Calculator
Formula Used
This calculator uses a common 70/110 holding entry sector method. It first finds the outbound course by adding 180 degrees to the inbound course.
Outbound Course = Inbound Course + 180°
For right turns, the sector angle is measured clockwise from the outbound course to the aircraft approach heading.
Sector Angle = Approach Heading - Outbound Course
For left turns, the measurement is mirrored.
Sector Angle = Outbound Course - Approach Heading
The angle is normalized between 0 and 360 degrees. A sector angle near 0 to 70 degrees gives a teardrop entry. A sector angle above 70 and up to 180 degrees gives a parallel entry. The remaining sector gives a direct entry.
Wind correction is estimated from crosswind. The calculator uses this planning relation:
Drift Angle = asin(|Crosswind| / True Airspeed)
The outbound wind correction uses a simple training estimate:
Outbound Correction ≈ 3 × Inbound Drift Angle
This tool is for planning and training. Always follow ATC clearance, charted procedures, aircraft documents, and instructor guidance.
How to Use This Calculator
- Enter the published inbound holding course.
- Enter your aircraft heading or track while approaching the fix.
- Select right or left turns.
- Add leg time, airspeed, wind direction, and wind speed.
- Use tolerance when the aircraft is near a sector boundary.
- Press the calculate button.
- Read the recommended entry above the form.
- Download the CSV or PDF file for briefing notes.
Example Data Table
| Inbound Course | Approach Heading | Turns | Sector Angle | Likely Entry | Initial Action |
|---|---|---|---|---|---|
| 090° | 220° | Right | 310° | Direct | Turn outbound on protected side. |
| 360° | 185° | Right | 5° | Teardrop | Fly 30° offset, then intercept inbound. |
| 270° | 040° | Left | 50° | Teardrop | Offset toward protected side. |
| 180° | 075° | Right | 75° | Parallel | Fly parallel, then turn inbound. |
Holding Pattern Entry Planning Guide
Why Entry Choice Matters
A holding pattern entry is a short but important maneuver. It places the aircraft on the protected side of the hold. It also helps the pilot intercept the inbound course without excess bank, overshoot, or confusion. The correct entry depends on the inbound course, the direction of turns, and the aircraft track to the fix.
Direct Entry
A direct entry is the simplest case. The aircraft crosses the fix and turns directly into the holding pattern. This entry is common when the approach direction already places the aircraft near the protected side. The pilot should brief the outbound heading, expected timing, and inbound intercept before crossing the fix.
Parallel Entry
A parallel entry is used when the aircraft approaches from a sector that makes a direct turn awkward. The aircraft crosses the fix, flies outbound parallel to the inbound course on the non-holding side, and then turns back toward the protected side. Timing starts at the fix. Wind may require an adjusted outbound heading.
Teardrop Entry
A teardrop entry uses an angled outbound path. After crossing the fix, the aircraft flies about 30 degrees toward the protected side. It then turns in the holding direction to intercept the inbound course. This method keeps the aircraft inside protected airspace and creates a controlled inbound intercept angle.
Wind and Timing
Wind changes both heading and distance. A strong tailwind outbound can increase leg distance. A strong headwind can reduce it. Crosswind also creates drift. Many pilots use a larger outbound correction because the aircraft must return to the inbound course accurately. This calculator estimates drift and shows a practical correction value.
Boundary Awareness
Holding sectors are planning aids. A heading near a boundary may allow more than one acceptable entry. The tolerance field helps identify those close cases. In real operations, pilots should use published guidance, clearance wording, aircraft performance, and local procedures. When training, ask an instructor how your school applies boundary calls.
Brief Before the Fix
A useful holding brief is short. State the fix, inbound course, turn direction, altitude, leg time, entry type, and expected first heading. Then confirm wind correction and missed approach needs. A clear brief reduces workload and helps the pilot fly the entry smoothly.
FAQs
1. What does this holding calculator determine?
It estimates whether a direct, parallel, or teardrop entry fits your inbound course, approach heading, and turn direction. It also shows outbound heading, sector angle, drift, and timing estimates.
2. Should I enter heading or track?
Use track when available because wind changes the aircraft path over the ground. Heading is acceptable for simple training problems or calm wind planning.
3. What is the outbound course?
The outbound course is the reciprocal of the inbound course. The calculator adds 180 degrees and normalizes the result between 0 and 360 degrees.
4. Why does turn direction change the result?
Left turns mirror the holding sectors. A heading that gives a teardrop entry for right turns may fall into another sector when left turns are assigned.
5. What does sector tolerance mean?
Sector tolerance widens boundaries by a few degrees. It helps with practical cases where heading, wind, or cockpit interpretation places the aircraft close to a sector line.
6. Is the wind correction exact?
No. It is a planning estimate based on crosswind and airspeed. Actual correction depends on aircraft handling, bank angle, ground speed, and ATC or charted instructions.
7. Can this replace published procedures?
No. Use it for study, briefing, and planning support. Always follow ATC clearance, charted procedures, aircraft manuals, and instructor guidance.
8. Why are CSV and PDF downloads included?
The CSV file helps store calculation data. The PDF file gives a simple briefing sheet that can be saved, printed, or reviewed during training.