Wednesday, 21 September 2011 Photo log: Tabatinga to Vilhena
Here are some photos of the trip from Tabatinga to Vilhena in Brazil
[k2gallery path=”world_2011_21-9-2011_tabatinga”]Tuesday, 20 September 2011 Some thoughts from James
I've only just got to the internet for the first time today, having again just looked at the numbers for the Atlantic crossing again. Phew, it's closer than I thought!
Answers to a couple of questions –
When Michiel asked me about fuel consumption I was under the impression that he was talking about fuel consumption for the Sling 4 at ordinary weights. Although she performs incredibly well at heavy weights, the performance does change quite substantially when very heavy. Fuel burn increases quite substantially as she gets really loaded up (well, well above the ordinary MAUW of such an aircraft) and of course she goes slower. When she takes off in Rio she'll be burning something like 27 liters per hour and she'll be flying with high throttle settings because of the weight. Close to Cape Town she'll be light and she'll be burning about 23 liters per hour. The throttle setting will still be quite high, since she'll probably be at quite high altitude, but even at 100% throttle, at 13 000 feet she burns only about 24 liters per hour. Overall I think the average fuel burn will be 25 liters per hour, and that's what we've worked on. Incidentally that's not particularly conservative, it's probably almost dead on – for reasons which I'll explain below.
On the question of speed – it seems that the Sling 4 likes generally to cruise slightly faster than the Sling 2, but at a slightly higher throttle setting and burning just ever so much more gas. Because she's has a turbo motor she likes to cruise quite high. At ordinary weights she'll cruise comfortably at 115 knots (TAS) at about 9 500 or 11 500 feet, but she'll be burning about 23 liters per hour. When as heavy as Mike and Jean will be, however, she'll have a much higher angle of attack, more drag and go much slower. Also, she'll be at a low altitude – probably 2 500 or 3 500 feet for the first 6 or so hours, then 5 500 feet for the next 6. There she cruises at only about 96 to 100 knots. At the weight she'll be on this trip it may be even less for the first quarter of the journey. We've done our calculations for the journey on the basis of an average true air speed of 100 knots. Actually I think that that's more conservative – there's probably a little bit of fat in that. Since we've mostly flown lighter than the weight this time, however, it's difficult to know absolutely for sure. Low altitude hours early on will also lower this figure somewhat. I personally hope that this is where we'll benefit from conservatism.
On fuel burn and throttle settings more generally – I had many hours sitting gazing at the twin MGL Voyagers in the Sling on the first half of the journey. In a car when you throttle back mostly the fuel consumption per kilometer decreases. It's not the same in a plane, though. There's the famous “lift / drag bucket graph” which shows that drag relative to lift is minimised at a certain optimum speed / angle of attack. Slower than that (with a higher angle of attack) you get disproportionately more drag for the additional lift. All other factors being equal in principle you want to fly with a full throttle at a reasonably high altitude. Flying the Sling 4 for enough hours to become familiar the parameters through gazing at the instruments while changing throttle settings, my intuition was surprised by how high the throttle setting for optimum range always proved to be. It must be admitted that on almost the entire flight from Johannesburg to Los Angeles we flew into headwinds (which favour flying faster and burning more gas for range, relative to tail winds), but still I was kind of surprised. And this seemed to me to be exaggerated when the aeroplane was very heavy. We took off from the Marshall Islands with enough fuel for Los Angeles, including a good reserve, so we were heavy. Early on, low down, our speed was pretty poor, despite a high'ish throttle setting. We were burning quite a bit of gas, but any reduction on the throttle resulted in a substantial slackening off of speed – it just wasn't worth it. So one find's oneself little bit between a rock and a hard place! When that happens you'd better have done your homework in advance!
So that's where it's at. Actually endurance is only 29 hours, but hopefully Mike and Jean will be flying a little faster than the speed we've used to make the necessary calculations. Everyone please hold thumbs!
That's all for now. As things stand ZU-TAF will aim to leave Rio about 0900Z (11am SA local time) on Thursday 22 September, aiming to arrive in Cape Town at about 1300Z (15h00 SA local time) on Friday 23 September. It'll land at CT international to clear customs, hopefully quickly, then fly on to Stellenbosch where we hope supporters will join us for a celebration, hopefully commencing upon their arrival at 16h00 to 17h00. I'm going to fly down to CT on Thursday with Michiel de Koker in his Sling ZU-MDK (well equipped, also with a Rotax 914 and a nav radio), leaving exactly the same time as Mike and Jean. We'll beat them there by about 22, we hope, follow them on the tracker through the night and meet them Friday. We'll all fly back together on Saturday morning for a party at Tedderfield Air Park, The Airplane Factory's hangar, starting with our arrival at 14h00 Saturday and continuing until late into the night. Theme for the party will be announced tomorrow, together with details for those who wish to fly in with the Sling 4. For now fly-along is projected to start at Parys at about 13h00.
Ate logo
James
Monday, 19 September 2011 Andes to Rio
With the Andes disappearing behind us, we descended out of the forest of charlies to a reasonable altitude where the Amazon introduced itself to us. We have all seen pictures of the Amazon forest, the Amazon river and Amazon wildlife. I remember as a child reading National Geographic and being amazed at everything I saw and promising myself, to one day when I´m big I would go walk-about there, little did I know that I would fly over a vast portion of it in an airplane that I had a little part in helping create. I am a very lucky lad.
Mike and I were just starting to relax after the Andes crossing and getting excited about the jungle when we were rattled back into serious pilot mode again by turbulence and a wall of rain and lightning. The next hour or so was spent staring into rain looking for the the slightest hint of light in the dark sky ahead where the storm may end. Messages from Sias on the Indigo were encouraging and helped us find the thinnest part of the mayhem to navigate through. As my sailing instructor always told me, ” The great thing about storm is you know it is going to end!” and of course it eventually did.
As the rain thinned, we suddenly exploded into the most remarkable world, a site that is burnt into my memory forever. A sunlit ocean of green jungle from horizon to horizon! What a blessing and sense of joy! To top it, we spent the rest of the day savouring the delight of this unspoilt and untouched wilderness that is part of the lung of our precious planet. The price we had to pay was to dodge more rain storms and by so doing also learn why these are called “Reforests”. In the entire flight over the forest ( it is just one big one) I never saw one bit of diseased canopy or dead patch. Just remarkably healthy growth. From the beginning at the Andes until we got close to the border of Colombia and Brazil only rivers broke the perfect carpet below.
After cruising for a while and between storms we started to discuss ways of handling a forced arrival atop this ´carpet´´below. In a way our situation was similar to being out over the ocean. There was no civilization for many many miles and for long periods no comms. We never fired up the HF, probably should of. Anyway we were being advised of weather by Sias and so we knew the tracker was working and sending out our position faithfully, so we were actually in a good situation as far as being found was concerned. Back to our thoughts on the best way to arrive on the tree tops in the case of engine silence. If were by some stroke of incredible luck near a river with a slight bank then that would probably be the best option, but these were few and far between. So lets think about it. That canopy is made up of lots of leaves and branches and vines and all sorts of creepers and is about probably about four stories high off the ground. Two options exist in the Bullet, Try land as slowly as possible on the canopy( there really is no open ground, nothing, niks!) or slow right down and pull that red handle in the middle of the console. Consider option one. A perfect landing into wind would get our wheels tangled into the canopy vines and branches at about maybe, say 35knots. I am pretty damn sure that we would be stopped quite abruptly and nosed in. Depending on the type of growth at that point we may either be suspended or dropped about three or four stories onto our lovely silver spinner. That is of course if we are not turned into human sosaties for the carnivorous wildlife to devour. Can you imagine the insect attack?
Option two seemed far better. Slow right down and pull that handle! A loud bang should be heard and after a couple of seconds all hell breaks loose as the cables rip out of the canopy frame and a sharp jerk felt as our flight is arrested. Then hopefully silence as we gently float down under two round life saving canopies, and finally 'crrrrrunshch! 'as we land with our butts in Tarzan land. Now if the wind is not too strong or we are not in a storm this should put us in a reasonable situation to enjoy the experience.( It is now that I like to think in a perfect world) The Bullet would be nicely perched on top of a dense forest almost in perfect tack. Our perspex canopy still in one piece, keeping out the zillion insects and and no branches up our butts. The parachutes lying around us making us easy to spot. PLBs activated and the indigo set on alert we could crack the seal on the bottle of J&B (that Chris and Gareth went and got us just before we left and has flown with us so far for just this occasion) and sit back and wait to be rescued. So that is the prettier picture and the one I tried to keep in my mind for the rest of the flight over south American jungle.
The day ended with a decision at in the last 15 minutes of flight to not land in Colombia as filed, but to cross the border into Brazil and land at Tabatinga. This was facilitated by quick and competant action on the radio by Mike. Although we got stuck another day with paper problems the stay was interesting and pleasant and friendly. We got airborne a little late in the day because Mike was led to believe we could pay landing fees etc. in dollars but when he tried they refused and he had to get a taxi back into town to exchange cash to local currency. This late departure resulted in us landing just after sunset at our next destination.
Conditions on this flight were fair for most of the way and we were quiet relaxed taking turns to dose off. Sias had done a fine job of steering us around storms and big charlies but did make it clear that our arrival at sunset was not going to be in the finest conditions. A rather significant cell had developed right over our destination. He tried to put it in the least intimidating manner on the short message facility on the Indigo. Finally just before hitting the first wall of rain and streak of lightning his message read something like this, 'no other way but straight through it hope you ok' So with this we stuck our heads forward and attacked the task of trying to remain just the right side of being completely terrified and able to make decisions to steer through areas of least electrical activity and downpour. Trying to describe the mental experience of that last hour would do the reality no justice, it needs to be lived to be appreciated. All I can say is that Rainier´s GLS and autopilot worked wonders in getting us onto finals after our meander through a little hell!
A good nights rest, a pre -dawn take off and the blessing of fine weather set us up well for a relaxing flight to Rio. We were able to chat and think positively and creatively about the rest of the trip home. A very fine sunset welcomed us to Rio as we flew low level over the mountains surrounding the city. A warm welcome in Marica and a safe parking for the bullet rounded the day off perfectly. A good nights rest and look what happens!
Ever heard of the Cape to Rio yacht race?
Monday, 19 September 2011 Major route change – Home much quicker – Post from the factory
OK, having serviced ZU-TAF and prepared themselves for the road ahead, Mike and Jean, together with Sias and Tim, had a good look at the various ways home, the weather and things philosophical. Jean and Mike have both been away from home for a long time now and they’re definitely getting a bit homesick! Anyhow, the long and the short of it is that there’s an exciting change to the route home – Instead of flying up north to Recife, crossing to West Africa (again into headwinds) and then navigating down the African West coast, the Sling 4 is going to navigate its finest ocean crossing yet – from Sugar Loaf Mountain to Table Mountain – Rio to Cape Town.
The logic is this – a look at the weather over the past few days, months, years (and possibly millennia) suggests that a well timed flight from Rio to Cape Town will give tailwinds of at least 15 knots average the whole way (possibly quite a bit more). Our baby has out-performed even her parents expectations substantially, to the extent that it’s become increasingly clear that a well timed take-off from Rio should result in a safe and satisfactory landing at Cape Town International Airport a maximum of 29 hours later. Now fully confident that we can use our full fuel complement without any performance problems, fully fueled up ZU-TAF will cruise for a minimum of 30 hours without a fill-up. Moreover, with our satellite tracker working beautifully, an HF radio on board and the satellite telephone providing even social communications if desired, Sias Dreyer is able to give real time weather advice to the pilots, routing them around storms and into the best tail-winds. Given that position, it just seems to make no sense at all to head off north again into the trade (head) winds to battle down the African coast.
So the decision is taken, Mike and Jean will stay in Rio just until the weather is perfect for a flight directly across the Atlantic Ocean to Cape Town. Right now it looks like a departure Wednesday evening (from 1800Z) would work nicely, but of course this will need to be monitored closely as time passes. There appears to be a window of opportunity from then until Friday, whereafter they’ll have to wait until the next “cycle”. Please hold thumbs. All things being equal that’ll put Jean and Mike in Cape Town on Friday afternoon 23 September 2011. I hope to join them there and return to Johannesburg on Saturday for a reception and after-party. Please diarise to meet them at Stellenbosch Airfield on Friday evening, or Saturday afternoon at Tedderfield if you live near Johannesburg.
We’ll keep you updated as we go.
Ate logoJames
Monday, 19 September 2011 A great time in Rio!
It is seven on a glorious morning in Rio. Mike and I both woke around quarter to five in our little hotel room. I was lying awake and heard Mike tossing and turning.
“How's your head?”
“Mmmmmmm…………” came the reply.
Yep, we had a fine evening out in the the little town of Marica hosted by our new friends who helped us service and prepare the Bullet. The steaks were particularly good and the local beer “Black Princess” flowed quart after quart causing serious pounding in our heads this morning. Headache pills working, showered and in the dinning room for an early start, both on the computers tapping away. We will spend the morning prepping a few details for the next leg and then make our way into Rio for a tour that we have been invited on by a friend of one of the pilots. We will take lots of photos and post them later.
Enjoy your monday! J&M
Saturday, 17 September 2011 Arrived safely in Rio de Janeiro
Mike and Jean were able to leave early this morning from Vilhena and were nearly halfway to Rio de Janeiro when we found out that the airport that they were heading to, was in fact closed. So the guys' flight plan was adjusted and they headed to Maricá Airport, just east of the famous Baia de Guanabara (Rio Bay)…landing just before sunset.
We expect the guys to catch their breath first after today, and go and have a night on the town if they have the energy…so as soon as we get any posts from them we will update the website.
Friday, 16 September 2011 Safely in Vilhena
Mike and Jean landed safely in Vilhena at about 22:06:00 UTC after leaving Tabatinga at 12:49:34 UTC this morning, with a fuel stop at Porto Velho.
Jean will hopefully be able to send the second part of his log (if they have internet where they will be staying) on the experience it was to start flying over the Amazon, after they had made it over the Andes.
UPDATE – E-mail from Mike & Jean:
Hey Sias. Thanks so much for your help. It made us happy to know you were there . Jean was just saying you have the largest radio controlled plane in the world … just tell us where to go and we do it. The storm at the end was hectic … the lightning scared me the most. Once we had a blast straight overhead. As you said … but we weaved our way through ok by just avoiding the worst rain.
Tomorrow we want to get airborne by 10 Z latest and are trying for SDNY direct. 11.5 hrs. We have 14 hrs fuel on board. And water and sweets. And 4 fresh hamburgers!.
Must sleep.
(For our new visitors to the journey, Sias is our weather guru and he is able to send messages to the satellite tracker to inform Mike and Jean about weather along their way)
