Airbus is facing a second category of technical problems with some of its family of A320neo aircraft on top of previously reported engine glitches that have delayed deliveries of its latest medium-haul jet, industry sources said.

The problems are related to the hydraulic systems and particularly an increased noise created by a hydraulic pump when taxiing on one engine, they said.

Some planes are also affected by excess temperature in the hydraulic system, which can be a nuisance in hot climates, they added.

Speaking separately in Dubai, Qatar Airways chief executive Akbar Al Baker said the aircraft had issues "with the hydraulic system and the software".

Airbus reiterated any glitches would be resolved by the summer.  - Reuters