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FLUG REVUE flies the A380
In mid-September, Airbus invited the international aviation press to a three-hour test flight on board MSN001. DLR test pilot Steffen Gemsa took up the front left seat in the cockpit on behalf of FLUG REVUE.
“Oscar Whiskey, wind 280 at 9, cleared for take-off runway 32 left,” reports the Toulouse Tower Controller over the radio with a slight French accent, clearing us for take-off. While keeping the brakes on, we initially select only 30 percent thrust so as to bring the huge engine blades up to speed as sparingly as possible. We then release the brakes and push the four throttle levers to the last but one stop, “FLEX T/O”. The engine computer now works out how much power is needed for take-off, given the payload, runway length and meteorological conditions. Today it is 75 percent thrust. This will avoid unnecessary noise and wear. For full take-off power, on the other hand, one would choose the TOGA (Take-Off/Go-Around) setting.
Softly and without the otherwise usual hard push, our A380-841 – it is prototype MSN001, tail code F-WWOW – accelerates. Each of its four Trent 972 engines can generate around 32.6t of thrust at full power on the ground. Together they produce an impressive 130t, whereas the maximum take-off weight is 560t. For ease of comprehension, for the first time, irrespective of engine manufacturer, power is presented on the A380 as a percentage of the currently available power rather than in terms of engine pressure ratio (EPR), as was standard on Rolls-Royce engines in the past.
We pass the decision speed V1 at 130kt. We are past the point of no return and the take-off will continue whatever happens. At 140kt, I begin to pull the sidestick back with about half deflection in order to lift the nose from the runway. I had not expected the controls to be so insensitive at this phase of the flight, one actually has the feeling of lifting a huge, heavy aircraft from the runway. However, it is probably the only moment in which one has this impression. At a pitch attitude somewhat in excess of 10º, the A380 is finally in the air after 1300m of runway and 36 seconds. The tail has a safety clearance of nine feet (2.74m) to the runway on rotation. A380 chief test pilot Jacques Rosay in the right-hand seat confirms a positive climb rate and I command to retract the undercarriage.
I now try resolutely to track the course and altitude readings on the electronic cross-point of the flight director on my attitude indicator (primary flight display, PFD). In the “NAV” operating mode, this display guides me through the departure route to an altitude of 2,000ft (600m), at which point I note that the climb rate is 1,600ft/min. Somewhat quiet, but as soon as I push the thrust lever back into the “CL” (= “Climb”) position, the engine computers increase the thrust to 96.3 percent and our A380 begins to make up for any lost speed. At 200kt Jacques then retracts the slats, and at 250kt we climb, initially at a rate of 3,300 ft/min, past the 5,500 ft altitude mark. At 7,000ft (2,130m), I can see that thrust performance is 98 percent and we are now climbing at 4,500ft/min.
The huge Rolls-Royce engines give the impression of having an easy job of it, given that on this occasion the Airbus “only” weighs 390t. At an altitude of just under 9,000ft, we disappear into the clouds of the bad weather front which is moving across Toulouse. Today we have to manually activate bleed air to de-ice the engine while flying in the clouds, as the normal automatic system is not yet working in our test aircraft.
But an orange-coloured fault indicator now warns on the flight deck ceiling that the de-icer system on engine 2 cannot be activated manually either. At the same time the screen pertaining to bleed air automatically appears on the system screen and shows us a valve on engine 2 which is not working today. An electronic checklist also appears automatically and advises the pilot to avoid areas in which ice could build up.
At this point it is worth taking a brief look at the A380 systems. In principle only the four engine intakes and the short area of the number 4 slats, i.e. only within the outboard engines, are protected with hot bleed air against icing. Because the clouds contain little ice today and Airbus has already thoroughly tested the A380 with the de-icer system deliberately switched off, test engineer Fernando Alonso allows us to continue the flight. At an indicated airspeed of 310kt and a climb rate of 3,000ft/min, we break through the cloud cover at an altitude of 17,900ft (5,455m).
In the meantime we have activated the autopilot and the automatic thrust control indicates that it is responsible for the climb profile which has been set by the Flight Management System (FMS). At flight level 250 (about 7,600m) we continue the climb at 98.5 percent thrust and 1500ft/min. 700ft before we reach our chosen cruising altitude of FL300 (9,144m), there is a brief warning and then the aircraft automatically levels up at the preselected altitude and speed of Mach 0.8, equivalent to 305kt indicated airspeed (KIAS) and 472kt true airspeed (KTAS). The engines are now running at around 65 percent thrust and are consuming about 3,300kg of kerosene per hour and per engine.
There is still time for Jacques to explain the new FMS, which has not been installed in any Airbus before and is controlled via the keyboard and cursor control unit (KCCU). We navigate through the menus using trackball and wheel, just as one would use the mouse on a home PC. We can even click waypoints directly on the navigation display and thus edit the flight plan without having to actively be in the FMS. The interface seems very intuitive and straightforward, even if one has to admit of course that the architecture and the opportunity provided in a brief PowerPoint induction the day before plus 20 minutes practice during the flight are not sufficient to cover every page of the menu. Nevertheless, Jacques succeeds in conveying an idea of the possibilities and the unequivocal ease of operation. Standard functions such as the weather radar, Terrain Awareness and Warning System (TAWS) and Traffic Collision Avoidance System (TCAS) are displayed on the navigation screen just as they are in the systems of most other aircraft types. A brief theoretical induction is sufficient to understand the system approach.
According to this computer game, things should get quite exciting now: Jacques exchanges the right-hand cockpit seat with his Airbus test pilot colleague, Peter Chandler. As discussed with Peter before the flight, during the descent from FL300 back to Toulouse, with automatic thrust control deactivated and without flight director or autopilot, I am allowed to take the A380 beyond the red line for maximum permitted speed at around 50 percent thrust.
At 340 KIAS, the automatic warning sounds, warning of a potentially dangerous exceedance of the maximum speed. Despite this, I deliberately leave the Airbus to its own devices in this flight attitude. The still accelerating aircraft decides to take action to rescue itself from the danger zone: slowly the nose automatically lifts towards the horizon and the speed drops below the red area. One could hardly protect oneself against the pilot in a less spectacular fashion. I return the thrust lever to the idle position.
Having descended to FL140 (4,300m), we now want to examine the other end of the speed spectrum, the slow speed flight. The A380 decelerates to below 200kt and provides us with the opportunity to test its air brakes: the computer automatically trims away every change of load distribution, only light vibration can be discerned and at the bottom left edge of the situation display (PFD) the extended spoilers are shown. Peter now begins to extend the flaps to position 2 and I allow the A380 to get slower and slower. Once again the automatic trim evens out all changes of load distribution. Fortunately the cockpit still has an angle of attack indicator installed and when an angle of attack of about 13º is reached, the Airbus defends itself against the imminent stall, just as all its predecessors with electronic flight control do: it automatically opens the throttle fully. If we had forgotten to do so, it would also automatically retract the air brakes and take us out of the immediate threatening danger zone. As soon as I use the sidestick to command an angle of attack below the critical angle, I regain control over the aircraft. Once again the mighty thrust of the engines is very impressive in this flight phase.
We fly a few more steep turns. Below 33º banked attitude, the A380 complies with every banked attitude commanded without further ado. On the other hand, in sharper turns, one has to keep hold of the deflected sidestick, otherwise the A380 independently rolls back to a more moderate 33º. The electronics allow banked attitudes of up to 67º.
The flight control system of the A380 is not fundamentally different from the other fly-by-wire types, although the actuation of control surfaces is itself fundamentally different. The control surfaces are controlled by only two hydraulic systems instead of the previous three, but with system pressure raised from 3,000psi to 5,000psi. For the unlikely event that both hydraulic systems were to fail, control could be assumed by the also redundant electrical hydrostatic actuators and electrical backup hydraulic actuators. This system is completely independent of the two hydraulic circuits and requires only electrical power. In an emergency, this can also be generated by the retractable ram air turbine on the nose.
The A380 now continues its descent, keeping to normal procedures, just as it will soon be used in daily A380 scheduled services. Once again Peter relinquishes his right-hand seat to Jacques, and Toulouse clears us to descend to 4,000ft for the first landing with overshoot on runway 32L. With the aid of the flight director and the automatic thrust control, I steer the Airbus towards its home airport. Jacques programmes our runway into the FMS, whereupon it automatically sets itself to the appropriate frequency for the instrument landing system (ILS).
Naturally we could also do this manually, but we confine ourselves to monitoring the system. Unfortunately the weather has deteriorated significantly since our take-off from Toulouse and we approach the ILS in thick clouds with heavy rain. Below 200kt, Jacques sets the first flap position for me, and the automatic thrust control automatically starts to reduce speed. With flap position 2 we reach the glide path and extend the entire 22-wheel undercarriage. With fully extended flaps we follow the ILS at 139kt and 357t landing weight.
The distinctive turbulence in the clouds leaves the Airbus almost untouched and it becomes apparent that the less one moves the sidestick to counter the gusts, the more accurately the aircraft follows the ILS. At about 1,000ft above ground, the runway comes into view in the rain. Blagnac Tower reports a 10kt wind from the right. Evidently the weather is not going to help us today.
I am not used to viewing the runway from this cockpit perspective. As we approach, I have the urge to increase the descent rate for the first few seconds as I feel that I am approaching too high. A quick glance at the instrument reassures me that we are following the glide path exactly. My seated position is a good 10m higher than the one I am used to. The voice from the computer is counting down our radar altitude and at 50ft I begin a slight pull to set the Airbus down. At 20ft, I put the engines into idle and the giant touches down surprisingly softly and unspectacularly on the runway. Unlike the A340-600, which would now automatically set the nosegear down on the runway and “derotate”, the nose of the A380 is lowered manually onto the runway. To the Airbus test pilots the flying characteristics in this phase seem too forgiving.
I try not to spoil this impression and set the nose wheel on the runway as softly as possible. But to prepare for the go-around, I immediately raise the engine thrust to 50% and wait until Jacques has reconfigured the flaps for take-off. At his command, I open the throttle fully, in the TOGA setting with almost 100% thrust the A380 accelerates unbelievably quickly to the take-off speed of 140 KIAS. At 500ft we turn towards the right and climb back to 4,000ft for the next landing. At 2,000ft we disappear into clouds again and, with retracted undercarriage and flaps, we accelerate to 250kt. Again I allow the automatic thrust control to help me. The somewhat notchy engine levers are evidently not built for manual engine control.
This second approach is also successful although Toulouse guides us somewhat more tightly onto the ILS and there is little time remaining to configure the aircraft, then at exactly the right moment we enter the glide path and are able to retract the landing gear. The two next flap settings follow and then we return through the clouds and rain to runway 32L. This time we see the runway a little later than on the first approach. The aircraft follows my control inputs directly and if my seat position did not feel abnormally high, I could swear that I was sitting in a much smaller aircraft. I have no sensation of the 70m fuselage behind me. The second landing is also soft.
As I approached the aircraft that morning, I had almost begun to doubt that the aircraft ahead of me really was an A380. It is only when one is close up to it that one becomes aware of the massive size of the aircraft; from a distance the A380's dimensions seem smaller because of its compact shape. It was in this department that my biggest “doubts” lay: how would the biggest passenger aircraft in the world taxi on the ground?
The view from the cockpit is surprisingly good, but the huge cockpit windows on the side are some way away from the pilot's seat due to the width of the cockpit. To the front the yellow line disappears 20.6m in front of the pilot's eye, which is still a good seven metres above the ground, under the aircraft. It is not possible to see the wingtips from the pilot's seat, so that one has no clue as to the huge size of the machine one is steering over the taxiway.
In practice, it seems less dramatic. I start by activating the taxi cameras. Instead of displaying the accustomed artificial horizon, the PFD now shows the nose wheel and the area in front of the aircraft in the top half and a view of the aircraft from the vertical stabiliser in the bottom half. Five percent thrust is sufficient to get the aircraft moving on the ground. With the aid of the two cameras and the bearing markers which have come into view and mark the point at the start of a bend along with the position of the main landing gear beneath the aircraft, I manually move the aircraft along the taxiways at about 10kt. After a short period of getting used to it, my doubts are gone. The soft response of the brakes, which hold the aircraft back as required as it moves forward, is nice. Even with the ramp surrounded on three sides by high jet deflectors, executing a turn is effortless. If need be, the A380 can turn in an area of only 60m. As we taxi back to the parked position, Jacques grins at me and says, “It's just an aircraft.” Well, OK, but it is the biggest one in the world.
From FLUG REVUE 11/2006
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