Potential conflict near gliding sites.
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Potential conflict near gliding sites.
Please can you help me to understand why some light aircraft and particularly helicopter pilots fly quite so close to my gliding club? An example; yesterday, midday I was about to launch when a helicopter flew roughly east-west at less than 1,000ft above airfield height, a quarter of a mile to the south of our field. About two hours later, while I was airborne at about 2,000ft, a helicopter flew directly beneath me, a few hundred feet below. It looked like the aircraft that I’d seen earlier and it was on the reciprocal track. The airfield has been in existence for many years and is marked as a gliding site on half mil and quarter mil charts. We all have equal right to be there - there is no question of ‘right’ or ‘wrong’, just one of, ‘what is sensible’? On most days, within a radius of a mile or so of the field, there are likely to be a number of gliders flying at around 1,000 to 1,500ft. These will include training aircraft and early solo single-seaters as well as cross country pilots returning to our site. It happens occasionally and so we are very alert to the sound of approaching aircraft. We stop launching if we think one is getting too close. Would it not be a good idea for powered aircraft to give gliding sites a wider berth to minimise the potential for conflict?
Last edited by snapper1; 11th Sep 2009 at 08:12. Reason: Changed the font - didn't mean to 'shout'!
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How wide a berth???........class G airspace see and be seen.......what happens on a good thermal cross country day and all your gliders bog off 30 miles down wind...what then.........not being pedantic but come on you really cannot be serious!!! At least good airmanship would dictate that at the very least any powered aircraft or helicopter will maintain an extra good lookout whilst transiting close by a recognised glider site.........many years ago I was halfway up a winch launch at Feshiebridge when an USAF F111 bomber flew 400 metres away at the same level....now that was close!! 
Does the glider site have an ATZ? Is there a 'cable launch hazard altitude' marked on CAA 1/2 and 1/4 mils? (NB Jeppesen charts do NOT show this as far as I'm aware).
Anyone who does this is asking for trouble in my opinion; I've warned repeatedly on these forums about cable launch hazards but people are seemingly oblivious of the damage a 1/2 inch steel cable can do to a metal or wooden wing. When winch driving many years ago at Halton, I've 'chopped' the launch more than once when I saw a powered aircraft clearly flying towards the cable below the glider.
As for flying in the vicinity, well I've experienced a mid-air between a glider and powered aircraft inside my ATZ and I don't want it to happen again..
Anyone who does this is asking for trouble in my opinion; I've warned repeatedly on these forums about cable launch hazards but people are seemingly oblivious of the damage a 1/2 inch steel cable can do to a metal or wooden wing. When winch driving many years ago at Halton, I've 'chopped' the launch more than once when I saw a powered aircraft clearly flying towards the cable below the glider.
As for flying in the vicinity, well I've experienced a mid-air between a glider and powered aircraft inside my ATZ and I don't want it to happen again..
Oh Shazbat!
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Snapper
I can think of a glider field opp t'North sitting between two MATZ pan handles with a microlight field further down the corridor (plus two other active airfields with a couple of nm radius). As the glider field is on top of a hill, it's a bit difficult to fly below the panhandles so it's either stay in the narrow strip of Class G with everyone else, or do the radio stuff.
During weekdays that space can get congested as you suggest & the odd Tucano or two lining up on the airfields doesn't engender a wish to go into restricted airspace unless it's absolutely necessary. Whilst I agree with the sentiment of giving a wider berth in cases like above it can be very difficult.
I can think of a glider field opp t'North sitting between two MATZ pan handles with a microlight field further down the corridor (plus two other active airfields with a couple of nm radius). As the glider field is on top of a hill, it's a bit difficult to fly below the panhandles so it's either stay in the narrow strip of Class G with everyone else, or do the radio stuff.
During weekdays that space can get congested as you suggest & the odd Tucano or two lining up on the airfields doesn't engender a wish to go into restricted airspace unless it's absolutely necessary. Whilst I agree with the sentiment of giving a wider berth in cases like above it can be very difficult.
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Just as a matter of curiosity, I am fairly sure that there is no official 'sanction' available for 'busting' one of these gliding sites, a parachute DZ or other airsports venue. Am I wrong, and if so, can someone give me chapter and verse as to the 'rules' please.
Now I know it is not sensible or good airmanship and I do appreciate the dangers before the incoming starts arriving.
DD
Now I know it is not sensible or good airmanship and I do appreciate the dangers before the incoming starts arriving.
DD
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I'm not a lawyer, but I should have thought that the following are relevant:
Re flying near winch cables: Air navigation order; Endangering safety of an aircraft
73. A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein.
Otherwise, Rules of the Air:
Rule 17 (5) (a) conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome, or keep clear of the airspace in which the pattern is formed; . . .
Chris N.
Re flying near winch cables: Air navigation order; Endangering safety of an aircraft
73. A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein.
Otherwise, Rules of the Air:
Rule 17 (5) (a) conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome, or keep clear of the airspace in which the pattern is formed; . . .
Chris N.
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I don't condone blasting through gliding sites on a VFR bimble, however, how do you know that the helicopter was not a pipeline survey, or other type of survey aircraft. I speak from experience of trying to negotiate 'clearance' into gliding sites to survey, and a lot of the time have been sharply told 'we're busy all day, stay clear', only to go and 'have a look' and find that there's nothing going on, not even a car in the car park! Even then I feel guilty flying over the bloody place, I've worked over Hinton, Weston and various other 'dangerous' place and almost felt welcome.
A change of attitude is required.
A change of attitude is required.
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I know nothing whatsoever about gliding so can someone who does please explain to me the issues surrounding winch launches.
One sees cable warning information given on CAA half mil charts at varying heights up to and in excess of 3000 feet. Are there really many gliding sites with 1000 metre runways and 1000 metre cables? and at what point on the winch launch would the cable be released? Surely there must come a point during the launch (45 degrees?) where the cable begins to drag the glider back down towards the ground rather than up in the air, in which case a cable release at say 45 degrees would cut the height risk down to say only 1500 feet rather than 3000 feet? or am I being thick about this?
One sees cable warning information given on CAA half mil charts at varying heights up to and in excess of 3000 feet. Are there really many gliding sites with 1000 metre runways and 1000 metre cables? and at what point on the winch launch would the cable be released? Surely there must come a point during the launch (45 degrees?) where the cable begins to drag the glider back down towards the ground rather than up in the air, in which case a cable release at say 45 degrees would cut the height risk down to say only 1500 feet rather than 3000 feet? or am I being thick about this?
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Perfectly valid point (about desirability of giving wide berth to winch launching sites), somewhat diminished by snapper1 shouting about it 
Some possible reasons ...
- people using GPS rather than chart? Few (if any?) GPS include gliding sites by default. I know I had to create my own waypoints for all gliding sites (easily done, but few users seem to bother).
- ignorance about gliding operations and possible dangers?
- charts do not make distinction between winch sites and aerotow only places (it's the winch cable, not the gliding that's the problem
)?
- lack of consideration for others (in all spheres of life)
Some possible reasons ...
- people using GPS rather than chart? Few (if any?) GPS include gliding sites by default. I know I had to create my own waypoints for all gliding sites (easily done, but few users seem to bother).
- ignorance about gliding operations and possible dangers?
- charts do not make distinction between winch sites and aerotow only places (it's the winch cable, not the gliding that's the problem
)?- lack of consideration for others (in all spheres of life)
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It is fair to say fixed wing pilots should give gliding sites a wider berth when they are active, just as they should stay clear of the cloud base on a reasonable day at the weekend. Safety and good airmanship suggest it would be a good idea. The reality is some decide it's their 'right' or find themselves not doing so for whatever reason.
As far as I am aware pilots must report airprox events, if you feel any event was dangerous report it.
An ATZ has a legal status in the ANO as do NOTAMs and the AIP.
As a glider pilot you might like to consider; We constantly have gliders fly though our ATZ without being in radio contact even though this requirement is published anywhere you might expect to find it. We also have gliders fly through our airspace when parachuting is taking place (published and NOTAM'd). Gliders continually land at our airfield without a PPR or being in radio contact. One glider pilot recently decided it would be a good idea to land on the taxiway, not speaking to us even with working radio fitted.
Glider pilots are not alone - Recent 'fixed wing moments' include a pilot who executed a crosswind join, not in radio contact with parachutes in the overhead. Then there were 3 aircraft on the live side of the circuit, over a built up area, below 3000', within the ATZ, not in radio contact conducting a aerobatic display.
Almost every day I work in the tower there are 'moments' which do not result in anything further however, the laws of chance demand that one day this will not be the case.
As far as I am aware pilots must report airprox events, if you feel any event was dangerous report it.
An ATZ has a legal status in the ANO as do NOTAMs and the AIP.
As a glider pilot you might like to consider; We constantly have gliders fly though our ATZ without being in radio contact even though this requirement is published anywhere you might expect to find it. We also have gliders fly through our airspace when parachuting is taking place (published and NOTAM'd). Gliders continually land at our airfield without a PPR or being in radio contact. One glider pilot recently decided it would be a good idea to land on the taxiway, not speaking to us even with working radio fitted.
Glider pilots are not alone - Recent 'fixed wing moments' include a pilot who executed a crosswind join, not in radio contact with parachutes in the overhead. Then there were 3 aircraft on the live side of the circuit, over a built up area, below 3000', within the ATZ, not in radio contact conducting a aerobatic display.
Almost every day I work in the tower there are 'moments' which do not result in anything further however, the laws of chance demand that one day this will not be the case.
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I know nothing whatsoever about gliding so can someone who does please explain to me the issues surrounding winch launches.
One sees cable warning information given on CAA half mil charts at varying heights up to and in excess of 3000 feet. Are there really many gliding sites with 1000 metre runways and 1000 metre cables? and at what point on the winch launch would the cable be released? Surely there must come a point during the launch (45 degrees?) where the cable begins to drag the glider back down towards the ground rather than up in the air, in which case a cable release at say 45 degrees would cut the height risk down to say only 1500 feet rather than 3000 feet? or am I being thick about this?
One sees cable warning information given on CAA half mil charts at varying heights up to and in excess of 3000 feet. Are there really many gliding sites with 1000 metre runways and 1000 metre cables? and at what point on the winch launch would the cable be released? Surely there must come a point during the launch (45 degrees?) where the cable begins to drag the glider back down towards the ground rather than up in the air, in which case a cable release at say 45 degrees would cut the height risk down to say only 1500 feet rather than 3000 feet? or am I being thick about this?
TO put it another way, the cable speed is 60 knots or so, it's 1/2" circumference (approx) steel rope and makes a very effective saw. We accidentally tried ours out a low speed on the launch caravan and it cut straight through a cast aluminimum handle. I'm sure it will be equally effective on a Cessna or similar.
The heights given on the CAA charts are like all other information - the best / worst possible case (have you looked at how high it suggests Ben Nevis is?), depending on if you are in the glider or the other craft. Our site is cleared to launch to 2,000' and occasionally we manage it. On other days we barely get above 1,000', but using the information on the charts will make sure you are well clear of any cable-related activity.
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Are there really many gliding sites with 1000 metre runways and 1000 metre cables? and at what point on the winch launch would the cable be released? Surely there must come a point during the launch (45 degrees?) where the cable begins to drag the glider back down towards the ground rather than up in the air, in which case a cable release at say 45 degrees would cut the height risk down to say only 1500 feet rather than 3000 feet? or am I being thick about this?
Here's a typical launch. It's done in three stages.
Once the winch starts pulling you are airborne in about 20 meters. You then pull the nose up to about 45 degrees. This is rather shallow but that's for safety if the cable breaks. The speed builds up to about 140 km/h in 2-3 seconds. Small wonder with a 600 kg MTOW glider and a 300 BHP winch. A Ferrari accelerates slower.
Once you reach 50 meters in altitude you pitch up to about 70-80 degrees. You then play the back pressure and the speed so that you maintain about 100 km/h. Yes, initially that's a 100 km/h almost straight up. The cable at this stage is almost perpendicular to the aircraft.
After reaching 100 meters (in about three-four seconds) you have reached the safety altitude. If the cable breaks you can now fly a normal abbreviated circuit instead of having to land straight ahead. You keep playing the back pressure to maintain a speed of about 100 km/h.
This goes on until you are almost overhead the winch. At this point the winch operator will throttle back, which you feel in the aircraft. You release the back pressure and then release the cable. The cable has got its own parachute to keep tension on the line while the winch operator winches it in.
The total cycle from one launch to the next on a normal day is about a minute and a half. The launch itself is about 20 seconds or so to 500 meters. I haven't timed this though and it might seem longer than it is due to Einsteins Relativity effects and things like that - your first few launches feel like approaching light speed. If you have a good team and you're launching gliders for a competition, the cycle time can be a lot faster.
Depending on the wind, at the site where I flew from even us novices regularly managed to reach 500m in altitude from a 1000m cable. The site is marked as '2300 AGL'.
After the launch it's normally an immediate left or right turn towards the nearest good-looking cloud to see if there's lift there. Beginning glider pilots normally stay rather close to the field, looking for lift, at altitudes up to the cloud base. But always within gliding distance of the field. I think the regulation calls for early students to remain within 5 km of the field. More experienced pilots venture farther away, obviously.
Oh, and glider pilots fly a normal circuit just like powered traffic, although obviously they are descending slightly. They will never, ever, fly over their own launch site, for obvious reasons, unless they are well above the marked altitude.
As others have said, drive up to a gliding field and watch the launching for a while. Have a chat with some of the guys there. You'll find that, due to the nature of gliding operations, there are always plenty of people on the ground helping out and waiting until it's their turn. In fact, unless it's very busy, a trial flight can usually be arranged on the spot and will cost you somewhere in the neighborhood of 30-50 euros.
Last edited by BackPacker; 11th Sep 2009 at 09:10.
Thread Starter
Bambuko.
Sorry I didn't mean to 'shout'. I set the thing up in Microsoft Word and then pasted it in to Prune. I've done my best to modify it.
Sorry I didn't mean to 'shout'. I set the thing up in Microsoft Word and then pasted it in to Prune. I've done my best to modify it.
Thread Starter
Tom Ace
I hadn't thought about pipeline surveys. What speed would a helicopter fly at if conducting this work?
At my site we don't have a problem in accomodating the odd helcopter as long as they talk to us. Last month on quite a busy day we got a call from the police helicopter asking if they could land at our field and wait a while in order to extend the time of their sortie. We had a nice chat with the crew and gave them tea. Occasionally we get a call from the Air Ambulance advising that they are attending an emergency nearby and giving us their route. We stay in radio contact with them until they've cleared the area.
The ones we worry about are those that zip through at uncomfortable height and close to the airfield when they could just as easily have tracked a couple of miles further out where there's likely to be less traffic.
I hadn't thought about pipeline surveys. What speed would a helicopter fly at if conducting this work?
At my site we don't have a problem in accomodating the odd helcopter as long as they talk to us. Last month on quite a busy day we got a call from the police helicopter asking if they could land at our field and wait a while in order to extend the time of their sortie. We had a nice chat with the crew and gave them tea. Occasionally we get a call from the Air Ambulance advising that they are attending an emergency nearby and giving us their route. We stay in radio contact with them until they've cleared the area.
The ones we worry about are those that zip through at uncomfortable height and close to the airfield when they could just as easily have tracked a couple of miles further out where there's likely to be less traffic.
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Snapper, I don'y fly rotary, but would hazard a guess at 90-150kts! Some interesting stuff on this thread, think more education is needed for both parties (me included) and more cohesion/communication between the gliding and GA world so that we can accomodate each other.
Red On, Green On
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I hadn't thought about pipeline surveys. What speed would a helicopter fly at if conducting this work?
I don'y fly rotary, but would hazard a guess at 90-150kts!
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Launch heights vary with wind speed and direction.
With a 20kt wind straight down the runway, most winching sites can achieve something very close to the maximum height marked on the chart.
The other thing to note is the speed of transition from ground level to climb. It really is a matter of a few seconds from the launching glider being nowhere near you to it being at circuit height.
The most obvious thing a transiting pilot can do to decrease the risk is to pass the gliding field downwind, as winch launches will be fired off in the other direction.
With a 20kt wind straight down the runway, most winching sites can achieve something very close to the maximum height marked on the chart.
The other thing to note is the speed of transition from ground level to climb. It really is a matter of a few seconds from the launching glider being nowhere near you to it being at circuit height.
The most obvious thing a transiting pilot can do to decrease the risk is to pass the gliding field downwind, as winch launches will be fired off in the other direction.