Engine quits - what approach speed
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A reasonable question I think.
Priority 1 wings level & under control
Firstly hitting the cables : they might just snap if you hit them at the right angle, but likely to change your angle of attack to something you cant predict, and would not want anyway. A smallish force at the front or back could do this. It all depends on where on the airframe you hit, and at what angle, but no way would I think about going through......
Priority 2 Slow as possible.
I would go below the wires. By pointing the nose down you would increase the airspeed, and controlability. If fully flapped, this is one of the most efficient ways of getting rid of excess energy. It is likely that you would have slowed significantly by the time you decide to let the mains touch.
This can be practiced if next time you try a glide approach, come in higher than usual. Put in full flap, and point the nose down. The airspeed does not jump through the roof, and what you pick up bleeds off quickly once going into the flair.
My 2p worth
Questions and discussion are good.
Priority 1 wings level & under control
Firstly hitting the cables : they might just snap if you hit them at the right angle, but likely to change your angle of attack to something you cant predict, and would not want anyway. A smallish force at the front or back could do this. It all depends on where on the airframe you hit, and at what angle, but no way would I think about going through......
Priority 2 Slow as possible.
I would go below the wires. By pointing the nose down you would increase the airspeed, and controlability. If fully flapped, this is one of the most efficient ways of getting rid of excess energy. It is likely that you would have slowed significantly by the time you decide to let the mains touch.
This can be practiced if next time you try a glide approach, come in higher than usual. Put in full flap, and point the nose down. The airspeed does not jump through the roof, and what you pick up bleeds off quickly once going into the flair.
My 2p worth
Questions and discussion are good.
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Actually, I was just thinking, I was clearing out behind one of our barns the other week and amongst the rubish and soil was a tangled bundle of telephone wire, it wraped itself around the tractor wheels and bucket and as I reversed out it streched to enormous lengths before snaping, it is very tenacious stuff! ( I had forgoten all about that )
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HWD,
I'm not sure your average spam can would snap a telegraph pole in two. I think a head on would probably involve the engine block being pushed back through your stomach!
Sorry HWD, after reading your post again - you did say cables!
Yorkshire,
1) Trying to fly under them - snap off your tail and plunge head first into the ground.
2) Fly into them - break your prop - be sent spinning into the ground.
3) Pull up over them - now you're at 100 feet in a nose up attitude with your airspeed gone to sh1t. Spiral into the ground.
Durr, do you think?
PS Listen to Dublinpilot, your answers are aggressive and while you may not 'give a fig', people will soon start to ignore your questions. And you can't ask your whippets can you?
I'm not sure your average spam can would snap a telegraph pole in two. I think a head on would probably involve the engine block being pushed back through your stomach!
Sorry HWD, after reading your post again - you did say cables!
Yorkshire,
1) Trying to fly under them - snap off your tail and plunge head first into the ground.
2) Fly into them - break your prop - be sent spinning into the ground.
3) Pull up over them - now you're at 100 feet in a nose up attitude with your airspeed gone to sh1t. Spiral into the ground.
but we are told to avoid them like the plague so that suggests they are very dangerous
PS Listen to Dublinpilot, your answers are aggressive and while you may not 'give a fig', people will soon start to ignore your questions. And you can't ask your whippets can you?
Last edited by Sans Anoraque; 13th Dec 2005 at 13:04.
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sorry Sans Anoraque,
I am really not interested in your opinion, sensible and polite answers only. I think your quotes above speak volumes.
Durr, do you think?
And you can't ask your whippets can you?
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Hi guys
I fly them nasty glider things, so I've been in a few fields over the years.
Points to note:-
a) You'll never see the wires themselves until it's too late, it's the poles you may be able to see.
b) From overhead, if the poles are out in the field you may get crop marks around them as a clue
c) If they're embedded in the hedge, especially if there are trees around as well, you may well not see the poles either.
d) If there is a road next to the hedge, the chances are there will be wires as well.
e) That's why not leaving it too late and flying some kind of a circuit round the field to assess slope, surface, stock and obstructions can keep you alive.
f) It's better to climb out of the wreckage at the far end of the field than to be dug out of it at the approach end (no I've not done either!)
g) Hitting wires while still airborne is right out
h) Hitting fence wires on the ground run is right out (if you're in a glider)
So don't plan on just scraping over that nice low hedge, give it 15 feet more (if you can)!
I fly them nasty glider things, so I've been in a few fields over the years.
Points to note:-
a) You'll never see the wires themselves until it's too late, it's the poles you may be able to see.
b) From overhead, if the poles are out in the field you may get crop marks around them as a clue
c) If they're embedded in the hedge, especially if there are trees around as well, you may well not see the poles either.
d) If there is a road next to the hedge, the chances are there will be wires as well.
e) That's why not leaving it too late and flying some kind of a circuit round the field to assess slope, surface, stock and obstructions can keep you alive.
f) It's better to climb out of the wreckage at the far end of the field than to be dug out of it at the approach end (no I've not done either!)
g) Hitting wires while still airborne is right out
h) Hitting fence wires on the ground run is right out (if you're in a glider)
So don't plan on just scraping over that nice low hedge, give it 15 feet more (if you can)!
Forgive me but the answer to this question seems rather obvious. Best glide speed is so called because it maximises the distance flown. No amount of climbing/decending accelerating or decellerating is going to extend your range and hence enable you to clear the wires (wherever they may be).
ANY variation from best glide speed will shorten the distance travelled. Full stop.
ANY variation from best glide speed will shorten the distance travelled. Full stop.
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c-bert, I agree with the principles of what you say but you could set up your whole forced landing based upon the poorer performance of a higher speed, if you then found the wires in your way perhaps you could safely fly over them by climbing 10 ft, using the exces airspeed.
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c-bert,
Actually, for many aircraft, your best glide range doesn't really change if you increase/decrease the best glide speed by 5kts or so (depending in type). If you increase the your glide speed slightly, then not only will you be covering just about the same amount of ground, but also you may be able to afford a little nose up as you exchange that extra 5-10kts for a little height with little net deficit.
Another wee factor to consider is that on final, you will hopefully be into wind, increasing your glide speed again gets you a little more distance. For an extreme example just to make the point, imagine a 65kt best glide speed and a 65kt headwind.
Actually, for many aircraft, your best glide range doesn't really change if you increase/decrease the best glide speed by 5kts or so (depending in type). If you increase the your glide speed slightly, then not only will you be covering just about the same amount of ground, but also you may be able to afford a little nose up as you exchange that extra 5-10kts for a little height with little net deficit.
Another wee factor to consider is that on final, you will hopefully be into wind, increasing your glide speed again gets you a little more distance. For an extreme example just to make the point, imagine a 65kt best glide speed and a 65kt headwind.
Last edited by High Wing Drifter; 13th Dec 2005 at 15:03.
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so in scenario 2 a little more speed might help avoid the stall, possibly.
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Would it be fair to ask (without setting Yorks off on another rant 
)at what time a pilot starts to reduce from best glide speed to a more suitable touch-down speed? Would such a time be some distance before said wires, and therefore there may be the possibility that in fact there is no excess speed available to hop over the wires?
)at what time a pilot starts to reduce from best glide speed to a more suitable touch-down speed? Would such a time be some distance before said wires, and therefore there may be the possibility that in fact there is no excess speed available to hop over the wires?
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Foxmoth
As regards going under the wires, it would depend surely.
In the case of wires being some distance into the field, that may well be possible, but my reading of the description was that the wires were somewhere on the approach (ie at the hedge-line or preceding field)
Assuming there was actually room to do so, to get under telephone wires your wheels (well, mine actually) would be on the ground, which would mean embedding myself in the undershoot field or the hedge at around 65kts.
If you are really on the ball, (and in this situation who would be) you could (just) convert speed to height and back again to clear the wires.
In reality, I think this is fairly academic. You wouldn't want to scrape so low into a field that a 10-15' obstruction would mess it up. And if you were caught out, well, you do what you can.
I've seen pictures of Cessna's caught up in telephone and low-voltage electricity cables and held off the ground.
As regards going under the wires, it would depend surely.
In the case of wires being some distance into the field, that may well be possible, but my reading of the description was that the wires were somewhere on the approach (ie at the hedge-line or preceding field)
Assuming there was actually room to do so, to get under telephone wires your wheels (well, mine actually) would be on the ground, which would mean embedding myself in the undershoot field or the hedge at around 65kts.
If you are really on the ball, (and in this situation who would be) you could (just) convert speed to height and back again to clear the wires.
In reality, I think this is fairly academic. You wouldn't want to scrape so low into a field that a 10-15' obstruction would mess it up. And if you were caught out, well, you do what you can.
I've seen pictures of Cessna's caught up in telephone and low-voltage electricity cables and held off the ground.
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Robin
If you read my previous posts I think you will find I have said pretty much what you are saying, the earlier suggestions was that it was a "normal" PFL with wires in the way in which case you are landing well into the field and the wires would not be a problem and you could either go over them or, if they were further into the field land under. It was then that it was talked about landing over the hedge in which case I said much as you have - read the earlier posts before you comment!
If you read my previous posts I think you will find I have said pretty much what you are saying, the earlier suggestions was that it was a "normal" PFL with wires in the way in which case you are landing well into the field and the wires would not be a problem and you could either go over them or, if they were further into the field land under. It was then that it was talked about landing over the hedge in which case I said much as you have - read the earlier posts before you comment!
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Yorks said
Not all forced landings are like landing a glider, things can go horribly wrong very quickly and what Yorks has said above is the rule I applied when my engine went bang
and it is because of this I won the CAA Safety Award and none of my passengers or people on the ground were hurt.
When faced with visibility down to a minimum due to oil on the windshield and smoke in the cabin you cannot judge what the picture is going to be like on your final approach. So increasing the glide speed can allow you to trade speed for height in the last moments, it gave me the option to pull up avoiding people on the beach and option two had I needed to land in the sea.
Every forced landing is different and should in my opinion be treated so.
Would it be sensible to fly a faster approach to give the opportunity to climb briefly if needed without the risk of stalling.
Not all forced landings are like landing a glider, things can go horribly wrong very quickly and what Yorks has said above is the rule I applied when my engine went bang
and it is because of this I won the CAA Safety Award and none of my passengers or people on the ground were hurt.When faced with visibility down to a minimum due to oil on the windshield and smoke in the cabin you cannot judge what the picture is going to be like on your final approach. So increasing the glide speed can allow you to trade speed for height in the last moments, it gave me the option to pull up avoiding people on the beach and option two had I needed to land in the sea.
Every forced landing is different and should in my opinion be treated so.
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When faced with visibility down to a minimum due to oil on the windshield and smoke in the cabin you cannot judge what the picture is going to be like on your final approach.
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Fox
agree 100% standard procedures are extremely important in training. I was just adding a bit of reality into the scenario in that the idea of a PFL is very different to the actual.
agree 100% standard procedures are extremely important in training. I was just adding a bit of reality into the scenario in that the idea of a PFL is very different to the actual.
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power cables etc
Years ago we used to have some farm crops sprayed and fertilised using aerial application via a Pawnee,which carried 500kgs of chemical.
The pilot was either South African or Rhodesian,and around 50 years old.
When I asked about the fatality rate he told when you get to his age you are past all the fatalities!
He flew under all the cables,and had a cutter bar thing in front of the cockpit in case he hit anything.
In fact he hit some power cables on another local farm,and put the whole area out for a while but he survived.
When he was applying stuff in small areas I had to mark for him by standing under his path with a flag.
He used to go over me at around 10-15 feet,I thought it was great but was a lot younger then!
Imagine what the health and safety bods would say about that today?
He also told me although it was a single seater he had taken the occassional passenger, if they were very pretty.
I smiled my best smile, but no such luck.
Lister
The pilot was either South African or Rhodesian,and around 50 years old.
When I asked about the fatality rate he told when you get to his age you are past all the fatalities!
He flew under all the cables,and had a cutter bar thing in front of the cockpit in case he hit anything.
In fact he hit some power cables on another local farm,and put the whole area out for a while but he survived.
When he was applying stuff in small areas I had to mark for him by standing under his path with a flag.
He used to go over me at around 10-15 feet,I thought it was great but was a lot younger then!
Imagine what the health and safety bods would say about that today?
He also told me although it was a single seater he had taken the occassional passenger, if they were very pretty.
I smiled my best smile, but no such luck.
Lister