Operating at non-towered airports requires adherence to standardized procedures to maintain safety and efficiency. Non-standard departures, such as departing on the crosswind, can significantly increase the risk of collisions with inbound traffic. This is particularly dangerous when considering the potential for conflicts between aircraft departing on the crosswind and those arriving on a 45-degree entry to the downwind leg.
Standard Departure Procedures
The FAA's Pilot’s Handbook of Aeronautical Knowledge (PHAK) stresses the importance of standard departure procedures to maintain safety at non-towered airports. Typically, a standard departure involves taking off into the wind and climbing straight out to before making any turns until 300’ of the TPA. As per the graphic above the “standard” departure is straight out or a 45 degree turn into the direction of the traffic pattern after reaching pattern altitude (AIM 4-3-1). This helps ensure that all departing aircraft follow a predictable path, minimizing the risk of mid-air collisions.
Risks of Non-Standard (Crosswind) Departures
1. “Collision Risk with Arriving Traffic:”
One of the most significant dangers of a non-standard crosswind departure is the potential for collision with aircraft entering the pattern on a 45-degree entry to the downwind leg.
2. “Reduced Situational Awareness:”
Predictability is key to maintaining situational awareness at non-towered airports. Non-standard departures disrupt this predictability, making it harder for arriving pilots to anticipate the movements of departing aircraft.
3. “Confusion and Miscommunication:”
Effective communication is essential at non-towered airports. The PHAK and AIM stress using standard phraseology and regular position reports to ensure all pilots understand each other’s intentions.
4. “Operational Hazards:”
Advisory Circular 90-66C provides guidance on operations at non-towered airports, emphasizing the importance of adhering to standard traffic patterns. Non-standard departures disrupt these patterns, causing operational inefficiencies and increasing risks, especially during high traffic periods or in adverse weather conditions.
FAA Guidelines and Best Practices
To mitigate the risks associated with non-standard departures, the FAA provides several guidelines and best practices:
1. “Adherence to Standard Patterns:”
The AIM and AC 90-66C advise pilots to follow standard traffic patterns and departure procedures. Consistency helps create a predictable environment, reducing the likelihood of conflicts and enhancing overall safety.
2. “Effective Communication:”
Pilots should use the CTAF to announce their intentions clearly and frequently. The AIM recommends making position reports and using standard phraseology to avoid misunderstandings.
3. “Pre-Flight Planning:”
Thorough pre-flight planning is crucial (in-fact it’s required as per 91.103). Pilots should review the airport’s traffic patterns, current wind conditions, and any NOTAMs before departure. Hint, ForeFlight can be a great help here as it depicts the traffic patterns.
4. “Situational Awareness:”
Awareness of the traffic around the airport and understanding the intentions of other pilots are key components of safe operations at non-towered airports.
Differences Between AC 90-66B and AC 90-66C
Advisory Circular 90-66C, which supersedes AC 90-66B, includes several updates and clarifications aimed at enhancing safety at non-towered airports:
1. “Updated Traffic Pattern Guidance:”
AC 90-66C provides more detailed guidance on standard traffic patterns, including the importance of entering the pattern at a 45-degree angle to the downwind leg and avoiding straight in approaches. This helps standardize entry procedures and reduce the risk of collisions.
2. “Emphasis on Communication:”
The new circular places a stronger emphasis on the importance of clear communication on the CTAF. It includes more specific recommendations for position reports and communication practices to ensure all pilots are aware of each other’s intentions.
3. “Enhanced Situational Awareness:”
AC 90-66C includes additional recommendations for maintaining situational awareness, such as advising pilots to make more frequent position reports and to be vigilant in scanning for other traffic, especially when conducting non-standard operations.
4. “Safety Enhancements:”
The new circular incorporates lessons learned from recent incidents and studies, providing updated best practices and safety tips to further mitigate risks associated with non-standard departures and other operations at non-towered airports.
Recommended Height for Opposite Direction Departures
The Aircraft Owners and Pilots Association (AOPA) recommends that pilots departing in the opposite direction of the traffic pattern should climb to at least 500 feet above the traffic pattern altitude before turning to ensure adequate separation from arriving and departing aircraft. This additional altitude helps mitigate the risk of conflicts and provides a safety buffer.
Recommended Procedure for a Downwind Departure
The FAA and AOPA provide guidelines to ensure safe operations when conducting a downwind departure at a non-towered airport. The procedure generally includes climbing to a safe altitude while maintaining situational awareness and proper communication. Here’s the recommended procedure, along with the specific guidance on when to climb to 500 feet above the traffic pattern altitude (TPA):
FAA Guidance (AIM and AC 90-66C)
1. “Climb to Traffic Pattern Altitude (TPA):”
After takeoff, climb straight out to the within 300’ of the TPA, which is usually 1,000 feet above ground level (AGL) for most general aviation airports.
2. “Turn to Crosswind Leg:”
Make a 90-degree turn to the crosswind leg. Continue your climb to the TPA
3. “Enter the Downwind Leg:”
Make another 90-degree turn to enter the downwind leg, parallel to the runway.
4. “Communication:”
Use the Common Traffic Advisory Frequency (CTAF) to announce your position and intentions. For example, "Anytown traffic, Cessna 12345, downwind departure to the south, Anytown."
5. “Climb to a Safe Altitude:”
Continue to fly the downwind leg and climb to at least 500 feet above the TPA when abeam the downwind end of the runway (i.e., 1,500 feet AGL if TPA is 1,000 feet AGL) before departing the traffic pattern. This helps ensure you are well above aircraft operating within the pattern. Be aware that you might have turbine traffic at 1500 AGL ensure you have positive separation from that traffic before climbing.
Conclusion
Non-standard departures at non-towered airports pose significant dangers, particularly due to the risk of collision with aircraft arriving on a 45-degree entry to the downwind leg. Adhering to FAA guidelines and best practices, as outlined in the PHAK, AIM, and AC 90-66C, can help mitigate these risks. By following standard departure procedures, communicating clearly, and planning thoroughly, pilots can enhance safety and ensure more predictable operations at non-towered airports.
References
5. Aircraft Owners and Pilots Association (AOPA), https://www.aopa.org/-/media/files/aopa/home/pilot-resources/asi/safety-advisors/sa08.pdf (Page 8)
Dan O’Brien
SAW Instructor