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-   -   Mallard Down in Perth (https://www.pprune.org/pacific-general-aviation-questions/590122-mallard-down-perth.html)

zzodr 30th Jan 2017 11:52

Yup.
If the wind is blowing strong enough, you can fly backwards like a Super Cub can for example.
You can do a 180deg turn no problem. But if the wind died off suddenly, and you were low, well then things could get interesting.

Airbubba 30th Jan 2017 13:23


Originally Posted by Capn Bloggs (Post 9657877)
When you're looking at the screen taking the shot/video it is, but when you look at the finished product, it is as though someone took a shot of you. That is, the orientation is correct. Take a selfie with some text on your shirt: it comes out correctly when you view the image.

It works that way on some phones but not others. You can easily find examples of reversed text in selfie videos on Facebook and YouTube.

Blake777 30th Jan 2017 13:35

To return to the accident itself, a comment from a poster who was actually there and saw the plane's movements, and replied to a question I put, has been deleted.

I was commenting on the FR24 track, in which the original circuit apparently included an unsuccessful attempt at splashdown. Upon go round, the Mallard approaches on a track slightly north of his earlier circuit, giving much less room to successfully execute the turn and touchdown in the prescribed box.

I'm a little puzzled as to why he would have given himself less leeway on the second attempt? If he was unsuccessful on the first attempt at splashdown, how on earth did he think increasing the difficulty of the manoeuvre would improve things? It does not seem to allow for this beast's performance capabilities within the parameters prescribed unless he was a stunt pilot from way back. Low+slow+attempted tighter circuit than previous+shallow water = disaster? Plus girlfriend in cockpit+pressure for a big occasion performance. All a recipe for a catastrophe waiting to happen, it appears.

Very sad for the loss, and for the crowds witnessing. RIP to Peter and girlfriend. A tragedy for FMG also.

https://www.flightradar24.com/data/a...h-cqa/#c464eb9

Thanks for correction Air Bubba. Flight Aware not quite as conclusive.

Airbubba 30th Jan 2017 13:46

You might want to edit that FR24 link.

See if this one works:

https://www.flightradar24.com/data/a...h-cqa/#c464eb9

FlightAware has this plot:

VH-CQA 26-Jan-2017 YSEN - YXRP FlightAware

flopter 30th Jan 2017 13:51


Originally Posted by Flyer069 (Post 9656932)
I am a 14,000 hour Agpilot 4,000 hour float plane pilot , most of you guys scare me with your theories on flying. I hope none of you are instructors.

Finally.. Someone with Real Life flight Experience at AG low level and Float Plane. Please share and elaborate Your Thoughts Flyer069.

FlexibleResponse 30th Jan 2017 14:06

An aircraft's response to changing wind is dependent on the inertial mass and drag of the aircraft.

A light aircraft will respond quickly to adapt to changes in the velocity of the air mass (through wind changes or maneuvering in a constant air mass) and a heavy aircraft will take longer.

Inertial mass is space/time dependent for frame of reference.

However, on the other hand, the kinetic energy of an aircraft flying at 100 knots IAS into wind will be lower than the kinetic energy of the same aircraft flying downwind at 100 knots, in RELATION to the EARTH.

The increase in kinetic energy required to change from flying into wind to flying downwind takes time and is dependent on the inertial mass and drag of the aircraft.

sablatnic 30th Jan 2017 18:30

Downwind turn / upwind turn!
Just want to say, that during the many hours I have been flying gliders I have never felt anything different turning upwind or downwind!
(Gliders - you know them when you see them - absurdly long winged things with ridiculous adverse yaw problems, which spend most of their time circling a few knots above stalling).
Went to flying models when I lost my medical to some kidney problem, and the models haven't heard about downwind turn problems either, not even free flight models, which also fly very close to stall.

itsnotthatbloodyhard 30th Jan 2017 19:50


A light aircraft will respond quickly to adapt to changes in the velocity of the air mass (through wind changes or maneuvering in a constant air mass)
Manoeuvring in a constant air mass isn't a change in the velocity of the air mass.



However, on the other hand, the kinetic energy of an aircraft flying at 100 knots IAS into wind will be lower than the kinetic energy of the same aircraft flying downwind at 100 knots, in RELATION to the EARTH.

The increase in kinetic energy required to change from flying into wind to flying downwind takes time and is dependent on the inertial mass and drag of the aircraft.
Sorry, you're confusing your frames of reference. Otherwise it'd be incredibly difficult to reverse direction when walking down the aisle of a moving train.

But there have been so many examples in the last few pages showing why the downwind turn thing is a myth - all completely ignored by the true believers - there's probably no point bringing up any more.

9 lives 30th Jan 2017 21:20


why the downwind turn thing is a myth
In the context of a turn toward final approach for landing, might that be because it is uncommon for pilots to elect for a downwind landing? So turns progressing toward the final approach would most often be more and more into the wind in most circumstances?

Surely if a pilot were aware that a downwind landing were inevitable, they would greatly increase their allowance for speed and space. The approach turns I saw on the video were not being flown with a demonstrated concern for the possible effects encountering downwind conditions for final approach and landing.

Sure, a turn out of the wind could affect the plane's handling. But not so much as flying a low altitude progressively tightening turn, with slow and possibly decreasing airspeed, and low awareness of an impending unsymmetrical stall.

jack11111 30th Jan 2017 21:22

Last time I checked, when I'm doing steep turns at altitude, my airspeed seems to remain constant.


I'm so thankful nobody stuck that "downwind turn peril" in my mind when I was learning to fly...seems like it is hard to shake off.

X35B 31st Jan 2017 04:22

In a Perfect World.
 
Long before the event, Pilot and Co-pilot and Some Wiser Heads get together to do a Risk Assessment.

1st is that the Grumman Mallard that has sent many fine souls off to first name terms with God. This may or may not be of concern. But if this is a machine that does not tolerate errors gladly then that is a matter to be considered.

2nd is that people die at Airshows in many ways. Is there an opportunity for this to happen?

Consider doing some time to address the stall at low altitude. Both pilot and co-pilot spending time in a cockpit of a sailplane doing endless turns on the edge of a stall, might prove useful.

Have a plan and be wary of the stall at low altitude. Do a few hours in the air learning how this beast behaves at a reasonable height. Learn how to recover and definitely learn how to pick up a stalling wing. Get your co-pilot up to speed on going full throttle with propellers to low pitch. Be ready to get out of trouble.

Learn the ancient and honorable art of sideslipping.

Practice landing somewhere else which is like the area you are to land in if possible.

Ask some questions like: Where are the windsocks to be located?

Is there enough room for a safe circuit ?

Ask yourself, why did all those airshow crashes happen and is this going to be more of the same?

Leave the passengers at home.

Capn Rex Havoc 31st Jan 2017 04:42

Step Turn -

Sure, a turn out of the wind could affect the plane's handling.
:ugh:

I Don't even want to know what you mean by that.

a turn out of the wind? :confused::confused:

FFS if you are on a travelator, walking and close your eyes and stop walking and walk backwards you are not going to feel any different acceleration than when you are walking forwards.

framer 31st Jan 2017 05:36

The problem here is that one lot are talking about a theoretical perfect parcel of air and the other lot are talking about real life. In the travelator example above for example, what would happen if some sections of the travelator were moving faster than others and some were even moving vertically? Every now and then some people, depending on their walking skills would fall over :)

9 lives 31st Jan 2017 06:14


a turn out of the wind? :confused::confused:
Let me help....

If you takeoff and climb into a brisk wind, maintaining a constant airspeed, so far so good. If you then turn downwind, it will be necessary to accelerate relative to earth, to maintain that airspeed. Sure, the downwind will assist with that, but before it does, you will have suffered an indicated airspeed loss, which may affect handling, depending upon how close to stall speed (Vx speed range) you were while climbing into the wind. This can be evident as stall warning as you turn out of wind, I have experienced this and demonstrated it many times during training, when altitude was ample. This is a "gotcha" for seaplane pilots, who may be trying to turn away from rising ground after a confined area takeoff. Increasing wind intensity encountered climbing up out of terrain can also be a factor.

It is certainly a hazard known to helicopter pilots, as the helicopter can come back out of translation, and require more power to maintain altitude, combined with affects upon control. Certainly if you're climbing out at Vy+, or in cruise speed, the affects of turning out of wind are probably negligible. It's the low speed maneuvering where the hazard presents itself.

I'm not suggesting that this was a factor in the Mallard accident, as I presume that the pilot was turning into wind, so as to land into wind, so things just get better when that happens. Though, I do not know the wind conditions experienced by this pilot.

Ex FSO GRIFFO 31st Jan 2017 06:19

Re 'Sure, the downwind will assist with that, but before it does, you will have suffered an indicated airspeed loss,'

And, 'This can be evident as stall warning as you turn out of wind,'


God, Give me strength......... I'll say my prayers before I go to bed....honestly.....

No cheers:ugh:
NOPE !! NONE at ALL.. !!

josephfeatherweight 31st Jan 2017 06:58


If you then turn downwind, it will be necessary to accelerate relative to earth, to maintain that airspeed. Sure, the downwind will assist with that, but before it does, you will have suffered an indicated airspeed loss, which may affect handling, depending upon how close to stall spee
Singularly the most inaccurate claptrap I have read on PPRUNE and I've read a lot...

Capn Rex Havoc 31st Jan 2017 07:56

Framer- I talking about a constant parcel if air, not a wind shear situation. That is what we are taking about in the upwind/downwind situation. Ie you have 25 kts of wind and you change your direction while in that 25 Kt wind stream. I know you know the deal but Step Turn on the other hand - :ugh:

Step Turn is from Canada - The northern hemispere has Trump physics to deal with.

Capn Rex Havoc 31st Jan 2017 08:05

Framer if you are moving on one travelator that is travelling in one direction than decide to step onto an adjacent one that is travelling in the opposite direction then yes - you will definitely have acceleration issues.

That is the same if you are flying in an airmass that is a constant headwind then you descend into an airmass that is travelling in the opposite direction. That is called wind shear.

I am giving Step Turn the benefit here and perhaps he is describing taking off and climbing from one wind condition and flying into a tailwind condition. Then you will lose performance.

Eg Taking off out of Tehran - 10 Kts head wind, passing through 500 ft AGL you encounter 25 Kts Tail wind - Then your performance descreases.

Pinky the pilot 31st Jan 2017 08:21

Griffo and josephfeathreweight; Gentlemen; You have just witnessed unequivocal proof of a theory I have had for quite some time now.:hmm:

The website known as the Professional Pilots Rumour Network, is no longer dominated by Professional Pilots!:eek::sad::mad:

No-one who has gone through all the theory courses and examinations required to gain even the basic CPL of the 1980s would come up with some of the rubbish I have read on this thread!:mad::mad:

itsnotthatbloodyhard 31st Jan 2017 08:33


Originally Posted by Pinky the pilot (Post 9659302)

No-one who has gone through all the theory courses and examinations required to gain even the basic CPL of the 1980s would come up with some of the rubbish I have read on this thread!:mad::mad:


You'd think so, Pinky, but I've heard this sort of nonsense from 20000-hr veterans of the industry. And if you point out that absolutely nothing happened to the IAS when we were flying orbits in a 50 kt wind only 10 minutes earlier, you get met with either blank incomprehension or '"But that was different.."


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