I'm not sure this is really time-saving.
\documentclass[border=2]{standalone}
\usepackage{array}
\newcommand{\noeq}[1]{\multicolumn{1}{r!{#1}}{}}
\begin{document}
$\begin{array}{r!{=}l}
TS &TU \times\cos\hat{T} \\
&7.5\times\cos 41.5 \\
\noeq{\approx} &5.6
\end{array}$
\end{document}

I'd do it like this; note that the spacings are the normal ones around the relation symbols.
\documentclass[border=2]{standalone}
\usepackage{array}
\begin{document}
$\begin{array}{r@{}>{{}}l}
TS &= TU \times\cos\hat{T} \\
&= 7.5\times\cos 41.5 \\
&\approx 5.6
\end{array}$
\end{document}

This might be even more appealing, as it automatically takes care of the space at either side.
\documentclass[border=2]{standalone}
\usepackage{amsmath}
\begin{document}
$\begin{aligned}
TS &= TU \times\cos\hat{T} \\
&= 7.5\times\cos 41.5 \\
&\approx 5.6
\end{aligned}$
\end{document}
\cos\,41.5
is wrong. – egreg Dec 15 '15 at 14:32