RichOffDuty
07-20-2006, 06:10 PM
STANDARD TERMINOLOGY.
Duration.
Occasional. Less than 1/3 of the time.
Intermittent. 1/3 to 2/3 of the time.
Continuous. More than 2/3 of the time.
Note: Duration may be based on time between two locations or over a single location. all locations should be readily identifiable.
Intensity.
Light chop. slight, rapid and rhythmic bumpiness without major changes in altitude or attitude.
Light turbulence. slight, erratic changes in altitude and/or attitude. occupants may feel a slight strain against seatbelts. unsecured objects may be displaced slightly. Food service may be conducted and little to no difficulty is encountered in walking.
Moderate chop. rapid bumps without appreciable changes in aircraft altitude or attitude.
Moderate. Changes in altitude and/or attitude occur but the aircraft remains in positive control. it usually causes variations in indicated airspeed. occupants feel definite strain against seatbelts. unsecured objects are dislodged. Food service and walking are difficult.
Severe. Large, abrupt changes in altitude and/or attitude. Large variations in indicated airspeed. aircraft may be momentarily out of control. occupants are forced violently against seatbelts. unsecured objects are tossed about. Food service and walking are impossible.
Extreme. aircraft is violently tossed about and is practically impossible to control. May cause structural damage.
Types.
Thunderstorm turbulence. turbulence associated with thunderstorms or cumulonimbus clouds. a cumulonimbus cloud with hanging protuberances is usually indicative of severe turbulence.
Clear air turbulence. turbulence above 15,000ft not normally associated with cumuliform cloudiness. Windshear turbulence even when in cirrus clouds.
Mountain wave turbulence. turbulence as a result of air being blown over a mountain range or a sharp bluff causing a series of updrafts and downdrafts.
GENERAL PROCEDURES.
If turbulence is expected before the flight departs, the preflight briefing to the lead flight attendant must include turbulence considerations. the briefing should include:
- What the captain wants the cabin crew to do when turbulence is expected.
- Intensity of turbulence expected.
- Methodology for communicating to the cabin the onset or worsening of turbulence (cabin interphone or pa).
- Phraseology for the cabin crew to communicate the severity of turbulence.
- Expected duration and how an “allclear” will be communicated.
- Use a positive signal of when cabin crew may commence their duties after takeoff and when they should be seated and secured prior to landing.
If flight into turbulence is unavoidable:
- Passengers should be informed of routine turbulence via the pa system.
- Do not rely on the seatbelt sign alone.
- Cabin crew should be informed of routine turbulence via the interphone.
- If the cabin crew experiences uncomfortable turbulence without notice from the flight crew, they should take their seats and inform the flight crew.
- All service items must be properly stowed and secured when not in use.
INJURY AVOIDANCE.
Expected turbulence. if advance notice exists enabling the captain to brief the cabin crew either prior to the flight or in-flight via the interphone, flight crew should:
- Brief the cabin crew on the expected turbulence level and its duration.
- Clearly articulate expectations from the cabin crew and request confirmation of completed actions.
- Instruct the cabin crew to immediately and plainly report any deviations from the expected turbulence level.
- Develop a method to inform the cabin crew of the completion of the turbulence event.
Little warning. in a situation when sufficient warning exists to seat the passengers and for the cabin crew to perform their duties:
- Captain turns on seatbelt sign and makes a public address announcement: “Flight attendants stow your service items and take
your seats. passengers please remain seated until this area of turbulence has passed and i have cleared you to move about the cabin”.
- Cabin crew stow all applicable service items, perform cabin compliance check, and secure themselves in their jump seats.
- Lead flight attendant informs captain of the completion of these items.
- When conditions improve, captain uses the public address system to advise the cabin crew that they may resume their duties and whether or not the passengers may move about the cabin.
Imminent turbulence or turbulence occurring.
If there is sudden, unexpected or imminent turbulence requiring immediate action to protect cabin crew and passengers:
- Captain turns on seatbelt sign and makes a public address announcement: “Flight attendants and passengers be seated immediately.
passengers please remain seated until this area of turbulence has passed
and i have cleared you to move about the cabin.”
- Cabin crew take first available seat and secure themselves.
- No compliance checks are performed and items are secured only if they present no delay in securing a person in a seat.
- When conditions improve, captain makes public address announcement advising the cabin crew that they may resume their duties
and whether or not the passengers may move about the cabin.
From Page 44-46 Flight Safety Australia May/June 2006
Adapted from US Federal Aviation Administration advisory material.
Duration.
Occasional. Less than 1/3 of the time.
Intermittent. 1/3 to 2/3 of the time.
Continuous. More than 2/3 of the time.
Note: Duration may be based on time between two locations or over a single location. all locations should be readily identifiable.
Intensity.
Light chop. slight, rapid and rhythmic bumpiness without major changes in altitude or attitude.
Light turbulence. slight, erratic changes in altitude and/or attitude. occupants may feel a slight strain against seatbelts. unsecured objects may be displaced slightly. Food service may be conducted and little to no difficulty is encountered in walking.
Moderate chop. rapid bumps without appreciable changes in aircraft altitude or attitude.
Moderate. Changes in altitude and/or attitude occur but the aircraft remains in positive control. it usually causes variations in indicated airspeed. occupants feel definite strain against seatbelts. unsecured objects are dislodged. Food service and walking are difficult.
Severe. Large, abrupt changes in altitude and/or attitude. Large variations in indicated airspeed. aircraft may be momentarily out of control. occupants are forced violently against seatbelts. unsecured objects are tossed about. Food service and walking are impossible.
Extreme. aircraft is violently tossed about and is practically impossible to control. May cause structural damage.
Types.
Thunderstorm turbulence. turbulence associated with thunderstorms or cumulonimbus clouds. a cumulonimbus cloud with hanging protuberances is usually indicative of severe turbulence.
Clear air turbulence. turbulence above 15,000ft not normally associated with cumuliform cloudiness. Windshear turbulence even when in cirrus clouds.
Mountain wave turbulence. turbulence as a result of air being blown over a mountain range or a sharp bluff causing a series of updrafts and downdrafts.
GENERAL PROCEDURES.
If turbulence is expected before the flight departs, the preflight briefing to the lead flight attendant must include turbulence considerations. the briefing should include:
- What the captain wants the cabin crew to do when turbulence is expected.
- Intensity of turbulence expected.
- Methodology for communicating to the cabin the onset or worsening of turbulence (cabin interphone or pa).
- Phraseology for the cabin crew to communicate the severity of turbulence.
- Expected duration and how an “allclear” will be communicated.
- Use a positive signal of when cabin crew may commence their duties after takeoff and when they should be seated and secured prior to landing.
If flight into turbulence is unavoidable:
- Passengers should be informed of routine turbulence via the pa system.
- Do not rely on the seatbelt sign alone.
- Cabin crew should be informed of routine turbulence via the interphone.
- If the cabin crew experiences uncomfortable turbulence without notice from the flight crew, they should take their seats and inform the flight crew.
- All service items must be properly stowed and secured when not in use.
INJURY AVOIDANCE.
Expected turbulence. if advance notice exists enabling the captain to brief the cabin crew either prior to the flight or in-flight via the interphone, flight crew should:
- Brief the cabin crew on the expected turbulence level and its duration.
- Clearly articulate expectations from the cabin crew and request confirmation of completed actions.
- Instruct the cabin crew to immediately and plainly report any deviations from the expected turbulence level.
- Develop a method to inform the cabin crew of the completion of the turbulence event.
Little warning. in a situation when sufficient warning exists to seat the passengers and for the cabin crew to perform their duties:
- Captain turns on seatbelt sign and makes a public address announcement: “Flight attendants stow your service items and take
your seats. passengers please remain seated until this area of turbulence has passed and i have cleared you to move about the cabin”.
- Cabin crew stow all applicable service items, perform cabin compliance check, and secure themselves in their jump seats.
- Lead flight attendant informs captain of the completion of these items.
- When conditions improve, captain uses the public address system to advise the cabin crew that they may resume their duties and whether or not the passengers may move about the cabin.
Imminent turbulence or turbulence occurring.
If there is sudden, unexpected or imminent turbulence requiring immediate action to protect cabin crew and passengers:
- Captain turns on seatbelt sign and makes a public address announcement: “Flight attendants and passengers be seated immediately.
passengers please remain seated until this area of turbulence has passed
and i have cleared you to move about the cabin.”
- Cabin crew take first available seat and secure themselves.
- No compliance checks are performed and items are secured only if they present no delay in securing a person in a seat.
- When conditions improve, captain makes public address announcement advising the cabin crew that they may resume their duties
and whether or not the passengers may move about the cabin.
From Page 44-46 Flight Safety Australia May/June 2006
Adapted from US Federal Aviation Administration advisory material.