Minimum visibility for Airliners???

[Guest Water Mango]

I flew into KMSP last night with 0.50 visibility in snowy conditions. I have a couple of questions as to what's realistic:1. What's the minimum visibility airliners can operate in using ILS autolanding equipment???2. For aircraft like the CRJ, what's the minimum visibility they can safely fly the ILS course down to the runway???Thanks for all comments... :-)

[Guest guyjr]

It all depends on the equipment installed in the plane, the equipment installed at the airport, and the certification level of the pilot-in-command. I believe CAT-III ILS is the only one certified down to 0/0 weather, and you have to have specialized autoland equipment installed in the plane as well. I also think the pilots have to have additional recurrancy training to be able to legally fly a CAT-III 0/0 approach, but I'm not positive on that one - at the very least, an instrument rating is required.One airport I know for sure allows 0/0 landings is Hartsfield (KATL). I actually was on an airliner which performed a landing like that there - looking out the passenger window, you literally could not see the runway until about 5 seconds before touchdown (which would put the plane a LOT lower than the typical 200 foot minimum on a standard ILS approach).--Guy

[mgh 89]

The UK minima for precision approaches are:Cat 1 - DH not lower than 200ft: RVR not less than 550mCat 2 - DH below 200ft but not lower than 100ft: RVR not less than 300m Cat 3A - DH less than 100ft: RVR not less than 200mCat 3B - DH less than 50ft or no DH: RVR lower than 200m but not less than 75mThese are the absolute minima and more restrictive limits may apply depending on the carriage of approved equipment and the composition of the flight crew and their competence and experience, as well as the aerodrome layout, obstacles etc. In addition, Cat 2 and 3 operations can only be flown by operators whose minima have been accepted by the CAA.

[Guest Adverse Yawn]

Cat IIIB permits zero viz landings. But in reality a 75m limit is usually imposed because it is not possible to taxi safely otherwise.

[scott967 62]

Here's the chart for RWY12L and RWY35 CAT III:http://forums.avsim.net/user_files/145080.jpgscott s..

[Hornit 3]

There aren't a whole lot of airplanes that do 0/0 landings. Most aircraft today do CAT III down to 600 or 700 RVR. RVR=Runway visual Range and is in feet. 600 feet is about two or three runway edge lights and really gets your attention. We have a fifty foot alert height(radar) which means as long as I see some type of light, we will land but only the AUTOPILOT can do it. I cannot fly this type of approach "hand flown". At fifty feet, if I dont see anything, we do an autopilot go around and missed approach. If I do see something, George gets to do the landing and I announce "Land 3" to my co-pilot.I do not take over until the nose is on the ground when I go into reverse thrust, once under control and slowing I disconnect the autopilot and bring it to a stop. Exiting the runway in these conditions involves specific procedures also as far as routes and comms and we have a special chart for it. The training is very specific and involves calling out every mode change and watching all the systems. For CAT III nothing can be broken on the aircraft or the airport and we always run the APU as a backup power source during the approach. Some of the newer aircraft can do the 0/0 thing but there are very few runways certified for this. I have never seen in 16 years where we could not get in with 600-700 RVR. That is really low vis! :) For those who might forget or not know, I'm an MD-88 Captain for Delta.

[michal 44]

>At>fifty feet, if I dont see anything, we do an autopilot go>around and missed approach. Go around declared at 50 ft ??? How does it work so close to the ground? By the time you change pitch and add power and engine actually spool up the airplane continues to sink .. how low does it get before it actully starts climbing out, 20 ft?Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

[Ralgh 43]

Its not unheard of for the plane to actually touch the runway during a CAT III go around. I have only done one CAT III in real life and that was to a landing but we did a lot in the simulator and every once and a while you would feel the wheels just bump the runway.

[michal 44]

Cool.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg