code: private static Integer getHourUtc(AisExtractor extractor, int slotTimeout,
  			int startIndex) {
  		if (slotTimeout == 1) {
  			// skip the msb bit
  			int hours = extractor.getValue(startIndex + 5, startIndex + 10);
  			return hours;
  		} else
  			return null;
  	}
docs: Returns hour UTC as per 1371-4.pdf.
  
  @param extractor
  @param slotTimeout
  @param startIndex
  @return