MikiMouse carb diganosis on the wing

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Hobot

Hobot

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Wes and I tend to do off the cuff engine exam-diagnosis on the fly. Feel for loose bowls, coil terminals shocking shorts rubbed raw HT leads. etc. Makes me flash back to early aircraft with engineers creeping out on wing to service some more again. Saw Wes today and told him his 71 sounds nice and even firing authoritative passing my office on his way home, then he said it had given him fits just prior, hard to start, coughing surging then while leaning a turn - down his steeple chase paved section it died so whipped out his Leatherman tool and rapped the TM34 carb and it lit back up fine, hmmm problem located. Pulled carb to find a wasp got up the over flow tube then body block main flow and pieces got into other passages. Should stuff a bit of fiber in for future protection. Hey a bunch of modern cars got recalled because the gas tank vent hose allows spiders to get in an clog system, so many times its 100s of reports.

Oh yeah his clothes pin brake switch broke so Wes bought a new inline switch that didnt last a ride or two so put the worn out original back in for functional brake light at cost of less effective whoa effort. Commando means never ending on going ever loving worshiping rituals.
 
Those wasps can be a real menace. I know someone who was flying along in his aeroplane, and noticed the skin on one of the wings was collapsing.
Did a landing real pronto, lucky it was close by, and opening the fuel cap there was a huge rush of air in, and the skin popped back out. Found the fuel tank breather pipe had been blocked by a wasp, and as the fuel pump was pulling fuel out of the wing tank, the tank was crushing down.
Plane now sits with bungs and flags hanging all over it in wasp season, must be 10 of them or more.
A real wing story...
 
Bugs like mud dubbers filling blind bolt hole is a hassle here too. What got my attention with Wes taie was as he spoke it he mimiced his posture-action -> leaning over at least 45* one hand on bars the other swing out wide to grab the Leatherman swing good rap while watching out for hazzards in tight steeps. Wes was present last month after SuVee set up couple seasons got fixed to start and instantly fill garage with rotting meat BBQ smell-smoke of still juicy dead mouse. Shut off and had to get away, to smoke it outside. Some burnt hair blasted out on first few blips success - before stink sunk in.

Part of Commando mastery to me is learning to feel parts while seated, through gloved fingers, at night and avoid burns or knocking good connections loose.
 
It continues to puzzle me why people will crash good airplanes due to loss of a single or even multiple airspeed indications or even complete air data. If the power is set at a normal setting and the attitude is normal for the phase of flight then you're fine. Sort it out. Pitching the plane up to reduce an outrageous increase in speed not justified by the performance characteristics makes no sense. Yes, I have experienced mud wasps building nests in pitots in just a few hours and I've also had blocked pitots in flight, due to failed heating and ice in the days before the heat was monitored.

For those interested, a blocked pitot tube traps the current air pressure and results in an apparent increase in speed as one climbs sometimes causing pilots to reduce thrust or pitch up in an attempt to lower it. The proper response is to use another source or establish normal pitch and power settings. Nice for me now that the planes I'm now flying have 4 air data sources with comparators that will flag when any disagree. It wasn't always that EASy.

I now return the thread to wasps blocking motorcycle openings, rant over.
 
My mates Quad would conk out usually on the hill no one could bottom it a real puzzle. I found a sheep tick in the float valve. How it got past the fuel filter is anybody's guess.
 
last one here for me too< Air France Flight 447 was interesting, pilots can end up putting opposite inputs into the sidestick controls (one up, the other down) without knowing what the other is doing?! ... plane ends up averaging out the inputs
http://www.standard.co.uk/news/damn-it- ... 84212.html
Robert tries to take back the controls, and pushes forward on the stick, but the plane is in “dual input” mode, and so the system averages his inputs with those of Bonin, who continues to pull back.
Click to expand...

http://www.theguardian.com/world/2012/j ... ing-pilots
Central to this accident is the fact that when the automation failed, the pilots were presented with conflicting information which was obviously incorrect, said William Voss, president of the Flight Safety Foundation in Alexandria, Virginia. But they were unable to look through this and understand what the aircraft was actually doing. "Pilots a generation ago would have done that and understood what was going on, but [the AF447 pilots] were so conditioned to rely on the automation that they were unable to do this," he said. "This is a problem not just limited to Air France or Airbus, it's a problem we're seeing around the world because pilots are being conditioned to treat automated processed data as truth, and not compare it with the raw information that lies underneath."
Click to expand...

https://www.google.ca/search?q=air+fran ... s+accident


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JimNH said:
It continues to puzzle me why people will crash good airplanes due to loss of a single or even multiple airspeed indications or even complete air data. If the power is set at a normal setting and the attitude is normal for the phase of flight then you're fine. Sort it out. Pitching the plane up to reduce an outrageous increase in speed not justified by the performance characteristics makes no sense. Yes, I have experienced mud wasps building nests in pitots in just a few hours and I've also had blocked pitots in flight, due to failed heating and ice in the days before the heat was monitored.

For those interested, a blocked pitot tube traps the current air pressure and results in an apparent increase in speed as one climbs sometimes causing pilots to reduce thrust or pitch up in an attempt to lower it. The proper response is to use another source or establish normal pitch and power settings. Nice for me now that the planes I'm now flying have 4 air data sources with comparators that will flag when any disagree. It wasn't always that EASy.

I now return the thread to wasps blocking motorcycle openings, rant over.
Click to expand...
 
Jim, does not a blocked pitot tube give a frozen or reduced airspeed indication? Agreed, a blocked static vent would give the indications you say. Just remind me which airline you fly for? :)
 
gripper said:
Jim, does not a blocked pitot tube give a frozen or reduced airspeed indication? Agreed, a blocked static vent would give the indications you say. Just remind me which airline you fly for? :)
Click to expand...

A blocked pitot traps the pressure in that line. As the plane ascends the static pressure decreases therefore the differential across the airspeed indicator or air data computer see it as an increase in speed. If it becomes blocked at altitude, it would indicate an increase with any climb or a decrease in any descent. A blocked static does essentially the opposite and counters the impact pressure on the pitot giving a decreased speed in a climb or, if it becomes blocked at altitude, an increased speed in descent. Since the altimeter is connected to the static only, it gives a fixed reading of the pressure altitude where it became blocked.

Some pitot tubes have a moisture drain and those may give a zero indication when blocked as the ram air is blocked and the drain acts as a static port causing no differential pressure across the indicator. On those tubes, if I recall, the actual pitot tube is recessed inside the pitot head.
 
The plane I now fly, a Falcon 7X, has very similar side sticks and control laws for the fly-by-wire controls as Airbus uses. When one stick is moved the other does not. If both pilots attempt to use the sticks at the same time the sticks vibrate and a voice annunciation says "dual input". I don't know if Airbus has that voice or vibrates.

In any case the inputs are indeed summed. If both roll left the rate will be the sum of both inputs. If both put in opposite inputs they may sum to null. If one guy insists on pulling up when the correct input is nose down there's a priority button that gives exclusive control to the one who pushes it and will announce "priority right or priority left". Boeing fly by wire planes use conventional control columns and wheels so you can see what the other guy is doing.

Both Airbus and Dassault limit the pitch attitude. Airbus limits roll but Dassault does not. In any case a pitch or roll attitude beyond a fixed limit requires a continuous input while one below that limit will more or less stay there. For example the 7X will simply stay in a 35 degree bank with no more input - you can let go of the stick and it will pretty much stay there until it runs out of gas. If you want to bank a turn at 45 degrees it will stay if you hold it but will relax to 35 +/- if you let go. Boeing, I believe, does not limit pitch or roll. I don't know much else about their control laws. The last Boeings I had anything to do with are now called Jurassic jets.

As for the Air France guys:

At the beginning of my initial 7X training it was preached: You cannot stall or overstress this plane. Yes, well, true, when in normal laws and maybe in alternate laws. In direct laws the plane behaves like any other and can be stalled and over stressed. The Air France plane did fail down to a lower control law and they stalled it. If you read the whole report, one guy wanted to get on top of the clouds all along. When they lost all air data and the control laws failed down he responded with full back stick, probably to get on top as he wanted to all along. He stalled it and kept the stick back pretty much all the way to the water. Sadly, the air data systems recovered and if they did nothing but leave the power to normal cruise, let go of the sticks, and reset the flight controls we never would have heard of it. If he had never touched the stick, the same. I don't know if Airbus announces dual input but I'm pretty sure there's a priority button and the guy who wanted to get the nose down could have if he pressed it.

I'm not Monday morning quarterbacking, we all just filed that one away. Most times there's no hurry to do anything.
 
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