Free Flying on The South Downs
Safety Notices
Pre-flight check or die!
Also be extra careful with leg straps with a flight deck or a canoe (pg or hg) harness...
As we have seen here, a flight deck is enough to cause this problem, it is not limited to canoe harnesses. The mandatory pre-launch check which we all perform before each and every launch (!) will ensure this doesn't happen to one of us...
http://www.dhv.de/web/fileadmin/user_upload/monatsordner/2004-06/Ausbild...
We have had two serious 'failure to clip-in' events (FIC-ups!) within the club in recent years, one pg and one hg. Let's not have any more.
In a similar vein, always complete the check by confirming that the airspace is clear, including behind you, before starting to launch.
DHV investigation of current beginner/intermediate gliders
http://www.dhv.de/web/en/safety/articles-statistics/ltf-a-and-b-class-sa...
Their summary:
The test series conducted here clearly supports the general suspicions regarding LTF and EN testing: the norms are at best a coarse sieve – large discrepancies are quickly found, but smaller ones may find their way through. We haven't found any really dangerous gliders in the A and B classes, but it is somewhat frightening to see gliders tested to be as safe as possible, that still require 60m of height to recover from a massive collapse. In doing so they pitch forward alarmingly, rotate through almost 360° and have sink velocities of over 20 m/s. This is not the kind of glider that belongs in the hands of a beginner. Accident investigations clearly show what beginner and low-airtime pilots tend to do in the event of a collapse – nothing! They are usually much too frightened and inexperienced to calmly and coordinately react in the heat of the moment. What they need in such a moment, irrespective of the piloting errors they may have made beforehand, is a particularly friendly glider with moderate reactions. This is often promised for the LTF-A class, but these promises are not always kept.
The performance gliders in the high-end B class are marketed, quite correctly, as cross-country machines. They belong in the hands of experienced pilots and are definitely not for “Sunday” flyers. The thin line between “just OK” and “clearly over-demanding” regarding what pilot skills are required to recover from instability provide a lot of food-for-thought. A slightly steeper folding angle on an asymmetric collapse, a bit more of the span on a frontal collapse or a little more sink in a spiral can change a moderate glider into one that's hard to recognise again. Between “typical behavior for its class”, and cravats, dives or stable spirals lies very little margin for error in some cases. Gliders in this segment are only for pilots capable of active flying, able to recognise the onset of instability and react immediately to prevent collapsing.
The general impression we were left with is that more intensive testing is required, and not just two norm flight tests for certification. To provide realistic judgments on glider characteristics, a test program with several collapses, stalls and dives is necessary. Only then can we determine the entire testing results bandwidth and inform pilots appropriately.
We often hear of the evil surprises that some gliders provide in extreme situations, such as the fatal crash last season of a school pilot after an asymmetric collapse, cravat and spiral dive into rocks. Or the pilot with 20 years experience who moved up to a high-end B glider and dies after not being able to exit from a spiral dive.
To simply write off these incidents as “pilot error, bad luck” does not do them justice. Paragliders are built for pilots, and pilots do make mistakes. In glider classes for beginners and low-airtime pilots passive safety characteristics must have utmost priority. And there we still have plenty of room for improvement.
Advance Impress 3 reserve container issues
Subject: IMPRESS 3: Service Bulletin
As a result of new information the IMPRESS 3 reserve inner container has been remodelled and the permissible reserve volumes for the S and M size harnesses adjusted. The new container can be obtained free of charge from our dealers.
In recent weeks it has come to our notice that a few IMPRESS 3 pilots have had difficulties releasing their reserve parachute. Of course we take this seriously and have carried out and assessed hundreds of releases with various pilots and dealers. After detailed analysis, and after talking to the harness certification authorities we have come to the satisfactory conclusion that the current system works without problem, so long as the instructions in the manual are followed and the technical requirements adhered to.
It is clear that, independent of model, there are configurations (and always will be) that don’t work properly. These can be avoided by a proper compatibility check - always required for every reserve installation.
Having carried out all these tests we found that the formula for calculating the volume of a reserve (weight in kg x 2.7 = volume in litres) results in only a gross approximation: so from now on we will be specifying the maximum volume for each harness size. The IMPRESS 3 L remains at 7 litres, the M becomes 6.5 litres and the S has a maximum volume of 6 litres.
This large testing programme has certainly been of value to us. On the one side we can say with a clear conscience that the system is ok, on the other we were able, using the experience gained, to modify the inner container so that even more combinations will work flawlessly.
So that present as well as future IMPRESS 3 pilots can benefit from this improvement we have decided to give all IMPRESS 3 owners this new container. Progressively from March 21st we will be delivering our official dealers the appropriate number of inner containers so that you can supply this new pod free of charge for all the harnesses you sold already.
This new pod also replaces the version delivered from January, 2012 which brought an improvement for the reserves to the superior limit of the volume.
Team ADVANCE
Mount Caburn site rules refresher
We are seeing a number of Mount Caburn site rules being disregarded of late. Please ensure that you adhere to all of the site rules as the landowner lives locally and does not need our custom!
Rules being disregarded:
- Do not launch from below the 'top of the hill' i.e., not from half way up the hill to avoid the walk up. See the last item in this list.
- Keep the car park locked at all times. In particular when pilots are in the field as this can encourage non-members to enter.
- Right hand 360 only until more than 1000' above launch
- Do not overfly the cottages near to the farm complex at the bottom of Mt. Caburn
- Do not overfly the cottages near the car park at the bottom of Mt. Caburn
- Do not overfly the car park
- Do not slope land on the main face of Mt. Caburn other than at the no longer visible 'white mushrooms', which were situated:
- One by the lowest stile into Airworks' landing field
- One by the tree line at the east near the top of the hill
- One by the tree line at at the east just before it diverts east and some 100m above the cottages
- Slope landing is permitted on all parts of the western ridge, but do avoid interfering with any training.
- Do not land in Airworks' landing field except in an emergency.
- Do not park at the western end of Ranscombe Lane. Park only in the club car park or in Glynde village car park (if parking here, walk up the public footpath opposite the post office)
- Do not re-launch from the western ridge of Mt Caburn if Airworks are training there (The rule is do not launch at all, but they are accommodating.)
- No commercial coaching or training on the western ridge.
- Only walk up the eastern edge of the hill, currently following the line of the established path, though there are moves afoot to move us further east.
- When on the main face, do not stray from the path, especially at this time of year when ground nesting birds are present and various protected flora will be soon to flower.
Yesterday at Mt. Caburn
As usual the spring mayhem returned with a vengeance with the sea breeze!
Why is it that pilots put their gliders away in September and think that they will be perfectly competent when their wings next see the light of day in February or March?
Granted there were a couple of low airtime pilots who were not exactly helping the reputation of red ribbon pilots, but the majority of the people flying badly were of at least 'intermediate' level, if not actually very high airtime pilots.
Some of the pilot's causing concern were not UK trained and not Polish! Sebastian has intimated that he would like to help integrate these pilots into the club as they may feel too intimidated or whatever to approach our existing coaches for guidance. I can only applaud this initiative - over to you Seb!
All this winging about poor piloting does no real good when the pilots concerned do not realise what it is that they are doing wrong, so I'll start a list:
- Telegraph your intentions to other pilots
- Fly predictably
- Avoid creating 'boxes' of gliders to trap one another.
- Think about the nearby pilots and their options and intentions
- Small changes of course to make the next pilot's life easier will usually make them less stressed and ultimately make your life easier.
- Observe air law, but remember that the rules are for collision avoidance; If you are out from the ridge but with it on your right, you cannot expect an oncoming glider which is tight to the ridge to move out in the expectation that you will move in! Only move in when it is safe to do so and then take your rightful place close to the hill.
- Observe build-ups of craft in any particular region and fly in the opposite direction! We managed to safely and without conflict complete a number of soaring tasks and top landings with a number of pilots through the afternoon. We only had to stop for a very short while in the middle of the afternoon when there were no unoccupied regions of the sky.
- Other than the fairly short period I mentioned above, it was not overcrowded per se on Sunday, so operating the red banner to close launch would not have helped. It was just that the few pilots who were there were flying so inconsiderately that they made it seem busy. If you think it is too busy for you, don't launch. If you cannot keep away from other pilots, whether you feel that it is them flying poorly or not, it is time for you to land. Remember, a good pilot will find more thermals than a bad one, even though there is a large amount of luck involved in locating them. This same 'luck' is involved in whether a pilot finds the sky overcrowded or not. The difference is that the pilot who is overwhelmed by the level of crowding they perceive will hurt someone...
- If you think it is too busy and you cannot be certain to fly in a manner not to make it worse, don't launch! There were a number of very experienced pilots who felt that the mayhem would have put their lives at risk and so they chose to wait until the culprits had exhausted themselves mentally and had to leave for an early bath, after which it became pleasantly uncrowded :0)
P.S. I am so glad that the Dyke webcam is down! I would not like to see a general weather forecast page/section that would encourage a zillion people to go to an already crowded site, though I would like to see one to encourage people to try sites further afield.
TTFN
SteveP
SHGC SAFETY OFFICER
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AIRWORKS PARAGLIDING & HANG GLIDING
The Old Station
Glynde
BN8 6SS
APCO Force
A force recently suffered line detachment during a spiral dive. As yet there is no information regarding the age or history of the wing nor the severity of the manoeuvre, however, Force owners are recommended by Apco to 'in the meantime reasonable steps of precaution you suggest should be followed and extra inspection of the wing, as well as avoiding wild manuevers'
Windsocks - let's use them, safely.
As Wolf (?) says, windsocks are dead handy for making sure the landing is right on the spot, but lets try to make sure they're placed a good bit upwind of the target itself. We should also only use windsock sticks that are safe to fall / drop a glider on. Pass the risk assessment form someone....
Failed Maillon Report
Original at:
http://bhpa.co.uk/pdf/safety_notices/sn032.082011.pdf
Unformatted text:
British Hang Gliding
and Paragliding
Association Ltd
8 Merus Court
Meridian Business Park
Leicester LE19 1RJ
Tel (0116) 289 4316
Fax (0116) 281 4949
www.bhpa.co.uk
SAFETY NOTICE
Issued by Angus Pinkerton - Chairman of the Flying & Safety Committee 23 August 2011.
All paraglider power pilots, Instructors, Coaches and Safety Officers must READ, DIGEST AND TAKE
ACTION on the contents of this Notice and keep it for future reference.
If you hold a copy of the BHPA Technical Manual this notice must be inserted into it and retained until it is
withdrawn or superseded on instructions from the Chairman FSC.
3.5mm mAIllONS FITTEd TO wINgS FrOm
pArAmANIA mANuFACTurEd SINCE mArCh 2011
During the second flight of a brand new Paramania Revolution 2 paramotor wing the pilot
noticed one of his A riser maillons open up. He was able to carry out a safe landing.
Initial inspection of the maillon showed that the nut was correctly done up and the bottom
threaded section had been released.
Continued..........
Ref. no.: FSC.SN.32
Date: 08/2011
Pages: 2 (Pink)
b) There is considerable variation in the finished dimensions of these
maillons, particularly in the length of the nut and the size of the
opening. On nearly all of the maillons examined the nut length was
less than that shown on the design drawing, and the opening was
larger. This has the effect of significantly reducing the number of
threads actually engaged on the bottom threaded member. (The
design shows four threads engaged over a 4mm length. On two
of the maillons examined the actual distance engaged was less than
2.40mm.)
Continued..........
Further detailed examination and testing of the failed maillon and other identical maillons
has revealed that:
a) The failed maillon had improperly formed threads on the lower
threaded component (manufacturing defect).
c) This particular maillon type is manufactured in Taiwan by ‘Pro-Metal’.
This maillon type has been fitted to other glider types from other
manufacturers but, with the co-operation of the manufacturing
company, all of the affected gliders have been accounted for. Improved
quality control procedures have also been put in place to ensure that
defective maillons do not get incorporated into new gliders in future.
The BHPA Flying and Safety Committee advise that any pilot who has a Paramania wing
manufactured since the beginning of March 2011 fitted with 3.5mm maillons should contact
their dealer for details of the checking and replacement procedures Paramania have
established for ensuring the airworthiness of the maillons fitted to their wing.
Hurstmonceaux Laser
The XC heads will be familiar with the thermal from by the Hurstmonceaux observatory and may have noticed the laser warning shown on the air chart. One of the staff informed me that it is very big, very powerful and is operated at any time of day or night. It's used to measure movement of tectonic plates by bouncing off a satellite or the moon to be picked up at receivers all over the planet. Apparently when it goes off it looks like something from star trek!
While it's only an advisory on the chart, it didn't sound like something you'd want to fly through.
More details when I've spoken to the laser walla.
Summer 2011
Sorry, but this Safety Briefing is anything but brief and is really a concoction of several missives I have posted over the last few years, all of which remain painfully relevant today:
Once upon a time in the Southern Club there was gentlemanly behaviour in the sky. And it was Good.
Pilots on the ground were aware that they are the lowest form of aviation and justly gave way to all those above them. They even looked to check.
Pilots thermalling were given right of way and ridge soaring pilots would turn back before interrupting the thermalling pilot's 360.
When it was seen to be getting too busy, pilots would either thermal away or gracefully bow out after a few minutes ridge soaring to allow others the chance to do so.
In the early days of paragliding, once paraglider performance had advanced to the point where soaring was commonplace, we would often land unbidden to allow a waiting group of hang glider pilots free use of the sky. It would usually take only a few minutes before they were high enough to permit usual service to resume.
Wouldn't it be nice if those days returned?
It has been notable how close together everyone is flying nowadays.
Please do try to give each other more room.
Also it is important to telegraph your next move as clearly as possible. I'm not
saying give hand signals, though providing you are flying in accordance with the
ANO that is not a bad idea, just make it obvious where you are planning to go and
try not to make erratic course changes when other are in close.
Please don't sit just behind and outside a ridge soaring glider as
this effectively prevents them from turning back, almost as if you were overtaking
them on the outside. If you are closely following another ridge soaring glider, aim
to be directly behind or better still towards the ridge.
A number of pilots have 360'd into the hill recently. Fortunately
they had very nearly completed their turn and so got away with little more
than a suprise stop. I would hazard that in most cases this was not caused by
inexperience, but by a little rustiness from the poor weather. Do
take extra care flying at rising ground and remember that your skills will atrophy
suprisingly quickly if you don't fly every day.
Also, when top landing, get your glider pointing into wind, even if you have
already landed. This will slow your progress across the ground significantly and
may save you having to explain yourself to an irate pilot who's maid out wing you
just trashed. With a paraglider it is never to late to be able to turn into wind,
just to late to choose to do so. In the same vein, don't attempt to land anywhere
near rigged hang gliders. The current batch cost an absolute fortune, which your
insurer would not be keen to pay.
Mind the Ice Cream Vans!
Collision avoidance:
1. If it is too crowded for you, don't launch.
2. If by launching you will make it too crowded for the pilots already airborne, don't launch.
3. Overtaking. It is the absolute responsibility of an aircraft performing an overtaking manoeuver to maintain clearance from the craft being overtaken. No pilot is expected to look far behind them before executing a turn. Try that on a 747 and see how much you can spot. The pilot is of course expected to check that a planned turn will not endanger another aircraft, but only by checking the space ahead, to the side and astern as reasonable. The vast speed differential of a hang glider compared to a paraglider can cause the hang glider to 'appear out of nowhere' to the perspective of a PG pilot being overtaken. Hang glider pilots should also be aware that the view of a hang glider flying straight at you is of a very thin white line and the top of someone's head, not the most visible of profiles.
4.If it is too crowded for you and you are in the air, make your way to an immediate safe landing.
5. Fly-on-the-wall landings are potentially very painful and expensive and should be avoided unless you have absolute confidence in your ability or no alternative option.
6. It is common courtesy for paragliders to slope land if there are hang gliders airborne and struggling to maintain height. The inconvenience of stopping your flight for a few moments hugely outweighs the inconvenience of being forced to bottom land a hang glider, with the attendant hour or so of de-rigging and rigging.
7. ANY pilot can call for a red ribbon half hour. You don't need to seek anyone's permission, though of course you will be expected to justify your actions to the growing angry mob of pilots waiting to launch. If in doubt, ask a coach.
8. Hang gliders invariably find themselves overtaking paragliders if they are being flown together, imagine flying in a forest and you get the idea. For this reason the hang glider pilot needs to be doubly sure of their abilities before venturing into a cloud of paragliders. If there is a mid-air collision, evidence has shown that the hang glider pilot will normally come off worse, usually fatally so.
9. Low sun is a major hazard at this time of year. Pilots must be aware that if they are approaching another aircraft from 'out of the sun' it is probable that they will not have been seen.
10. We used to also operate a hang glider half hour/paraglider half hour separation system. This has not been required of late because there have been few inexperienced hang glider pilots flying when the paragliders are present. If, as it would appear, we are now seeing an increase in the number of low airtime hang glider pilots then I see no reason that this system should not be re-instated, unpopular as it was...
If the system is reinstated, then any pilot can call for it to be brought into play. I'd suggest referring to a coach as there are plenty of them about now.
If we don't resolve conflicts due to overcrowding then it is almost inevitable that we will have ANOTHER FATAL MID-AIR COLLISION. It is the responsibility of ALL PILOTS to behave as educated adults and to avoid exposing themselves or others to this risk.
The last SHGC mid-air collision between a hang glider and a paraglider occurred when no other gliders were in their immediate vicinity. (There were three gliders above them and no other present)
They were both working the same thermal and had been for a short while?with apparently acceptable separation.
The paraglider may have entered an area of stronger lift, climbed into?the path of the hang glider, who was unable to take evasive action?within the time available.
The hang glider struck the trailing edge of the paraglider with his?control frame and became enveloped/attached.
The paraglider pilot deployed their reserve, after which the craft?separated, with the hang glider inverted.
The hang glider pilot was able to regain control and make a safe?landing. The paraglider pilot landed with a significant downwind element?(Their main may have been providing some lift in that direction) and was?arrested by the barbed wire fence behind launch.
Neither pilot suffered any immediately apparent major injury.
The hang glider was not visibly damaged.
The paraglider suffered significant damage.
A couple of comments/lessons to be learned:
Paragliders are prone to involuntarily 'stopping' in mid-air and rising?violently in thermic conditions. Consequently hang gliders should avoid?thermalling within a short vertical separation. The same can be said for?paragliders!
Hang gliders have limited control in roll and yaw; paragliders should?avoid forcing them to explore those limits.
The hang glider pilot should really have deployed his reserve. It was?high enough to have deployed had he been able to throw it beyond the?disturbed air caused by his inverted wing. Having chosen not to deploy,?in this case, generated the best possible outcome. That would not?usually/necessarily have been the case. Certainly research has shown?that most fatal paraglider accidents could have been avoided by?deployment of the reserve.
When did YOU last pack your reserve? I recommend 3 month cycle - it?makes a huge difference!
This is the first HG/PG midair of which I am aware in that the HG pilot?survived... This was as a result of the high structural integrity of?the king-post-less glider when inverted and the consummate skill of the?pilot in recovering the situation.
This report does not seek to apportion blame.
The 'glider falling from the sky into me' scenario has troubled me for?years. More by the grace of God than anything else, this seems to be a very?unusual occurrence, even in competition where separation in thermals is?miniscule. I suspect that in part this is because we tend not to thermal?below people who are not in good control of their wings by virtue of?out-climbing them, but this is not a given.
I clearly recall tucking a HG in a thermal and losing several hundred feet,?while watching the PG below me perform a similar exercise and hit the?ground. Had he not done so, there is every possibility that I would have?taken him out anyway. There really is no safe distance to be below another?glider when thermalling, but the duty of care has to rest with the higher?pilot, who should at least scream if they are falling into another...(!)
As for an enveloped HG pilot being unable to deploy their reserve: In the?example in question, I suggested that the reserve could have been deployed?once they had separated and he was inverted. In the case of an enveloped?pilot, yes it would be very difficult to deploy. Therefore great care must?be taken to ensure that there is no mid-air collision in the first place!
To a hang glider pilot, paragliders are effectively flying trees. Given the?great disparity in speeds, the PG pilot can take little effective action to?recover an imminent collision with a HG. Therefore, they should exercise a?little respect and if there are HG struggling to climb out, they should give?them space. Equally, the HG should fly with consideration to the flying?characteristics of the PG.
Since the demise of the HG half hour, flying at the Dyke has become far less?stressful - If PG pilots do not give the HG guys a little space when needed,?then perhaps we should consider returning to this system?
- Desperation?Probably the biggest hazard, as always, is the human factor. You may have had a?long lay off waiting for flyable conditions at the weekend. Consider watching the?forecast and planning a midweek day flying. At this time of year the forecasts are?at their pretty useless though, so be prepared for last minute changes of plan.
When you get to the hill, if it is too windy, don't push your luck, the hill will still be there tomorrow! Remember, if you break yourself, you'll miss much more flying than a few minutes gale hanging...
- Sea Breeze?The sea breezes are well established now. The advancing sea breeze is often, though not always, betrayed by either a clearing of cumulus development towards the sea or by an advancing line of from curtain cloud to fracto-cumulus again with little or no cloud on the seaward side. The sea breeze can be very rough when it first arrives and is usually stronger when it first comes in, settling down after half an hour or so. For this reason, you don't really want to be in the air flying at Mt. Caburn when the sea breeze actually arrives unless you are competent to go over the back with the convergence. As always, if you see a linear cloud feature approaching, if you are at all unsure, land and wait for it to pass.
?At inland facing sites such as the Dyke or more so Ditchling, the advancing sea breeze will tend to back up behind the hill, then pour over in a big turbulent rush. No pilot who doesn't enjoy being tossed about like a cork in a storm wants to be in the air when this occurs. There have been numerous accidents over the years because of this.
As a relatively low airtime hang glider pilot, seeing an obstruction in no way?prevents me from hitting it. Please don't mess about or launch from the paddock if hang gliders are present, and certainly not if the red windsock is displayed.
There have been a number of injuries recently following attempted paraglider slope landings, which turned into controlled flight into terrain events. To hopefully reduce the incidence of these needless injuries please refresh your slope landing technique:
- Never approach the hill at an angle greater than 20 degrees to the slope.
- Maintain a contouring flight path as you flare. Do not turn away from the hill as you flare as you could drift 5m or more away from the ground before the stall occurs. Do not turn into the hill as it'll hurt.
- Slope land on the into-wind leg or the into-wind section of the hill. I.e., if the hill starts falling away the leg may gain an increasing downwind component.
- ALWAYS STAND PROPERLY WELL BEFORE THE LANDING This applies to all landings and means sliding off the seat and adopting a PLF position, with ankles directly below the shoulders and hips and the knees slightly bent.
- Under no circumstances lift your legs to land on your backside. EVER!
- If the landing looks too fast then turn away from the hill and continue flying. If this is not possible, be prepared to PLF.
- Having slope landed, if collapsing your wing is proving difficult, aim to fly it forwards in a controlled manner into the ground. Once on the ground and facing down, release the brakes to stop it flogging.
If you still have issues with slope landing, or for that matter, top landing, see your instructor or a coach.
Fly safe!
SteveP.
Appendix:
Exerts fromCAP 393:
Avoiding aerial collisions?8.—(1) Notwithstanding that a flight is being made with air traffic control clearance it shall?remain the duty of the commander of an aircraft to take all possible measures to ensure that his?aircraft does not collide with any other aircraft.?(2) An aircraft shall not be flown in such proximity to other aircraft as to create a danger of?collision.?(3) Subject to sub-paragraph (7), aircraft shall not fly in formation unless the commanders of the?aircraft have agreed to do so.?(4) An aircraft which is obliged by this Section to give way to another aircraft shall avoid?passing over or under the other aircraft, or crossing ahead of it, unless passing well clear of it.?
Overtaking?11.—(1) Subject to paragraph (3), an aircraft which is being overtaken in the air shall have the?right-of-way and the overtaking aircraft, whether climbing, descending or in horizontal flight,?shall keep out of the way of the other aircraft by altering course.
Approaching head-on?10. When two aircraft are approaching head-on, or approximately so, in the air and there is a?danger of collision, each shall alter its course to the right.
Order of landing?13.—(1) An aircraft landing or on its final approach to land shall have the right-of-way over?other aircraft in flight or on the ground or water. [But the other pilot needs to know that you are landing! S.P.]?(2) An aircraft shall not overtake or cut in front of another aircraft on its final approach to land.?(4) If the commander of an aircraft is aware that another aircraft is making an emergency?landing, he shall give way to that aircraft.?(6) Subject to paragraphs (2), (3) and (4), if two or more flying machines, gliders or airships are?approaching any place for the purpose of landing, the aircraft at the lower altitude shall have the?right-of-way.
Landing and take-off?(3) If take-offs and landings are not confined to a runway—?(a) when landing a flying machine or glider shall leave clear on its left any aircraft which has?landed, is already landing or is about to take off;?(b) a flying machine or glider which is about to turn shall turn to the left after the commander?of the aircraft has satisfied himself that such action will not interfere with other traffic?movements; and?(c) a flying machine which is about to take off shall take up position and manoeuvre in such?a way as to leave clear on its left any aircraft which has already taken off or is about to?take off.?(4) Subject to paragraph (5) a flying machine shall move clear of the landing area as soon as it is?possible to do so after landing.