# How can I remove the extra vertical space above the first equation in a cases environment?

This problem seems to be related to the AIAA class that I have to use to submit the paper that I am writing, as I cannot reproduce it with other classes.

The latest Aiaa.cls class file can be retrieved from here (link found at this page).

MWE:

\documentclass{AIAA}
\ProcessOptions

\usepackage{amsmath}

\begin{document}
$$\boldsymbol{S}\left( u \right) = \begin{cases} x\left( u \right) = a_{x} \cdot u\\ y\left( u \right) = a_{y} \cdot u\\ z\left( u \right) = a_{z} \cdot u \end{cases}$$
\end{document}


Visualization of the problem:

How can I get rid of that extra white space/ extra long upper curly brace?

• I don't have this problem with your code, which I had to modify: the class is aiaa-tc. There must be something else in your real code. Apr 21, 2016 at 10:15
• I also did not get this problem. I compiled with aiaa.cls V2.4 (22 FEB 1999) and had to download dropping.sty (V0.12, JUN 12 1997). Apr 21, 2016 at 10:21
• @Bernard I compiled the code posted and the result is in the image. how did you came to the aiaa-tc class? Apr 21, 2016 at 10:21
• With AIAA I have an error message: cls unknown. So I read the documentation. How comes you can compile? Apr 21, 2016 at 10:24
• @Bernard I have dowloaded the aiaa.cls file Apr 21, 2016 at 10:24