During back taxi; an air carrier crew reports crossing temporary runway end at GRK. Aircraft was taxied back onto the runway and departed without problems.
Synopsis
During back taxi; an air carrier crew reports crossing temporary runway end at GRK. Aircraft was taxied back onto the runway and departed without problems.
Narrative
This event took place in November 2009; during the first flight of the day for the crew. Starting from intersection C and Runway 15; the crew received instructions from Tower control to back taxi from C intersection on Runway 15 to the start of the runway. I acknowledged the transmission with a proper read back and the Captain began to back taxi after repeating to me the said transmission and making a comment about the poorly painted runway markings. At this point I decided to double check the release to make sure that the aircraft had the required performance figures for its current weight and balance. While I did this; my head was focused down at the release which was laying in my lap. Upon looking up; I noticed that the aircraft was moments away from crossing the threshold of the runway and entering the stopway. I hesitated momentarily on voicing my concerns as I was unsure of myself as the runway is poorly marked and lighted. The tower contacted the flight crew and explained that they had taxied onto the closed portion of the runway and advised to perform a 180 degree turn and taxi back onto the start of the runway. The flight was conducted with no further issues.An event was determined to have happened after the tower informed the flight crew that they had crossed the end of the runway and were in fact on a closed portion. The event occurred due to the flight crews inability to stop the aircraft prior to taxing onto a closed portion of the runway. Probable causes as to why the flight crew continued onto the closed portion of the runway could include nighttime; poor lighting; runway markings that were painted on top of old markings making it difficult to distinguish the new and the old; my head down during taxi. While the runway is under construction; temporary markings should be more easily recognizable. I could have had my head up earlier. I could have applied brake pressure instantly during the split second of uncertainty. The captain could have voiced his concern of being unsure of where the runway end was. The crew could have told ATC of being unfamiliar with the new runway.
Second reporter narrative
The last 1000 feet of Runway 15 was closed and we did not know the reason for this; but I assumed there was construction of some kind. While back taxiing I noticed that there was no centerline and was having trouble seeing some of the runway markings. I mistook the blast pad as a displaced threshold. As soon as I reached the blast pad section I saw the chevrons and realized that this was indeed not a displaced threshold. I had inadvertently taxied onto a small portion of the blastpad; and I immediately braked and began to turn the plane around.
NASA callback
Reporter stated the runway end markings are difficult to see at night but are discernable and would have prompted a comment had I not been head down until almost over the line. The threshold has been displaced to accommodate workers during day light hours and did not cause any problem for the tower.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.