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AUCKLAND REGIONAL MICROLIGHT AERO CLUB. (ARMAC)

SAFETY OFFICER'S CORNER

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Carb icing. Two main kinds, one where components in the fuel freeze and chemically change the fuel, and or block parts like jets in the carburettor. Not common now as technology has been able to solve most of these problems. (Yeah right!.. we hope!) The common one is where the carb simply gets so cold it ices up disrupting air and fuel flow. This can cause rough running , loss of power and complete stoppage. Moisture has to be present before it will form, unfortunately in most of N.Z. it nearly always is. The next ingredient is the temperature. Usually an air temperature of around 8 degrees C around the carburettor is the danger temperature but this various from engine to engine. The carb itself acts like a refrigerator, the air going through the venturi gradually cooling the whole assemby down so that the 8 deg surrounding the carb is cooled until it freezes. Not many microlights have carb heat, and some aircraft have good ice free records. Some manufactures state their model doesn't need it due to the proximity of the carbs to the exhaust. For around $30.00 a dual temp gauge is available from Dick Smiths. The "outside" probe can be fastened to the aircleaner to give the air temp in the vicinity of the carbs. The "inside" probe is in the indicator so this can be used to see if you are comfortable or not just in case your shiver mechanism isn't working. You will probably find that on takeoff with an inside reading of say 15, the carb reading could conceivably be around 30. During cruise they will get closer. Be aware that 8 deg is an area to avoid. Once down to say 4, likelyhood of ice forming drops again. What can you do if it reaches 8. Descent to warmer air may do the trick. Slowing down and getting into a higher drag configuration with more power might raise the temp around the carb as well. Also consider landing, switching off for a while and resuming flight in half an hour. If none of these options seem palatable then hone your skills at finding good paddocks and make a mental note to fit carb heat.

A new link is available on the Contact & Links page that gives amazing detail and gen on facets of flying instruction that most books don't mention. Look for "the instructor guide instructor instructors use". This USA publication is written by John Denker. After over 40 years of flying and most of it instructing, I didn't know there was so much I didn't know!

 Engine Failure. Don't forget to regularly include a full glide approach to keep your hand in just in case. And occasionally go up and go through the whole drill. Professional Pilots do this every 3 months and they do heaps of hours compared to us. Remember though that most microlights have geared engines and this can have quite an impact on the "closed throttle" training scenario compared with the "real thing". When the geared engine quits it will generally stop completely, whereas the old Lycoming will continue to windmill and a closed throttle will be fairly representative. With the prop stopped the drag will reduce and you are going to go further. By how much depends on how many blades you have and of course, on the aircraft. In my own ZenairCH701, the difference is remarkable, a far better glide, elevator authority to much lower speeds, and quieter as well! A good trick would be to go out with your instructor to a good long beach where it won't matter if you muck it up a bit, and have a go. Try and record some figures so you can work out a throttle setting that equates to the stopped prop drag so that you can later on practice without having to shut down the engine. 

Strip Flying  Following an accident on a strip last year where the pilot gave a full and frank report to the Club and to C.A.A. it is timely to remind pilot's to review procedures. Whilst we operate in and out of short strips all of the time, strip flying is specialised.  The C.F.I. has reviewed techniques at a subsequent Club meeting and given us good gen in the time available. Strips often mean downwind take offs and or landings, uphill or down hill take offs, horizontal disorientation due to sloping ground, turbulence, down draughts on short final and rotors. An uphill take off into wind requires an intimate knowledge of your machine's performance at that weight, density altitude and head wind. Many aircraft can't cope at all. Also an uphill into wind take off has an automatic built-in downdraught! Sloping strips are usually short and often have no overshoot escape route or ground overun area. Approaching from the air, make your first run "down slope". The slope is easier to ascertain and performance and overshoot path are preserved. Be aware that on final, the high level of concentration means the scene is set to overlook some other trap lying in wait. This is not meant to scare you off the very thing that microlights are best at. It serves as a reminder that there are a large number of variables and there is no substitute for making your first operation in and out of an unfamiliar strip with someone who is qualified and current with that strip.

Hypothermia. 

• This is subtle and deadly. Open cockpit aircraft provide the ideal environment. It doesn't even have to be a cold day. To explain it as briefly as possible, the brain alerts defence mechanisms as soon as it realises systems are at risk. Skin puckers and thickens to provide insulation. Shivering starts as a warning. Blood flow is diverted from non essential services and system shut down begins. You feel cold and miserable. This is the good part. Now for the bad. Once body temperature drops only just a few degrees the brain realises that doom is inevitable and decides to make your last minutes on earth, (or above it), as comfortable as possible. Shivering stops and blood is readmitted to the shutdown services. A feeling of well being and drowsiness is experienced. Rational judgement is quickly lost and worse, you couldn't care less. It's all down hill from here and death is not now too far away. What can we learn from this? Dress appropriately and remember that a huge percentage of heat loss occurs from the head. Consider keeping a balaclava on board as part of your survival equipment. A foil space blanket is good, weighs nothing and is compact. Getting wet is a a gold embossed invitation to hypothermia. A thin plastic sheet can keep you dry.
  
  
  LIFE JACKETS & CELL PHONES
  
• Did you know a recent investigation of a shipping disaster revealed that a huge number of people drowned because they were not wearing life jackets. But here is the rub, .... not because they didn't have them, but because they could not put them on! And why not? Because either they didn't know how or , and this applies to us, they are nearly impossible to put on once they were in the water. Consider this, every flight from Pikes Point is over water. What can we learn? Make putting your lifejacket on a standard preflite procedure. 
• Recent news, Sept 01, windsurfer rescued by cell phone off the coast of England by a call made to his dad who was in Switzerland. Now we usually carry cell phones but how good would they be if we ditched? Well a lot better if we could keep them dry! Consider zipping them up  in a grip lock bag. Leave a bit of air inside for bouyancy.

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