Dieselten

The "Pasha Bulker" will likely be there for a very long time if they don't get it off the beach soon. Usually a beached or grounded bulk-carrier will start to crack at the point between the forward engine-room bulkhead and the rear bulkhead of the aftmost hatch. Engine-rooms are heavy, empty hatches are not, and water-ballast is held in the ballast-tanks to even out these stresses and prevent local stress concentrations devloping. The hull is taking huge hits from rollers at the stern, and the cumulative stress will start to fatigue the steel until it undergoes brittle fracture. Hard aground as she is, the hull is unable to move in response to the impacts, so the steel itself must absorb the impact energy. The water-ballast is actually holding her on the sand, exacerbating the situation. This ship is in extremely serious trouble. She has to have a certain amount of ballast in her to remain upright if and when they try to re-float her, so they can't pump all the water-ballast, fuel, lube-oil and medium diesel (for the alternators) out to lighten her. Then there is the suction of the hull firmly embedded in the sand to be overcome. A king-tide and some good strong salvage tugs might work, but time and the weather is not on the side of the salvors. There is a very good likelihood it will begin to break up in situ and end up being scrapped where she lies, unless she is allowed to just corrode away as the "Sygna" has been doing since about 1975 on Stockton Beach. Anyone who wants to see her intact should fly there ASAP. If you prefer flying over wrecks, you may only have to wait a few weeks. The next problem is likely to be how to deal with three different types of oil coming ashore on Nobby's Beach.

Eight hours bottle to throttle! Don't buy an airplane before you do several hours flying training. Hsten slowly. There are a lot of recreational aircraft from which to choose. Also remember that the moment you acquire something, you automatically acquire the problem of how to get rid of it when you no longer want - or need - it.

I only caught the last part of the last episode, and was dismayed (but perhaps not all that disappointed) to hear the "Douglas 727" referred to on a couple of occasions. Such a simple, boneheaded mistake in basic journalism bespeaks a program whose integrity and veracity must surely now be questionable. As to the interpretations of the factual basis of things like the 1989 pilots strike, one can only wonder what left-wing spin the writers have placed in their script, given they can't even get the manufacturer of one of the world's greatest first-generation tri-jets correct. On that basis I will not be buying the series when it (inevitably) becomes available on DVD. "Never let the facts get in the way of a good story" is the journalist's credo. I vividly recall telling one high-priced Channel Nine female journo I was overqualified for journalism. When she asked why I simply replied "because I can read and write!"

A strobe unit consists of an inverter to turn DC into AC, a voltage-multiplier circuit to raise the AC to about 400 volts, a dump-capacitor (high-voltage electrolytic type usually) to store the high-voltage, and an oscillator circuit to regularly fire a small pulse into the trigger transformer. The dump-capacitor is connected directly across the Xenon tube, but until the gas inside it is ionised, no current will flow, and it takes a good deal more than 400V to ionise Xenon. Our stored charge of 400 volts waits patiently... Enter the trigger-transformer and a third electrode, either a wire wound around the tube in a spiral, or a plated-on electrode on the outside of the tube. When the oscillatopr fires a short-duration pulse into the trigger-transformer, the transformer sends out an equally short pulse of several KV into the electrode - enough to ionise the Xenon. Now the stored charge in the dump-capacitor flows through the strobe tube itself, holding the ionised gas (Plasma, the fourth state of matter) in this state for perhaps a millisecond, possibly much less. The ionised gas emits an enormous amount of light as electrons which have been raised to higher "orbitals" fall back to their natural state in the lower "orbitals", emitting photons as they shed their extra acquired energy. This is the intense flash of light we see. As you can see, strobes are not ridiculously simple and there is a fair bit of electronics inside each unit, as well as a potentially dangerous high-voltage in the inverter/voltage multiplier section. Fault-finding is best left to qualified technicians. One test you can do is to listen closely to the strobe control unit and see if you can hear a faint whining sound...that's the sound of the inverter powering up and charging up the high-voltage section. If there is no whine, then chances are the inverter is stuffed...again a job for a technician as inverters use positive feedback to go into oscillation. Another check is examine the unit closely for broken wires or components that have become loosened from the printed circuit board. I built some strobes for a microlight and spent hours re-soldering cracked joints due to vibration. I had to literally glue several components down with Silastic to solve this problem. Unless you are electronically-qualified or savvy, I'd suggest getting a professional electronics tech to examine the unit.

I second the recommendation to use the crimp-on BNC connectors. I have put literally hundred of these on both 50-Ohm radio cable and 75-Ohm TV cable. The screw-on variety are a PITA and will let you down with poor performance almost from day one. Typically people pull them off the end of the cable and just push them right back on again and expect them to work. They do - sort of - due largely to capacitive coupling, but they are very poor compared to crimp-on BNCs. The centre-pins are especially prone to coming adrift. The BNC is a very good connector with a wide frequency range and substantially constant impedance throughout these frequencies. Using a cheap one to save a few cents is false economy. Using a decent one saves all sorts of radio problems, especially poor receive performance (on receive, microvolts are induced at the antenna terminal, and any deficiency in the connector will manifest itself as noisy reception or no reception at all.) Practically anything will transmit (over a limited range), even a 50-Ohm resistor (such a device is called an "artifical antenna" or a "dummy-load"), but receive is where you really learn how good your installation, cable and antenna system are. Use crimp-on BNCs and get a competent person to install them. Take the screw-in ones and throw them into the nearest lake, ocean or bottomless pit. Incidentally, the BNC stands for Bayonet Neil Concelman, and not British Naval Connector, as is popularly believed. A variation of the BNC is the TNC, where the outer section of the male connector (the one with the pin in the centre) has a screw-thread rather than a bayonet fitting. Some handheld radios use TNC (GME ELEctrophone UHF handhelds for example,) but they are not commonly encountered in aviation VHF units. Also, for best radio transmision and reception, make sure the antenna is resonant and mounted as high on the aircraft as possible, with a decent ground-plane if at all possible, and impedance matched to the output inmpedance of the transmitter (nominally 50-Ohms). A slight impedance mismatch is acceptable because we are not continuous duty-cycle radio transmitters. Use high-quality coaxial cable (preferably with a MIL-spec number on it) and eschew cables with no brand or identifiication at all...they are cheap junk. As a rule, the more braid the cable has the higher the quality. If your radio receives poorly, suspect bad connectors before just about anything else. Chances are you'll be correct.

I've had the Mizer fuel-flow meter on the microlight for several years and it has been a very good unit. Needs to be cailbrated for the fuel you are using, but once set it is quite reliable. Shows quantity remaining, total used for trip, total used since last reset, has a low-level alarm threshhold that can be customised by the user and shows flow as well. Can be set for US gallons, Imperial gallons or Litres but not pounds or Kg. Is approved for 95-32 aircraft but the installation must be done/signed off by a Level 2.

Seems like I was in error saying Comunica gear no longer available, the URL is:- http://www.comunica-aviation.co.uk apparently their technician took over the working of the company and they are still making gear, several PDF files to download for catalogues, datasheets etc.

The link to Sydney Microlight Centre is outdated, the new URL is:- www.sydneymicrolightcentre.com Comunica intercoms no longer available as the people operating the company in the UK have retired and no-one took it over. Lynx intercoms seem OK (work a little different to Comunica) and interface with either Microair or Xcom radios. Comunica were "hot-mic" units (which I infinitely prefer). In my experience VOX intercoms are mostly a PITA. FWIW, the Xcom radio seems better ergonomically than the Microair. Both approximately the same size physically. Microair seem prone to ignition/alternator noise. My main beef with Lynx is their headsets weigh rather a lot compared to the Comunica/Peltor I am currently using. I believe they have a battery inside the headset, whereas Peltor are powered by the intercom itself. The latest Icom radios are not 12V units but are 7.2V units to make them physically smaller - problem is they lack enough audio drive to operate some intercoms properly. Icom seem determined to keep changing their handheld aviation-band radios regularly with different headset and mic impedances...another PITA for those building/designing intercoms etc. Smaller is not necessarily better, but the Japanese manufacturers will doggedly design radios small enough to operate on a mere 3V and to hell with anyone trying to design or build an intercom to use with the units. The manufacturer is dictating to the consumer what the consumer will buy. That's Japanese corporate thinking and marketing for you. The best Icom radios for intercoms are the A20 and A22, so if you find them on offer, consider buying so they work with some of the more commonly available trike intercoms. Actually, the issue of radio/intercom units for trikes is becoming a rather vexed question. Lynx/Mircoair or Lynx/Xcom? If only Lynx could design and build a light headset, they'd be on awinner. I sometimes do 5 hours flying in a trike a day, and if the helmet and headset is getting heavy after 3 hours, after 5 hours it is a burden I really don't need.

Hi all, just arrived, looks like an interesting BBS. Fly at YWOL.

Here is the gen (I own one of the trikes in that hangar):- Airborne Edge-XT - base totally destroyed Pegasus Quantum - base totally destroyed Edge-X 582 base - severe fire damage Edge-X 582 base - moderate fire damage Edge-X 582 base - moderate fire damage Edge-X 503 base - slight damage Streak Mk1 wing - written off Wizard Mk1 wing - written off Jabiru SP470 - probable write-off, both wings u/s, fuselage heat-affected Grumman Cougar - paint smoke and soot-damaged Super Ximango motorglider - slight smoke damage Globe Swift - minor smoke damage hangar roof - Alsynite burnt out, structural members distorted, roof cladding warped. The T-handle that locks the mast on the Edge-XT was not, repeat NOT, the cause of the fire. There are no suspicious circumstances. The definitive cause will probably be determined by forensic investigator and possible coronial enquiry. Investigations are ongoing. Sydney Microlight Centre are back training again with one machine (Edge-X, Mk2 Wizard).