Over the fence
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Over the fence
Heard this expression before? E.g. 75kts on final, decreasing to 70kts over the fence.
This might seem like a really obvious question to those who already know, but I can't find an actual definition of it anywhere. Does this refer to an invisible fence of 50ft over the approach end of the runway, or the actual aerodrome boundary fence?
This might seem like a really obvious question to those who already know, but I can't find an actual definition of it anywhere. Does this refer to an invisible fence of 50ft over the approach end of the runway, or the actual aerodrome boundary fence?
Good question. "Over the fence" is the British/Australian version of the American FAA standard fifty foot tall tree that stands at each end of the mythical standard runway.
Which brings up the matter of whyferchrissake? The answer to which is that your Landing Distance table is based on the assumption that you arrive at the threshold at the specified V ref at exactly 50 feet altitude with zero head or tail wind.
........and if you arrive much faster than Vref in a Cessna 172 you will float and bounce from one end of the runway to the other.
Which brings up the matter of whyferchrissake? The answer to which is that your Landing Distance table is based on the assumption that you arrive at the threshold at the specified V ref at exactly 50 feet altitude with zero head or tail wind.
........and if you arrive much faster than Vref in a Cessna 172 you will float and bounce from one end of the runway to the other.
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And as pilots do arrive at the fence going like the clappers becauase thats what they are taught to do , float and bounce to the end and in some cases the end seems to come up be the floating stops.
Its not normally the pilots fault, it will be blamed on the wet grass or the tail wind!!
Its not normally the pilots fault, it will be blamed on the wet grass or the tail wind!!
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standard fifty foot tall tree
.. which, apparently, is where the design requirement originated back in the very early US civil regulatory olden days .. related to a parade ground at a military base where an early demonstration flight was made ..
.. which, apparently, is where the design requirement originated back in the very early US civil regulatory olden days .. related to a parade ground at a military base where an early demonstration flight was made ..
VH-Vin, I'm told that a certain flying school doesn't even put the placards on the C172 firewall since its added labor to remove them again when the wall is inevitably changed.
Yes I bent one, but when I went to have a look, there were five others much more bent awaiting repair.
Yes I bent one, but when I went to have a look, there were five others much more bent awaiting repair.
That is facinating JT! No sarcasm, I really mean it. Amazing where some requirements come from.
During a line check some years ago, I was asked what runway conditions would give the greatest performance margin at a certain aerodrome, wet or dry? If the runway was long enough and there were no terrain considerations the numbers can often be the same. Apparently not! If length and climb gradient were not factor, the wet runway would in some cases provide a marginaly better performance!
During the certification process the "fence" at the end of a wet runway is considered to be 35 feet in height, whereas the "fence" at the end of a dry runway is considered to be 50 feet! Where do they get this stuff.
Anyway, it was a means by which the checkers could demonstrate their superior knowledge. My appologies to those out there that knew the answer, but it certainly had me stumped. Once the word had got around, the decision was made to alter the performance tables to match the most conservative case, and put a stop to a lot of head scratching.
During a line check some years ago, I was asked what runway conditions would give the greatest performance margin at a certain aerodrome, wet or dry? If the runway was long enough and there were no terrain considerations the numbers can often be the same. Apparently not! If length and climb gradient were not factor, the wet runway would in some cases provide a marginaly better performance!
During the certification process the "fence" at the end of a wet runway is considered to be 35 feet in height, whereas the "fence" at the end of a dry runway is considered to be 50 feet! Where do they get this stuff.
Anyway, it was a means by which the checkers could demonstrate their superior knowledge. My appologies to those out there that knew the answer, but it certainly had me stumped. Once the word had got around, the decision was made to alter the performance tables to match the most conservative case, and put a stop to a lot of head scratching.
Off topic but here goes anyway.
Well firewalls are regularly being bent through those new to the Cessna 172 not appreciating:
1) The behaviour of the little feller when it is landed at 70 knots rather then 60 or 55. I watched one float the whole length (or so it seemed) of 35L, or perhaps the guy was in a hurry to get to the loo.
2) The meaning of the term "Pilot Induced Oscillation".
3) The cure for (1) and (2).
One of the problems of the latest CASA "Competency based" training method (or whatever its called) is that once you have demonstrated the competency, that's it, you have your rating/endorsement/GFPT/whatever you are considered competent.
The fly in the ointment is that you never find out what happens when you are incompetent. Going back a few years I was told "protect the nosewheel" - from what? Spaghetti monsters? And how? Let alone the all important "What if I don't?"
In my case I had a perfectly normal endorsement on a C172 (I already had a PPL) and on the day I got it I had about a 20 knot breeze down the runway, so the fact that I was speeding on final was masked.
Nobody told me: "Now listen Sunfish, if you try and land this thing at more than 60 knots, it will have too much kinetic energy, the aircraft will bounce, which will mightily surprise you, and if you try and chase the aircraft with the elevator, each bounce will be progressively worse, and after watching you attempt a touch and go this way three times the tower staff will be weeping and call you in, and the insurance excess will be $1500."
I don't mind confessing, I have no shame, I'm an unaerodynamic clod with no expectations of gracing the drivers seat of anything jet powered.
But I am concerned about what is not required to be taught, and I am slowly trying to address these matters, preferably in an aerobatic aircraft with suitable instruction.
Questions that I want answered include:
1. How do I recognise and recover from a spin with the least loss of altitude?
2. Exactly what does a stall/spin in landing configuration during the turn from base to final feel like? How do I recognise it and recover? (preferably tried at 6000ft.)
There are many things I know I don't know and I hope to spend time finding the answers under controlled conditions.
Well firewalls are regularly being bent through those new to the Cessna 172 not appreciating:
1) The behaviour of the little feller when it is landed at 70 knots rather then 60 or 55. I watched one float the whole length (or so it seemed) of 35L, or perhaps the guy was in a hurry to get to the loo.
2) The meaning of the term "Pilot Induced Oscillation".
3) The cure for (1) and (2).
One of the problems of the latest CASA "Competency based" training method (or whatever its called) is that once you have demonstrated the competency, that's it, you have your rating/endorsement/GFPT/whatever you are considered competent.
The fly in the ointment is that you never find out what happens when you are incompetent. Going back a few years I was told "protect the nosewheel" - from what? Spaghetti monsters? And how? Let alone the all important "What if I don't?"
In my case I had a perfectly normal endorsement on a C172 (I already had a PPL) and on the day I got it I had about a 20 knot breeze down the runway, so the fact that I was speeding on final was masked.
Nobody told me: "Now listen Sunfish, if you try and land this thing at more than 60 knots, it will have too much kinetic energy, the aircraft will bounce, which will mightily surprise you, and if you try and chase the aircraft with the elevator, each bounce will be progressively worse, and after watching you attempt a touch and go this way three times the tower staff will be weeping and call you in, and the insurance excess will be $1500."
I don't mind confessing, I have no shame, I'm an unaerodynamic clod with no expectations of gracing the drivers seat of anything jet powered.
But I am concerned about what is not required to be taught, and I am slowly trying to address these matters, preferably in an aerobatic aircraft with suitable instruction.
Questions that I want answered include:
1. How do I recognise and recover from a spin with the least loss of altitude?
2. Exactly what does a stall/spin in landing configuration during the turn from base to final feel like? How do I recognise it and recover? (preferably tried at 6000ft.)
There are many things I know I don't know and I hope to spend time finding the answers under controlled conditions.
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Hopefully Sunnie you've also changed flying schools/instructors. To have been sent solo let alone reach a ppl and not have been made aware of PIO is not CASAs fault but solely rests with an incompetant training organisation - especially considering you are also seeking answers to the other two basics one would have expected to be taught.
Sunfish
I learned to fly in a C150 (owned by my instructor) and have never understood how firewalls of 150/172/182 etc get bent with regularity - mostly by pilots who did not learn in a C150, I suspect.
I had - accurate speed control on approach / holding off with the nose well up until the aeroplane was done with flying / immediate go around if I f*cked it up - absolutely hammered into me from my first hour in the circuit.
If I didn't get a squeek from the stall warning just before the main wheels touched - then I hadn't done it right.
The majority of landings were made with full-flap (40o) so the significant change in nose attitude from approach to flare became very familiar - as did the need to PUSH THE CONTROL COLUMN FORWARD TO MAINTAIN THE CORRECT NOSE ATTITUDE ON A FULL-FLAP GO-ROUND.
I have never ever understood how people manage to stall-spin a C150/152/172 on a go-round with full flap.
Being my instructor's own aircraft, he was damn sure that I was going to do it right before going solo.
There was NEVER any of this 3-wheeler touchdown stuff that you see so commonly around many training aerodromes today.
1) Why? In 35 years of flying I have never had an aeroplane stall/spin that I hadn't intended to do so or anticipate that it might (ie when chasing loo paper thrown out the window in order to cut same.
No, I lie. I once went up to teaching myself snap rolls. C150 Aerobat in one hand - aerobatics "how to" manual in the other. My first attempt at a snap roll ended with me recovering from a spin some 1000' or so below my starting altitude. Fortunately, I am basically a coward an I had climbed to about 9000 for my self taught lesson.
2) Did you not do this in training? A scan back through my log book reveals - stalls (no power, no flap), stalls (no power, 20o flap), stalls (power, no flap), stalls (power, 20o flap), stalls in climbing turns, stalls from descending turns, stalls - accelerated entry, incipient spins etc etc
I am spin/aerobatics trained but I believe that if an aeroplane inadvertantly spins on me it will most likely happen at low level and I will probably die with the words "What the f*ck!" on my lips.
Dr
PS: Sunny, I don't know when/where you learnt to fly but I think some of this is a reflection on low time/low experience/poorly taught instructors who are not comfortable doing this stuff!
I did my initial IF training in NZ - my instructor's idea of "recoveries from unusual attitudes" with me under the hood on limited panel was to spin the aeroplane (Tommyaxe) and say "you have control!". Slackie knows to whom I refer. In 20+ IR renewals I have never had more interesting recoveries from unusual attitudes.
I learned to fly in a C150 (owned by my instructor) and have never understood how firewalls of 150/172/182 etc get bent with regularity - mostly by pilots who did not learn in a C150, I suspect.
I had - accurate speed control on approach / holding off with the nose well up until the aeroplane was done with flying / immediate go around if I f*cked it up - absolutely hammered into me from my first hour in the circuit.
If I didn't get a squeek from the stall warning just before the main wheels touched - then I hadn't done it right.
The majority of landings were made with full-flap (40o) so the significant change in nose attitude from approach to flare became very familiar - as did the need to PUSH THE CONTROL COLUMN FORWARD TO MAINTAIN THE CORRECT NOSE ATTITUDE ON A FULL-FLAP GO-ROUND.
I have never ever understood how people manage to stall-spin a C150/152/172 on a go-round with full flap.
Being my instructor's own aircraft, he was damn sure that I was going to do it right before going solo.
There was NEVER any of this 3-wheeler touchdown stuff that you see so commonly around many training aerodromes today.
Questions that I want answered include:
1. How do I recognise and recover from a spin with the least loss of altitude?
2. Exactly what does a stall/spin in landing configuration during the turn from base to final feel like? How do I recognise it and recover? (preferably tried at 6000ft.)
1. How do I recognise and recover from a spin with the least loss of altitude?
2. Exactly what does a stall/spin in landing configuration during the turn from base to final feel like? How do I recognise it and recover? (preferably tried at 6000ft.)
No, I lie. I once went up to teaching myself snap rolls. C150 Aerobat in one hand - aerobatics "how to" manual in the other. My first attempt at a snap roll ended with me recovering from a spin some 1000' or so below my starting altitude. Fortunately, I am basically a coward an I had climbed to about 9000 for my self taught lesson.
2) Did you not do this in training? A scan back through my log book reveals - stalls (no power, no flap), stalls (no power, 20o flap), stalls (power, no flap), stalls (power, 20o flap), stalls in climbing turns, stalls from descending turns, stalls - accelerated entry, incipient spins etc etc
I am spin/aerobatics trained but I believe that if an aeroplane inadvertantly spins on me it will most likely happen at low level and I will probably die with the words "What the f*ck!" on my lips.
Dr
PS: Sunny, I don't know when/where you learnt to fly but I think some of this is a reflection on low time/low experience/poorly taught instructors who are not comfortable doing this stuff!
I did my initial IF training in NZ - my instructor's idea of "recoveries from unusual attitudes" with me under the hood on limited panel was to spin the aeroplane (Tommyaxe) and say "you have control!". Slackie knows to whom I refer. In 20+ IR renewals I have never had more interesting recoveries from unusual attitudes.
Last edited by ForkTailedDrKiller; 29th Feb 2008 at 04:22.
75kts on final, decreasing to 70kts over the fence
I'm told that a certain flying school doesn't even put the placards on the C172 firewall since its added labor to remove them again when the wall is inevitably changed
there is NO excuse for bending a firewall
Exactly what does a stall/spin in landing configuration during the turn from base to final feel like
if an aeroplane inadvertantly spins on me it will most likely happen at low level
I'd like to hope the "bent firewall" epidemic is a thing of the past. I suspect it has something to do with language matters that has hopefully now been rectified. In my case it wasn't language, just a gap in my learning.
I wouldn't blame instructors quite so fast either. Stall recovery clean and dirty have to be demonstrated for your licence, but stalls in turns and spin recovery are not part of the syllabus these days.
I wouldn't blame instructors quite so fast either. Stall recovery clean and dirty have to be demonstrated for your licence, but stalls in turns and spin recovery are not part of the syllabus these days.
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my instructor's idea of "recoveries from unusual attitudes" with me under the hood on limited panel was to spin the aeroplane (Tommyaxe) and say "you have control!"
Forkie
Your instructor must have been related to mine, he loved doing the same thing to me......and that was just PPL under the hood training
Really would like to do more of it actually.
J
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Sunnie and the Dr have both noted something which I see regularly, approach speeds well above what the book calls for.
When I was based in Alice Springs I used to see it, especially from 210 drivers. Your attention was drawn to the aircraft floating inelegantly down the runway having overflared and now struggling to get it back into reasonable proximity of the runway before it runs out of steam.
Having said that, I have seen it elsewhere as well.
I still think it goes back to improper training where getting the aircraft properly set up for landing and speed control does not appear to be emphasised. Is this the product of too many instructors being trained as an add-on from becoming a commercial pilot? Perhaps CASA should start looking at increased minimum experience levels for an instructor rating? After all, if the basics are not there, then the rest will be founded on shaky foundations. Not good for the future of aviation.
When I was based in Alice Springs I used to see it, especially from 210 drivers. Your attention was drawn to the aircraft floating inelegantly down the runway having overflared and now struggling to get it back into reasonable proximity of the runway before it runs out of steam.
Having said that, I have seen it elsewhere as well.I still think it goes back to improper training where getting the aircraft properly set up for landing and speed control does not appear to be emphasised. Is this the product of too many instructors being trained as an add-on from becoming a commercial pilot? Perhaps CASA should start looking at increased minimum experience levels for an instructor rating? After all, if the basics are not there, then the rest will be founded on shaky foundations. Not good for the future of aviation.
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Jaba/FTDK -we must be of the same vintage... spinning a Rat**** Hatchet is truly one of life's more memorable experiences. Especially if you look over your shoulder when it's fully developed! More of it? 'Fer sure, just not in a Rat**** Hatchet. It was a frequent part of my early training from ab initio (2nd flight) to CPL; don't feel the need to watch that tail slapping around any more.
The venerable 172... much used, much abused. That any 172 (or any other airframe) needs suffer a bent firewall due mishandling in the landing phase is beyond me. It should be bred out of the trainees before they are sent solo -either sufficiently developed handling skills that it is unlikely to happen or a well-developed self-preservation instinct: firewall it and get the hell out of dodge until you/the conditions settle enough to have another go. That should really be the end of that story.
The change from 40deg flap to 30deg flap (bought about by the number of Yanks killing themselves in 172's trying to go around with the barn-doors all the way down) was IMO a bad move. The approach with only 30deg is far shallower, flare considerably less positive, speed more difficult to control and the aircraft just feels 'mushier' for wont of a better word. Give me the 40's any day -rail those puppies out, things start happening. You needed to be on the ball if going missed, but the aircraft was/is truly docile and easy to handle in all phases of flight I reckon, if just a bit gutless.
Spin recoveries? Done a few, reckon the easiest and most likely successful recovery technique I've ever been taught is one I learned not that long ago in a Pitts S2B:
It works.
As for the stall/spin/crash/burn/die in the landing phase... why would you ever allow yourself to put an aircraft into a position likely to cause it???? If you think it's likely, best get some more instruction from those experienced enough to show you how.
The venerable 172... much used, much abused. That any 172 (or any other airframe) needs suffer a bent firewall due mishandling in the landing phase is beyond me. It should be bred out of the trainees before they are sent solo -either sufficiently developed handling skills that it is unlikely to happen or a well-developed self-preservation instinct: firewall it and get the hell out of dodge until you/the conditions settle enough to have another go. That should really be the end of that story.
The change from 40deg flap to 30deg flap (bought about by the number of Yanks killing themselves in 172's trying to go around with the barn-doors all the way down) was IMO a bad move. The approach with only 30deg is far shallower, flare considerably less positive, speed more difficult to control and the aircraft just feels 'mushier' for wont of a better word. Give me the 40's any day -rail those puppies out, things start happening. You needed to be on the ball if going missed, but the aircraft was/is truly docile and easy to handle in all phases of flight I reckon, if just a bit gutless.
Spin recoveries? Done a few, reckon the easiest and most likely successful recovery technique I've ever been taught is one I learned not that long ago in a Pitts S2B:
- Close the throttle completely
- Let everything go -I do mean everything, particularly the stick
- Kick full rudder opposite the rotation, hold until the rotation stops, then ease
- Centralise the stick
- Recover smoothly to S&L, bringing the power back up.
It works.
As for the stall/spin/crash/burn/die in the landing phase... why would you ever allow yourself to put an aircraft into a position likely to cause it???? If you think it's likely, best get some more instruction from those experienced enough to show you how.
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Originally Posted by PLovett
approach speeds well above what the book calls for.
The book recommends 1.3 Vs. That should be any amount of speed for bloody near any conditions or configuration. Often a lot less will be appropriate, certainly as experience and familiarity with type grows.
excess speed and the Landing
When I was based in Alice Springs I used to see it, especially from 210 drivers. Your attention was drawn to the aircraft floating inelegantly down the runway having overflared and now struggling to get it back into reasonable proximity of the runway before it runs out of steam. Having said that, I have seen it elsewhere as well.
We had an excellent demonstration of how 210's handle on their nosewheels, in our area, a couple of years ago. People (let's just say that they should've known better) in question appeared to conduct a nice 3 point at approx 80kts. Only 20 deg flap with half nose down trim, relax back pressure on contact with ground, and enjoy the ride.
Most impressive from the sidelines.
As to 40 deg flap, you could point the nose at the ground and still only get about 70 kts max in the older C172's.
185.