Originally Posted by
Lake1952
Am I alone in doubting the wisdom of even attempting a rolling takeoff with visibility of 1/8 mile?
Very good point and a lucid find, not discussed before.
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Note 1: the actual observed viz was probably much higher than 1/8 (200) for SWA.
Note 2: Some companies
here enforce LVO TKOF to a standing start, which is unnecessarily restrictive and achieves nothing apart from crew discipline and quality assurance check-point (diplomatic). With large operators, however, formal strong discipline has a value of its own; but one presumes US/SWA run on completely different metrics which is much envied looking outside in.
Note 3: With 300m RVR one can do a technically rolling takeoff, but with a gentle braked turn it will not expedite much. Thinking here single digit seconds if liftoff is the reference. More a case of not taking a halt after heading alignment.
Note 4: In ground freezing conditions my engines (same CFM as here but different casing) require 70%N1 (darn lot) run-up of 30 seconds on each, one by one. Let's hear from a B737 expert.
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One of the cheese holes SWA may have slipped through. They reported ready as a casual heads up to the tower, but not expecting or in the mindset of being launched.
Tower told them to line up and suggested the required timing by circumstantial info '3 NM traffic'. And unlike other normal day, the crew missed the dire relevance and focused on their engine ice-shedding procedure instead.
In a world with R/T phraseologies both parties would had the tool of 'IMMEDIATE'. One to explain himself and the others to reject it.