3. Weather/Dispatch/GOM Flashcards
What are the standard takeoff minimums for the A320?
Standard take off minimums for 2 engine aircraft are 1SM or 5,000’ RVR.
Are we allowed to operate with lower than standard takeoff minimums?
What provides authorization to do so?
o Yes
o Ops Spec C056: IFR takeoff minimums, Part 121 airplane operations
What are we allowed to reduce our takeoff minimums to?
o Ops Spec C078: IFR lower than standard takeoff minima
o Lowest authorized takeoff RVR: TDZ RVR 5, MID RVR 5, ROLLOUT RVR 5
What is our lowest authorized takeoff minimum for takeoff on JFK RWY 31L?
TDZ RVR 5, MID RVR 5, ROLLOUT RVR 5
What are the runway requirements when operating at RVR 5/5/5?
HIRL + CL
Is reported visibility or RVR for the takeoff runway controlling?
RVR reports, when available for a particular runway, shall be used for all takeoff
operations on that runway.
JFK RWY 31L has three RVR reports: TDZ/MID/ROLLOUT. If reported RVR is 5/4/5, are we
allowed to takeoff? If reported RVR is 5/INOP/5 are we allowed to takeoff?
o No/Yes
o If RVR is more than 1,600 RVR
- The TDZ RVR report if available is controlling
- The MID RVR report may be substituted for an unavailable TDZ report
o If RVR is less than 1,600 RVR
- A minimum of 2 operative RVRs are required
- All reporting RVRs are controlling
When is a takeoff alternate required?
If the current departure airport weather is lower than the landing minimums
published for the airport.
What is required to list an airport as a takeoff alternate?
o Must be within 1 hour from the departure airport at normal cruising speed in still
air with one engine inoperative.
o Must meet the criteria in Ops Spec C055 for filing as an alternate.
What is the weather requirement at our destination airport to dispatch?
Weather must be at or above the authorized minimums at the ETA.
The main body of the TAF for our destination airport is reporting visibility at the ETA of ½
SM, however there is a TEMPO for ¼ SM. Can we depart?
o Yes, Exemption 3585 can be applied
o Requires a second alternate
The main body of the TAF for our destination airport is reporting visibility at the ETA of ¼
SM. Can we depart?
o No, main body of the report is controlling
When is a destination alternate required (domestic)?
An alternate must be designated unless the appropriate weather reports or
forecasts, or any combination of them, indicates that the visibility will be at least
three (3) miles with a ceiling of at least 2,000 feet for at least one (1) hour before
and one (1) hour after the estimated time of arrival at the destination airport.
When is a second alternate required to be on the release?
o When exemption 3585 is used
o When weather at the destination and first alternate is marginal
How is marginal weather defined?
o A ceiling of less than 500’ above DA(H) or MDA(H) or
o A visibility of less than ½ mile above the lowest operational approach minimum
How do you determine that the alternate listed on the release is legal?
o Reference Ops Spec C055: Alternate Airport IFR Weather Minimums
o We use the 1 NAVAID/2 NAVAID rule to derive alternate weather minimums.
- 1 NAVAID: for airports with at least 1 operational navigational facility
providing a straight‐in NPA, or Category 1 precision approach, or, when
applicable, a circling maneuver from an IAP:
• Add 400 ft to MDA(H) or DA(H), as applicable
• Add 1 SM to the landing minimum
- 2 NAVAID: for airports with at least 2 operational navigational facilities,
each providing a straight in approach procedure to difference suitable
runways:
• Add 200 ft to higher DA(H) or MDA(H) of the 2 approaches used
• Add ½ SM to the higher authorized landing minimum of the 2
approaches used