Hi All,I know that we have Landing minima for Landings in low Visibility and all landings, but what about takeoff minima?? What makes a flight be cancelled due to low visibility? What is the minimum visibility a 737-800 can takeoff in?Just had a flick through the FCTM but couldn't find much about it... Obviously this would probably bring in some RVR..?Just came to though earlier :)Thanks,Tristan

Take-off minima can be typically found in charts. I do not think airplane has any bearing on then, as typically no equipment is used during take-off. How HUGS enters into the equation, I know not.

Takeoff minimums are found at the front of each set of approach plates. You can see them online at fltplan.com or skyvector.com - http://tiles.skyvector.com/sky/files/tpp/1203/pdf/SW1TO.PDFThey are dependant on runways and obstacles and the same for all aircraft.

Take-off minima can be typically found in charts. I do not think airplane has any bearing on then, as typically no equipment is used during take-off. How HUGS enters into the equation, I know not.

Takeoff minimums are found at the front of each set of approach plates. You can see them online at fltplan.com or skyvector.com - http://tiles.skyvect...3/pdf/SW1TO.PDFThey are dependant on runways and obstacles and the same for all aircraft.

Thanks!It's just I am flying tomorrow on a 737-800, Thomson Airways (UK)And the visibility here has been quite bad, it probs won't cancel the flight but it just sprung to my mind as to if there were any minima :) So if there is thick fog, why can't aircraft depart?? :/I'm still confused about all this.. Had a look at some UK charts and found nothing about it..Thanks for your help!

Standard Vis is 1sm. You can lower that by adding lighting to the runway and markings. Airlines typically go down to 600RVR with 500RVR becoming common. With the HUD, you can go down to 300RVR, if your airline/aircraft/crew is equipped, trained, and certified. That's in feet. I think we did 75M when I was in Asia. I forget.Look at the back of the 10-9 Jeppsen charts for airport specific info.

As long as they are able to taxi to the runway they will allow planes to depart, at least as far as I understand. Sometimes the visibility can get so low that its impossible to taxi to the runway tho, and they will have to hold all departures.EDIT : posted after Spin737. It makes sense that a minimum RVR of 75m is required for departure, as that is the minimum rvr for CAT 3b approaches as well.EDIT2: BTW, here's a cool slightly OT video that shows CAT 3b minimum RVR. Its hard to taxi to the runway under these conditions

but what about takeoff minima?? What makes a flight be cancelled due to low visibility? What is the minimum visibility a 737-800 can takeoff in?

If you fly Part 91 there are no takeoff visibility minimums, you can takeoff in absolute fog, perhaps not smart but legal. But I doubt something of the size of 737 could be flown according to Part 91 (say as your private jet) but this is where my knowledge of regs ends.

Besides FAA/JAA/Etc minimums, there are company minimums.

No way!!!!!!!!!!!!!!! That video is intense! You can't see anything! You wouldn't want to play chicken on that runway :)How cool is that! the 747 blows the fog away for the crew :) hahaA Frew.

You have to realise you will have to control the airplane on the runway - being able to keep it on the centerline, and that includes rejected take-off and whatnot. You need to see at least something.Also there is the problem of emergency services finding you in the fog, or even driving around as such. I hear that is one of the bigger problems with true CAT IIIc. Also IIRC there was an accident where the death cound was unneccessarily high because the services could not find the aircraft in fog. I think I am, more likely then not, wrong here, but the Tenerife DIsaster does spring to mind here,

If you fly Part 91 there are no takeoff visibility minimums, you can takeoff in absolute fog, perhaps not smart but legal. But I doubt something of the size of 737 could be flown according to Part 91 (say as your private jet) but this is where my knowledge of regs ends.

any airplane can be flown under either 91,121 or 135.

Besides FAA/JAA/Etc minimums, there are company minimums

That is true. My company limit is=RVR (Runway Visual Range) 600 (200 meters). When less than RVR 1600, but equal to or greater than RVR 600, the crew may take off, provided the runway has a minimum of 2 functioning RVR readouts (minimum RVR 600 on all functioning readouts) and runway centerline lighting is operational. When 3 transmissometers are installed, all are controlling. If the runway has only one functional RVR readout or no centerline lighting, the minimum RVR is 1600.

As for take off minima... remember that sometimes, very often actually, plane that just took off has to return to same airport. Again, usually due to technical problems. So there are lots of reasons.

If you mean minimums that you set the BARO knob to, then it will be EO ACCEL (Engine Out Acceleration Hieght) + runway elevation. So for example for EHAM this will be 1000 + (-11) = 989 feet.

As for take off minima... remember that sometimes, very often actually, plane that just took off has to return to same airport. Again, usually due to technical problems. So there are lots of reasons.

And that's what we call a departure alternate. In my ops, if the weather is below approach minimums at the airport i'm departing, I must file a departure alternate.