XSLT Aggregating Elements

[C177LVR]

What is the technique of using XSLT to transform the input to the output below? Although I have use XSLT for a short while, the new issue for me is aggregating common elements in the input (in this case airplane makes).

Input:

<Airport>
<Airplane Make=&quot;Cessna&quot; Tail=&quot;N11111&quot;/>
<Airplane Make=&quot;Cessna&quot; Tail=&quot;N22222&quot;/>
<Airplane Make=&quot;Piper&quot; Tail=&quot;N33333&quot;/>
<Airplane Make=&quot;Piper&quot; Tail=&quot;N44444&quot;/>
</Airport>

Output:

<Airport>
<Airplane Make=&quot;Cessna&quot;>
<Tail Number=&quot;N11111&quot;/>
<Tail Number=&quot;N22222&quot;/>
</Airplane>
<Airplane Make=&quot;Piper&quot;>
<Tail Number=&quot;N33333&quot;/>
<Tail Number=&quot;N44444&quot;/>
</Airplane>
</Airport>

 

[palbano]

<Airplane Make=&quot;Cessna&quot;>
<xsl:for-each select=&quot;//Airplane[@Make = 'Cessna']&quot;>
<xsl:element name=&quot;Tail&quot;>
  <xsl:attribute name=&quot;Number&quot;><xsl:value-of select=&quot;@Tail&quot;/></xsl:attribute>
</xsl:element>
</xsl:for-each>
</Airplane Make=&quot;Cessna&quot;>

hope that helps, it's not tested so probably a few errors exist

_{1010100 1000111 1001001 1000110}
-pete