Finding Descendents in XML

I have this problem with my C# API that I unfortunately posted incorrectly & got partially incorrect answers, so I'm going to try again since I've still not solved it (trying for ages)

Here's my XML file :

<HandlingData>
    <Item type="CHandlingData">
      <handlingName>Plane</handlingName>
       <fMass value="140000.000000" />
      <SubHandlingData>
    <Item type="CFlyingHandlingData">
       <handlingType>HANDLING_TYPE_FLYING</handlingType>
       <fThrust value="0.630000" />
  </SubHandlingData>
    </Item>

Please note: SubHandlingData is in separate sub-section within the same item, a 2nd item type is called.

Here's the C# Code :

var items = doc.Descendants("HandlingData").Elements("Item");
var query = from i in items

            select new {
                HandlingName = (string)i.Element("handlingName"),                             (decimal?)i.Element("fThrust").Attribute("value"),
                HandlingType = (string)i.Element("handlingType")
            };
StringBuilder test = new StringBuilder();
foreach (var item in query)
{

var k = item.dunno;
    test.Append(k);
 richTextBox1.Text = test.ToString();

}

The above code works fine, but doesn't work with SubHandlingData. This means such values as HandlingType is not seen, I've added the element for this & it returns errors, have also tried including multiple decedents which then doesn't find HandlingName, or HandlingType. I want my output to be if handlingType == "HANDLING_TYPE_FLYING", richtextbox1.text = this.HandlingName. I hope I have explained this clearly enough to gain an answer as this has troubled me for ages.

My Problem in short: Program does not find HandlingType inside SubHandlingData of my XML document.