Words and terms

How fast a pack can safely deliver current, as a multiple of its capacity.

Also called discharge rate.

Used in Add a battery

The number of cells in series in a pack, written with an S. A 4S pack has four cells.

Also called cells, 3S, 4S, and 6S.

Used in Add a batteryUnderstand internal resistance

Center of gravity: the point where the model balances. Too far back makes it unstable. Too far forward makes the nose hard to lift.

Also called center of gravity and balance point.

Used in Find your way aroundRead your model's manualMeasure a wing from a photoMeasure a wing from plansMeasure the wing-to-stab distanceLevel the model on a balancerWork out where the CG should beFind the CG from the neutral pointFind the CG by weighing

The width of a wing or control surface, from its leading edge to its trailing edge.

Used in Measure a wing from a photoSet control throwsCheck incidence and decalageWork out where the CG should be

A flat reference on the fuselage, such as the wing saddle. Angles and distances are measured from it.

Also called reference line.

Used in Measure the wing-to-stab distanceCheck incidence and decalage

The difference between the wing and stab incidence angles. It affects how the model trims as its speed changes.

Used in Check incidence and decalage

The upward angle of each wing panel. It helps the model level its wings by itself.

Also called polyhedral.

Used in Check dihedral and washout

The transmitter setting that limits how far each servo moves, so the linkage doesn't bind.

Also called travel adjust and ATV.

Used in Set control throws

What the receiver does when it loses the transmitter's signal. Set it so the throttle goes to idle or off.

Used in Run the pre-flight checklistSet up a model's checklist

The line a control surface pivots on.

Also called hinge.

Used in Set control throws

The angle of the wing or stab compared with the fuselage datum.

Also called angle of incidence.

Used in Check incidence and decalage

How much a cell resists current, in milliohms. It rises as a pack wears out.

Also called IR and milliohms.

Used in Find your way aroundLog charges and charger readingsUnderstand internal resistance

The front edge of a wing, stab or control surface.

Also called LE.

Used in Measure a wing from a photoMeasure the wing-to-stab distanceCheck incidence and decalageCheck dihedral and washoutWork out where the CG should beFind the CG by weighing

Mean aerodynamic chord: the average front-to-back width of a tapered wing. CG positions are given as a percentage of it.

Also called mean aerodynamic chord.

Used in Measure a wing from a photoWork out where the CG should beFind the CG from the neutral point

Milliamp-hours: how much charge a pack holds, or how much the charger put back in.

Also called milliamp-hours and capacity.

Used in Log a flightAdd a batteryLog charges and charger readings

The CG position where the model would be neither stable nor unstable. The CG must be ahead of it.

Also called NP.

Used in Measure the wing-to-stab distanceFind the CG from the neutral point

A small sticker your iPhone reads when you hold it close. Maiden writes a link to a model or battery on it.

Also called NFC, sticker, and NTAG213.

Used in Run the pre-flight checklistPut NFC tags on models and batteriesPrint QR codes for models and batteriesAdd a battery

A LiPo pack that has swollen. It can catch fire, so stop using it and dispose of it safely.

Also called swollen and puffy.

Used in Understand internal resistance

Throw settings you switch between on the transmitter. Low rates are gentler for normal flying, and high rates are for aerobatics.

Also called dual rates, high rate, and low rate.

Used in Read your model's manualSet control throws

The inner end of a wing or stab, where it meets the fuselage.

Also called wing root and root chord.

Used in Measure a wing from a photoMeasure a wing from plansCheck dihedral and washoutWork out where the CG should beFind the CG by weighing

The width of the wing from tip to tip. Half-span is one side, from the centerline to the tip.

Also called wingspan and half-span.

Used in Measure a wing from plansMeasure wingspan with the tape measureWork out where the CG should be

How far the CG sits ahead of the neutral point, as a percentage of the MAC. More margin is more stable.

Used in Find the CG from the neutral point

About 3.8 volts per LiPo cell. Packs kept at this level last longer than full or empty ones.

Also called storage charge.

Used in Log charges and charger readings

How far the tip's leading edge sits behind the root's. Forward sweep is a negative number.

Also called LE sweep.

Used in Work out where the CG should be

How far a control surface moves from center, in degrees or as travel at its trailing edge.

Also called deflection and travel.

Used in Read your model's manualSet control throws

The direction the motor or engine shaft points. A few degrees of down-thrust or right-thrust is common.

Also called down-thrust and right-thrust.

Used in Check incidence and decalage

The outer end of a wing or stab.

Also called wingtip and tip chord.

Used in Measure wingspan with the tape measureCheck dihedral and washoutWork out where the CG should be

The back edge of a wing, stab or control surface.

Also called TE.

Used in Measure a wing from a photoSet control throws

A twist that sets the wingtip's leading edge lower than the root's. It helps the root stall before the tip. The opposite twist is wash-in.

Also called twist.

Used in Check dihedral and washout