September 2012 the first time not in April - will the winds be better?
One of the most frustrating and eventful weeks on Cable downs. My two boys, James and Andrew, came up to observe and to keep the sheep station kid Ethan, company.
Mike, Mick and Roger arrived on Monday September 24th. Setting up the winch and base station took about 2 hours so it was about 11 am before we could launch and didn't leave much time to have a crack at the record, especially with some dead patches to negotiate. An 8 - 12 knot breeze was blowing from the south and we quickly ran the big white and black DT delta up to 4,000 ft. The new hydraulic tension gauge was wonderful, thanks to Doug La Rock. It showed that with moderate winds, line tension varied between 10 and 40 lbs, a lot less than I anticipated.
From 4,000 ft. we struggled to make any progress and eventually we decided to retrieve the kite to adjust the bridle's angle of attack. Unfortunately this put off any hopes of a record flight until Tuesday 25th. We relaunched and the new setting gave a noticeable increase in lift and a higher flying angle. The kite reached over 5,000 ft. but we decided not to try for higher altitudes as there was insufficient time to climb to 15,000 ft and winch the kite back by last light.
Friday September 28th
. Refer to sounding of September 27th, 23Z. The wind went "off the dial" at 3,000 ft and we didn't have the benefit of weather station balloon data telephone reports. A storm that came through also added to our problems. The kite was already distressed with wings bent back and not gaining any height. The tension gauge showed a constant 120 lbs which, surprisingly, was the limit of the winch motor's capacity. I had miscalculated the effect of a larger motor pulley (2.5" increased to 3"). I assumed the maximum to torque generated to equal 200 lb line pull. The motor will be upgraded to 1.5 hp from 1 hp. We were struggling to retrieve the kite because the winch only operated with enough torque at low rpm.
Consequently the storm squall line roared through with the kite still at 1,000 ft. It was ripped beyond repair and the only salvageable parts were the spars. The line was intact as it should be being 450 lbs and 1.5 km was recovered easily with no signs of damage. We retired to the wool shed to assemble another kite. We carry 1 spare assembled kite, 3 spar skins and spars on each record attempt. So we have a total of 5 record capable kites on every series plus 3 spar line sets, a backup motor, 3 sets of telemetry and 4 Garmin GPS units. We also have a repair tools and spare spars. The telephone communications is a task in itself. We have a 4 meter mast and cabling to connect my Telstra 3g phone. It's mandatory that I contact Air Services to open and close the zone at the start and finish of any flights.
The good grazing conditions had again given way to dry soils, low dam levels and heading toward drought yet again. Farming requires a great deal of patience and skill to extract a decent living even from a property of 50,000 acres as is Cable Downs. Stock numbers were built from 600 in 2007 to over 1,000 in 2012 I believe. Without rain these gains may be nullified. We could not give up with the kite record attempt not only because of our will to succeed but also as a gesture of support for the struggle that the Viants went through on a daily basis. n this image it is mid-morning and there is little wind so we just wait, lubricate the winch, make a few minor repairs and sit around drinking coffee. We could do this between November and March as often the temps are in the low 40's degree C.
Doug la Rock's great hydraulic tension gauge provided better than anticipated line tension readings. The needle is steady and the mechanics very robust and durable. We joked that it made my winch looked amateurish. The surprise was the 30 lb tension in moderate winds and the 120 lb maximum tension in very strong winds. I expected at least 200 lb tension as a maximum and normal tension in the range 50 - 100 lbs.
The winch was refined over 7 years but some niggling problems persist that require a more permanent and robust solution. 12,000 meters of line is now the standard length on the storage reel. Here is white 450 lb Dyneema from French company, Cousin-Trestec. The line was supposed to be 250 lb but was mislabelled. It looks thin enough in the image but is actually 40% thicker than 250 lb line, a major factor in not achieving record altitude on day 4. Two other reels are available, each with 12,000 meters of line. Another issue which was critical was the overrun on the storage wheel. If the winch was stopped suddenly on line release the spool would continue to spin for a few revolutions. On one occasion during the early stages of the 12,700 ft. flight, the pink 180 lb Dyneema snagged on the winch frame. There was no visible damage but enough fibres must have been severed for the line to break under 120 lb tension. The kite drifted 19.9 km but was tracked by GPSFlight telemetry. I was able to contact the mine management at Endeavour and then they recovered the kite with the GPS coordinates I gave them. The issue of reel overrun was fixed with a disc brake controlling freewheeling line release. Also some guards were installed to prevent line from tangling with the winch frame and moving parts.
The computer screen constantly displays the kite's position and altitude from data transmitted at 0.1 sec intervals. This is just a small section of the data displayed.
This image taken below the line as it leaves the winch makes the line look like it is fat and snaking. High frequency vibrations produce this effect as well as a high pitched scream.
Preparing the kite for launch on day one. This kite has made over 30 flights since 2007. Unfortunately it was destroyed by a storm a few days later, flying in 50 knot winds.
The woolshed has been our home for the last few attempts since our camp was washed out in 2009. It's drafty but very durable and offers a degree of comfortcompared to the dusty air strip but would be rated as one star by hotel critics but I have fond memories of staying in the shed with my team :).
The same kite ended up 19.9 km east of the air strip south of the Endeavor mine after line breakage. Here the mine engineers reassembled it after recovering it near the mine railway. A bit of unusual excitement for the crew. Thank you for your efforts recovering the kite.
Tuesday 25th and Wednesday 26th September no sonde graphs available
Conditions were warm and mostly calm with light Easterly to North Easterly breezes, calm periods and thermals. The only flights possible were with medium deltas and a rok to 700 - 1000 ft. Mike and Mick amused themselves flying a Platz glider near the wool shed. The calm was a contrast to the high winds and storms over the next 3 days.
The graphs are from the Australian Atmospheric Soundings site, a service for glider pilots. The data is fed from the Australian Bureau of Meteorology balloon sonde flights. Unfortunately cost cutting has reduced these flights at Cobar to Monday, Wednesday and Friday. If the auto balloon launch fails then often the launch is not repeated. Occasionally there will be an extra flight if a significant weather event is occurring. This happened on September 26 with an additional flight at 8am (see 26th UTC 00Z) You can see why it was near impossible to launch the big kite because of winds in the 3 - 6 knot range from ground to 6,000 ft. Same day 11 hours apart, you can see significant differences 25 hours later (below) winds were just too strong and we suspended kite flying. A reminder to keen observers that balloon sondes are conducted by UTC or (Universal Time Clock) set at GMT (Greenwich Mean Time). For Australian EST (Eastern Standard Time) 10 hours has to be added. Normally, outside EDST (Eastern Daylight Saving Time), the balloon sonde is released at 23000 UTC or 0900 at Cobar weather station. In daylight saving time it is UTC 0000 or midnight which is 1 hour later but 1000 local time. To align the GPS data the balloon sonde will always show the previous day's date which is very mind boggling at times.
Monday September 24th
These graphs were downloaded after return to Sydney and were not available at Cable Downs.
A late start is usual on day one. Unless the whole team is on the strip by 6am it is difficult to setup the base and be prepared for launch by 9am. With ideal winds from ground to record altitude it would take 4 hours to reach our target and 3 hours to retrieve the kite. In marginal conditions up to 12 hours would be need for the entire flight. Unfortunately we were unable to capitalise on potentially good conditions due to the late start and line which proved to be the wrong grade. 450 lb line was supplied as 250 lb and while the breaking strength is not in itself a problem but the larger diameter causes excessive wind drag and to a lesser extent the extra weight contributed to line sag. This error in line selection was a major issue for the whole week and on one day in particular, may have prevented record altitude.
Other issues were the telemetry battery lasting due to incorrect charging and possible low temperatures causing Garmin GPS shutdown.
A major surprise was the La Rock tension gauge showing lower than expected line tension and the winch motor being overcome at 120 lbs tension.
The kite bridle setting was not giving sufficient pull nor a high flight angle on day one and this limited it's ability to power through some soft layers. it wasn't to mid-afternoon that we retrieved the kite from a 4,500 ft. maximum then relaunched after adjusting the angle of attack. By 4.30 pm the kite was back up high had gone beyond 5,000 ft but it was too late to try for anything higher and be down before last light.
Disappointing news was the reduction in balloon flights at the Cobar weather station to 3 days a week. This reduced our available wind data, effecting the flight strategies significantly. I understand this cost saving measure has been applied to many stations across Australia.
Thursday September 27th
The times at the top of the graphs are in UTC or 10 hours before local times. 23Z on 26th September is actually 10 hours later or 9am on 27th Sept. The sounding gives a snapshot of conditions and so it although it is accurate at that time, it may vary a lot within an hour or stay similar for many hours. The "vary a lot" could mean big low wind layers develop or there are increases in certain zones. The kite would probably struggle on the 27th at 7,500 - 10,000 ft. then again at 14,000 - 15,000 ft. if these conditions shown on the graph remained static. They didn't but the kite struggled because the line was too thick and heavy for these light to moderate winds. The kite may have reached 13,000 ft. but the telemetry stopped transmitting at 10,000 ft. because the battery wasn't fully charged. I'll never know the true height because the backup Garmin unit also stopped recording at around 9,000 ft. These niggling issues with batteries are easily fixed but remain crucial for the record attempt to be properly recorded
Saturday September 29th there is no sonde data as no balloon flight was made from Cobar weather station but this excel spread sheet was able to display and graph the GPS data available
With the new kite we launched at 8am with high hopes. It seemed to be progressing well until 6,000 ft when high winds again cause the kite to stall. Through the theodolite it look distressed with folded back wings and the line tension again heading over 100 lbs. We persisted until mid afternoon when we decided to abort the attempt. Our maximum was about 8,500 ft above the launch point. Not trivial in most kite fliers eyes but we had become accustomed to routine flights over 10,000 ft so 8,500 ft seemed a bit ordinary. Unfortunately Mike, Mick and Roger decided to return home as they had a kite festival to run and work committments so we packed up and headed back to Sydney. We returned in 20014 and on September 23rd broke the world record.
What next? We intended to try again in 2013 but 2014 was the first opportunity that we all were able to get together for another bash at the record. It did give me 2 years to prepare with the following jobs:
1. New line 180 - 200 lb ultra thin Dyneema 30,000 metres.
2. All line fault tested with capstan to capstan brake system.
3. Larger disk brakes on capstan to control rapid line release.
4. Brake on reel to eliminate overun on rapid line release.
5. Larger 1.1 kw Teco motor.
6. Stronger capstan shaft mounting to eliminate runnout.
7. Better line guide to improve line behavior on capstan.
8. Use only upgraded reels to elimate vibration and runnout.
9. Use 0.75 kw motor as backup.
10. Improve motor control switches.
11. New laptop.
12. Laptop screen surround to improve screen visibility.
Were all these completed by September 2014? No but 1o out of 12 is OK. The reel to reel line breaking tests were not done but damage inspection and some random bench breaking test were done. No new line required.
FYI This is a NOTAM from Air Services Australia for our kite flying zone at Cable Downs. We have this approved space for every series of high altitude kite flights. It's a generous period of 4 weeks which gives us a large window of opportunity to get in a week or two of record attempts. Looks like the codes state dates from 12/09/2012 to 12/10/2010, times 08.30 to 19.30 daily, size 15 nautical mile radius (28 km) and 18,000 ft above sea level which is 17,370 ft above ground level. On the first day of flights i ring Air Services and open the zone then I ring when the kite is about to be launched. I ring them again when the kite is retrieved and then again when there is no further flying for the day. I do this each day and on the last day before we return home I deactivate the zone. If I and my team mates had unlimited time we probably could have stayed for four weeks and beat the record in 1/4 of the time.
B) 1209231930 C) 1210140830
E) TEMPO RESTRICTED AREA ACT
AT CABLE DOWNS STATION, COBAR 15NM RAD OF S31 15.18 E145 32.57 (20NM NW COBAR AD) DUE HIGH ALTITUDE KITE FLYING ACTIVITY.
NO FLIGHT PERMITTED WITHIN THE AREA WITHOUT THE APPROVAL OF THE CONTROLLING AUTHORITY CTC AIRSERVICES AUSTRALIA TEL 03 9235 7420 OR ML CEN FREQ 124.9
F) SFC G) FL180
The storm pounded the kite into submission and also the vibration from the flapping wings loosed the battery connection to the GPS. It would have been interesting to watch the traces of the giant loops it was doing in the estimated 95 kph winds like a big stunt kite.
Friday September 28th
I don't recall why the GPS data stopped but the maximum altitude was 9,932 ft avove the launch point. Perhaps it was a flat battery or loose connection.
We started very early hoping to take advantage of any good winds and give plenty of time for counter winching if required. It was problematic day with a GPS telemetry aerial connection vibrating loose and the kite was returned to repair this. Then the winch motor overheated as the kite entered a high wind zone at 4,000 ft. Later a pulley was changed to increase the line torque but decrease the speed. After that was sorted, it was too late to do any more flying. Murphy 1, kite team zero!
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Kite Altitude World Record