Tail Strike Awareness
한 줄 요약: B777 기종별 Tail Strike Pitch Attitude 한계, 감지 방법, 이륙 시 5대 위험 요소 — FCTM 8.34 기반.
1. Typical Takeoff Tail Clearance (FCTM 3.10)
“The following diagram and table show the effect of flap position on liftoff pitch attitude and minimum tail clearance during takeoff.” (FCTM 3.10)
| Model | Flaps | Liftoff Attitude (All Engine) | Minimum Tail Clearance | Tail Strike Pitch Attitude |
|---|---|---|---|---|
| 777-200 / 200LR / F | 5, 15, 20 | 8.5° | 37 in (94 cm) | 12.1° |
| 777-300 | 5, 15, 20 | 7.0° | 36 in (91 cm) | 8.9° |
| 777-300ER | 5, 15, 20 | 8.5° | 30 in (76 cm) | 10.0° (SLG Operative)* |
NOTE
“777-300ER values valid when the Semi-Levered Gear (SLG) is operative. When the SLG is inoperative, use 777-300 values.” (FCTM 3.10)
⚠️ GOTCHA / DIFFERENCE
777-300은 Tail Strike Pitch Attitude가 8.9°로 All Engine Liftoff Attitude(7.0°)와 여유가 1.9°에 불과함. 300ER(1.5°)과 함께 가장 취약한 기종 (FCTM 3.10).
2. 감지 — Identification (FCTM 8.34)
“A tail strike can be identified by the flight crew or cabin crew.” (FCTM 8.34)
다음 중 하나라도 발생하면 tail strike 징후 (FCTM 8.34):
- “A noticeable bump or jolt” — 기수 회전(Rotation) 또는 Flare 시 뚜렷한 충격/흔들림 (FCTM 8.34)
- “A scraping noise from the tail of the airplane” — 항공기 후방 마찰음 (FCTM 8.34)
- “The TAILSKID or TAIL STRIKE EICAS message or light may be displayed.” (FCTM 8.34)
🚨 LIMITATION
“Anytime fuselage contact is suspected or confirmed, do the appropriate NNC without delay.” (FCTM 8.34)
3. 이륙 시 주요 발생 요인 — Takeoff Risk Factors (FCTM 8.34-8.35)
“Understanding the factors that contribute to a tail strike can reduce the possibility of a tail strike occurrence.” (FCTM 8.34)
1) Mistrimmed Stabilizer (FCTM 8.34)
“This usually results from using erroneous takeoff data, e.g., the wrong weights, or an incorrect center of gravity (CG).” (FCTM 8.34) FMS 입력 오류 또는 stabilizer 세팅 오류 포함. “The flight crew can prevent this type of error and correct the condition by challenging the reasonableness of the load sheet numbers.” (FCTM 8.34)
2) Rotation at Improper Speed (FCTM 8.35)
“This situation can result in a tail strike and is usually caused by early rotation due to an unusual condition, or rotation at too low an airspeed for the weight or flap setting.” (FCTM 8.35)
3) Trimming during Rotation (FCTM 8.35)
“Trimming the stabilizer during rotation may contribute to a tail strike. The PF may easily lose the feel of the elevator while the trim is running which may result in an excessive rotation rate.” (FCTM 8.35)
4) Excessive Rotation Rate (FCTM 8.35)
“Flight crews operating an airplane model new to them, especially when transitioning from an airplane with unpowered flight controls to one with hydraulic assistance, are most vulnerable to using excessive rotation rate.” (FCTM 8.35)
5) Improper Use of the Flight Director (FCTM 8.35)
“The flight director provides accurate pitch guidance only after the airplane is airborne.” (FCTM 8.35) 정상 rotation rate으로 35 feet에서 약 15° pitch attitude 도달. “However, an aggressive rotation into the pitch bar at takeoff is not appropriate and can cause a tail strike.” (FCTM 8.35)
Cross-References
- Visual Approach & Traffic Pattern — 느린 접근 속도 시 aft body clearance 감소 (착륙 tail strike 관련)