PPRuNe Forums - Approach Ban (UK/ Europe)

PPRuNe Forums (https://www.pprune.org/)

- Questions (https://www.pprune.org/questions-67/)

- - Approach Ban (UK/ Europe) (https://www.pprune.org/questions/618805-approach-ban-uk-europe.html)

Jemy	25th Feb 2019 22:41

Approach Ban (UK/ Europe)

My company conduct LVO training and is authorised to CAT 3B no DH landings. Frequently the approach scenario is that above 1000 ft RVR's are:- TDZ RVR 75, Mid RVR 75 and Stop RVR (Relevant) 75m. The crew plan for a cat 3B no DH landing with no reversion. (Minimum RVR is 75m). The crew fly the approach but then, the RVR beyond 1000ft is then reported as being lower than that- say 50m, 50m, 40m, and the crew carry on as the RVR at 1000ft was acceptable. All good.

However, (it's highly theoretical), but if the RVR below 1000ft increases to acceptable CAT 3A limits of 200m, 125m, 125m, and then there is a subsequent downgrade in A/C systems meaning CAT 3A RVR is required. Can you rebug the 50 radio DH and carry on? Or should one go around due to the downgrade in aircraft state replan and fly another approach to CAT 3A limits?

Thoughts welcome

Denti

26th Feb 2019 14:36

On the 737 we did set 50ft on radio, CAT I minimum on baro, flipped it back over to radio and blanked it for no DH approaches. That way the CAT I triangle shows up (which usually coincides with the 200‘ alert height) and we could reactivate the 50‘ for CAT IIIa in case we got a downgrade prior to the alert height or even flip it over to baro for a CAT I minimum if needed.

On the bus any monitored and announced downgrade below 1000‘ is a mandatory go around. But we can continue for non monitored failures, most we wouldn‘t notice anyway.

wiggy

26th Feb 2019 14:59

Quote:

However, (it's highly theoretical), but if the RVR below 1000ft increases to acceptable CAT 3A limits.....

I haven’t found chapter and verse for RVRs improving after 1000 feet AAL but certainly as far as I am aware and certainly I have always been taught that (for better or worse) you are “locked in” to the RVRs last received by the Approach ban point and the consequences thereof...

Jemy	26th Feb 2019 16:09

Colleagues, thank you for the replies.

I agree Wiggy, I think that the decision is made at 1000 and the "gate shuts" then. Any improvement or deterioration thereafter is irrelevant and should be dismissed.

Safe flying all

Jemy

All times are GMT. The time now is 12:27.