AviZone

                On 27 November 2008, an Airbus A320-200 crashed into the sea off the coast of Perpignan  during an airworthiness check flight and was destroyed, killing all 7 occupants.                      According to the investigation’s report, the accident was caused by the loss of control of the  aeroplane by the crew following the improvised demonstration of the functioning of the Angle  Of Attack (AOA) protections, which were inoperable at the time because the AOA sensors had  jammed making it impossible for the protections to trigger.               The jamming of the AOA sensors had been caused by freezing of the water which was  present as a result of incorrect rinsing procedures being used on the aircraft three days before  the accident flight.            The purpose of this I...

                       A helicopter was recently reported as having made a precautionary landing after the crew were alerted  to a carbon monoxide warning. Any indication of carbon monoxide (CO) entering the cockpit should be  treated extremely seriously; the colourless and odourless gas is with justification referred to as ‘the  silent killer’.                        In 2001 the crew of a PA24 were killed when their aircraft spun into the  ground 12 minutes after take-off. The accident investigation concluded  that the occupants had been poisoned by CO leaking from a failed  exhaust manifold into the cockpit. The aircraft was not carrying any  detectors which could have warned of the presence of carbon monoxide.  CO can usually only be recognised in an aircraft by associated engine exhaust smells. Symptoms are  subtle...

                          However, we need to remember that high  temperatures can have serious effects on our  performance. Cockpits can reach temperatures well  above ambient, especially if they include large areas of  perspex, and pilots could experience dehydration  unless they drink sufficient water. Sunburn, apart from  its own effects, can be associated with dehydration.  Take water, cover your head and exposed areas of skin  when you are in the cockpit or out and about on the  airfield, and remember that you may remain relatively  dehydrated because of alcohol long after its initial  effects have worn off.                            Of course, it is not only the pilot which may experience reduced performance. High air temperatures  reduce air density and consequently reduce both engine...

           Pre-flight checks on the first flight after maintenance           It need to be more particular than usual in  pre-flight  checks on the first flight after maintenance has been completed. A recent occurrence report emphasises  that point.                      It seems the engineers had been interrupted  in their work, and two inspection panels were n ot  closed properly; only a few screws had   been replaced, and these were standing   proud. When the crew arrived to take the  aircraft for its first flight after the  maintenance, the panels were still loose.  However, because they were under the low  wing they were not easily seen, and indeed  they were not noticed. After take-off, when  the airflow caught the panels, they were  damaged and one actually came off.        ...

                 What is  the importance of keeping  aircraft clean. Apart from reducing the incidence of  surface corrosion , it makes it easier to spot any minor  damage , which might lead to further and deeper corrosion,   early. However, we also advise that after washing an  aircraft, it is important to ensure that grease and oil  necessary for lubrication of moving parts, for example  aileron hinges, are not removed, or if they are, that they  are immediately replaced.                Many Flight Manuals contain advice on recommended  cleaning methods, and if that is not the case the  Maintenance Manual may well do. However, it is very  tempting, to use a proprietary  pressure washer, especially if you are attempting to wash off salt water a long way from the nearest   source of fresh. However, by their very design, pressure w...

Heavy Rain Can Cause Frozen Brakes           It is reminded that carbon disc brakes can retain moisture from exposure to heavy rain or washing; leading to the possibility of frozen brakes upon landing.             Climate conditions well above freezing at departure are irrelevant if moisture levels in the brakes are sufficient to freeze during cold soak at altitude.       A Bombardier airplane experienced damage during a landing from a blown MLG tire. The airplane was exposed to a significant amount of rainfall apprx. 12 hours before the airplane departed from a dry runway. As the airplane climbed to high altitude in sub-freezing conditions, moisture in one of the brakes froze causing the wheel to lock on landing.          FAA reminds maintenance personnel to protect wheels and brakes from direct washing spray and inform flight crews if aircraft or landing gears were washed recently...