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Boeing 747LCF - The fattest Jumbo of all times
By Sebastian Steinke
“On the maiden flight we had not finally calibrated the air data sensors. As a result, we deliberately took off at a slightly higher speed. Otherwise, the take-off was just like any regular 747-400,” reports Captain Joe MacDonald, Programme Chief Pilot at Boeing for the entire 747 programme, at the end of October, talking about his first flight with the Large Cargo Freighter (LCF) on 9 September in Taipei. “Once we had attained a stable climb, I made a few light control inputs to see how the aircraft would react. We then flew with a 264 tonne take-off weight to 10,000 feet (3,050m) retracted the landing gear and flaps and accelerated to 250 knots (460km/h). Perhaps we will find a few more differences later on in the flight test programme, but so far it has flown exactly like a 747-400,” says the chief test pilot, clearly pleased with the results. “But then that could be because one has previously flown regular 747's with both 200 tonne and 410 tonne take-off weight, and that was with centre of gravity positions between 9 and 33 percent. Those differences are much greater than the transformation of the 747-400 into a Large Cargo Freighter. But calculation-wise, we expect a slightly higher sensitivity to cross-wind during take-off and landing, though we have not yet measured it in practice.”
After the two hour and four-minute long maiden flight and after only two further short test flights in Taiwan, the next major hurdle the LCF encountered came on 16 September, when Joe MacDonald flew his latest protégé across the Pacific to Seattle, where the rest of the flight testing is taking place, in a 13 hour 17 minute non-stop flight. “We drew up a detailed test plan for the first three flights in Taiwan a year ago, and we practised them in real-time in the simulator to ensure that all the practical masses and centre of gravity positions which are required during ferry flights could be confirmed in advance. The fuel consumption figures are more or less as expected, though on this occasion we gave ourselves the luxury of holding additional fuel reserves.”
Joe MacDonald talks about some of the restrictions which applied to the flight planning of this long flight. “Because flutter testing had not yet been completed, our maximum speed was 500km/h. And because the air data sensor was not yet calibrated, we were not allowed to use any airways with reduced vertical separation minimum (RVSM). As a result, we were only able to climb to flight level 270 (8,230m) on the eastward flight. A large part of the flight was planned carefully so that we would never be more than 90 minutes away from suitable alternate airfields.”
The weather apparently almost prevented them from departing and then landing in Seattle on time. “On the day of departure there was a typhoon off the coast of Taiwan. So we flew the first two hours with medium turbulence and cruised around the biggest towering clouds. Only after that did things quieten down. We had to hurry, as we wanted to fly if possible to Boeing Field airport in Seattle, which because of building work on the runway was due to be temporarily closed. We got there just in time, 40 minutes early. That was quite an achievement.”
Kurt Kraft, LCF Chief Project Engineer at Boeing, expects the LCF to achieve Federal Aviation Regulations Part 25 certification by the beginning of 2007 after about 250 test hours in the air and 500 on the ground. After that, any pilot with a 747-400 type rating will be allowed to fly an LCF as long as he has received induction training in the technical peculiarities of the freighter. These include the fact that there is no auxiliary power unit so that the aircraft relies on a ground supply of power and compressed air to start up. The cabin also departs from the 747-400 in certain respects. The pressure cabin is much smaller in area. Right behind the front main deck door is a new pressure bulkhead leading to the cargo bay, which is no longer pressurised. In the nose section, where once the First Class passengers sat, the flight test engineers make themselves comfortable at their consoles. The upper deck, which now contains a small kitchen with refrigerator and oven plus a toilet, is accessed by climbing a new ladder next to main deck door 1R. There is also sufficient space for a small rest area with a choice of two armchairs or two beds. According to the certification conditions, apart from the two pilots in the cockpit only another two relief pilots will be allowed on board later on, no couriers or business travellers.
The test team has already worked its way forward to a take-off weight only 22 tonnes short of the maximum. The regular transport flights for the 787 programme are scheduled to commence early in 2007. These will entail initially two and later three LCFs flying between Nagoya in Japan, Grottaglie in Italy, Wichita in Kansas and Charleston in South Carolina with a cargo of 787 fuselages, wings and subassemblies bound ultimately for final assembly in Everett near Seattle. All the LCFs are being converted by Evergreen Aviation Technologies Corp. in Taiwan from used passenger aircraft. The Large Cargo Freighter can theoretically take off and land at any airport capable of handling jumbo jets. However, if the rear is to be opened for the purpose of loading, as will later only be necessary at the five predefined factory airfields, a special wheel-mounted brace will be needed to stabilise the rear from outside. The pull cables for control purposes, the electrical cables, hydraulic lines and pressurised air lines which run inside the aircraft will remain connected during this manoeuvre.
Project engineer Kurt Kraft concedes that the LCF flight test programme was slightly late in getting off the ground. “We adjusted our test programme accordingly and we are hoping to still finish on time. All the tests have confirmed our predictions.” Test pilot Joe MacDonald adds, “Even the fat fuselage has not caused any problems so far. We have already flown at speeds between 185km/h and 630km/h.” So far the test team have encountered only “two or three” minor problems. As McDonald explains, “The manual controls for the pressure cabin do not yet work properly, for example.” Because the pressure cabin is now so much smaller, finer adjustment is required. On the other hand, the automatic systems apparently work without any problems.
Whereas most of the flight testing will take place in Seattle, the aerodynamic performance measurements will be carried out at Edwards AFB, California in November. Where the hot weather trials will be carried out has not yet been determined. As soon as FAR 25 certification has been granted, Joe MacDonald expects the first distance test flights to be carried out by the future operator, Evergreen International Airlines. These will include a first visit to Europe in the first quarter of 2007. When asked whether he finds his new jumbo unattractive, the test pilot responds, “No, definitely not. Its beauty lies in the functionality. It is a workhorse and an important element of our 787 programme. It is unique and will create quite an impression all over the world. I am proud to be a part of the programme.”
From page 6 of FLUG REVUE 12/2006
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