Old Koreelah

...Jabiru have always stressed not to overprop the engines. It's a bit like getting into top gear too early and making the engine LUG excessively....

I asked a highly-respected LAME how all the engines he maintains never seemed to suffer thru bolt problems. He was careful to avoid loading the prop, because that could lead to detonation, a very effective way of demolishing light engines.

... the main thing was that the engine stopped because the plug leads tore out , just before the whole engine was lost from the plane.

Losing your engine would sure put the C of G behind the aft limit huh...

Good point, Bruce. I've read of Rotax engines vibrating so badly on losing a prop blade that carbies are ripped out of their rubber mounts, thus stopping the engine before it removes itself from the airframe.

So unclamped carbies may be a clever design feature.

My early hydraulic-tappet 2200 is going well after a dozen years. It runs well with good leak-downs and fairly even temperature spread on heads and exhaust gas. Mine is fed AvGas and I don't mind paying the extra to know it's getting clean fuel. It starts easily and purrs away for hours without a worry.

I love this engine because it's simple and has the best power to weigh ratio available in that class.

Without Jabiru engines, lots of us could not afford to fly.

...An instructor of mine told me the story of him getting in a cub one day and finding a washer on the floor. The pilot said, "ah it doesn't look important, ignore it", so they did until at 3,000 feet enroute, the rudder cable disconnected from the pedals. They had a very interesting landing some of which was on an airstrip.

Hence my paranoia.

I understand your concerns, myshed2; how old is your aircraft?

The only new car I ever bought had a slight bulge under the carpet. After removing seats and the carpet, I found a small plastic frame, presumably discarded when some worker installed a component.

Could your strange item have a similar origin?

Victor 1 is a great trip, especially if you’re flying some one else’s aeroplane.

Air Avionics ATD-57 AIR Traffic Display is a relatively cheap collision avoidance system. Ping is another.

This needs its own thread, where tech numpties like me can ask dumb questions.

My BRS is activated by pulling on a handle (12kg pull, from memory). This cable activates a pair of strikers onto primers similar to shotgun cartridges. One yank is all you get; at least one of the strikers should fire the rocket, which burns rubber disks.

Rescuers should simply cut the cable; replacing the safety pin may not be enough if structural damage has allowed tension to be put on the cable.

I think that what Turbo is saying is that if you just follow the magenta line...

I once did that for twenty minutes until I noticed the country below didn't match my expected location.

I had confused my track with a nearby restricted airspace boundary and had followed the red line instead!

Marty your mate's technique is pretty much what I did to build my wheel spats and cowls for two different engines.

I achieved a pleasing shape and greatly enjoyed the shaping process. Bypassing the whole plug-mould thing also made it fairly easy for me to make several modifications to my cowl since I first built it

After building mounting points with dzuss fasteners I covered the whole engine area with glad wrap, then built up the cowl with "planks" of 10mm Klegecell PVC rigid foam, glued together with epoxy. After achieving the approx. shape, it's easy to rasp it into a streamlined shape. I made up a long wooden shaping tool on which to mount one-metre strips of sandpaper. A few layers of fibreglass cloth each side gave me a good strong result.

What I learned:

A reasonable finish requires lots of work at night with a strong light to show up imperfections. There are some very light fillers available.

Mine is rigid and quickly-removable because it has few mounting points, but weighs more than one with lots of attachement points.

As your mate says, you can mould piano hinge into the joins. I had to form air-tight overlaps to all joints to stop pressure leaks.

I used some vinyl-esters resin in the areas above the engine where, after shut-down, it gets cooked.

Possible fixes:

-fitting a distinct strake forward of the fin;

-extending the rudder so a small part if it is below the tailplane.

I note that the F4U had a similar design, but the rudder was huge and not slanted back, ensuring it caught plenty of air during a spin:

Do you regard the Piper Cherokee as an unsafe aircraft Old Koreelah? Rudder configuration looks very similar to the Bristell to me.

Good point, Bristell; they sure look similar, but as M61 points out, a subtle variation might be very important.

I've done some experimenting with my own rudder and found what a difference a small change makes.

... the rudder extends all the way down past the stab.

That little bit of rudder below the elevator might save a life.

Have look at 3-D pix of various aircraft and notice where the tail fin and horizontal stabiliser are mounted.

The safest designs have the rudder well behind the horizontal stab, or at least projecting down below the tailplane.

If the aircraft enters an incipient spin the rudder needs to be in "clean" air to counteract the rotation..

Some aircraft are in trouble here, because the rudder is in the "shade" of the tailplane.

Marty your itinerary is now set: i hope the rest of your family are as enthusiastic about planes...

That would be ominous for civilization, OT.

We have a developing crisis with antibiotic-resistant super-bugs, as pharmaceutical companies spend less on developing new antibiotics, preferring to maximise profits by pushing up prices for existing drugs.

Given the forces currently affecting global trade, the economic forces driving innovation may be easing off. It's conceivable that we might be entering an era of technological stagnation which would require some painful adjustments.

Many people believe this is as good as it gets. I hope it isn't.

Flight will have no significant change in what we have today in our lifetime or even the next few generations...

Sounds like a lot of brave, but famously wrong predictions.

In the late 19th century it was predicted that the US Patent Office would soon have to close down, because all the inventions had already been made.

IBM thought there was a world market for a dozen or so computers.

Bob Menzies couldn't see any future in computers (Australia built the world's fourth mainframe whle he was PM- it's still intact and now the world's oldest). Menzies couldn't see any future in space even through Australia was a pioneer...

The next quantum leap in aviation efficiency will happen when we develop man-made, larger versions of wing feathers, individually controlled by flight computers.

... and down much of the east coast, possibly inland -

Marty you are very welcome in Quirindi; just keep an eye on the Events calendar and you might align you trip with local get-togethers.

I don't believe any pilot has been taught "you mustn't exceed 30 deg"...

Turbs you are probably right, but what matters is which aspects of the training "stick".

Not every instructor has the gift of prefect communication.

I know one new pilot who concentrated on doing nice square turns in the circuit, because that's what he thought was most important. Other aspects seemed to be secondary, such as airspeed, attitude, bank angle, altitude, angle to aiming point...

The Matilda is tiny; the one preserved in a park in Singleton looks like it couldn't fit anyone inside, let alone a crew of four.

...This seems to be the "marketer's disease" that more features need to be added with each release to keep sales going... "feature-itis...

I used AppleWorks for years. This integrated suit of programs allowed me to share data between the Word Processor, Spreadsheet, Database, Paint, Draw and communication layers. This simple to use and totally integrated package did everything I needed to do and came on -wait for it- two floppy discs. I miss its simplicity and reliability, but Apple has killed it off.

But how in hades do you get into and out of one?

...the X-Air standard... are they standing up to the test of time?

 

...also including the Jabiru 2200 (eek).

Craig thousands of us are happy with our Jab 2200...

One of our club members has an X-Air and flies it more than the other aircraft he owns.

Back to aeroplanes:

https://www.bbc.com/future/article/20200211-the-electric-plane-leading-a-revolution

...if you were landing at a property airstrip and you made contact by radio to someone at that airstrip that could give you a barometric pressure reading...

Jack if your flight planning was up to scratch, I'd expect you'd know the elevation of the strip you're going to land on, plus the height of nearby terrains and towers, etc.