APenNameAndThatA

2 hours ago, FlyBoy1960 said:

okay naysayers, I checked my sources with a quick phone call last night and can give you real figures regarding flying with the engine at idle flying with the engine stopped

 

The Pipistrel Sinus airframe with the engine stopped and the propeller unfeathered has a sink rate of around 210 ft/m, with the propeller feathered 187 ft/m

 

The Pipistrel Sinus airframe with the engine at idle has a sink rate of 90 ft/m and of course this is why the aircraft must use both flaps and airbrakes for a normal landing with the engine at idle otherwise it sits in ground effect for more than 1000 m before it will slow enough to settle.

 

As demonstrated by these figures with the engine stopped the sink rate is around double of what it is with the engine at idle, and this is the point I was trying to make.

 

People practice "engine failed landings" but still have the engine at idle will therefore have a performance which is significantly better than it is with the engine stopped.

 

Regardless of what creates more drag has nothing to do with what we are talking about, we are talking about sink rate, what will get you to the ground fastest and that is definitely stopped engine.

 

Again, I am not the expert I'm just repeating parrot fashion the information from a two times NASA/CAFE challenge winner pilot and one time team owner winner who does know what he is talking about.  (provided I have understood him correctly)

So in summary, if we practice dead stick landings with the engine at idle we are going to get better performance both in sink rate and distance than we are with the engine  stopped. The point I was trying to make through all of these comments is that you can practice with the engine at idle as much as you want BUT when the engine is stopped there is going to be a deep crease in performance which may/can/does catch out many experienced pilots because the sink rate is significantly less and turning is not helped by those extra 15 hp of the engine at idle pulling you through a turn back to the runway. The message here is, unless you have KNOWN performance of your aircraft sorted out or you have an excessive height beyond what you think you can get away with than just land straight ahead

This might be the most important post ever. It means that we are all practicing forced landings wrongly, and should be banking on twice the rate of descent than we get when we are practicing forced landings. That means that when we are practicing forced landings, we should be half as far from the field. It also means that in an actual forced landing, our turns would need to be tighter and *our nose would need to be much lower*.

Maybe, what it means is that we should practice forced landings with full flaps, and that in the even of an engine failure, we should expect the same performance with half or no flaps.

Maybe, the reason that people spin when they are trying to return to the airfield is not that they try to stretch the glide, but that they use the same view through windscreen as they are used to, when, in fact, they need the nose much lower than they have ever had it in the past!

13 hours ago, spacesailor said:

Elevator  !! ELEVATES THE AIRCRAFT? LoL.

spacesailor

The elevator turns and elevates the aircraft. More accurately, in coordinated flight, the elevator controls the angle of attack of the wing, and the wing turns and elevates the aircraft. When the aircraft is banked, the horisontal component of lift turns the aircraft and the vertical component of lift elevates the aircraft.

The rudder does not turn the aircraft at all in coordinated flight because the rudder acts at right angles to the direction of acceleration of the aircraft. The rudder has to act at right angles to the direction of acceleration of an aircraft in coordinated flight, because the ball is in the middle! (Turning an aircraft is acceleration because turning means a change in velocity. Velocity is defined in terms of speed and direction.)

31 minutes ago, facthunter said:

The rpm ,pitch and airspeed determine whether you have thrust or not. Just because an idling motor will prolong the ground run doesn't extend to it providing thrust when the plane's going faster.   It has some resemblance to the gearing of any vehicle, in that respect.. When any engine is IDLING it's very close to actually stopping just before each cylinder fires. The actual horsepower it's making is miniscule. The slightest load on it and it stalls. Nev

This does seem to be the truth of it. I had been thinking that an idling engine provided least drag (because power from engine), then stopped prop providing next least drag (stalled prop), then windmilling prop providing the most drag (because the prop is using the gravitational potential energy of the plane to turn the engine over.) But, if an aircraft is going really fast, an idling prop will provide more drag than a stopped prop, because the air is turning the prop rather than the prop providing any thrust at all. 

2 hours ago, facthunter said:

Torque forces are of a pretty low order unless you are "Driving"  a Griffon powered plane. Geared and big.. It's easy to overcomplicate things with smaller stuff. What engine torque figures are we actually working with?  120 ft lbs? Nev

The torque effect being referred to here is the precession effect. Lifting up the nose of the plane tilts the engine back (exerting a torque on it) and the precession effect means that the engine exerts a force (torque) turning to the aircraft to the right. It doesn't have anything to do with the torque produced by the engine. The torque produced by the engine is in a different plane. But, it is smaller stuff. I have checked for it and haven't managed to feel it. The torque produced by the engine will push the left wheel down harder and made the plane turn to the left, but I think that this is more a function of power than torque!

Applying more right rudder is important to me when the roll starts. At that time, in a tricycle grear aircraft, P factor will not come into play either. So, it seems the wind on the tail is the only effect that is important.

2 hours ago, facthunter said:

Pen name, If you are applying a lot of back pressure you are at risk of getting a high ROD and stressing the plane or flick rolling it in the turn. . None of this is a good idea. UNLESS you do it with a qualified pilot/instructor in a very strong plane with plenty of air underneath you to cover all possibilities.  Nev

That's how come I stopped.

2 hours ago, old man emu said:

OK. So you've got a Cub. Good luck to you. I repeat:

THIS TOPIC RELATES TO THE PILOTAGE OF AIRCRAFT WITH TRICYCLE UNDERCARRIAGE DESIGN.

 

If you notice, there are two pairs of eyes in that cockpit, with one pair being told to keep a look out ahead. The instructor, is the one who has his head inside the cabin and is operating the control column. I guess he has the experience to operate the control column while the student maintains direction with the rudder. Also, there is no intention to do anything more than a fast run along the ground, simulating and maintaining the attitude of the early part of a take-off run.

You have obviously twigged to this method after your years of experience. I posted the video for the information of inexperienced pilots.

When a tricycle undercarriage aircraft lifts its nose, torque pushes the nose to the *right* (so long as the propeller turns clockwise, viewed from the pilot's seat.)

THE SPIRIT OF ST LOUIS WAS A TAIL DRAGGER, SO I GUESS THIS TOPIC RELATES TO THE PILOTAGE OF AIRCRAFT WITH CONVENTIONAL UNDERCARRIAGE DESIGN.

2 hours ago, FlyBoy1960 said:

I was speaking about this with a professional pilot at our airfield and he explained, and it all made sense to me.

 

There is a huge difference in aircraft performance between a simulated engine failure with the engine at idle and the propeller still turning and the engine stopped and the propeller stopped.

 

"just as an example"

 

At idle any 80/100 hp engine is still producing maybe 15 hp and producing some thrust.

 

This depending on your aircraft may give you a sink rate, of let's say 300 ft/m.

 

The same aircraft with the engine completely stopped and a stationary fixed pitch propeller will significantly increase the sink rate, perhaps 500 feet to 600 ft/m sink rate. So it is substantially different and the controls will be significantly different and most probably more "mushy" because of the reduced airflow over the control surfaces and in particular rudder.

 

This all makes sense to me, this same person also told me that about 95% of pilots will never experience what their aircraft flies like with the engine turned off and in a glide, they wouldn't know the sink rate of a fixed/stopped propeller or any other performance characteristic of their aircraft because they never fly the aircraft in this configuration.

 

It was his advice that this huge performance decrease compared to what some pilots train with the engine at idle is really the big killer and catches many experienced pilots out because they are looking for a 300 ft/m sink rate and they get more than double this with the engine completely stopped and of course they pull back on the stick to try and slow the sink rate forgetting about airspeed, combined with different performance on the controls and it is all over before you start.

 

He insists that all recreational pilots must train in their aircraft (at altitude of course) with the engine turned off so you will know your actual real performance, trim requirements and aircraft outlook you should be looking for when the engine fails.

 

I have never forgotten this story because it all just made absolute sense

This is a very good point I have practiced impossible turns at height. I can turn around withing 4-600 feet. I climb at about 65 kt (Vy is 54). After I have cut power and waited three seconds, my speed drops to about 45 kt. To get around as fast as possible, I have to push the nose way down, bank to 45 to 60 degrees and, as speed increases, put in a fair bit of back pressure. I don't even want to practice any more because I'm worried I will over stress the plane do an accelerated stall. There area at either end of my runway is very built up. I don't think I'll attempt to turn at less than 800 ft. Which means, not unless I have already turned downwind at 500 ft.

The thing about flying is the sheer physicality of it, and the high stakes. IMHO riding a bicycle is a better simulation of flying than Flight Simulator is. 

One theory is that the Americans bombed in daylight to down enemy fighters and thereby make the invasion easier. 

I know far less about this than others. If you love measuring things, you can buy harness testing kits to measure the hardness of concrete. They are a variation of the Mohs scale of hardness. Some concreters are literally criminals. For some reason, there are far more criminals in concreting than other trades. Buyer beware.

On 06/12/2020 at 12:45 PM, aro said:

 

Dividing people into Bernoulli and Newton camps is completely misunderstanding what Bernoulli and Newton are about. They are both correct* - they are just different ways of looking at the same thing. It depends on whether you choose to view air as a fluid or a stream of molecules.

 

* Some people - usually those who divide people into Bernoulli and Newton camps - use Bernoulli's principle incorrectly. But that doesn't mean Bernoulli was incorrect.

 

I agree entirely. They can't not both be correct.

19 minutes ago, turboplanner said:

He doesn't have to supply commercil in confidence information. He's one of the few suppliers that puts up with some of the crap dished out here.

And probably the only supplier who dishes it out. He said that I recommended a silver-tongued approach, again deliberately misrepresenting what I said. What I said was that he could be more polite *and* better promote truth. Promoting truth is the opposite of being silver tongued. 
 

He also accused me being a hypocrite. It is true that I recommend politeness and am rude. However, I don’t recommend that he be polite to be more moral. I recommend that he be polite so he can sell some aeroplanes. 

If to be a supplier one needs to supply someone with something, Skippy might not be an aeroplane supplier at all. 
 

I’m sure he feels better now you have put me in my place. 

37 minutes ago, skippydiesel said:

I take it you have been ordained by some higher authority that authorises you to lecture to others - I say it how I read/find it -  t like or not, that is your prerogative.

 

You on the other hand appear to prefer/advise the "silver tonged"  approach - may that philosophy serve you well - I have no intention of adopting it

 

Those in glass houses should not throw stones - you may like to review your recent  passive aggressive language  and non to subtle accusations, that you feel so free to launch at me - "cast out first the beam out of thine own eye;"

 

Yeah, but how many aeroplanes have you sold? 

On 05/12/2020 at 7:58 AM, skippydiesel said:

Point taken - I should sell planes and ignore the disinformation and errors being perpetuated by others, either through ignorance or malice. 

 

Fascinating ! It would seem that you would prefer the obfuscation & hype of some sale persons.  My manor may be a little direct even abrasive, for that I apologise but at least you will get the truth and  on going enthusiastic support. 

That’s a straw man argument: not the kind of thing that someone who prides themselves on debating and searching for truth should engage in. It goes without saying that if you call someone hairy chested, you are doing the opposite of trying to find the truth. 
 

It would be best, in a conversational or sales context, to find and amplify any truth in what someone says. By doing that, you have more opportunity to lean, and the person who you are talking with will be more likely to listen to anything you say that is true. 
 

For example, if someone says that 27 kt is unrealistically slow, then you might acknowledge that indicated speed can be inaccurate, 16 degree angle of attack might make a difference to the reading, and that you were at 4000 rpm and 100 kg below max weight where as official figures are at max weight and closed throttle. You can say that you don’t blame them for being cynical because there is a long history of fibbing. Then you can go out and video yourself measuring speed by GPS in two directions. You could check the stall speed closed throttle at max weight and see if it was the same as book after all. 
 

How many aircraft have you actually sold? 
 

On 05/12/2020 at 7:18 AM, old man emu said:

Listen, mate.

I'm getting well and truly sick of you flaming me. I have yet to see you make a positive contribution to any topic on this forum. You might think that you are being quite smart, but all you are doing is showing what a moron you are. If you can't stop flaming me then F off.

OME, I don’t blame you for being angry. This time were going well and looking clever, until you said that something that had a weight of 2.3 kg had a mass of 0.23 kg. 😞

With the previous thread about the carburettor ice, I said that a trimmed aircraft that loses power would lose height rather than airspeed. At first I thought that making an important point would be a “positive contribution”, but in the light of your objective I guess my post was very negative. ☹️
 

Earlier on this thread you got upset at someone for answering this question the wrong way. The same thing happened the last thread too. It looks like if you keep posting you are going to feel worse and worse. I suggest that you try blogging. You will have administrator privileges so when someone makes a negative comment, you can change things so you look better. If you write the whole thing in Latin you will be able to keep the riff raff away. 👍  

On 03/12/2020 at 8:52 PM, old man emu said:

 

You messed up because you don't know the meaning of Newton's First and Second Laws. Inertia is a concept. Inertia is simply the tendency of an object to follow a straight line trajectory at a constant speed, unless acted upon by an external force. The tendency of an object to resist changes in its state of motion varies with mass. The more inertia that an object has, the more mass that it has. A more massive object has a greater tendency to resist changes in its state of motion. The sense of the word "inertia" comes from the Latin "iners", which means "lazy"

 

The Momentum of a body is something that it possesses due to the product of its mass and its velocity. We can measure both these quantities to calculate the momentum the body possesses.

 

NO. Momentum is the thing that changes due to acceleration (positive or negative). You can only change the inertia of a body by adding or removing mass.

I stand corrected. Well done on clawing one back. The issue wasn’t that I don’t know Newton’s laws. The issue was that I didn’t know the definitions. As far as I can tell, inertia = mass. Momentum = mass x velocity, broadly speaking. 

8 hours ago, skippydiesel said:

 

Not intentionally rude, colourful at times, yes - if offence taken - my apologies.

 

Like most , I will try and correct an error, refute an unfounded accusation and enter into vagarous debate where/when I feel I might have something to contribute.

The issue is if I have taken offence or not. I haven’t. I’m actually trying to do you a favour. You seem to value being right above selling aeroplanes. Given the plethora of low winged composite aircraft on the market, someone reading this forum would be nuts to buy a plane from you. I can only imagine that if I had a problem with my aircraft you would swiftly “correct an error, refute an unfounded accusation and enter into vagarous debate”. As a customer, I couldn’t imagine a more unpleasant experience.

17 hours ago, skippydiesel said:

  there is little merit it being a hairy chested hero and flying in turbulence when you dont need to.

Are you rude to people who buy aircraft from you? Or do you change completely? Or is it too early to tell?

5 hours ago, Russ said:

We’ve done a full lap coastal, and a top end half lap. A jab 160 can be packed to the ROOF, has great legs, cumfy. Would do it again in a blink. Have only encountered jabs doing the same epic trips ( RAA ) he jab handles shyte great, handles ruff strips. Downside.......you want to do it again and again. Buried in there is 2x10L fuel,10L water, tent,air beds,bedding,clothes,cooker,food plus plus. ( 631 kg ) and it flew beautifully. ( took a while to get off the ground tho ) Rang a chap to get advice re “that weight” he said “no probs at all”.... so there you go. The specs are grossly under estimated.

Where was the CoG? I imagine that the plane could be overloaded and still have the CoG within limits.

3 hours ago, old man emu said:

You have confused "inertia" with momentum. 

 

Newton's First Law of Motion provides the definition of "inertia" - A body at rest ..... The amount of inertia a body possesses is solely dependent on its Mass. Mass is the total of the atoms and molecules in the body. Weight is related to mass by being the size of the force a mass can exert when accelerated by the local force of Gravity.

 

Since Force = Mass x Acceleration, if we put an object on a weighing scale and find that the scale reads 2.35 kilograms, then that is the Force the object is exerting on the scale mechanism. But what is the mass of the object?

Since Force = m.a, and the object at sea level is being subjected to the acceleration due to Gravity (9.81 metres/per second/per second), then

2.35 = m x 9.91

2.35/9.81 = m

m = 0.239 kgs

 

But for practical purposes, we equate Mass and Weight.

 

Momentum is the property possessed by an object in motion. Its magnitude is the product of its mass and its velocity.

 

a) Inertia and momentum are the same thing.

b) If something is weighed on a scale and the scale says 2.35, then the mass is 2.35 kg. (Assuming the object is not being accelerated and the scale is accurate and being used on the surface of Earth.)

c) You messed up because force is measured in newtons, not kg.

1 hour ago, facthunter said:

Australia is NOT continental Europe, where there's dealers everywhere.. Protecting your "Jigger" on the ground is an an issue and the environment is harsh on US too. I reckon in a few places you wouldn't last half a day without water. (and shade). Nev

Yes. Some people have posted here about what survival kits they would carry. The survival kit that you should carry for remote areas is very simple. a) Sat phone, b) EPIRB (or whatever the correct acronym is), and c) as much water as you can carry, say 10 L per person.

Disclaimer: I have about 90 hours. On the other hand, I have bought my aircraft for touring and exploring the desert so have given it some thought. I think that if you want to see the sights, you are better off with a high-wing aircraft. If you want to avoid misery half the year, avoid something with a bubble canopy. Your aircraft will not be hangered for the 12 months. I was not game to get a composite aircraft because I did not know what the sun would do to it, so I was keen on getting something that was not composite. I suspect that if you are touring, you will want the ability to land on short, rough, soft fields. I have not landed there, but, for example there is a strip to the north of Fraser Island that I would not want to take a plane with small wheels. I needed tricycle undercarriage because I am inexperienced. That left aluminium, high wing aircraft large wheels.

The Foxbat is mostly aluminium, but the control surfaces are fabric and the cowel is fiberglass. That is what I ended up getting. The Zenith is a kit plane. I might have got a Savannah but I did not fit. Even if I did fit, the cabin would have been much smaller than the Foxbat, which is roomy and has excellent visibility. The Brumby did not have enough useful load, and a review in Australian Flying said it lacked rudder authority (!) IIRC, the SuperSTOL, Highlander and Hornet are all tricycle gear, and the Hornet is very slow.

There are lots of Foxbats in Australia, and the support from Foxbat Australia is excellent. They use them on cattle stations a lot. Foxbats cruise at 90 kts. There is the Vixxen which is much faster and is more expensive, but is not approved for use with big tyres like can be used on the Foxbat. IIRC, they are 6 x 6.00. I have been told that if you put big wheels on a Vixxen, it ends up no faster than a Foxbat. There is an older version of the Foxbat with a lower MTOW that is much less expensive and would be okay for flying alone. Eurofoxes are fabric and smaller inside that the Foxbat; they need attention to the rudder when flying but have a very benign stall. There are other planes that are older relatives of the ICP Savannah and look a bit like it. 

I would not emphasise speed in my purchase decision. If you have a fast plane, there will be lots of places you cannot get to at all because of the landing strips, and you will be wondering if your plane will be able to handle a particular strip.

The actual answer is that whichever ship has the most favourable tides will go faster, this factor being much more important than air density. It also overcomes the issue of hull speed. 
 

About flying in your mind, you can do the same thing when you are learning to navigate long trips. You can sit in a lounge chair, look at your watch, plot on the map and fill out your flight log. 

20 hours ago, Downunder said:

Best to do your training in bulk lots....

Anything less than a few hours a week, your simply wasting your money relearning......

Buying bulk hours can get you a discount.

 

FTF's can have varstly different rates.

It can be more viable and cheaper to travel to a regional centre and stay several nights in a motel than pay city rates.

 

Avoid at all costs training at a controlled (class c/d) airport.

You're paying by the hour. It's not much value sitting around waiting 20 minutes out of the hour waiting for atc...

The school will like it as it will take you longer to learn so more $$ for them and if you're on the ground, you're not burning fuel, so making them more money again.

Go to a ctaf.....You will get mix of dealing with other aircraft but be able to make your own decisions.

13 hours ago, Jase T said:

No one learned to fly alone, No one passed a test by themselves.. Make friends, accept advice, ASK QUESTIONS, shut up and listen, Be a knowledge sponge, its not below you to clean or push around aircraft and sweep hanger floors..  filter out the BS... Ask your instructor, enjoy the experience its expensive and its adictive. 

 

I train at Archerfield and don't find that I get held up for more than a few moments. There are other reasons to train at a non-controlled field, and I suppose some controlled fields do waste your time. I passed the RA-Aus theory exams by myself, but I did physics (gasses, momentum, acceleration) and maths (vectors) in Grade 11 and 12, which helped a lot. The other thing, which I hinted at before, is that it does not matter if you attempt an exam and fail. In fact, the more you fail the more you learn.

I found stalling too frightening to do. So I went on the thrill rides at Dreamworld and Movie World (the giant drop, the claw, the tailspin, rollercoasters) about 90 times. I went from keeping my eyes and barely being able to go on the ride to not hanging on and being a bit scared (the giant drop) to enjoying them (the rest). As I bragged on this forum earlier, I performed and recovered from an inverted spin. That was great fun. I was on the rides with little kids and the occasional intellectually disabled adults, so it is a phobia that some people have and some don't.

The risk of dying is about 1 in 1000 per year for the general population. RA-Aus has a fatal accident every 100 000 hours. That means a risk of death of about 1 in 2000 if you fly 50 hours per year. As best I can determine, it is more dangerous than driving and less dangerous than riding a motorbike. My own view is that it is not dangerous but it is not safe either. Other people who post to this forum have a completely different way of viewing risk.

I suggest that you wear a helmet. The inside of Most LSA's have steel bars at head height that would be completely illegal in a car. Helicopter pilots wear helmets and fixed wing pilots tend not to. The difference is therefore more based on culture and cost than risk. Wearing a helmet also slows things down and they are a nuisance to fit. MSA is said to be better than Alpha. I suspect that Evolution/Evo helmets are merely helmet-shaped objects, but I might be wrong. There are other, cheaper brands that are much cheaper and vastly better than nothing. My family and I are the only people I know of who wear helmets in enclosed  RA-Aus aircraft, so this is a minority opinion. Also about the fatality statistics, for every fatality, there are probably an order of magnitude more nasty accidents. One of my jobs is assessing the psychiatric permanent impairment from physical injuries. I see lots of people whose lives are badly affected by soft tissue injuries that just never stop hurting.