APenNameAndThatA

I was surprised that the aircraft hit the wake turbulence when it was at the same altitude as the helicopter. 

On 8/7/2022 at 6:07 AM, RFguy said:

90% of my practice work is without an instructor. 

I always have a small notebook with me and or my inline voice recorder on the mic so I can make notes

like.... hmm let me think things I have done in the past...Forgot to retract flaps on late go around...... or....was way too deep downwind for the wind, or ...didnt do in-climb engine check... or  didnt remove the carb heat at late final, or didnt do bumfish check due to distraction on that downwind or... etc etc I think all of those sort of errors occur when I not flying regularly and there is in circuit traffic and radio traffic.

Exactly. People make mistakes all the time flying. IIRC, 1.6 per flight for airline pilots. Hence the need to engineer safety. 

On 8/7/2022 at 10:36 AM, onetrack said:

I really don't understand how such an experienced pilot could fail to carry out what is the most basic preflight check, on every single thing that flies.

One can only presume that this was a developing pattern of "shortcuts" in preflight procedures on the part of this pilot, that no-one picked up.

 

Complacency, combined with familiarity, combined with developing bad habits, will get you killed every time.

One thing to consider here is the so-called fundamental attribution error. The error is that we tend to blame our mistakes on our circumstances and blame others’ mistakes on their character. Simple example: when I’m irritable it’s because I’m under pressure but when someone else is irritable it’s because they’re an a-hole.

In the case of the mistakes that others make, IMHO, it is most productive to wonder what things could happen *to* us to put us in the same position. My own thoughts are: the I’m safe acronym, being under time pressure, being rusty, and forgetting my written check lists. 

When a checklist is interrupted, it is very easy to skip items. Habit capture is where we are supposed to do something different but forget to when the time comes, and just keep doing what we do out of habit; maybe he moved the control lock to a different part of his checklist. In this case, target fixation is just a type of distraction from the list.  

On 8/7/2022 at 6:39 PM, Flightrite said:

Like pilots rely on engineers to do their job properly they in turn rely on pilots to do likewise, obviously not in this case!

The whole idea of human factors engineering is to organise it so that if the pilot stuffs up no one dies. I had never even thought of putting the control lock in such a place that if it is in place, the yoke no longer feels in a natural place and the plane won’t fly. I spose they are placed so when they are in place, there is no tension in the system. 

21 minutes ago, danny_galaga said:

Are you all confused? Labor is governing with a majority. They don't have to placate any other party, unlike the inbuilt placation the Libs have had to do since what? The 70's?

On 7/7/2022 at 12:31 PM, spenaroo said:

Nah, the greens have stuffed themselves at the moment.
with the whole not standing in front of the flag, and declaring the parliament invalid.

don't think the government wants to be seen as working with them

Anthony Albanese was practically picking a fight with them. The Greens might have sunk any referendum associated with the Uluru Statement, too - that’s a fight you can’t win by fighting. Greens 🙄 

‘cording to Youtube, shiny aluminium is coated aluminium - aluminium alloy that is coated with pure aluminium. 10% weaker than aluminium alloy. I don’t understand why it’s made of shiny aluminium, unless they are going to make it do that people don’t have to paint it. Which would make it more likely to leak water.   

The tribe have voted and I was wrong. Sorry. 

47 minutes ago, Student Pilot said:

Air Tractors mainly, right up to the 802

Dude, given how much flight time you have, its silly of you to big note yourself and discourage less experienced pilots from doing flight plans.  

1 hour ago, Student Pilot said:

Haven't done a flight plan in years, leave a flight note or make sure somebody knows where I'm going.
Do all you blokes put a road plan in when you go driving? Do you use a road tracker/recorder when driving? A car could disappear on any of the main roads and not be found for weeks or longer. Do any of you check/get weather for driving? 

It depends on the type of flying you do. If people here only fly within 25 miles of home, with no airspace, no frequency changes, never in iffy weather, never with enough weight to need to leave fuel at home, always with much more fuel than they need, and just go to the same place over and over for years, then they will probably not do flight plans either. 

On 27/6/2022 at 10:03 PM, RFguy said:

 

 

 

 

On 27/6/2022 at 10:03 PM, RFguy said:

one might wonder if drag proortional to  velocity squared , why is the power to overcome it proportional to velocity cubed ?

 

drag is a force. drag is proportional to velocity squared (putting aside Reynolds) 

and work done= force  x  the distance that force is applied over.

 

example. suppose a shopping trolley has a high friction wheel.... 

if you push a shopping trolley 0 m, you have done no work.

if you push a shopping trolley 100 meters you have done work.

 

so workdone  = dragforce x distance 

so, per second......

so  workdone per second = dragforce x distance per second

and

Power is measured in units of  workdone per second (power )

and our distance per second  measured in meters per second (velocity)

so.... substituting in ....

power = dragforce x velocity.

 

 

 

I wonder if that means that, roughly speaking, relative to airspeed, your fuel consumption for a given trip between two set points will be squared and your fuel flow will be cubed? 

I would much rather an aircraft with eight motors and propellers - lots of redundancy. Two rotors? Hell no! If one stops, you crash, end of story. 

On 18/6/2022 at 8:06 PM, spacesailor said:

YES ,.

I agree older drivers have a higher statistical number of accidents! .

BUT

I have noticed that due to my 'SLOWER ' speed, l get cut off & tailgated a lot more often.

Whenever l try to use a normal speed, the wife reminds me " We are Not in any hurry now, enjoy the trip ".

I have only been involved in ONE serious accident, but Not the driver, 

AND

 It made utube for almost a year, ( wheel ripped off speeding stolen car, hitting our vehicle ).

Our driver was a professional truckie ! & could do nothing about getting side swiped. 

I didn't feel at all like driving for 18 months afterwards.

64 years with only ' speeding tickets plus 3 for parking, & l won one parking case.

AND now one ' red light ticket ' of 0.5 seconds, shows how Slow l drive, LoL

spacesailor

 

That’s your wife being wrong - unless she’s scared of your driving and not game to say. 

My understanding was that very old and very young drivers have about the same number of accidents.  

21 hours ago, meglin said:

Dear friends and colleagues! I understand how difficult it is for you to sort out our problems. We can't really figure this out ourselves. Here are two concepts for you to seed: Russian (by nationality) and Russian (citizenship). The automatic translator does not distinguish between these concepts. And we are very different. Journalists translate randomly, mostly incorrectly. Russian - nationality. Russian citizen - citizenship. I am Russian by nationality. And at the same time, I am a Ukrainian by citizenship. We're all mixed up here. Millions of Ukrainians live in Russia. Millions of Russians live in Ukraine. Therefore, when we read about the crimes of Russians in Ukraine, it hurts us, because we are talking about Russians, among whom there may be Chechens, Tatars, Bashkirs, Buryats, Kalmyks, etc. In our Ukraine, parties were banned without a trial, the press and TV channels were banned. Russian Russian is spoken by everyone in our city, there is not a single sign in Russian, there is not a single TV channel or newspaper, there is not a single school. Although everything used to be. Even in the subway, stops were announced in two languages. This cannot but offend half of the population of Ukraine. This is an unfair and stupid policy. And Russia uses it.

They tried to use it but failed. What is more, the separatists from the two have been conscripted with very little training and are being killed in large numbers. My view is that Russians in Ukraine were being treated badly but that was being used as an excuse by Putin to try and have USSR 2. 

5 hours ago, RFguy said:

- GPS antenna should be above the sky echo. if 50cm is all you can get, it is what it is... I would think 50cm is heaps , especially if the GPS antenna is above the skyecho.

-Not doign any mods right now sorry, bit busy.  wait till I get my plane back in the air.

 

 

That is an important idea: mound the SkyEcho as low as possible. My aircraft has see-through doors, so I can mount it low on a door and it will be able to see out sideways. ✅

39 minutes ago, spenaroo said:

There is a great section in eric winkle brown's auto biography about his test flight in it.
having prisoners of war as the ground crew, that had to have signed statements that they wouldn't be punished if things went wrong before they would touch it.

sounds like an awesome experience but a short range, and limited tactic - basically rocket up - dive down at a bomber, ignite again to climb. then dive once more and land

The range would not the be the only short thing. 

Will 50 cm away be far enough? My iPad is on one side of the cockpit, and the GPS antenna for the Dynon is just below the windscreen, so 50 cm is about as far as I can get. 

2 hours ago, onetrack said:

Facthunter is correct, don't use WD-40 on natural rubber products, because it contains a large percentage of petroleum spirit as a carrier.

Despite the WD-40 site saying it is safe for rubber - there's rubber, and there's "rubber".

 

The manufacturers site says you can use WD-40 on weatherstrips to keep them soft and pliable - but the fact is, weatherstrips don't contain a lot of natural rubber - and if the natural rubber in them is softened by WD-40 - well, that's O.K., because you want weatherstrips to remain soft and pliable. But you don't want rubber tyres and tubes being softened by WD-40.

 

Weatherstrips are made of EPDM rubber - a thermoplastic elastomer (TPE) mix of plastic and rubber, and a thermoplastic olefin (TPO) polymer/filler blend.

 

Tyres and tubes still contain a very large percentage of natural rubber, even though they also contain butyl and other ingredients such as oils.

So, the natural rubber in tyres and tubes, WILL be adversely affected by spraying WD-40 on it.

 

Talcum powder, baby powder, French chalk - all basically the same thing - powdered talc (the main additive is perfumes) - is highly suitable as a rubber lubricant.

Talc used liberally between tube and tyre will prevent a tube from being destroyed if it goes flat at speed, because of its lubricant ability.

I've personally proved this over several adverse, high-speed tyre deflation events on both gravel and bitumen roads.

 

Talc also reduces heat buildup as a result of friction between tube and tyre - not that that is generally a problem with aircraft, unless you do a lot of high-speed taxiing over long distances.

Grit-free handcleaner makes for a simple tyre bead lubricant, and you can use it to wash your hands when you're finished. Otherwise, a weak solution of washing-up detergent works well, too.

 

How the —— do people on this site know so much? Excellent idea about tyre temps. 

As far as I know, you need a backup phone for your phone/tablet before you can ditch paper maps. The cost and inconvenience of paper maps is considerable. 

7 minutes ago, facthunter said:

I wouldn't put WD40 near any tyre or tube..   The "old" ton is 2240 imp. Lbs (20 cwt). Nev

I think you might be right. What about baby powder? 

3 minutes ago, Bruce Tuncks said:

Apenname, I thought a liter of water was exactly a kilogram. Thus a kiloliter is exactly a tonne.

 

Not everyone on this forum agrees with you…

This is advice from a motorbike adventure rider. 

Motorbikes have tubeless tyres but he still carries tubes in case of sidewall damage. Also, tyre iron. He inflates tubes for 24 hours to make sure stay inflated.

I think I should add a second can of air/goo, and something for the valve. 

Instead of a jack, I think I would support the plane and dig a hole. 

EDIT: not a good idea to use WD40 on tyres, as Fact hunter points out. 

Is an mr funnel a Mr Funnel funnel? 

On 4/10/2020 at 3:10 PM, Blueadventures said:

Skip I personally would not bother with a CS on your aircraft.  The electric I have seen need attention to the commutator surface and brush dust deposits etc. I reckon a 3 place e-prop is the go and good while they have a return policy if not happy. Will no doubt provide improved service. I plan to get one next July. Will be superior to the Fiti prop. IMHO.

There is a guy on here who has carefully tested props and reckons that they all perform about the same. Truth — I have no clue. 

2 hours ago, APenNameAndThatA said:

I think that if a CS prop actually gave a 33% shorter ground roll AND a 20% improvement in cruise then you would get much less argument from people. I bet the performance improvement would be nowhere near that good. I think the disconnect in the convo is that no one believes those figures.   

 

To get a 20% improvement in cruise, you need to effectively have 1.73 times more power. I the efficiency of your standard prop is 0.6, then that is not possible. IIRC, the average prop has an efficiency of 0.8. (By efficency, I mean converting engine power to prop power/work. (1.2 cubed = 1.73)

 

(As for the mighty Foxbat: revs just below yellow on takeoff and just below yellow full throttle at 8000 ft cruise!) 

The above only takes into account the blade efficiency. So it’s basically wrong. What you could do is compare the revs at WOT on cruise and takeoff. If the WOT RPM at takeoff is higher than at WOT RPM at cruise, you will be able to calculate the engine power difference from charts that show power at full throttle at different density altitudes and different RPM’s. From the difference in power, you will be able to calculate (speculate about) how much extra power you will have from a CS prop. 

Are you allowed to cruise at WOT in a 3300? (can in a Rotax). Is max RPM for takeoff same as max RPM in cruise (higher in a Rotax, which is a reason for CS props in a Rotax.)

Another factor is that if you move your C of G forward with the 8 kg on the nose, you will reduce your efficiency because your elevators will need to produce more downforce. I don’t know if significant. Stall speed higher, too, IIRC. Don’t know if significant. I suppose your Cof G envelope will tell you if it is too far forward.