Down Time

The down time statistics are based on individual fault reports. In Table 1 I give the general down time statistics for period 50.

A total of 101 fault reports were submitted, with an average time lost of 10 min per fault, for a total down time of 0.8% (0.4% on scheduled observing nights). Of these, 79 reported no time lost, 20 reported $<$ 2 hrs lost, and 2 reported 2 or more hrs lost.

This compares to a down time of 0.3% over all nights (0.2% on scheduled observing nights) in period 49, and 0.4% over all nights (0.4% on scheduled observing nights) in period 48. Of the 68 fault report in period 49, 49 reported no time lost, 19 reported $<$ 2 hrs lost, and none reported 2 or more hrs lost. Of the 65 fault report in period 48, 40 reported no time lost, 25 reported $<$ 2 hrs lost, and none reported 2 or more hrs lost.

Table 1: Technical down time statistic period 50: 2014-10-01 to 2015-04-01

Night included	Time lost	Nights	Percentage$^a$	Last semester	Last Winter
All nights	1010 min	182	0.8%	0.3%	0.4%
Scheduled observing nights$^b$	465 min	156.5	0.4%	0.2%	0.4%
Technical nights	545 min	25.5	3.2%	0.0%	0.3%
Service nights	230 min	42.5	0.8%	0.5%	0.4%
Visitor instruments	0 min	0	0.0%	0.0%	0.0%
$^a$ Taking the average length of time within nautical twilight. Exact numbers for each night
are used when looking at ``All nights''
$^b$ Excluding technical nights and visitor instruments

The downtime was somewhat higher, mostly due to one major failure discussed below. Still, the amount of downtime is not high. There were relatively many fault reports due to some new software scripts developed for ALFOSC having some teething problems, while the `regular´ problems with the detector software is being reported more diligently.