View Full Version : Freezing Fog
Hi guys good night.
AWO question:
Are you allowed to shoot an approach when FZFG is reported? I had a discussion with a colleague today about it.
Thanks in advance!
JammedStab
27th Nov 2015, 03:26
Of course.
renard
27th Nov 2015, 08:02
It's approaches and departures in freezing rain and freezing drizzle that are prohibited.
de facto
27th Nov 2015, 08:41
Freezing fog is ok as long as you do some specific procedure,freezing rain on the other hand is considered "severe" icing...check your AFM.
I-2021
27th Nov 2015, 08:53
It's approaches and departures in freezing rain and freezing drizzle that are prohibited.
It depends. most de/anti icing devices will be able to protect you in -FZRA as well as most de/anti icing fluids will allow you some holdover time in this condition. It is often the case in northern Europe in winter time. Different story for moderate or heavy FZRA where airplane protective devices for approaches and fluids for departure might not suffice to grant you the required protection. The majority of anti icing fluids have no holdover guidelines for moderate FZRA and higher.
Intruder
3rd Dec 2015, 22:29
It's approaches and departures in freezing rain and freezing drizzle that are prohibited.
Is this an EASA thing? The US FAA prohibits departures, but not approaches.
despegue
4th Dec 2015, 01:01
Intruder,
While not explicitly forbidden word by word, the aircraft is NOT CERTIFIED to fly in FZRA. That is why it IS explicitly mentioned that when entering FZRA, you need to find an escape asap.
And even IF you could land safely ( although your icing equipment will not cope and in case of go-around, there exists no data for a successful aerodynamic climb), how do you think the RWY and taxiways will be like...
We ask this scenario during command upgrades to see if the future Captain can think further than his/her nose is long...
Intruder
4th Dec 2015, 18:47
OTOH, if there is no other feasible place to land, you may have to do it anyhow. While I do not advocate intentionally flying into a known area of freezing rain, it might be necessary at some point if your career. Also, inherently, landing/go-around performance is significantly better than takeoff performance because you land a a lower weight. You NEVER "have to" take off, but once you do, you eventually HAVE TO land...
FWIW, freezing fog is NOT the same as freezing rain/drizzle. However, it is usually very dense and can seemingly appear 'out of nowhere'. Expect Cat II/III visibility when it happens.
de facto
6th Dec 2015, 12:36
freezing fog---> low viz
freeing rain--->temperature inversion:E
renard
6th Dec 2015, 15:48
Intruder,
Our Ops Manual, Part A, was what I was referring to with regards to the prohibition.
I've only encountered freezing rain on the ground in South Wales and I could barely walk along the pavement(sidewalk) and there was no way I was going to drive a car.
Landing at airport affected by FZRA would be pretty uncomfortable.