     }
 
     func testGliderRegistrationHeader() {
-        let header = IGCHeaderField.parseHLine(hLine: gliderRegistrationString)
+        guard let header = IGCHeaderField.parseHLine(hLine: gliderRegistrationString) else { XCTFail("expecting a reg header but got nil"); return }
         switch header {
         case .gliderRegistration(let registration):
             print("glider registration \(registration)")

    }

    func testCompetitionClassHeader() {
        let header = IGCHeaderField.parseHLine(hLine: competitionClassString)
        switch header {
        case .competitionClass(let cClass):
            print("competition class \(cClass)")

    }

    func testPilotHeader() {
        guard let pilotHeader = IGCHeaderField.parseHLine(hLine: pilotHeaderString) else { XCTFail("expecting a pilot header but got nil"); return }
        switch pilotHeader {
        case .pilotInCharge(let name):
            print("pilot name \(name)")
