MSL Altitude Altitude expressed in feet measured from mean sea level (QNH).
Indicated Altitude The Altitude as shown by an altimeter. On a pressure barometric altimeter it is altitude as shown uncorrected for instrument error and uncompensated for variation from standard atmospheric conditions.
source: ICAO Aviation Chart Glossary
Please do not use this form to tell us that the definition you saw doesn't necessarily match the context where you saw it. We use an automated keyword-based system to match the tens of thousands of definitions in our glossaries with our material. Sometimes, when a term has more than one meaning or use or when an abbreviation might stand for more than one thing or resemble a 'normal' word, this results in a definition for a term being shown that doesn't necessarily match the context. Please do not report such issues here. Rather, please use your best judgment to evaluate whether such definitions apply to what you're reading. If the answer is 'no' but nevertheless you feel the term doen't have a good definition in our system but should, please go back and find the 'suggest a term' link in the app. Thanks!
We welcome your feedback.Please carefully fill out the specifics below. If you wish to comment on more than one term/definition, please fill out and submit this form separately for each.
Please Identify Yourself.It's important, so that we can get back to you with feedback or requests for clarification.
Please enter your email address above solely for the purpose that our editorial team might, if necessary, contact you with questions, comments, or requests for clarification.