facthunter

Landing Thruster.

Tony,

If you are seriously into analysing all this relating to thrusters, may I suggest that you avail yourself of some of the material from Tony Hayes. TOSG Central on this forum. Nev...

Valve seats.

Jetboy, sorry for the delay in reply. I would imagine that the welltite is a later fitting hence the stamping on the head. I would have thought that wear of this seat is very unlikely as it is extremely hard, (I am unaware of anything readily available that is better). In all the discussion on this matter the valve seat recession phenomenon hasn't been specifically narrowed down.

Is it 1. valve seat wear? ( the actual valve itself)

2. Valve mushrooming. ( valve deforming, bending up at the edges due to softening when overheated).

3. Wearing/erosion of the insert.

4. Insert impacting into the aluminium head, due to inertia & spring forces.

All of these will be reflected in reduction of valve clearance in service, which will not be obvious with hydraulic lifters. N...

Spins/spirals/flicks.

Tony, what is the reference to an inclinometer? The understanding I have of that instrument is that it is a simple pendulous device that will give an approximation of pitch attitude in unaccellerated flight. The DH 82 had a glass tube with coloured fluid in it, in the shape of a triangle ,when viewed from the side. They must be refering to the SKID ball.The flick is a horizontal spin ( one way of looking at it . Nev

Ian , they build up a lot lighter than those figures, but you could build the thing to take a Warner Scarab if you wanted to. They are a very versatile aeroplane. One that I have been involved with, empty weights at about 315 Kgs with a 100 hp rotax fitted Structurally they are very adequate & they have a nice control feel in the air Regards ...Nev..

Spin- what is it .

Why are you up so late disperse? This subject has been on this forum at great length before. Rather than dig those posts out , I would suggest that you look up all the excellent training material on the RAAus. site ,as a first step, and we can take it from there if you have any further queries . I mean this in the kindest way, not as a put-off. Regards ..Nev..

HKS 700

If you go by the dyno figures,supplied with it, the engine produces about 58 horsepower. They apparently require rejetting from ''as supplied' frequently as they run lean and the EGT's are too high as a result. Fix this early! The engine runs over 11/1 compression ratio and should run on high octane fuel ONLY. Since the temps seem to be on the high side I don't know how you would control them with a supercharger ( presumably turbo) fitted. The engine is air/oil cooled,& it would be a bit hard to force extra air over the motor to get rid of the extra heat.. N...

valve seats.

Jetboy , welltite is a proprietary brand of valve seat, which I use always ( if that means anything), for best performance. Nev..

750 Kg. auw.

I'm all for this , as every time I've looked at design parameters, ( excluding super composites,, ie carbon fibre).

To carry two people.

Fuel 4.5 hours plus reserves.

A bit of overnight gear plus tie-downs etc.

Have a decent set of brakes & wheels.

Make the aeroplane reasonably strong.

big enough wing to stall slow without too many devices.

Empty weight comes out at about 360 Kgs.

Just add the payload above & it comes out at about 750 Kg.

The downside of this scene is not obvious to me. You maintain simplicity, strength, can use steel tube ,wood ,sheet metal, glass fibre, ( all very proven ,long life materials) can run a metal prop decent sized engine,,etc. There is no liability in any of this, in fact you can beef-up a little here & there, without everything going off-scale. You could easily make a case for increased safety, as a result of the increased strength. You still stick to 2 people, as passengers are where you really buy into liability. Nev

Wiser.

True wisdom and dangerous are mutually exclusive, and I'm sure you are not dangerous. Ian ,you still need a certain amount of self-confidence to be able to give that of which you are capable. What I am trying to say is , analyse, but don't be too hard on yourself, after all you still fly the Corby don't you?

There has to be a time for us old-timers to stop kidding ourselves, I suppose, but we're not there yet, are we? Tail wheels forever!!!

Dangerous stage. def. when the wheels come off!

They used to say at 100 hrs you were the most dangerous, as you were flying pretty well, at that point, and would tend to become overconfident, and perhaps do things that a more cautious pilot would decide not to attempt. This would be an 'attitude' problem, and often these people think they don't need to learn any more, that they are somewhat gifted (in their own estimation.) They self-limit their own knowledge,, often carrying odd quirks/ ideosynchrasies in technique through their flying life, as a consequence.

The first step to maintaining a high ( safe ) standard is recognising the need to. The 'right attitude' in this instance.

Just as a little comment at this point. The achieving of some "greasey" landings seems to be regarded as some sort of defining point. We alll like to do them, but a fair average quality (FAQ) CONTROLLED landing gets higher marks from me. With the emphasis on CONTROLLED. All interesting stuff .......

Nev..

Emergency landing.

I wonder if it would have been any more remarkable if he had been leaning 'chalantly' against his plane. N..

IAF _Drunken dynosaur.

Looked up my log book .It's so long since I flew a Drunken Dynosaur that I don't feel I am current on it & so can't give a valid comment. It may heve been modified as well.. N...

Estimating distances.

I think that we are all pretty much agreed on the straight -in approach only being used at the appropriate time, ie you have radio, you know the wind direction, and you won't just bore into the circuit, if it's full of traffic, and you have some familiarity with the aerodrome. This could be an extensive briefing, or personal experience. If you don't do a straight-in remember that others may (RPT, & charter) You should be aware of them because of their radio calls. The best way to adjust for traffic in the circuit is by extending the downwind leg. Speed adjustments are not very effective and jeopardise safety.

Regarding the 5 mile estimate, I think you are supposed to be aligned with the runway BY 5 miles. as to estimating that distance, I feel without DME or GPS you really only having an enlightened guess, unless you are familiar with a known feature on the ground. I'm not against the straight-in approach as it reduces the number of aircraft cluttering up the circuit. Hopefully everyone knows the rules and keeps a good lookout and listens on the radio. Throw glider operations on a contra-circuit, on an adlacent strip, in and you really have a workload. no time to be checking up on the ERSA as you enter the circuit. Keep ahead of your aircraft Nev..

Slowing up.

Yes, sorry Mike ,but you never know ,someone may take you literally. I have tried to give real simple formulas that enable you to have a fairly good idea of where the other traffic might be. I myself need simple formulas because I reckon my brain goes to about half speed when I get in an aeroplane. Perhaps it's like that all the time.

The exaggerated plateau ( level flight to reduce speed ) is needed because of the very restrictive flap extend speeds most of these aircraft have, and to which you have referred, even though it makes the approach untidy. Often the speed will not come back if a descent is maintained. Nev..

Straight-in approaches.

Ian's CT. should not be doing 1500' circuits as the 120 Kts. and above is the NORMAL DOWNWIND speed for the aircraft type.

Most RPT approaches are 3 degrees and the final descent point is usually 10 miles/ at just above 3000' AGL. This is just above 300'/mile. If you want a 5 degree slope ( more like what we would use) it becomes 500'/mile. 6 degrees becomes 600'/mile and so on.(this is a still air distance to maintain a constant angle approach the power will have to be increased in a headwind) Nobody so far has allowed for slowing down to extend flap/undercarriage or just to get back to the normal approach speed. This is best done by arriving at a fixed height ,below the final approach slope and holding that height to bleed off airspeed, reconfiguring the aircraft & judging the whole procedure in such a way that you intercept the one mile final on the slope that you planned for. This requires a fair bit of judgement to get it right, and you need to be familiar with your aircrafts performance. Nev...

Tragedy for sure.

Good advice Mazda. You have said it all well. You would have to feel for this young fellow, and wonder how the situation could arise where he was put into the situation he was. How many of your low hours students would handle this Ok? Very few ,I would suggest, & perhaps others as well. An aeroplane is not like a car, where you can pull over. Let NOTHING distract you from FLYING your aeroplane, for FLY it ,you must. Nev..

Mixing & swapping avgas..

The avgas will keep better , but evaporates readily, so keep the lids on drums sealed. I have used it for years for racing,though it's not used now, and I am unaware of any difficulties with mixing with other fuels,(petrol) in any ratio. With motorcycle engines, ( even 2-strokes) there has been no need for major tuning adjustments. The most noticeable effect of using avgas is that you don't have to use as much choke when starting. DO NOT PUT ANY OF IT IN YOUR CAR AS IT WILL KILL THE CATALYTIC CONVERTER. Nev...

Full throttle cruise at altitude.

In a normally aspirated engine the manifold pressure is controlled by the position of the throttle,(think of it as a restrictor) up to the point when it is as far open as possible, where the air pressure available at your altitude determines the manifold pressure. (ignoring ram effect)

At sea level you will get around 30" and provided your propellor allows the revs for max. power to be achieved and the air temp is appropriate, You should get the rated power of your engine.At altitude, unless you have a manifold pressure indication, you will have to go off the performance tables that should be in your Pilot's Operating Handbook. As a rough rule of thumb, you would be only be able to get about 75% power at full throttle above 4000' and this would be provided the revs remained the same as for max power.

Full throttle at cruise height is particularly desirable where you have a geared supercharger, as it's pretty wastefull to throttle the airflow off ,then compress it later to force it into the engine, Otherwise, it's a bit academic. Note that with a CV. Constant Vacuum carburettor, Full throttle only lifts the dashpot piston ALL the way up if

1 the engine is in good condition.

2 the carburettor is the right size for the engine.

3 you have standard sea level pressure or higher

4 the engine has achieved the correct rev figure.

The fact that the needle is attached to the dashpot piston & moves with it , and is responsive to altitude effects (as well as the other factors listed) is utilised to achieve some measure of automatic altitude mixture compensation, if the taper on the needle is constructed appropriately. Also note that there must be some pressure drop across the dashpot, as this is inherent in the design. Nev..

Octane required.

vk3auu, I go along with that. I was actually refering to the 100hp motor. I should have made the point you raise. Nev...

Avgas in 912.

A few people I know have observed that continuous use of 100 LL avgas seems to cause compression loss, wheras occasional use does not cause this to occur. The reason is considered to be a build-up of lead deposits on the exhaust seat, part of which detaches and leaves a poorly sealing surface remaining. Compression seems to recover when unleaded is again used over a period of time. There would have to be a chance that the seat could be damaged in the meantime. Some engines employ very strong valve springs and narrow seats to ensure the high seat pressures to prevent the lead build -up in the first place. I am not sure of the spring pressures in the rotax The manufacturer's octane requirements would indicate that normal unleaded is marginal and that premium unleaded would be more suited.. Nev

Gyros

Have you contacted Paul Bruty, at Ballarat re gyros. The plane question? How much money?

one or 2 seat?

Slow or travel capable?

Tri or tailwheel?

Construction material. Rag & tube, Plastic (fibreglass) SUPERplastic (carbon fibre etc) Wood & rag (cheap & personal) Sheetmetal, For the gifted builder or buy outright.

High or low wing, Want to see in turns, get sunburned etc.

Bit like a chinese restaurant, So many choices, then you have to look at the manufacturers and models.

Much like picking a good wife, but a lot harder. Don't rush into it! Nev

Victa.

For a GA. Plane,privately owned by enthusiasts, support is everything. The website listed in this thread is worth a visit. The initial effect is to be a bit overwhelmed with the list of "things" to be looked at & you think "why would I want to get involved with all that". Well it's part & parcel of keeping your aeroplane safe, because all those requirements result from the experience of operations over some 45 years. You could argue a good case for a properly maintained AD complianced aircraft being safer than when they were new. This is the sort of experience based result we need to apply to our types as well. N...

Ethanol blend Value?& other considerations.

Purely on the value for money consideration, ( while recognising the appeal of a supposedly renewable product ) 10% ethanol plus 90% paraffinic, equates to 95% of the energy that you would have had with ALL petrol, therefore you would need a 5% price discount to cut even. (Your fuel economy will always be less with alcohol in the fuel)

All the discount that I have ever seen is 3 cents. Who is being had?

I have run alcohol in speedway motors 100% methanol.(very similar fuel chemically to ethanol. alcohols absorb water. I would not trust the mix near plastic fuel lines. I feel that plastic should not be used on aircraft in the fuel system anyhow. Other items that would be suspect, Fibreglass resins, various "O" rings, fuel pump diaphrams. bearing seals, some gasket cements, possibly some synthetic carburetter floats. and some aluminium alloys. The carburetters were always drained & the single use oil was always drained after each meet. The induction system runs much colder with alcohol use, in fact with 100% alcohol frequently the inlet side of the head would have ice on the pipe right up to the port. Never a dull moment is there? N....

LEGENDS.

How many legends have you got at shepparton ? N......

Good looks.

WELLLL ...Dunno Mazda There's worse.. perhaps the Meta sokel. Have I spelled that right? The Chrisley Ace ( designed by an airline pilot. how would that be any good) single engine TWO tails. If that was a dog ,it would be a happy one. but they are all lovely, on the right day. (not when you get an AD on the wingspar or the crankshaft). Hell perhaps I've upset all the Meta sokel pilots out there. How many are there? HELP! Aaaarrrgghh.. unsigned.....