Appreciate. I am certain it's all the same in essence and result, like riding a scooter vs. skateboard. Better yet, throwing a ball left or right-handed, and we are now discussing the grip differneces of opposite dexterity.
Sorry I hesitate posting better explanation about our side's *metric" way of handling lo-viz, to avoid embarrassing myself a bit of study is required to pass the message properly.
When conditions deteriorate below mark, the airport / ATC / vehicles / light and navaid crews / pilots go on a declared 'yellow alert'. The rules are specified and form Low Visibility Procedure (set) and Low Visibility Operations commence.
For instance in-trail approach spacing could change from 2.5 to 6 miles, but local procedures may vary.
The terminology is officialy AWO (all-weather operations) which nobody uses. LVO instead, using LVPs. For crews those are LVTO, CAT II/III approach, landing and rollout, and LVP taxi.
Hence reading here about FedEX calling a CAT III approach (themselves) sent the brains spinning at first. For us we double check with ATC that LVO is active (Airport is running the LVPs and ATC play their part of the game accordingly) and then fly the approach based on OpSpec and crew authorisation. No need, benefit or effect of any such call.
Do I get it right, that the implicit adjustment of procedures (but not called low visibility procedures
) for <1\2 SM was not adhered to by allowing the 737 onto the runway in the incident here? Would the 'best practice' be different if the approaching airplane did call only CAT II or not called any special approche type at all? (understood that 1/8 leave only one chocie IRL)