Mallard Down in Perth
Join Date: Oct 2014
Location: Windsor
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Conceded.
Another point to make is the aileron goes to mushy feel which further adds to the distress and confusion, rather than triggering an alert that a stall then spin is about one or two seconds away.
Sadly this pilot was just not aware of what was happening and the alerts that were being supplied were not registering.
Forgive my inability to express myself here, but there was enough indication, that something needed to be done and the pilot just did not twig, forgive that expression, that all sorts of hell was less than five seconds away, unless he took prompt corrective action.
unless you have stalled the wing.. exactly. Now the opposite aileron instead lifting the wing as it normally does, further slows that wing increasing the stall and wing drop. The pilot is going a bit fuzzy in the head and doubts what is happening is real, the aileron is mushy and does not work which further adds to the fuzz. If the pilot goes to full extent with aileron, that makes the wing drop further .. by now ... the pilot is confused and sadly doomed by the unexpected.
Which I suppose leads to my previous of doing training with flying near the stall for a hour or three with gliders and doing a few dozen spins ... thus a stall will be instantly recognised and corrected.
Another point to make is the aileron goes to mushy feel which further adds to the distress and confusion, rather than triggering an alert that a stall then spin is about one or two seconds away.
Sadly this pilot was just not aware of what was happening and the alerts that were being supplied were not registering.
Forgive my inability to express myself here, but there was enough indication, that something needed to be done and the pilot just did not twig, forgive that expression, that all sorts of hell was less than five seconds away, unless he took prompt corrective action.
unless you have stalled the wing.. exactly. Now the opposite aileron instead lifting the wing as it normally does, further slows that wing increasing the stall and wing drop. The pilot is going a bit fuzzy in the head and doubts what is happening is real, the aileron is mushy and does not work which further adds to the fuzz. If the pilot goes to full extent with aileron, that makes the wing drop further .. by now ... the pilot is confused and sadly doomed by the unexpected.
Which I suppose leads to my previous of doing training with flying near the stall for a hour or three with gliders and doing a few dozen spins ... thus a stall will be instantly recognised and corrected.
Last edited by X35B; 1st Feb 2017 at 09:14. Reason: add more
Another point to make is the aileron goes to mushy feel which further adds to the distress and confusion, rather than triggering an alert that a stall then spin is about one or two seconds away.
Could I also suggest that flying a glider near the stall would be very different situation to a heavier and highly wing loaded type such as the Mallard?
So many posters here with psychic powers!
The ATSB will be contacting you soon!
Sadly this pilot was just not aware of what was happening and the alerts that were being supplied were not registering
The ATSB will be contacting you soon!
There is a very important demonstration for glider pilots who winch.
Nose up 40 degrees.
simulated cable break.
nose to recovery attitude of 30 degrees nose down.
initiate turn without waiting for airspeed to recover using aileron and balancing rudder whilst looking over your shoulder at the airfield.
Add more rudder to "increase" the turn rate.
Nose starts dropping
Heave back on stick
Still killing pilots but not so many as part of the annual flying checks in the UK.
As to ground speed verses airspeed...spun a paraglider three times now on a steep slope with the wind partially across the slope giving both upwind and downwind beats added to wind gradient....and I've got fifty years of flying...there but the grace of Dog...
Nose up 40 degrees.
simulated cable break.
nose to recovery attitude of 30 degrees nose down.
initiate turn without waiting for airspeed to recover using aileron and balancing rudder whilst looking over your shoulder at the airfield.
Add more rudder to "increase" the turn rate.
Nose starts dropping
Heave back on stick
Still killing pilots but not so many as part of the annual flying checks in the UK.
As to ground speed verses airspeed...spun a paraglider three times now on a steep slope with the wind partially across the slope giving both upwind and downwind beats added to wind gradient....and I've got fifty years of flying...there but the grace of Dog...
Join Date: Aug 2007
Location: Chedburgh, Bury St.Edmunds
Age: 81
Posts: 1,174
Likes: 0
Received 7 Likes
on
5 Posts
Said this before on another thread. The Americans have/had a saying.''Watch him spin, watch him burn, he took off bank in a low speed turn''.
Ha this effect demonstrated to me in a T.21 Sedburgh when I was in the Air Training Corps in England. When I went on to a PPL I NEVER forgot that demonstration.
ULTRALIGHT. It WILL stall the wing if already very close to the stall!.
Ha this effect demonstrated to me in a T.21 Sedburgh when I was in the Air Training Corps in England. When I went on to a PPL I NEVER forgot that demonstration.
ULTRALIGHT. It WILL stall the wing if already very close to the stall!.
JEM60, I was taught that when I was very young, it was then, "hold off bank in a gliding turn and you will surely crash and burn." I believe it related to the fact that the Austers, Tigers and Chipmunks all had Gypsy engines turning back to front from modern engines. Also some of the Auster variants had heavy wooden cruise props, one of which I recall, mk 3? would smartly turn sharply if you closed the throttle without leading with a lot of rudder. You would have to try very hard to get into trouble but I suppose the possibility existed that you could end up with crossed controls at low level combined with a windshear. I was young and silly then and I am still here, so it couldn't have been too bad but all of those old sayings obviously existed because someone had died proving them.
Join Date: Oct 2014
Location: Windsor
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
A few accidents of note https://aviation-safety.net/database...ard/statistics
Total of crashes: 15
Total of fatalities: 59
Worst crash: Dec 19, 2005 with 20 fatalities
From http://www.baaa-acro.com/
ATSB - Collision with water involving Grumman American Aviation Corp G-73, registered VH-CQA, 10 km WSW of Perth Airport, Western Australia on 26 January 2017
Investigation Title - Nothing much at present.
Total of crashes: 15
Total of fatalities: 59
Worst crash: Dec 19, 2005 with 20 fatalities
From http://www.baaa-acro.com/
ATSB - Collision with water involving Grumman American Aviation Corp G-73, registered VH-CQA, 10 km WSW of Perth Airport, Western Australia on 26 January 2017
Investigation Title - Nothing much at present.
Last edited by X35B; 3rd Feb 2017 at 06:28. Reason: add more
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.
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.
The answer to the downwind turn lies in whether the aircraft has high mass and high density at one end of the scale or has low mass and low density at the other end of the scale.
Consider a rubber-band-powered balsa wood toy aircraft of a few grams turning downwind...yep, no easily measurable change in IAS. But a huge change in groundspeed.
Now consider a ballistic bullet fired in a straight line through a multitude of wind velocity changes. When the bullet experiences a headwind or a tail wind change, does the IAS of the bullet remain fairly constant or does the groundspeed remained constant?
Those who have experienced operating high mass and high density aircraft at low airspeed and rapid maneuvering at low altitude in high winds have a tale to tell...but only to those who might listen.
Vincent Chase's comments about his flying in a fully loaded cropduster indicate that he has experienced the phenomena causing him to crash. But he survived and has learned the bitter lesson of the downwind turn. He has a tale to tell...but only to those who might listen.
Good luck to the other Sky Gods.
In a previous life I use to drop bombs using a manual aiming system. The bombs pretty much fell to earth in accordance with the laws of Newton.
Unfortunately, the air mass velocity at the altitude at which they were released was always different from the many changes in wind velocity that the bomb saw on the way down. This would cause the bomb to miss the target. Therefore we had to compensate with an offset aim point by calculating an average wind velocity.
The offset was determined by applying the average wind velocity to the drift acceptance factor of the weapon. Heavy and high density weapons had a smaller drift acceptance factor than lighter and low density weapons which were obviously more affected by wind velocity changes.
Be careful when you think that you know everything about aviation...
Last edited by FlexibleResponse; 3rd Feb 2017 at 11:45. Reason: additional words added
Join Date: May 2007
Location: Australia
Posts: 190
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by FlexibleResponse
Now consider a ballistic bullet fired in a straight line through a multitude of wind velocity changes. When the bullet experiences a headwind or a tail wind change, does the IAS of the bullet remain fairly constant or does the groundspeed remained constant?
Once fired, a projectile's BC (and longitudinal axis stability, which affects BC) - otherwise known as its drag profile - will determine how quickly its velocity and kinetic energy are lost, as its mass remains constant.
A headwind will cause the projectile to strike the target lower, as it has more air mass to cover, more time to reach the target, more time for drag and gravity to act. A tailwind will move the point of impact up. A crosswind will move the POI to the side and down, as it increases the distance the projectile must cover. In all scenarios, the groundspeed differs in relation to nil-wind conditions.
Compare two projectiles of equal mass and velocity, but high and low BC ("pointy" versus "blunt" bullets). The more aerodynamic projectile is less affected by wind (in all conditions), and it's POI does not shift as much . . . which, as you can see, has nothing to do with mass.
Neither does gravity, for that matter - if a feather were as aerodynamic as a bomb, they would both fall at the same speed.
Where I think some are getting confused with mass and inertia is in relation to changing constants.
Why is a turn into downwind at low level a potential hazard? Because of the wind-direction. No, not the direction of the constant air mass, but the direction of any gusts or other changes in wind velocity (vectors) which are more likely to happen close to the ground due to friction and other variables, and are generally (but not always) in line with the prevailing wind direction.
If you are turning into a constant tailwind at a constant airspeed, and that wind suddenly gusts, your airspeed will instantly decay in direct proportion to the suddenly increasing tailwind component (vector). This is where mass (inertia) affects how long it takes for airspeed to recover and stabilise.
An aircraft in a constant air mass will not suddenly change direction in relation to the earth if that air mass suddenly changes direction. It takes time for the aircraft to accelerate, decelerate or otherwise change direction in line with the new constant (vector) due to its inertia (which has everything to do with mass).
This is basic aerodynamics that we learned in PPL. Maybe we should all read some Bob Tait?
Bob Tait's Aviation Theory School - Wind Shear - Bob Tait's Aviation Theory School Forums
An aircraft in a constant air mass will not suddenly change direction in relation to the earth if that air mass suddenly changes direction. It takes time for the aircraft to accelerate, decelerate or otherwise change direction in line with the new constant (vector) due to its inertia (which has everything to do with mass).
...and vice versa...a rapid air mass direction change...or a rapid aircraft direction change.
It takes time for the aircraft to accelerate, decelerate or otherwise change direction in line with the new constant (vector) due to its INERTIA (which has everything to do with MASS).
Thanks for the help in explaining.
Cheers!
Last edited by FlexibleResponse; 3rd Feb 2017 at 13:32. Reason: typo
Re... it was then, "hold off bank in a gliding turn and you will surely crash and burn." I believe it related to the fact that the Austers, Tigers and Chipmunks all had Gypsy engines turning back to front from modern engines.
HA HA HA ...!!!
NO CHEERS....NOPE....NONE AT ALL...!!!
Wot utter B/S......
HA HA HA ...!!!
NO CHEERS....NOPE....NONE AT ALL...!!!
Wot utter B/S......
Join Date: May 2007
Location: Australia
Posts: 190
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by FlexibleResponse
...and vice versa...a rapid air mass direction change...or a rapid aircraft direction change.
Imagine a motorcycle being ridden in a straight line on an aircraft carrier. If the aircraft carrier turns left, so does the motorcycle (in relation to the earth) - even though it's still driving straight. Now, put the same motorcycle on a runway and ask the rider to make a left turn. The motorcycle again turns left (in relation to the earth) - but the runway hasn't moved.
In both cases, the rider feels centrifugal force as the motorcycle banks left due to their combined inertia and needs to use the same leaning force into the same rate of turn to remain astride - even when he's riding "straight".
So you'll forgive me if I don't fully understand what other forces are at work to change the direction (air speed) of an aircraft in a constant angle of bank in a constant air mass.
Assuming drag, lift, thrust and weight don't change in a constant turn (in a constant air mass and density), what other force is there to upset the lift-weight/drag-thrust equation to cause velocity (air speed) to suddenly change?
Neither does gravity, for that matter - if a feather were as aerodynamic as a bomb, they would both fall at the same speed.
Both are dropped from a B1. Which hits the ground first?
There is a great video on youtube of a feather and bowling ball being dropped in a vacuum and both falling at the exact same speed (as you would expect with no air resistance).
In your example CS that's a hard one to work out. With inertia, air resistance etc all factored in I suspect the heavier bomb first but I am not really sure.
In your example CS that's a hard one to work out. With inertia, air resistance etc all factored in I suspect the heavier bomb first but I am not really sure.
Someone took me on on this subject after the MH17. If you have any doubt about which falls faster, get a basketball filled with concrete and a balloon the same size and roll them off a tabletop with your feet below. (Do this at home, not in a vacuum satellite testing silo with Brian Cox, nor on Mare Ibrium with David Scott).
But this is a digression from the real task at hand. I posted it as it does show that there are a lot of poor analogies, mistaken arguments and confused points scattered through this thread (not directed in particular about the poster above whom I quoted).
We've had standard turns in uniform parcels of air mixed with zoom climbing turns, windshear, non uniform air movement, gradient winds.
People talking about frames of reference, maybe, but its the terms of reference of the question that need clarifying before any answer.
You can't disprove the downwind turn theory (or lack of) in a uniform parcel of air by using examples of climbing turns in gradient wind.
But this is a digression from the real task at hand. I posted it as it does show that there are a lot of poor analogies, mistaken arguments and confused points scattered through this thread (not directed in particular about the poster above whom I quoted).
We've had standard turns in uniform parcels of air mixed with zoom climbing turns, windshear, non uniform air movement, gradient winds.
People talking about frames of reference, maybe, but its the terms of reference of the question that need clarifying before any answer.
You can't disprove the downwind turn theory (or lack of) in a uniform parcel of air by using examples of climbing turns in gradient wind.
In my post #207, I said...
In relation to the currently discussed vexing question of an aircraft turning downwind, I should really have said:
Inertial mass is earth/time dependent for frame of reference.
I hope I didn't annoy anyone out there who have an in-depth knowledge of the theory of Inertial Reference Units systems fitted to aircraft.
Inertial mass is space/time dependent for frame of reference.
Inertial mass is earth/time dependent for frame of reference.
I hope I didn't annoy anyone out there who have an in-depth knowledge of the theory of Inertial Reference Units systems fitted to aircraft.