Forum: aviation.stackexchange.com
Tags: <terminology><roll>
Title: What is it called when you roll without yawing or pitching?
Question: My instructor made me do an exercise that consists of banking the sailplane left and right around 30 degrees without moving from the axis. I need to aim for a specific point, and start with the exercise. This is a coordination exercise but does it have a name? It's like a dutch roll but I need to stay in the roll axis without moving.

Answers:
sents: text: In the aerobatic community we would call that the beginning of an Aileron Roll .
text: It's harder than it looks.
answer_details: author: aviation.stackexchange.com/users/52/Dan Pichelman
score: 21
sents: text: You do a roll change maneuver.
text: In German it is a " Rollwechsel ", and the time it takes to do this from -45° bank to 45° bank is an important measure for the agility of a glider.
text: The maneuver is meant to teach you how to quickly change the direction of circling, and for most gliders it limits the minimum size of their vertical tail surface.
text: The European certification regulations for gliders demand in section CS 22.147: Using an appropriate combination of controls it must be possible to reverse the direction of a turn with a 45° bank in the opposite direction within b/3 seconds (b is the span in metres) when the turns are made at a speed of 1·4 V$_{S1}$ with wing-flaps in the most positive en-route position, air brakes and, where applicable, landing gear retracted and without significant slip or skid.
text: Note the speed (v$_{S1}$ is the stall speed):
text: The faster you fly, the easier it is.
text: Since induced drag is highest at low speed, the adverse yaw resulting from the aileron deflection is impossible to overcome if you fly slowly.
text: Glider designers try to make the tail just big enough
text: so CS 22.147 can be fulfilled (the condition "without significant slip or skid" is crucial here!).
text: If you want to start an aileron roll this way: Please don't!
text: It takes a little more to roll a glider properly.
answer_details: author: aviation.stackexchange.com/users/1961/Peter Kämpf
score: 16
sents: text: Here at the University we call it a "Perfect Roll", it is commonly used to assess the turning characteristics of an aircraft.
answer_details: author: aviation.stackexchange.com/users/15202/Brilsmurfffje
score: 3
sents: text: In Argentina we used to call it "coordinación" (coordination).
answer_details: author: aviation.stackexchange.com/users/690/Martin Argerami
score: 2
sents: text: It sounds like the process of doing a slow roll, though the pilot usually does the role until they are at the 180 mark, that is inverted.
answer_details: author: aviation.stackexchange.com/users/15637/Carlo Felicione
score: 1
sents: text: In addition to being (mistakenly) called a Dutch roll, I hear that maneuver called "rolling on a point" or "rolling on a heading.
text: " This is probably the most unambiguous description, as you are rolling the plane while using coordinated inputs to keep the heading constant.
answer_details: author: aviation.stackexchange.com/users/40136/Shamtam
score: 0

Summary of the answers:
A roll without yawning or pitching is called a rool change maneuver, Roolwechsel in German, Perfect Roll, Coordinacion in Argentina, Rolling on point or Rolling on a heading.
Although it is often mistakenly called a "Dutch roll", in English it is more correctly called a "roll change maneuver", a "Perfect roll" or "rolling on a point". It is also similar to the "slow roll", though inverted. The German equivalent is called "Rollwechsel" and in Argentina they call it "coordinación" (coordination).