Back to Board Index
Back to Board Index
Forum help
| Air crash at Cork | |
Dave Wave   10th Feb 2011 11:20:11 | Just on the news, small commercial turbo prop crashed in fog at Cork.
Had gone around twice and crashed on 3rd attempt. Apparently CAT2 conditions. How hard is it to land in CAT2? |
Christian Smith   10th Feb 2011 14:20:23 | CAT2 Refers to the ability of that aircraft, in terms of what type of ILS it can handle.
So the types of ILS are: CAT 1/2/3a/3b/3c A International Boeing 747 is usally able to make a full CAT3c approach, this means it can make a fully automated landing. A small jet, such as a learjet is likely to be equipped with CAT2 capability. (Bear in mind I have no idea about the actual ILS approaches available at Cock) If the aircraft was on a CAT2 approach it would be pushing the limits a little in heavy fog. The required decision height would be 100ft from touch down. Based on the METAR at the moment, the pilot would have been likely to become visual with the runway approaching 200ft. The ground visibility suggests full visual around 0.5 miles from touch down! (Bear in mind that the RVR would be greater as the pilot could spot the runway lights earlier- none the less the pilot therefore had about 2 seconds to decide wether to continue or called missed) For an CAT2 approach the required visibility to the Runway (RVR) would be (I think) 1.2km, based on the current METAR which doesnt include the RVR, it would probably be around 1.6km. Again a very close call to make. A CAT2 approach is probably the one that 90% of FSOpen pilots make without realising it, 100 ft from touch down they disengage the autopilot and proceed to land. None the less if I was this pilot, after 2 missed approaches, I'm not convinced I'd go again! If anyone has better knowledge on Cork, chip in ;) |
Dave Nelson2  10th Feb 2011 14:33:04 | Very sad(R.I.P).
The aircraft was a Fairchild Metroliner, a 19-seat turboprop aircraft manufactured in San Antonio, Texas, in 1992.Should be fitted with ILS(instrument landing system) ORK Runways are cat1 and 2 so should have been ok for the weather conditions if within the limit at the time but even tower could not see the plane when it hit, they could only hear the bang,sounds like cat3 was more apt but it is not available at cork. Weather will be priority and a possible diversion-questions for Air Traffic control. Category I (CAT I) – A precision instrument approach and landing with a decision height not lower than 200 feet (61 m) above touchdown zone elevation and with either a visibility not less than 800 meters (2,625 ft) or a runway visual range not less than 550 meters (1,804 ft). Category II (CAT II) – A precision instrument approach and landing with a decision height lower than 200 feet (61 m) above touchdown zone elevation but not lower than 100 feet (30 m), and a runway visual range not less than 300 meters (984 ft) for aircraft category A, B, C and not less than 350 meters (1,148 ft) Aircraft was on approach for Runway17 Runway 1: Heading Runway 17/35, 2 133m (6 998ft), 063/R/C/W/T, ICAO Cat. 2, Aircraft size max: B747, ILS Numerous attempts to land first on R17 then on R35 and the last again on R17 and was left in a holding pattern for 20 minutes I am sure will be a discussion point, it is too early for any to comment but there must have been lenghty communications with tower (ATC) so hopefully answers for the families will be sooner rather than later. Passengers walking away incredible. |
Stephen Dubbie 10th Feb 2011 14:53:14 | :-( |
| Christian Smith 10th Feb 2011 15:08:00 | Thanks for clearing the Required RVR up Dubbie :)and the CATs available at Cork!! So on an ILS CAT2 App, and CAT2 equipped aircraft would use this approach to its fully capability!
I suppose to answer the orginal question a CAT2 Low Visibility approach would be VERY tricky! But 'do-able' if the weather conditions were just on your side. Just reading some news bits and it says the aircraft attempted to land in CAT2 Low Visibility Approach. This may even refer to the LVPs at the airport? Simply a Stage 2 LVP which would just mean that ATC had introduced low visibility procedures- these inform pilots of poor weather conditions, they can close taxi ways, oftern move runway holding points, and can change landing runways to a more suitable ILS. I also read the aircraft did enter a hold for 20 mins for the weater.... 2 missed approaches + 20 minute hold = Little fuel. The pilot probably didnt have the resources take another hold! Very sad news to see the lose of life :( and looking at the photos, I dont think either of the flight crew had a standing chance :( |
| Stephen Dubbie 10th Feb 2011 15:15:19 | one of these days im going to creat a new topic with the hardest questions i can think of,
i might just go through the ATPL bank and see what i can throw at you Mr Smith! |
| Dave Wave 10th Feb 2011 15:22:56 | So CATII/CATIII signs on a taxiway would be where the hold moves to when airports are under these conditions.
Does an airport announce that it is now CATII etc? |
| Christian Smith 10th Feb 2011 16:51:44 | Good question. So the category of the ILS remains the same- it depends on how good it is to be honest. The higher the better.
I'm not Too sure about this bit at all! But as far as I know this is the way it rolls: (Get it? Rolls?) The markings on taxiways approaching runways tells the CATEGORY OF AIRCRAFT where to hold. On FSX there is generally one runway hold marking- 2 Double yellow lines and then a dashed yellow line. The dashed line is a CAT1 holding point. The double yellow line is a CAT2/3 Holding Point. So, if I applied this to some useful phraseology: (Cessna 172) 'G-BCRS, Taxi to Delta 1 for Runway 24 via ***' (Boeing 738) 'Speedbird 2, Taxi to Delta 1 for Runway 24 via ***' Same insturction but different hold. The Cessna will roll right up to the Dashed line. The Boeing will hold short of the 2 thick double yellow lines :) If you have addon scenery you will notice that these 2 holding points have greater spacing (And usually a nice red sign next to them :)) So again the holding point is the same, but for the 2 example aircraft it tells each one where to stop- often a few meters apart. Check CAP637: It has some bits on this I think. So its what is the aircraft capability not the ILS capability of that airport. Also... the aircraft will only ever be able to do an ILS approach based on its type and the ILSs itself. If you go into Gatwick on a CAT3 Approach in an aircraft capable of CAT2 approach, it will use the capability of a CAT2. If you go into Cork on a CAT2 Approach, but with a CAT3 Capable aircraft it will only be able to complete a CAT2 Approach |
| Dave Wave 10th Feb 2011 17:42:09 |
Anyone know what the reason is for different aircraft to hold at different positions? |
| Stephen Dubbie 10th Feb 2011 17:47:06 | Chris will prob be able to give you a better answer,
but of what i know there is different holding points at some airports for weather and aircraft size, for example a 747 landing will have a bigger wingspan than a c172, so an aircraft holding would be givin more spacing due to the width of the aircraft, and if there is a strong X wind, extra spacing would also be givin incase the aircraft gets blown off cource |
| Mick McG 10th Feb 2011 22:40:58 | Hurumphhhhh! Some serious hoop here chaps. May I refer you to the "CAT I/II/III Holding Points and the ILS" thread.
M |
| Christian Smith 10th Feb 2011 23:44:48 |
^Dubbie! It worked! Whats the bet he shouted at the screen at the same time ;) |
| Laurence Woodside 13th Feb 2011 12:19:20 | Absolutely no idea in regard to the physics of the topic discussed, however on the morning in question. The fog came and went in banks very quickly. One minute I could see my outbuildings at the bottom of my garden some 900ft away and the next the kids trampoline was shrouded in mist 50ft away. A common occurrence in the area.
Further, the runways at cork bend over the horizon so much so that when an aircraft is at the holding point from the centre of the field you can just see the tip of the tailwing of a 737. I have been at the airport and in such conditions one cannot see the runway from the terminal building |
You need to Log on to post a reply. |
Forum help