  The short timescale of the solar flare reconnection process has long proved
to be a puzzle. Recent studies suggest the importance of the formation of
plasmoids in the reconnecting current sheet, with quantifying the aspect ratio
of the width to length of the current sheet in terms of a negative power
$\alpha$ of the Lundquist number, i.e. $S^{-\alpha}$, being key to
understanding the onset of plasmoids formation. In this paper we make the first
application of theoretical scalings for this aspect ratio to observed flares to
evaluate how plasmoid formation may connect with observations. We find that for
three different flares showing plasmoids a range of $\alpha$ values of $\alpha=
0.27$ to $0.31$. The values in this small range implies that plasmoids may be
forming before the theoretically predicted critical aspect ratio ($\alpha=1/3$)
has been reached, potentially presenting a challenge for the theoretical
models.
