</a><span class="kw">head</span>(flights)</span>
<span id="cb6-4"><a href="#cb6-4" aria-hidden="true"></a><span class="co">#    year month day dep_delay arr_delay carrier origin dest air_time distance hour    speed delay</span></span>
<span id="cb6-5"><a href="#cb6-5" aria-hidden="true"></a><span class="co"># 1: 2014     1   1        14        13      AA    JFK  LAX      359     2475    9 413.6490    27</span></span>
<span id="cb6-6"><a href="#cb6-6" aria-hidden="true"></a><span class="co"># 2: 2014     1  