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Old 31st May 2008, 23:22
  #55 (permalink)  
alf5071h
 
Join Date: Jul 2003
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More risk to manage = more likelihood of an incident / accident.

More risk:-
In addition to any downwind component during the landing, runway 02 has a down-slope (-69ft).

My meagre translation of the warnings on the airport chart indicate that during June-Dec the touchdown zones are ‘extremely slippery’, presumable this applies in any wet weather.
NOTAMS advised caution in the rainy season w.e.f. 16 May. IIRC ‘Slippery when wet’ classifications (ICAO) indicate a runway friction in the order of 0.4, there is no indication of such a warning in this incident or of any maintenance check of the runway to indicate this condition, or is that the intent of the chart warning and NOTAM?
Judging from the photo (#30) there is a lot of rubber on the runway surface;– a poorly maintained runway?

The airport chart indicates that the threshold for 02 is displaced. Measuring the chart, the landing distance appears to indicate 6190 ft – the stated length of hard surface. However, the depicted PAPI location and photo (#30) support the notion of a shorter distance due to a displaced threshold.
From the type A obstacle chart the landing distance for 02 appears to be only 5410 ft (poor translation capability, Spanish experts please confirm). Also, that the clearway (02) is approximately 225 ft, presumably the tarmac/grass before the overrun down slope.
There is only one fixed distance marking, so that there is no clear indication of the touchdown zone.

The threshold displacement appears to be due to the higher (down sloping) terrain on the final approach. From the charts a straight in approach is not authorized from the VOR/DME, thus with a slightly steeper, circling approach, a higher obstacle clearance plane might enable greater landing distance.
From an operational aspect, circling to runway 20 from a 02 VOR approach (lower minima) might be easier (and into wind) although Captain would be on the outside of the turn - circle East only.

“The real question is, where do we draw the line...” (77300ER #51) … well … further away from the current edge as indicated by the norm in some parts of the industry. This would require that the boundary of operation be determined for all runways likely to be used. The boundary – the edge of a safe operation, is not defined by any fixed standard as there are many variables involved requiring individual judgment. At airports such as this, special attention is required to avoid unnecessary risk.

The operating crew can draw a line, but this is usually limited to the immediate circumstances and conditions – last chance.
An analysis such as above, should be undertaken by the operator (ops planning), the airport management, and the regulator – proactive safety.
If more people were involved in ‘drawing the line’ perhaps it would be thicker so then the crew could choose the safer edge as their boundary.
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