United B738 at Calgary on Apr 13th 2014, hydraulic failure

A United Boeing 737-800, registration N12218 performing flight UA-1652 from Houston,TX (USA) to Calgary,AB (Canada), was on approach to Calgary's runway 29 when about 10nm before the runway threshold with the gear still retracted the crew received indication of #1 hydraulic pump low pressure and the quantity in hydraulic system A at zero. The crew aborted the approach and entered a hold to work the relevant checklists including manually extending the landing gear. The crew subsequently landed safely on runway 35L about 30 minutes after aborting the first approach.

The Canadian TSB reported the #1 engine driven hydraulic pump was replaced.