10 Essential Aviation English Phrases Every Pilot Should Know

Introduction

In aviation, language saves lives. Every word spoken between pilots and air traffic controllers (ATC) carries operational and safety implications. Miscommunication has been a contributing factor in numerous aviation incidents throughout history, which is why standardized phraseology is critical for global air safety.

To minimize ambiguity, the International Civil Aviation Organization (ICAO) developed a globally recognized set of aviation English phrases. These phrases ensure that no matter where a pilot flies—from Los Angeles to Tokyo—the meaning remains clear, precise, and universally understood.

This guide explains 10 essential aviation English phrases that every pilot must know and use correctly. We’ll explore each phrase’s meaning, the right context for its use, and common mistakes to avoid. Whether you’re a student pilot preparing for your ICAO English exam or an experienced aviator refreshing your communication skills, mastering these expressions will help you communicate clearly, confidently, and safely.

Let’s start with the foundational words that keep aviation communication efficient: Roger, Wilco, and Affirm.

1. “Roger” vs “Wilco” vs “Affirm”

These three are among the most frequently misunderstood aviation English phrases.

• Roger means: I have received your message.
  It does not mean you agree or will comply—it only acknowledges receipt.

• Wilco means: Will comply. It implies both understanding and intention to follow instructions.

• Affirm (not “affirmative”) means: Yes or That’s correct.

Example:
ATC: “Climb to flight level 180.”
Pilot: “Roger.” ✅ (Acknowledged)
Pilot: “Wilco.” ✅ (Will do it)
Pilot: “Affirm.” ✅ (If asked to confirm understanding)

Common mistake: Saying “Roger Wilco” together is redundant since “Wilco” already implies you’ve received and understood.

2. “Say Again”

“Say again” is the standard ICAO phrase for asking repetition when a transmission is unclear or lost.

• Use “Say again” instead of “Repeat” (which in military communication means “fire again”).

• Keep it concise: “Say again altitude,” or “Say again last transmission.”

Example:
ATC: “Turn left heading one-two-zero.”
Pilot: “Say again heading?”

Pronunciation Tip: Keep a steady, calm tone—avoid shouting or exaggerated emphasis.

Common mistake: Overusing “say again” for minor issues. If you only missed a detail, request clarification for that element: “Say again the squawk code.”

3. “Unable”

“Unable” is one of the most powerful aviation English phrases, signaling that the pilot cannot safely comply with an instruction.

Use it firmly but professionally—never attempt to perform an unsafe maneuver just to comply.

Example:
ATC: “Descend immediately to 3000 feet.”
Pilot: “Unable due terrain.”

You can (and should) give a reason if possible, such as “Unable due traffic” or “Unable due weather.”

Common mistake: Avoid replacing “Unable” with casual terms like “Can’t do that.” Keep it standardized.

Using “Unable” shows professionalism, safety awareness, and assertive communication—key traits in aviation.

4. “Stand By”

“Stand by” means wait temporarily for further instructions. It’s used to manage frequency congestion or when ATC needs time before responding.

Example:
Pilot: “Request taxi clearance.”
ATC: “Stand by.”

This indicates that ATC has received the request but isn’t ready to respond yet.

Time Limitation:
If you hear “Stand by,” remain silent and do not repeat your request unless the delay is excessive.

Common mistake: Pilots sometimes interpret “stand by” as approval to proceed—it is not. Wait until you hear a clear instruction like “Cleared for taxi.”

5. “Mayday” vs “Pan-Pan”

Both phrases signal urgent situations, but their severity differs.

• Mayday – Declares a distress situation involving immediate danger to life or the aircraft.
  Example: “Mayday, Mayday, Mayday — engine failure, descending through 5000 feet.”

• Pan-Pan – Declares an urgent situation that is serious but not immediately life-threatening.
  Example: “Pan-Pan, Pan-Pan, Pan-Pan — low fuel, requesting priority landing.”

Key difference: “Mayday” triggers full emergency response; “Pan-Pan” requests priority assistance.

Common mistake: Using “Mayday” for minor technical issues or saying it only once. It must be repeated three times to ensure clarity over radio noise.

6. “Cleared for Takeoff” vs “Line Up and Wait”

These two instructions sound similar but have critical safety differences.

• “Cleared for Takeoff” authorizes the aircraft to begin its takeoff roll.

• “Line Up and Wait” instructs the pilot to enter the runway and hold position, awaiting further clearance.

Example:
ATC: “Runway 27, line up and wait.”
Pilot: “Lining up and waiting, Runway 27.”

Later:
ATC: “Runway 27, cleared for takeoff.”
Pilot: “Cleared for takeoff, Runway 27.”

Common mistake: Taking off after hearing “line up and wait.” That’s a serious violation. Always wait for explicit takeoff clearance.

7. “Go Around”

“Go around” instructs a pilot to abort the landing and climb to a safe altitude for another approach.
This can be initiated by ATC or by the pilot if the approach is unsafe.

Example:
ATC: “Go around, I say again, go around.”
Pilot: “Going around, [callsign].”

Proper Communication: Report your altitude and intentions afterward:
“Going around, climbing to 3000 feet, rejoining circuit.”

Common mistake: Hesitating or questioning the order. “Go around” is mandatory—execute first, then clarify.

8. “Squawk”

“Squawk” refers to setting a specific transponder code so radar can identify your aircraft.
The ATC might assign a code like “Squawk 4721.”

Common codes:

• 7500 – Hijacking

• 7600 – Radio communication failure

• 7700 – General emergency

Example:
ATC: “Squawk 7600.”
Pilot: “Squawking 7600.”

Tip: Always read back squawk codes to avoid errors—misheard numbers can cause misidentification on radar.

Common mistake: Forgetting to return to your normal code after an emergency drill or leaving the transponder in standby mode.

9. “Holding Pattern”

A “holding pattern” is a racetrack-shaped flight path that allows aircraft to delay their approach until cleared to proceed.

Example:
ATC: “Hold over VOR at 5000 feet, expect further clearance at 25.”
Pilot: “Holding over VOR at 5000, expecting clearance 25.”

Standard phraseology:

• “Entering hold” when beginning.

• “Leaving hold” when cleared to exit.

Common mistake: Confusing “orbit” with “hold”. A hold is structured and pre-defined; an orbit is a one-time 360° turn.

Always read back holding instructions in full—fix, altitude, and expected clearance time.

10. “Fuel State”

Reporting fuel state accurately helps ATC prioritize aircraft in low-fuel conditions.

• “Fuel endurance” indicates how much flying time remains.

• “Minimum fuel” means you can’t accept undue delay but are not yet in an emergency.

• “Mayday fuel” (or “fuel emergency”) indicates you will land with less than final reserve—declare “Mayday.”

Example:
Pilot: “Minimum fuel, unable further delay.”
If the situation worsens:
“Mayday, Mayday, Mayday — fuel emergency.”

Common mistake: Saying “low on fuel” without the proper phrase. Use standardized wording to ensure correct ATC response.

Conclusion

Aviation operates on precision—and that includes communication. These ten essential aviation English phrases form the foundation of safe, standardized exchanges between pilots and air traffic controllers worldwide.

Using these phrases correctly ensures clarity, reduces errors, and promotes smoother operations. Whether it’s acknowledging a clearance, declaring an emergency, or managing instructions, precision in language is as vital as precision in flight.

To master these and other crucial expressions, consistent practice is key. Listen to real ATC recordings, role-play scenarios, and take specialized Aviation English courses focused on ICAO phraseology and communication skills.

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