diff --git a/internal/parsers/aviation_parser.go b/internal/parsers/aviation_parser.go
index 84e3cf9..e31ef5b 100644
--- a/internal/parsers/aviation_parser.go
+++ b/internal/parsers/aviation_parser.go
@@ -2,67 +2,37 @@ package parsers
 
 import (
 	"caatsm/internal/domain"
+	"errors" // Import errors package to handle errors
 	"strings"
 )
 
+const (
+	StartIndicatorPrefix = "ZCZC"
+	EndHeaderMarker      = "."
+	BeginPartMarker      = "BEGIN PART"
+)
+
 // ParseHeader parses the header of the message and returns a ParsedMessage struct
-func ParseHeader(fullMessage string) domain.ParsedMessage {
-	var (
-		startIndicator     string
-		messageID          string
-		dateTime           string
-		priorityIndicator  string
-		primaryAddress     string
-		secondaryAddresses []string
-		originator         string
-		originatorDateTime string
-		bodyAndFooter      strings.Builder
-		headerEnded        bool
-	)
+func ParseHeader(fullMessage string) (domain.ParsedMessage, error) {
+	fullMessage = strings.TrimSpace(fullMessage) // Trim leading and trailing spaces
+	lines := strings.Split(fullMessage, "\n")    // Split the message into lines
 
-	fullMessage = strings.TrimSpace(fullMessage)
-	lines := strings.Split(fullMessage, "\n")
-
-	for lineCounter, line := range lines {
-		switch lineCounter {
-		case 0:
-			if strings.HasPrefix(line, "ZCZC") {
-				parts := strings.Fields(line)
-				if len(parts) >= 3 {
-					startIndicator = parts[0]
-					messageID = parts[1]
-					dateTime = parts[2]
-				}
-			}
-		case 1:
-			parts := strings.Fields(line)
-			if len(parts) >= 2 {
-				priorityIndicator = parts[0]
-				primaryAddress = parts[1]
-			}
-		default:
-			if !headerEnded {
-				if strings.TrimSpace(line) == "." {
-					continue
-				} else if strings.HasPrefix(line, ".") {
-					originatorInfo := strings.Fields(line[1:])
-					if len(originatorInfo) >= 2 {
-						originator = originatorInfo[0]
-						originatorDateTime = originatorInfo[1]
-					}
-					headerEnded = true
-				} else if strings.HasPrefix(line, "BEGIN PART") || strings.HasPrefix(line, "(") {
-					headerEnded = true
-					bodyAndFooter.WriteString(line + "\n")
-				} else {
-					secondaryAddresses = append(secondaryAddresses, line)
-				}
-			} else {
-				bodyAndFooter.WriteString(line + "\n")
-			}
-		}
+	// Parse the start indicator line
+	startIndicator, messageID, dateTime, err := parseStartIndicator(lines[0])
+	if err != nil {
+		return domain.ParsedMessage{}, err // Return error if parsing fails
 	}
 
+	// Parse the priority indicator and primary address line
+	priorityIndicator, primaryAddress, err := parsePriorityAndPrimary(lines[1])
+	if err != nil {
+		return domain.ParsedMessage{}, err // Return error if parsing fails
+	}
+
+	// Parse the remaining lines
+	secondaryAddresses, originator, originatorDateTime, bodyAndFooter := parseRemainingLines(lines[2:])
+
+	// Return the parsed message as a domain.ParsedMessage struct
 	return domain.ParsedMessage{
 		StartIndicator:     startIndicator,
 		MessageID:          messageID,
@@ -72,6 +42,67 @@ func ParseHeader(fullMessage string) domain.ParsedMessage {
 		SecondaryAddresses: secondaryAddresses,
 		Originator:         originator,
 		OriginatorDateTime: originatorDateTime,
-		BodyAndFooter:      bodyAndFooter.String(),
+		BodyAndFooter:      bodyAndFooter,
+	}, nil
+}
+
+// parseStartIndicator parses the start indicator line
+func parseStartIndicator(line string) (string, string, string, error) {
+	if strings.HasPrefix(line, StartIndicatorPrefix) {
+		parts := strings.Fields(line)
+		if len(parts) >= 3 {
+			return parts[0], parts[1], parts[2], nil
+		}
 	}
+	return "", "", "", errors.New("invalid start indicator line format")
+}
+
+// parsePriorityAndPrimary parses the priority indicator and primary address line
+func parsePriorityAndPrimary(line string) (string, string, error) {
+	parts := strings.Fields(line)
+	if len(parts) >= 2 {
+		return parts[0], parts[1], nil
+	}
+	return "", "", errors.New("invalid priority indicator line format")
+}
+
+// parseRemainingLines parses the remaining lines of the message
+func parseRemainingLines(lines []string) ([]string, string, string, string) {
+	var (
+		secondaryAddresses []string
+		originator         string
+		originatorDateTime string
+		bodyAndFooter      strings.Builder
+		headerEnded        bool
+	)
+
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if headerEnded {
+			// Append line to body and footer if header has ended
+			bodyAndFooter.WriteString(line + "\n")
+		} else {
+			switch {
+			case line == EndHeaderMarker:
+				// Ignore end header marker
+			case strings.HasPrefix(line, "."):
+				// Parse originator and originatorDateTime
+				originatorInfo := strings.Fields(line[1:])
+				if len(originatorInfo) >= 2 {
+					originator = originatorInfo[0]
+					originatorDateTime = originatorInfo[1]
+				}
+				headerEnded = true
+			case strings.HasPrefix(line, BeginPartMarker) || strings.HasPrefix(line, "("):
+				// Mark header as ended and append line to body and footer
+				headerEnded = true
+				bodyAndFooter.WriteString(line + "\n")
+			default:
+				// Append line to secondary addresses
+				secondaryAddresses = append(secondaryAddresses, line)
+			}
+		}
+	}
+
+	return secondaryAddresses, originator, originatorDateTime, bodyAndFooter.String()
 }
diff --git a/internal/parsers/aviation_parser_test.go b/internal/parsers/aviation_parser_test.go
index 69e99ca..ed7569b 100644
--- a/internal/parsers/aviation_parser_test.go
+++ b/internal/parsers/aviation_parser_test.go
@@ -1,6 +1,8 @@
 package parsers
 
 import (
+	"fmt"
+
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -26,7 +28,8 @@ THUNDERSTORMS EXPECTED
 ALTERNATE ROUTES ADVISED)
 
 NNNN`
-			parsedHeader := ParseHeader(message)
+			parsedHeader, err := ParseHeader(message)
+			Expect(err).ToNot(HaveOccurred())
 			Expect(parsedHeader.StartIndicator).To(Equal("ZCZC"))
 			Expect(parsedHeader.MessageID).To(Equal("TAF6789"))
 			Expect(parsedHeader.DateTime).To(Equal("160530"))
@@ -68,7 +71,8 @@ SEVERE THUNDERSTORM FORECASTED
 ALL DEPARTURES/ARRIVALS EXPECTED TO BE DELAYED)
 
 NNNN`
-			parsedHeader := ParseHeader(message)
+			parsedHeader, err := ParseHeader(message)
+			Expect(err).ToNot(HaveOccurred())
 			Expect(parsedHeader.StartIndicator).To(Equal("ZCZC"))
 			Expect(parsedHeader.MessageID).To(Equal("NOTAM1122"))
 			Expect(parsedHeader.DateTime).To(Equal("171000"))
@@ -94,10 +98,12 @@ Q) EDMM/QOATT/IV/BO/A/000/999/4814N01120E005
 A) EDDM
 B) 2307150600 C) 2307151800
 E) AERODROME CONTROL TOWER HOURS OF SERVICE
-    0600-1800 DUE TO MAINTENANCE
-NNNN`
+   0600-1800 DUE TO MAINTENANCE
+NNNN
+`
 
-			parsedMessage := ParseHeader(message)
+			parsedMessage, err := ParseHeader(message)
+			Expect(err).ToNot(HaveOccurred())
 			Expect(parsedMessage.StartIndicator).To(Equal("ZCZC"))
 			Expect(parsedMessage.MessageID).To(Equal("NOTAM1234"))
 			Expect(parsedMessage.DateTime).To(Equal("230715"))
@@ -106,7 +112,15 @@ NNNN`
 			Expect(parsedMessage.SecondaryAddresses).To(Equal([]string{"GG EDDNYNYX"}))
 			Expect(parsedMessage.Originator).To(Equal("BERLINTWR"))
 			Expect(parsedMessage.OriginatorDateTime).To(Equal("230714"))
-			Expect(parsedMessage.BodyAndFooter).To(ContainSubstring("Q) EDMM/QOATT/IV/BO/A/000/999/4814N01120E005\nA) EDDM\nB) 2307150600 C) 2307151800\nE) AERODROME CONTROL TOWER HOURS OF SERVICE\n    0600-1800 DUE TO MAINTENANCE\nNNNN"))
+			fmt.Print(parsedMessage.BodyAndFooter)
+			Expect(parsedMessage.BodyAndFooter).To(Equal(`
+Q) EDMM/QOATT/IV/BO/A/000/999/4814N01120E005
+A) EDDM
+B) 2307150600 C) 2307151800
+E) AERODROME CONTROL TOWER HOURS OF SERVICE
+0600-1800 DUE TO MAINTENANCE
+NNNN
+`))
 		})
 	})
 })