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jcamp

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Posts posted by jcamp

  1. Just bear in mind that the testing at the link above was done a few years ago now (2005) when the concept of the digital 406Mhz beacon was newish and real EPIRBS were thin on the ground. Its like comparing the first DVD player to market with one that has come a number of years latter. On the GME website they talk about some of the problems the early 406 Beacons had with excessive battery usage due to a crystal oscillator temp controlled oven etc. Andy

    406 not a problem. The problems revolve around the short term stability of the oscillator (jitter) which is one of the reasons for improved resolution (in non GPS mode) which can be a bit awkward especially for handheld units. There have been some changes in the specs and in 2002/3 the GPS requirements related only to the codes transmitted and EMC, nothing to do with the GPS performance problems shown in the 2005 tests.

     

    Things were going on then, when we looked at it AusSar had some very optimistic stories about how quickly sub $500 units would be available. Rumour has it the French for some reason held up cheap chipsets for some years.

     

     

  2. I am looking to get a second one as I go to some fairly remote areas and have more trips planned. The choice for pocket size units is somewhat wider than a year ago with the GME unit available and the KTI unit apparently close. It seems to me that the type should be looked at fairly critically as there appears to be some variation in performance.

     

    http://www.equipped.com/406_beacon_test_summary.htm

     

    http://www.equipped.com/406_beacon_test2_toc.htm

     

    Is it wothwhile considering some form of testing?

     

     

  3. Mine is fully painted and I don't want to bend the trim tab, thinking its aluminium only to find its fibreglass and doesn't want to bend.

    Maybe find a very ancient LAME. IIRC when Pontius was a Pilot they used to stick cord to the one side of the trailing edge with the length determining the effect. Of course they didn't know much about flutter then and 120kts wasn't possible.

     

     

  4. Where should the sensor go in a Bing Carby? Does anything sticking out between the slide and the butterfly cause problems.

     

    Given the temperature, vibration and electromagnetic environment in the engine bay, cheap domestic grade electronics may be problematic.

     

     

  5. The way to get that sort of information is by measuring the distance an electron beam misses a target, when you accelerate the whole contraption at right angles to the beam, is that the idea?.

    The accelerometers are (somehat simplified) basically a weight on a beam with the deflection being measured by a strain guage. The whole thing is etched from silicon using the same process as is used for IC's (often the same piece as used for associated temperature measurement and signal processing) and they are packaged as IC's

     

    The gyros have tuning forks rather than spinning wheels and are made the same way

     

    All this stuff is widely used in cars hence are quite cheap - Putting a system together can be a bit tricky. For more info:

     

    http://www.analog.com/en/cat/0,2878,764,00.html

     

     

  6. 100 mile out of Birdsville the GPS shut down (remote aerial being dodgy we were using the normal one with the GPS bluetacked on the dash and it overheated)

     

    No real problem, known position, wind etc nailed down, topo generally like WAC (assume rain has made details being mainly lakes less reliable) 4 hrs daylight 6 hrs fuel so:

     

    1 - Revert to normal compass card (bit different with GPS next to compass)

     

    2 - Turn right 10 degrees to intercept the Diamentina upstream of BDV (always consider line features)

     

    3 - Pull out hand held GPS

     

    4 - Update plans C D & E

     

    ALWAYS have options

     

     

  7. Think that RAA is treading a fine line here:

     

    Kits and plans are for a/c that claim to meet the requirements for RAA rego re weight, stall etc.

     

    Kits are approved as meeting the 51% rule

     

    I don't think they are approved as such (in the form of a psuedo certification) - remember these are EXPERIMENTAL aircraft.

     

     

  8. My wife is having problems with the rudder pedals being too high for comfort in a J160C. Obvious solutions are:

     

    Some type of downward extension bolted (or clamped) to the bar - requires Reg 35 approval.

     

    Some sort of heel extension for her shoes

     

    A pad fixed to the floor which could be removed when she is not flying it - awkward and probably still needs reg 35.

     

    Has anyone had this problem and what was the solution?

     

    A related query - I was trying to find the min design strength for rudder pedals for VLA ie how hard can you stomp on them. I have seen figures for IIRC FAR23 but can't seem to find them - any clues?

     

     

  9. my main piority would be storage room. i want to be able to transport my model helicopters with me.... and as far as the j160 goes i dont think it has alot of room. the streach has a fair bit though but now the dollars start to play a big roll...

    please help

    The issue with a J160 is not weight but balance. There is a lot of space back there and where is important.

     

     

  10. I, and a number of of others I spoke to, had issues with the invstigation and conclusions.

     

    Loss of control leads to a spin or spiral dive (the two stable states for an a/c). In either case impact is at a high angle with reasonably concentrated wreckage unless there is an inflight breakup.

     

    This crash indicated low angle of impact with a slight bank which is a lot more indicative of CFIT with possibly a last second visual attempt to avoid rising terrain. From the presentation this was not addressed and mixed VFR/IFR is a guarantee of trouble even for experienced instrument pilots.

     

    The one I attended covered the asking for assistance but not "If the area frequency is busy, then they will ask you to change frequencies " which would not be helpful for someone sweating blood to maintain control.

     

    The most serious "hole in swiss cheese" lesson was brushed under the carpet. The radically revised area forecast was issued 8 minutes before the departure call and the pilot was critised for not obtaining it. The fact is that 8 minutes is within the time frame for walking to the a/c, inspection and loading and other a/c were presumably in a similar situation working with the previous forecast. While no pilot should consider a forecast as anything more than a horoscope with numbers these sort of changes should be notified via area frequency.

     

     

  11. my prefered insturent cluster would be Compass ,ASI, ALT, AH, DG, VSI,

    For a lower cost/weight setup why not look at a Dynon EFIS with all of that and a separate compass and ASI as backup.

     

    Have been fairly impressed with the mapping GPS to do things like crossing ranges by wandering from field to field while still maintaining some semblance to following the desired track

     

     

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