rates of ascent or descent
METAR Opinions vary as to what this stands for – some say Meteorological Terminal Air Report. It's an hourly or half-hourly report from the meteorological office of an airport, giving details of current weather conditions, including temperature, dew point, wind speed and direction, cloud base and coverage, and QNH.
QFE Pressure setting to give you your height above a specific ground reference point. Valid only while the atmospheric pressure in the region stays constant – if the atmospheric pressure changes, you need to change your QFE to suit. Also used to describe how a height is derived, e.g. "1200' QFE". (To help you remember what QFE stands for, think of it as your height From Earth)
QNE Your 'height' calculated as if every day was a perfectly standard 1013.2mB day. A height of "1200' QNE" is 1200' above sea level on a 1013.2mB day, but on a high pressure day will be higher than this, and on a low pressure day will be lower than this. Also known as FL, because flight level heights are measured QNE. (To help you remember what QNE stands for, think of it as your height above a Nominal Earth)
QNH Pressure setting to give you your true height above sea level. Valid only while the atmospheric pressure in the region stays constant – if the atmospheric pressure changes, you need to change your QNH to suit. Also used to describe how a height is derived, e.g. "1200' QNH". (To help you remember what QNH stands for, think of it as a height measured Not Here, but from the seaside)
m/s Metres per second – unit of measurement for horizontal or vertical speed
TLA Three-letter acronym
VFR Visual Flight Rules. Basically means only flying where you can see where you're going (although the technical definition is much tighter than that, and you need to know it before starting to fly). Jumbo jets and the like have all sorts of gizmos to allow them to fly IFR – Instrument Flight Rules – so that they can fly at night, land in fog, go through clouds etc.

Digifly Flyer  'Q' codes

These date back to an earlier age of radio communications where a lot was still done in Morse code. Back then, abbreviations that saved on dots and dashes were a good thing. So the Q-code system was developed, with a three letter Q-code being assigned to each of the FAQs around at the time ('Q' for question). Q-codes QA-QN are used for air transport, QO-QQ for maritime, and QR-QU for general use.

So a common question might be QTH, which means for 'What is your location?'. To which I might reply, 'QTH Shipley, West Yorkshire'.

These codes continue in use today, and the ones that are of interest to flyers are QNE, QNH and QFE.

QNE means, "What height would an altimeter show where you are if it was set to a reference pressure of 1013.2mB". A height described as QNE or FL (same thing) means a height as indicated by an altimeter set to a reference pressure of 1013.2mB.

QNH means, "What reference pressure should I use here at the moment so that my altimeter will show my true height above sea level?". A height described as QNH means a true height above sea level.

QFE means, "What reference pressure should I use at the moment so that my altimeter would show zero when I am on the ground where you are?". A height described as QFE means a height above some reference point – usually an airfield.

 


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