November 27 Update

[ventus99]

EFFECTIVE: 27 NOVEMBER 2025 NEXT ISSUE: 22 JANUARY 2026

Summary by CodeRabbit

• New Features

  • Added new airway segments across Canadian and North American routes.
  • Expanded route network coverage with enhanced waypoint definitions.

• Bug Fixes

  • Corrected waypoint positions and altitude boundaries.
  • Updated navigational parameters for improved route accuracy.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Walkthrough

This pull request updates the Canadian national airspace waypoint data file, adding and revising airway route segments (T719, T801, T856, etc.) with precise latitude-longitude coordinates, altitude levels, and navigation parameters for XCSoar flight navigation software.

Changes

Cohort / File(s)	Summary
Canadian airspace waypoint definitions data/content/airspace/country/CA-ASP-National-XCSoar.txt	Added new airway segments (T719, T801, T856) with waypoint coordinates, altitude constraints, and track vectors; updated existing waypoint entries with refined coordinates and altitude bands; included drift correction indicators (V D=+ / V D=-) for navigational accuracy

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10–15 minutes

Areas requiring extra attention:

• Verification of latitude-longitude coordinate accuracy for each waypoint to ensure no transcription errors
• Consistency of altitude level notations (FL280, FL600, MSL constraints) across related waypoint groups
• Validation that new airway segments (T719, T801, T856) align with actual Canadian airspace navigation charts

Possibly related PRs

• Update CA-ASP-National-XCSoar.txt #475 — Updates the same CA-ASP-National-XCSoar.txt file with overlapping waypoint coordinate and airway segment modifications

Suggested reviewers

• lordfolken

Poem

🐰 Through airways high, the data flows so bright,
New waypoints mapped from dawn to night,
T719, T801, routes so true,
Canadian skies, navigators' crew! ✈️

Pre-merge checks and finishing touches

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'November 27 Update' is generic and vague, providing no meaningful information about the specific changes made to the airspace data.	Replace with a more descriptive title that summarizes the main change, such as 'Update Canadian airspace routes and waypoints (November 27, 2025)' or 'Add and modify airway segments T719, T801, T856 for Canadian routes'.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 4

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 14dcbfd and 2e239d8.

📒 Files selected for processing (1)

• data/content/airspace/country/CA-ASP-National-XCSoar.txt (8 hunks)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: build

🔇 Additional comments (5)

data/content/airspace/country/CA-ASP-National-XCSoar.txt (5)

31369-31382: T899 addition looks fine; keep naming/altitude conventions consistent.
No obvious formatting issues in this hunk.

---

1-12: PR objectives (rebase/clean commits/no PR description): please ensure they’re satisfied before merge.
Not something I can confirm from the file content, but it’s explicitly requested in the PR description.

---

22182-22191: The V349 airway definition is correctly formatted per the file's design.

The forward+return pattern in airways (lines 22187–22197) is standard in this file format. V342 and V343 follow the same structure: point coordinates trace a path northward, then return southward to the starting point. The inserted DP points (52:12:09.8N 122:04:32.7W → 52:16:17.1N 122:15:41.5W → 52:59:37.8N 121:32:25.3W) maintain proper coordinate ordering without gaps or discontinuities. No action needed.

---

24233-24357: T645 additions are structurally consistent and parse-ready.
Validation confirms: 9 T645 segments with proper AC/AN/AL/AH headers, all altitudes in correct MSL format (12500MSL/18000MSL), and all 44 coordinate values (DP, DB, V X=) properly formatted as DD:MM:SS[.S][NS] DDD:MM:SS[.S][EW]. No structural errors or malformed tokens detected.

---

27629-27688: This is not an issue. T719 segments are individual bounded airway corridors, not sequential waypoints meant to connect end-to-start. Each segment is a self-contained closed-loop definition (like other airway examples in the file: GUELPH CORRIDOR, Calgary Arrivals SE/SW). The naming "DISCO to VIXOR" describes the geographic area covered, not a flight path sequence. The segments may overlap geographically, which is intentional for airway corridor coverage. The data within each segment is coherent.

[coderabbitai]

⚠️ Potential issue | 🟡 Minor

Fix spelling/metadata hygiene in header comments (“UNNOFFICIAL”, “nolowE”).
Typos reduce trust and make grepping/automation harder (e.g., “UNNOFFICIAL” → “UNOFFICIAL”).

🤖 Prompt for AI Agents

In data/content/airspace/country/CA-ASP-National-XCSoar.txt around lines 1-12
the header contains typos and inconsistent metadata casing: change "UNNOFFICIAL"
to "UNOFFICIAL" and correct the metadata token "nolowE" to the repository's
canonical token/casing (e.g., "NOLOWE" or the exact token used in other files);
preserve surrounding punctuation/spacing and run a quick grep to apply the same
fix wherever this header pattern appears.

[coderabbitai]

⚠️ Potential issue | 🔴 Critical

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Find any coordinates that look like "DD:MM:SS.N" or "DD:MM:SS.W" (missing seconds fraction + hemisphere attached to a dot).
rg -nP '\b\d{1,2}:\d{2}:\d{2}\.[NS]\b|\b\d{1,3}:\d{2}:\d{2}\.[EW]\b' data/content/airspace/country/CA-ASP-National-XCSoar.txt

Repository: XCSoar/xcsoar-data-content

Length of output: 196

---

Blocker: malformed coordinates like 49:54:21.N 122:27:57.W will likely break parsers.
These lack fractional seconds (missing values after the decimal point) and are inconsistent with the rest of the file's DD:MM:SS(.s)N/W format. Correct to full format like 49:54:21.0N 122:27:57.0W.

---

⚠️ Potential issue | 🟠 Major

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Detect DB lines where the two endpoints are identical (ignoring spacing).
python3 - <<'PY'
import re, pathlib
p = pathlib.Path("data/content/airspace/country/CA-ASP-National-XCSoar.txt")
db_re = re.compile(r'^DB\s+(.+?),\s*(.+?)\s*$')
def norm(s): return re.sub(r'\s+', ' ', s.strip())
degenerate_count = 0
for i,line in enumerate(p.read_text(encoding="utf-8", errors="replace").splitlines(), 1):
    m = db_re.match(line)
    if not m: 
        continue
    a,b = norm(m.group(1)), norm(m.group(2))
    if a == b:
        degenerate_count += 1
        print(f"Line {i}: {line}")

print(f"\nTotal degenerate DB segments found: {degenerate_count}")
PY

Repository: XCSoar/xcsoar-data-content

Length of output: 156

---

🏁 Script executed:

#!/bin/bash
# First check file size and line count
wc -l data/content/airspace/country/CA-ASP-National-XCSoar.txt

# Extract the relevant section (lines 23960-24069) and search for degenerate DB segments
sed -n '23960,24069p' data/content/airspace/country/CA-ASP-National-XCSoar.txt | grep "^DB" | while IFS= read -r line; do
  # Extract coordinates
  coords=$(echo "$line" | sed 's/^DB\s*//; s/,/\n/')
  first=$(echo "$coords" | head -1 | sed 's/\s\+/ /g' | xargs)
  second=$(echo "$coords" | tail -1 | sed 's/\s\+/ /g' | xargs)
  
  if [ "$first" = "$second" ]; then
    echo "DEGENERATE: $line"
  fi
done

Repository: XCSoar/xcsoar-data-content

Length of output: 264

---

🏁 Script executed:

#!/bin/bash
# Get exact line numbers for the degenerate DB segments in the specified range
sed -n '23960,24069p' data/content/airspace/country/CA-ASP-National-XCSoar.txt | grep -n "^DB" | while IFS=: read -r rel_line content; do
  first=$(echo "$content" | sed 's/^DB\s*//; s/,.*//; s/\s\+/ /g' | xargs)
  second=$(echo "$content" | sed 's/^DB.*,\s*//; s/\s\+/ /g' | xargs)
  
  if [ "$first" = "$second" ]; then
    actual_line=$((23959 + rel_line))
    echo "Line $actual_line: $content"
  fi
done

Repository: XCSoar/xcsoar-data-content

Length of output: 201

---

Fix degenerate DB segments with identical endpoints.
Lines 24002 and 24015 contain DB 50:10:32.8N 122:10:21.5W, 50:10:32.8N 122:10:21.5W—zero-length arcs that may cause geometry processing errors. Verify the correct second endpoint and correct both instances.

🤖 Prompt for AI Agents

data/content/airspace/country/CA-ASP-National-XCSoar.txt lines ~24002 and
~24015: two DB segments are degenerate because both endpoints are identical ("DB
50:10:32.8N 122:10:21.5W, 50:10:32.8N 122:10:21.5W"); locate the authoritative
source (chart/IFS/ingest) to determine the intended second endpoint and replace
the duplicate coordinate with the correct one in both occurrences; if the
correct second point cannot be determined, remove the duplicate endpoint so the
DB line becomes a single coordinate entry or convert the segment to the correct
DP/DP pattern to avoid zero-length arcs, and validate the file with the geometry
linter afterward.

[coderabbitai]

⚠️ Potential issue | 🔴 Critical

🧩 Analysis chain

🏁 Script executed:

rg -n "AN T825 Airway" -C5 data/content/airspace/country/CA-ASP-National-XCSoar.txt

Repository: XCSoar/xcsoar-data-content

Length of output: 662

---

🏁 Script executed:

sed -n '31250,31279p' data/content/airspace/country/CA-ASP-National-XCSoar.txt | cat -n

Repository: XCSoar/xcsoar-data-content

Length of output: 946

---

🏁 Script executed:

rg "AN T825 Airway" -A 20 data/content/airspace/country/CA-ASP-National-XCSoar.txt | head -100

Repository: XCSoar/xcsoar-data-content

Length of output: 894

---

🏁 Script executed:

python3 << 'EOF'
from math import radians, cos, sin, asin, sqrt

def haversine(lon1, lat1, lon2, lat2):
    """Calculate distance between two points in nautical miles"""
    lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])
    dlon = lon2 - lon1
    dlat = lat2 - lat1
    a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
    c = 2 * asin(sqrt(a))
    nm = c * 3440.065  # Earth radius in nautical miles
    return nm

def parse_coord(coord_str):
    """Parse DMS coordinate to decimal degrees"""
    parts = coord_str.replace('N', '').replace('S', '').replace('E', '').replace('W', '').strip()
    deg, min_sec = parts.split(':')[0], ':'.join(parts.split(':')[1:])
    minutes, seconds = min_sec.split(':')
    decimal = float(deg) + float(minutes)/60 + float(seconds)/3600
    return decimal

# Parse coordinates from review comment
coords = {
    "T825-1-DB1": ("49:33:21.7N", "123:57:16.0W"),
    "T825-1-DB2": ("49:23:42.9N", "124:24:07.3W"),
    "T825-1-DP1": ("49:33:24.7N", "124:32:25.5W"),
    "T825-1-DP2": ("49:43:04.4N", "124:05:29.6W"),
    "T825-1-VX2": ("49:38:15.4N", "124:18:58.9W"),
    "T825-1-DB3": ("49:43:04.4N", "124:05:29.6W"),
    "T825-1-DB4": ("49:43:04.0N", "124:05:29.2W"),
    "T825-1-DP3": ("49:33:21.7N", "123:57:16.0W"),
    
    "T825-2-VX1": ("49:38:15.4N", "124:18:58.9W"),
    "T825-2-DB1": ("49:43:04.9N", "124:05:30.0W"),
    "T825-2-DB2": ("49:43:04.4N", "124:05:29.6W"),
    "T825-2-DP1": ("49:33:24.7N", "124:32:25.5W"),
}

# Problematic DB pairs
problem_pairs = [
    ("T825-1-DB3", "T825-1-DB4"),
    ("T825-2-DB1", "T825-2-DB2"),
]

print("Distance analysis for problematic DB pairs:")
for name1, name2 in problem_pairs:
    lat1, lon1_str = coords[name1]
    lat2, lon2_str = coords[name2]
    
    lat1_deg = parse_coord(lat1)
    lon1_deg = -parse_coord(lon1_str)
    lat2_deg = parse_coord(lat2)
    lon2_deg = -parse_coord(lon2_str)
    
    dist = haversine(lon1_deg, lat1_deg, lon2_deg, lat2_deg)
    print(f"\n{name1} to {name2}:")
    print(f"  {coords[name1][0]} {coords[name1][1]}")
    print(f"  to")
    print(f"  {coords[name2][0]} {coords[name2][1]}")
    print(f"  Distance: {dist:.3f} nm")

# Compare with normal DB pair
print(f"\n\nComparison - Normal DB pair (T825-1-DB1 to DB2):")
lat1_deg = parse_coord("49:33:21.7N")
lon1_deg = -parse_coord("123:57:16.0W")
lat2_deg = parse_coord("49:23:42.9N")
lon2_deg = -parse_coord("124:24:07.3W")
dist = haversine(lon1_deg, lat1_deg, lon2_deg, lat2_deg)
print(f"  Distance: {dist:.3f} nm")
EOF

Repository: XCSoar/xcsoar-data-content

Length of output: 400

---

T825 Airway: DB endpoints are essentially duplicated coordinates—remove or correct.

The DB pairs in both segments have endpoints separated by only ~0.008–0.009 nm (approximately 50 feet), making them effectively identical points and invalid for airway definition. Line 31262 has DB 49:43:04.4N 124:05:29.6W, 49:43:04.0N 124:05:29.2W and line 31271 has DB 49:43:04.9N 124:05:30.0W, 49:43:04.4N 124:05:29.6W. Compare these to the first DB leg at line 31258 (DB 49:33:21.7N 123:57:16.0W, 49:23:42.9N 124:24:07.3W), which spans ~20 nm as expected. Verify the intended waypoints for each segment and correct the duplicated coordinates.

🤖 Prompt for AI Agents

In data/content/airspace/country/CA-ASP-National-XCSoar.txt around lines
31250–31279, the DB coordinate pairs for T825 segments are effectively
duplicated (differences of ~0.008–0.009 nm) and therefore invalid; replace or
correct them so each DB pair defines two distinct endpoints spanning the
intended leg length. Verify the correct waypoint coordinates from source
(chart/airway definition) and either remove the near-duplicate coordinate or
substitute the proper endpoint so DB entries are meaningful (e.g., make the
second coordinate match the far endpoint used in the other segment), and ensure
consistency with the adjoining DP/DB points and overall airway geometry.