Flying the DC-10
by Vic Bentley
DC-10-30, Canadian Airlines
The DC-10 is one of the second-generation of large jetliners. The first was the Boeing 747, the 4-engine behemoth that is still flying today. In its footsteps came the trijet Lockheed L-1011 and Douglas DC-10. The latter, first flown in 1970, was a long-lived aircraft and is still flying tons of freight around the world today. These two aircraft were popular for their long range and a moderate seating capacity. The DC-10 was from the ’steam gauge’ period when the flight and engine instruments were rows of circular gauges with a Flight Engineer at a separate station to monitor the many mechanical systems, such as fuel, hydraulics and electrics. The DC-10 was flown by airlines around the world, with short range -10 models mostly used for domestic flights and the larger -30 carrying out longer flights. Some airlines added extra tanks to make an Extended Range version for intercontinental flights of over 14 hours. A military version is used for in-flight refuelling and there is a tanker version for fighting forest fires.
Along with its successes were some spectacular failures in the early years. Two accidents were related to cargo door failures that caused flight control problems. Damage to an engine pylon caused separation of an engine on takeoff and loss of an aircraft. Another case was the failure of the centre engine at the base of the vertical tail fin that damaged the three hydraulic systems and led to severe control difficulties and a controlled crash landing. The aircraft acquired a bad reputation at this time, but overcame this to continue for many years. The last passenger flight was flown in 2014 (for a span of 44 years) with about 30 still carrying freight for FedEx.
Tokyo Next Stop
The three engines rise to their buzz-saw pitch and the Second Officer (S/O) calls, “Thrust set” in a determined voice. The aircraft slowly accelerates on its 12 wheels that give it a waddling gait over the runway surface. The Captain has a firm grip on the throttles while the S/O fine tunes the engine power. She keeps her head down below the glare shield so that she is not distracted by events outside the cockpit.
The First Officer (F/O) states, “Eighty knots!” and the Captain checks his airspeed indicator and replies, “Eighty knots.” By this time the runway is slipping by at an ever-increasing rate, but the end of Toronto’s Runway 33R is not visible over the hump in the middle of the airport.
Out of the lower edge of his vision the Captain can see the red warning lights on the engine exhaust temperature gauges blinking on and off. The S/O is doing a good job at maintaining maximum engine power without overheating the three huge GE engines. This takeoff is at a special high-power rating known as ‘black power’ that is only used in a restricted number of heavy-weight takeoffs.
The airspeed seems to climb so slowly but now is approaching 120 knots - the normal liftoff speed for a short-range flight. The end of the 11,000-foot runway comes into sight as the aircraft crests the rise in the runway. Oh! The runway end is getting closer by the second and we haven’t reached flying speed! But the engines continue with their steady note and the airspeed continues to rise. The Captain’s hand clench the throttles more firmly and is ready to slam the levers closed in the event of an engine problem. The F/O is leaning forward in his seat reading the creeping airspeed indicator. Finally, at 165 knots, he announces, quite loudly it seems, “VEE ONE, ROTATE.”
The Captain takes his hand off the throttles and grabs the control wheel with both hands and starts a firm, steady pull. The nose rises ponderously, first 5 degrees, then 8 degrees and finally 12 degrees and the aircraft lifts off as the boundary fence disappears out of sight below. But the drama is not finished yet. Once there is a positive climb rate shown on the instruments the Captain calls, “Gear Up” and the F/O snaps the lever in front of him into the Retract position. The four green lights change to the red ‘in transit’ indication. There is the rushing noise from beneath the cockpit floor as the nose gear doors open, the gear leg locks into place with a thump and the doors close bringing a reassuring calm. Then with the call, “Climb thrust” engine power is reduced by the S/O and the auto throttle is engaged.
The airspeed is kept at a steady 180 knots as the aircraft climbs through 1000 feet. The nose is lowered 2 degrees and the airspeed starts to inch up, closely monitored by all three pilots. Then the Captain calls, “Flaps 1” and the F/O selects the flap lever to the new position as the aircraft continues to accelerate. Next is the call for “Slat retract” and the F/O rattles the lever through the safety gate to the Up position. Now the aircraft is flying at 250 knots with wheels and flaps retracted, in the ‘clean’ configuration. The airspeed increases slowly to 280 knots for the initial climb speed, with the rate of climb a miserly 1000 ft/min.
We are handed off from Tower (with a cheery, “Good trip”) to Departure Control and given an initial altitude of 7000 feet. This will take quite a few minutes at this heavy weight. Gradually, the altitude limits are increased until we arrive at 26,000 feet - our maximum for several hours. Now we put away the Departure Charts and wait for a cup of coffee. The S/O hands the Captain a pencilled rest schedule and says, “What’s your choice?” Noted are a short break and a long break that give the four crew members some time to relax once settled in cruise flight.
The navigation system known as Inertial Navigation System (INS) needs constant attention and flight plan data is added at frequent intervals. Once the nine waypoints are loaded through a careful cross-checking process the autopilot takes care of the tracking across the globe. That is, until Air Traffic Control (ATC) decides to be helpful and gives a direct routing that eliminates the next four waypoints. OK, let's load the next group even though it will be 4 hours before they are needed somewhere west of Yellowknife. However, frequent cross-checking of the instrument panels is mandatory. The mantra on this aircraft is, ‘Speed, Track, Hold.’ These are shown in three indicator lights on the autopilot panel in the centre of the glareshield. They indicate that the autopilot is controlling the speed, that it is following the programmed track and that it is in the Altitude Hold mode to maintain the altitude assigned by ATC.
The datalink is used to check on the enroute, destination and alternate weather for the hourly actual weather and the forecast to cover what may be happening in 12 hours at our arrival. Has Dispatch sent any messages regarding navigation outages or severe weather? Are there any reports of turbulence from aircraft preceding us on this route? Anchorage weather is good, but what about the enroute alternate airports at Fairbanks and Khabarovsk - any outages there, or would we even get a notification at the latter?
This flight, at near the maximum range with a full load, is from Toronto to Tokyo/Narita. The 260 passengers, almost full fuel and lots of cargo make it an interesting flight into the prevailing westerly head winds. The flight planning computer has already looked at the upper wind forecasts for the next 18-hour period and selected the least-time track. This may cover more mileage over the earth (greater than the Great Circle Route), but will give the least flying time and lowest fuel burn. Heading across northwest Ontario, then Manitoba and the NW Territories, the flight is planned to pass well north of Yellowknife before entering Alaskan airspace. Sometimes the magic of the computer has us heading to the north coast of Alaska at 70 degrees North latitude, near Deadhorse, to keep us out of the westerly jetstream winds at lower latitudes. We will make use of these winds on the way home.
The sun is still shining in our eyes. We left Toronto at midday and followed the sun as we flew northwest. At higher latitudes we are keeping pace with the sun’s motion so it appeared steady, high in the sky. Sunshades and sunglasses are a necessity. As our course curved more to the southwest the sun slowly started sinking toward the horizon. By landing time, in the afternoon local time, it is still broad daylight.
After crossing northern Alaska and the Bering Sea, we are switched to Russian control. Anadyr Control comes back with, “Canadian 32 maintain nine tousand six hundid mete-ars.” We consult our charts and climb 500 feet to make a small adjustment to our altitude, to 31,500 feet, to comply. The acoustics of the Controller’s voice sound as though they are in a big concrete bunker well underground. Maybe they are, for only a few years previously this airspace was forbidden for Western airlines and the penalty for trespassing was to be shot down by missiles! By this time we have burnt off enough fuel to climb to a higher altitude for fuel economy. Our request for 10,600 meters is eventually granted, but the clearance has a rather grudging air to it.
The flight is handed off to other control centers with delightful Russian names such as Markovo, Chaybukha, Petropavlovsk and Yuzhno-Sakhalinsk while flying near the Kamchatka Peninsula and the Sakhalin Islands. Then it is into Japan’s control and we talk to Sapporo Centre. Now the controllers sound as though they are in a modern control centre and are happy at their work! Then comes the descent planning. We are at 35,000 feet - how long will it take us to descend? We are now back in the westerly jet stream and our INS shows we have a 95 knot headwind. We can leave our descent a bit later but have some points on our arrival that we have to cross at specific altitudes and speeds. We are already over 12 hours into our flight and all these calculations become a crew effort as we cross-check the figures. The S/O is pulling up the latest weather for our destination and for our alternate airport - Nagoya. The Cabin Director is asking for information on connecting flights - delegate that to the extra F/O who has now joined us in the cockpit.
The descent clearance comes through and we set the altitude alert to the new altitude and bring the huge engines back to a whisper. After all these hours at cruise power it seems as if the cockpit is suddenly quiet enough to induce a ‘nap-time’ feeling - stay alert and listen to the constant flow of instructions from ATC! How is our altitude versus distance from the waypoint we are aiming for? Is the pressurization bringing the cabin altitude down smoothly? How is our fuel burn compared to the flight plan? Are there any NOTAMs that affect our approach? Are there any changes to the weather? Which runway is in use at Narita? Get out the appropriate approach charts and brief the crew on the exact procedures at each point on the approach. What gate number will we be going to? After landing which taxiways will be in use to get to our unloading gate? A myriad of details come up for discussion as surprises are not welcome in this business.
Soon we are handed off to Approach Control and given radar vectors to get to the approach end of the active runway. Oh yes, this one has a requirement to lower the landing gear before crossing the coastline, some miles earlier than we would normally do. With the aircraft slowed down and the flap extension started according to the speed we are handed over to the Control Tower for the final landing clearance. Now we are clear of cloud and can see the coast and intense agriculture surrounding the airport. “Cleared to land” is the signal we have been waiting for. The landing gear is lowered and the four green lights checked and double checked as the Landing checklist is announced. Settle on the ILS with full flap and with the speed at the required value - slowed down to 155 knots now. Wait until the runway end flashes underneath, raise the nose slightly and retard the throttles to idle. Monitor that the spoiler handle has moved to the Extend position and bring the engines into reverse. Is the auto brake operating? Ease out of reverse as the speed drops to 80 knots. We have arrived after 12 hours and 43 minutes in the air. Now if we can navigate the myriad of confusing taxiways we will be able to unload our passengers.
Cat III approach LHR (London Heathrow) airport
What are the challenges faced when operating in the busy skies of Europe? Depending on the departure airport the flight may cross northern Canada, Greenland, Iceland and Scotland before entering English airspace. Departures from Toronto operate in the busy North Atlantic corridor that has pre-set tracks that all traffic must follow. For example the flight may be cleared by Route Victor. This has specific waypoints, such as 55 degrees North latitude when crossing 50 degrees West longitude, 57North at 40 West, 58N at 30W and so on. It is dark and you know that all around you is a huge fleet of aircraft leaving all the major North American cities for all the major cities in Europe. The coordination of the various Air Traffic Control centres is impressive. Oceanic control is from Gander Centre initially and then Shanwick (UK) for the final part approaching Ireland. A flight proceeding over the UK to Frankfurt or Paris is handed off to European controllers approaching the Continental airspace.
Image of the Trans-Atlantic traffic rush each evening.
(Flightradar24)
Weather delays or diversions happen sometimes in the winter season. But what about the legendary ‘pea-souper’ fogs of London? These are handled as a matter of course on those days. No drama, no shouting, no screaming! Just the cool controller voice giving the clearance “Cleared Category Three approach Runway 27 Right, visibility 150 meters.” Easy for him to say, but what happens in the cockpit in these conditions? If we are driving on the highway and encounter dense fog, then the prudent thing is to slow down to a crawl. But this is not an option for aircraft. Aircraft like the DC-10 will be approaching at about 160 knots (300 km/h) regardless of the weather.
The key to a successful operation in these conditions is being prepared. The preparation starts months or years before when you are first checked out on flying the aircraft. The simulator exercises include operations in poor weather, including low visibility. Every simulator check ride, at 6-month intervals, will include a Category III approach, sometimes with a critical instrument failure at low level. So when the day comes for an actual approach in these conditions it is just as though you have done it a hundred times before.
The aircraft is given a long steady approach to the runway and the crew have briefed the exact details of their actions 150 miles out, prior to even starting the descent toward the airport. Once on final approach, maybe 10 miles from the runway the aircraft is configured for the landing with flaps extended, landing gear extended and the three autopilots engaged. The auto thrust system will keep the engine power at the precise value to keep the aircraft at the desired speed. Now it is a waiting game as the altimeter unwinds down to the airport elevation. The radar altimeter makes its usual calls at 500 feet, 100 feet and 30 feet. At this last callout through the grey windshield there is a flicker of a string of lights in your peripheral vision - the runway lights, your first indication of terra firma. By this time the aircraft nose is gently rising and the engine thrust is starting to decrease. This is accompanied by the bump and rumble of wheels on ground. The nose lowers and when the nose wheel touches down it is time to make sure the thrust levers are at idle and then select reverse thrust. The F/O confirms the speed brake has extended and monitors the autobrake indication. Don’t touch the nose wheel steering - the autopilot is still controlling the aircraft heading. As the speed drops below 80 knots (a mere 150 km/h) the captain will disconnect the autopilot and watch for the string of lights leading from the runway to the taxiway. The reverse thrust is cancelled and speed brakes retracted.
But we are not finished yet! Now follow the string of centreline lights on the taxiway – when they turn, so do you. But then an unmistakeable sign shows up - a row of red lights right across the taxiway. Ok, we stop here. We have no idea why or for how long as we are still in dense fog with nothing in sight except the lights and the grass on the edge of the taxiway. We sit for a couple of minutes and then the red lights are replaced by the string of centreline lights heading off into the fog again. Not a word from the Ground Controller. Was there another aircraft just 100 meters away that was crossing in front of us? We never know.
After following the lights very carefully for some time there is a feeling that something is changing - the surroundings seem to be growing darker - and this is the middle of the day. The gloomy feeling grows stronger and then there are some pinpricks of light ahead. Oh! The lead-in light to the terminal gate. Here we are at Gate 57 and we haven’t seen anything of the terminal building. We edge up to the terminal until the green light changes to amber, then to red. Brakes are applied and the engines shut down. A crackling sound in the headset changes to a cheery voice, “Welcome to ‘Eathrow, chocks are in!” This is the signal to release the wheel brakes to let them cool off. All of a sudden you realize that you are feeling a bit weary. Carry out the Shutdown checklist and put away the approach charts. It will be good to have a long walk through the terminal to let your muscles unwind.
(This story appeared in the Winter 2021 issue of Glidepath - the quarterly publication of the Canadian Museum of Flight).