How to query properly

Hi guys,

I struggle with Sparql. Maybe you can help me.

I have the following RDF:
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="
http://purl.org/dc/elements/1.1/" xmlns:fh="http://swt.ffhs.ch">
<fh:airport>
<fh:callSign>ZRH</fh:callSign>
<fh:coords>47&#xB0; 27' 30? N, 8&#xB0; 32' 53</fh:coords>
<fh:name>Flughafen Z&#xFC;rich</fh:name>
<fh:Runways rdf:parseType="Collection">
<fh:runway>
<fh:callSign1>14</fh:callSign1>
<fh:callSign2>32</fh:callSign2>
</fh:runway>
<fh:runway>
<fh:callSign1>10</fh:callSign1>
<fh:callSign2>28</fh:callSign2>
</fh:runway>
<fh:runway>
<fh:callSign1>16</fh:callSign1>
<fh:callSign2>34</fh:callSign2>
</fh:runway>
</fh:Runways>
</fh:airport>
<fh:airport>
<fh:callSign>BSL</fh:callSign>
<fh:name>Flughafen Basel</fh:name>
<fh:Runways rdf:parseType="Collection">
<fh:runway>
<fh:callSign1>12</fh:callSign1>
<fh:callSign2>32</fh:callSign2>
</fh:runway>
</fh:Runways>
</fh:airport>
</rdf:RDF>

I want to query the number of runways per airport. So ZRH should have 3
runways, Basel 1 of them.

I use this query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX fh: <http://swt.ffhs.ch>
SELECT ?name  (COUNT(?r) as ?runways)
WHERE {
  ?a rdf:type fh:airport.
  ?a fh:name ?name.
  ?r rdf:type fh:runway.
}
group by ?name

Which results in 4 runways per airport, which is apparently not what I was
looking for. How can I make a relation between airport and runways? I
thought the collection takes care of that?

Thanks you!