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Astra / Westwind Spring 2001
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Weather Radar Tilt Management
- Jim Wheaton
Storm season is upon us! The technology of radar is a great tool to avoid damaging weather, but it is important to remember its limitations. Radar registers only “wet” objects such as rain, wet hail and wet snow. This excludes “dry” hail, ice crystals and dry snow which are most common at high altitudes. Recently, Duncan Aviation technicians have repaired several aircraft which were flown into damaging “dry” precipitation which was invisible to properly functioning radar systems and alert pilots.
To minimize this possibility, it is imperative that flight crews train, practice and master the use of their radar’s manual tilt function. Some pilots rely on the auto-tilt feature to track cells, but this feature is designed to compensate for aircraft altitude changes only. Instead, the flight crew should manually adjust tilt as the aircraft moves in relation to the storm cell and focus on the most reflective precipitation which is found in the bottom 2/3 of storm cells. Proper tilt management allows radar to see precipitation at lower altitudes and alert the crew to the potential of damaging precipitation at higher altitudes. According to multiple manufacturers’ technical reps, poor tilt management is the leading cause of radar performance complaints.
Ferry Permits
- Dick Hyde
A ferry permit is required to move a damaged aircraft from an accident site to a maintenance facility. A U.S. ferry permit is valid only from a U.S. border to a stated maintenance facility in the U.S. and may be acquired through the FAA at no cost. If a movement is required from outside of the U.S., an agent will need to contact an FBO within that country to secure the permits that will be needed in order for the airplane to leave. Flight permits are required from the country the airplane is departing from as well as each country that the airplane will fly over before entering the U.S. Depending upon the FAA and the temporary repairs needed, permits are usually granted within 2-3 days.
Technical Tool Tip
- Nick Tykoski & Dave Balling
Hi-lock fasteners are used throughout airframes as high strength fasteners. Some fastener locations make it difficult to get tools in position to properly install fasteners. Snap-On Tool offers a modified ratchet that can install the fasteners. The mod removes the locking ball (for socket retention) and drills a hole through the square drive so that an Allen wretch can be used to hold the fastener while the collar is installed. This creates the problem of having the socket fall off the ratchet when maneuvering the tool to the location of the hi-lock. The solution is to drill and tap your socket for a set screw. This will secure the socket to the square drive of the ratchet.
New Astra Service Bulletin
- Tim Garity
Recently released Astra Alert SB 1125-28A-230 pertains to wiring with Kapton insulation, which is used in the fuel tanks. Kapton insulation has a tendency to crack with age, possibly exposing the bare wire to the fuel. This SB replaces the wiring harnesses for the transfer, jettison and the interconnect valves. It is considered a mandatory SB and should be complied with within the next 150 hours.
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