Departing in fog

[Margrove]

Hello everyone

Departing a foggy MAN earlier this year, the Captain announced that just prior to take off,he would be increasing power to the engines- whilst keeping the brakes on for a short while, as it was standard procedure when taking off in foggy weather. I have a number of theories why this is and no doubt all of them are way off the mark so I would be grateful to know the real reason. If its relevant, it was a Jet2 737-300 by the way.

Thanks in advance

[deltahotel]

If it's a cold day there might be a need for a de-ice runup. In the 757 it's 60% for 10 sec prior to applying T/O power.

[Lord Spandex Masher]

Icing run up. 70% for 30 seconds.

[VS-Toga]

What they said.

Also, in fog, the two greatest dangers is loss of situational and directional awareness, and runway incursions from other traffic.

[John21UK]

Standard run-up to get rid of any ice that may have accumulatd during taxi.

On the E170/190;
On a normal takeoff we advance the N1 to 40%, wait for the engines to stabilize and then apply thrust levers to the TOGA detent.

When there's ice/fog we set the N1 to 54% for 30 seconds whilst holding the brakes. If there's noticable fan vibration you let it run longer till it dissapears.

It's good airmanship to notify cabin crew/pax as well of what you're about to do.

[Rollingthunder]

Is kind of cool. Once departed YVR with about 500' of RVR.....didn't see anything of city until Burnaby Mountain...then blue skies

[Margrove]

Thanks everyone for your replies. I was way off the mark!

[Piltdown Man]

It's good airmanship to notify cabin crew/pax as well of what you're about to do. What? You have to be kidding? This is a waste of time and effort. There really is no need to inform the passengers about "normal" techniques and I'd be really reluctant to tell them about abnormals unless they are so strange they might wonder what you are up to. And most cabin crew know what is and what is not normal.

PM

[John21UK]

I'd disagree with you there. Also, there's big difference between the clientele of my previous and current employer. Same goes for the type of c/c. We'd let them know in the pre/flight briefing and the pax during a PA. Might also be different because of the type/airport I used to operate on/from. It's a small effort that might help put some nervous flyers at ease. I'd appreciate the heads-up if I were one.

Another example, c/c (note) had to inform pax during pre landing PA that we'd be flying the approach with some of the speedbrakes extended untill touchdown. And as a result they would feel a very strong buffet, something for them not to wory about. And that comes from one of europe's leading legacy carriers.

And most cabin crew know what is and what is not normal Indeed most, but far from all. I've had many c/c (even seasoned ones) come up to me after the pax disembraked asking if there was something wrong after landing as there was lots of noise and vibration. Answer: full reverse thrust. We never used more than idle you see so even some were unfamiliar with that. To let you see where they were coming from, I think I used full reverse thrust max 5 times in a 1 year period. If that...