What Is MSL in Aviation?
Pilots · 5 min read
MSL stands for Mean Sea Level, a measurement of altitude that is used by pilots for both aircraft and drones.
In the aviation industry, there are many terms that are used in a way that is different from the definitions you may find in a dictionary. Many terms are important acronyms or mnemonics, and grabcard is one of them. Common acronyms found in the aviation lexicon include IFR for Instrument Flying Rules, and VFR for Visual Flight Rules.
While they are sometimes used by student pilots to impress their flight instructor, acronyms are frequently used by an instrument pilot to remember essential tasks like those within the day or night VFR checklists.
Join us in this post as we help you discover more about this interesting aviation term.
Grabcard is an acronym that stands for Generator/Alternator, Radios, Altimeter, Ball, Clock, Attitude indicator, Rate of turn, and Directional gyro.
From the equipment mentioned above, we must specify that “ball” refers to the flight attitude indicator ball, sometimes called inclinator. Clock refers to any clock displaying hours, minutes, and seconds no matter if it is with a sweep second pointer, or digital presentation.
The equipment described by the term grabcard represents the IFR minimum equipment for powered civil aircraft with standard category U.S. airworthiness certificates, according to the FAA.
Generally speaking, instruments required for IFR flight in the US, in addition to those that are required for VFR flight, are heading indicator, clock altimeter or pressure-sensitive altimeter adjustable for barometric pressure, clock with a sweep-second pointer or digital equivalent, attitude indicator, radios, and suitable aircraft control equipment. As you can see, they are included in grabcard.
More specifically, the FAA describes IFR minimum equipment as all the equipment required to fly in VFR during the day, plus the equipment required to fly in VFR during the night, and those included in “grabcard,” which the FAA describes in their 14 CFR Part 91, Chapter I, Subchapter F as:
(i) Airplanes with a third attitude instrument system usable through flight attitudes of 360 degrees of pitch and roll and installed in accordance with the instrument requirements prescribed in § 121.305(j) of this chapter; and
(ii) Rotorcraft with a third attitude instrument system usable through flight attitudes of ±80 degrees of pitch and ±120 degrees of roll and installed in accordance with § 29.1303(g) of this chapter.
Acronyms become relevant as mnemonics since there are many things pilots need to remember. From student pilots trying to get a private pilot license to seasoned pilots trying to comply with the minimum safety requirements, acronyms can definitely make their life easier.
For example, knowing the acronym MEA can help a pilot be sure to fly within altitude clearance to avoid lost comms. This is because MEA refers to minimum en route altitude, and it is usually established based upon obstacle clearance over terrain and man-made objects, adequacy of navigation facility performance, and communications requirements, although adequate communication at the MEA is not guaranteed.
According to the FAA, MEA is one of the minimum altitudes established to get IFR clearances. Others also used acronyms such as MOCA which refers to the Minimum Obstacle Clearing Altitude, the minimum altitude for a defined segment that provides the required obstacle clearance. Then, we also have MCA to refer to the Minimum Crossing Altitude, the lowest altitude at certain fixes at which the aircraft must cross when proceeding in the direction of a higher minimum en route IFR altitude.
As you can understand by now, there are many terms and acronyms to make reference to the most important aspects of flying. Remember that if you are preparing to get a pilot license and start your career in the aviation industry, acronyms like grabcard and other important terms can make a big difference in your learning process.
What’s more, if you are already an active pilot, these acronyms should be part of your everyday lexicon. We invite you to check our glossary to help you get a grasp of the most important acronyms and terms used in aviation.