We need the focus to be on: Principal Airworthiness Inspectors (PAIs), and Principal Operations Inspectors (POIs), in consultation with Chief/Director of Flight Standards and Airworthiness (and Director General of the aviation authority) as they administer an operators MEL (minimum equipment list). They have created bogus MELs, and allowed the center wing fuel tank to be loaded with trimethylaluminum for spraying operations. The pilots are unaware of the trimethylaluminum (TMA) loaded (in the center wing tank), they just know they cannot use fuel from the center wing tank (faked bad valve), and that the issue will be dealt with by (M) - a maintenance procedure and within a specified time frame. The aircraft is certified to dispatch because it is still very safe to fly without the center wing tank operational. The pilots are rostered to fly without fuel in center wing tank in such a way that no one flies with that permitted FAKED defect more than once a month - dissipating suspicion. The trimethylaluminum is injected into the hot exhaust - remotely controlled, causing aluminum oxide to be one of the reactions with heat. Visually, the spray pipes are small but they have high capacity pumps inside the pylon (inside the white access panel on the pylon) which forces out large quantities of CHEMICAL material in a small amount of time if required. Energy is diverted from the exhaust gas stream to power these pumps…. they are simple, foolproof, operate continuously when the engine is running and require no flight deck control. Going with this system means that flexibility is maintained. Using TMA (trimethyl aluminum) for longer range flights, loading can be done using the second hose. Lines carrying TMA and their access points, are part of just about all airports. Located only at the left hand wing, to keep the operation as simple as possible, they are pressurised to reduce the chance of air getting into them with the inevitable results. In the case of non TMA flights, the second hose is just there for show and is not being actually used. OTHER METHODS OF ALUMINUM OXIDE INJECTION: But in the case of aluminium oxide, the weight and bulk of the material means that this method cannot be used. Loading aluminium is done by the modified ULD (unit load device) container method. Even this method however has its safety considerations which must be followed. Cargo loading is critical and must take into account the weight and balance restrictions that all aircraft have. Real problems can be caused by mis-loading as the aluminium oxide slurry is very heavy. Every flight, even non spraying flights, must have containers loaded in correct sequences to avoid balance errors. The aluminum oxide is in a mixed slurry with methanol (for dispersion) – known by the flight managers of all of this as “METH” (sick – huh?) - in these ULD containers, with specialists making quick connections. The method used depends on the size of craft and its duty cycle, and the weight of this material and luggage and passengers are part of the overall total ZERO FUEL WEIGHT of the craft, so there are no weight issues because they make sure the weight on take off (minus fuel weight) is below the maximum ZERO FUEL WEIGHT. The pilot has no way to verify what’s on the plane. ALL visibly involved KNOW NOTHING, they just do their job not seeing anything weird. Duty load dispatchers aren’t required to know what is in the containers, just what each one weighs in order to get the sequence correct. ULDs that are modified for spray purposes are always loaded first at either cargo door. Loading them this way is essential because they have pipe arrangements which hook into the onboard spray system, and the heaviest containers must go as close as possible to the Center of Gravity. One can see that CPT 2 and 3 (for a 737) have the heaviest allowable weights, 20 and 15 tonnes respectively which is fortunate because they are the areas that must be used by the modified ULD containers. ULD use is ubiquitous and the modified ones can be found at holding areas at airports around the world if one knows what one is looking for. Suffice to say, if you are looking for evidence about how ULDs can be modified, check out “envirotainer” and imagine how simple it would be to do the required modifications. CPT 2 and 3 are in front and back of center of gravity of the aircraft – for weight and balance issues.. Using the ADSB system (Automatic dependent surveillance-broadcast (ADS-B) is a surveillance technology for tracking aircraft as part of the Next Generation Air Transportation System) , the inflight position of the aircraft is always known by spray controllers. New ATC procedures mean that the position of spray aircraft are always broadcast to satellite receivers that sites such as FlightRadar24 do not have access to. Spraying, even over oceans, can therefore be targeted very accurately and efficiently.
Posted on: Wed, 31 Dec 2014 15:44:35 +0000
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