Ansett Pleased with 737 Performance

In the time they have been flying with Ansett, they have proved reliable and popular with crew and passengers alike.

Flight 76 from ex-Melbourne’s Tullamarine Airport is due to depart at 6. 50 p. m. and the aircraft scheduled is VH-CZP which is parked on the Ansett finger having come down from Brisbane earlier in the afternoon.

Captain Ted Walters and First Officer Doug Thornell are the crew and at 4. 57 I meet Doug at Flight Planning. The planned Flight Level is 330 (thirty-three thousand feet) as per the 737 planned programme. The fuel planned is as follows

Compared with a DC-9, the 737 uses more fuel but can carry a greater payload with a better performance on weight-limited takeoffs. Cruising speed is Mach 0. 75-0. 76 depending on whether the distance is less or greater than 600 nm. An extra 100 kilos of fuel is added to the O. 75 and 200 kilos of fuel is added to the 0. 76.

From the synoptic chart, thunderstorms are predicted and a wind component of 180°/35 knots.

With Doug looking after the paperwork and setting up the Omega, Ted makes a visual inspection of the aircraft, walking around from the nose wheel to the starboard wing, checking the engine, wheel well, oleo, wing leading edge, trailing edge, external aerials, tailplane, rudder and back up the port side of the aircraft. Then it’s time to climb aboard and prepare for the departure Doug has calculated from prepared tables, the takeoff speeds –

Melbourne ATIS is Information Whiskey, Runway 16, wind 190/15, temperature 25, cloud 2 octas at 3000. Doug enters the flight plan into the Omega, which will retain the information to direct CZP to Sydney, while the checklists are shown on the colour radar screen.

While Ted reads off the list, Doug operates a switch on the glare shield which selects either lines or pages as required, and as each line is selected it appears in orange text as against the green text of the check-list; a checked turn blue, an emergency check-list when selected on, the action line turns red, and then blue on completion.

The Performance Data Computer System (PDCS) also installed in the 727-200LR is a Boeing-Lear Sieglar System, and controls auto-throttle, auto-pilot, Omega navigation system, and the flight director. The data is shown on a cathode ray tube screen and provides command inputs to the airspeed indicator and EPA dials.

The data provided covers all parameters from takeoff, climb, cruise, descent, holding, and engine out to go-around and turbulence modes. The Omega navigation system is a Global GNS 500A, VLF system, with provision made for a second unit to be installed for over-water flights.

The interconnection between the two systems, i. e. Omega and PDCS is where the 737 becomes the Space Invaders game of the airways. With connections to the auto-pilot, the system can be programmed to display Omega tracking information on the HSI, and navigation information on the CRT display screen. The Smiths auto-throttle speed control system operates in conjunction with all three systems to provide auto-throttle from takeoff to landing.

The Automatic Flight Control System is a dual control system capable of operating down to Category Ill (50 feet) and it integrates the operation of all the systems. Control is mounted on the glare shield and displays are on both pilots’ instrument panels.

The 737 is fitted with auto-brakes and auto-spoilers; the auto brakes operate automatically on landing at a preselected strength – minimum, medium or maximum – selected by main wheel spin, as are the spoilers. When the RTO system is selected prior to takeoff the system is armed above 90 knots and should the takeoff be rejected by throttle closure, then autobraking takes over, at the maximum level.

The colour weather radar, an RCA Primus 90, shows different colour variations according to the precipitation density and has a greater range than black and white sets. It is connected to the Data Nav 111 display system and the Omega. The Data Nav system displays navigation data from the Omega on the radar screen.

The aircraft’s course can be monitored on the screen by means of the moving pictorial display. Up to nine-way points can be selected and the cursor selected for whatever track is required, the aircraft will then fly that track and the display will show it in relation to the Earth. Checklists are also stored in the Data Navlfl with some 120 checklist pages available.

A sore point with some passengers was the pressurisation system on the DC-9s. With the 737 the cabin pressurisation system is electronically controlled and completely automatic.

All flight controls are hydraulically operated by two independent systems. A third system operates the rudder and a manual backup system operates elevators and rudder. Leading edge slats and Krueger flaps, inboard of the engines on the leading edge of the wing, and triple-slotted trailing flaps provide high lift performance.

The crew select the flight mode on the AFCS in the centre of the glare shield.

Course -039 Speed 140 Heading 320 Altitude 330

At the push of a button, any mode can be selected.

The PDCS keyboard is located at the top of the centre console, directly below the instrument panel. A typical page showed OAT°C 25, OAT°F 77, Dest Elev. 20′ (Sydney). RSV + ALT 1. 6 (10% + 30′), ZFW 38. 00. The take-off will be at a reduced EPR of 2. 08, based on an assumed temperature.

Passengers on board 65, take-off weight 46, ZFW 35. 8 (Zero Fuel Weight). The mean aerodynamic chord 20% is set on the trim selector as 5-2/10 stabiliser trim.

With all checks completed, and the load sheet signed by the Captain, he calls for push-back and start. The start sequence which is carried out whilst we push back, is Start number two, the start switch on the roof panel is selected on, and fuel control is engaged at 20% N2. EGT is 400°C. With the two engines started in sequence the engine instruments show N2 55, oil pressure 45 psi, N1 35%.

Ted talks to the tug driver on the ground intercom and after disconnecting the tow-bar, he calls for taxi clearance on 121. 7 and requests a 16 intersection departure. Approval is given. Taxiing out, the before-takeoff checklist is carried out and we are requested to cross the short runway. Fokker F27 FNQ lands from our right on 16 and behind him on a 31⁄2 mile final is al Qantas 747 OF 15. We are cleared for takeoff and turn right 270° at our best rate of climb. Ted depresses the two buttons beneath the handles on the thrust levers and we charge down the runway, to the chagrin of the pilot of QF 15 no doubt, but the 737’s rapid acceleration ensures that we reach Vr in what seems like a flash, and Ted rotates CZP with a pull back on the control column, 134 knots IAS, and she climbs out at a steady 140 knots. The computer shows that the best rate of climb would be faster than 210 knots, but this would carry us too far south, so Ted keeps the speed back until our Departure controller gives us a heading of 010° and the IAS is then set at 210 until the flap is retracted. The PDC shows the best climb speed as 307. EPR 1. 87. Our climb rate is 2000 feet per minute. A new checklist is selected and this is the after takeoff checklist Page 1.

The Omega displays 313/9, TAS 372, HDG 041, G. Speed 375, Track 049. A second page shows from Amml 6. 59 to SBG 07. 14, DIS 43. 3, ETE 0. 4, Ground Speed 411, To Bindook 303 miles. This information is fed to the HSI from the Omega and the aircraft flies on these headings.

At cruise, the PDC will automatically establish cruise Mach or airspeed and provide EPR limits for the auto-throttle.

The display shows IAS 320, Mach 0. 75, Wind 27, and EPR 1. 82.

The Data Nav 111 is selected on and Ted shows me how the designator can be moved 360° so that the aircraft can fly a track over the Omega way-points in relation to the weather radar. While doing a checklist the Data Nav 111 can be set to a target which when activated will drop the checklist and display the weather causing the alert. The designator can be positioned to avoid the weather, and on entering or engaging, the aircraft will divert to the displaced position. The PDC can show the optimum Flight Level at any particular weight, and the best economy with wind strength being experienced. CZP’s range with fuel shows 1229 miles and 1577 to empty tanks.

The list of options is seemingly endless.

At the top of the climb, the PDCS shows the exact time and distance for the start of the descent. At the commencement of the descent, the throttles automatically retard.

Doug tunes in the Sydney ATIS and records runway 07, wind 030/15-25, QNH 1008, temperature 20, CAVOK. Up ahead we have some heavy buildups. During our climb, Ted made an announcement on the public address system regarding our ETA and weather conditions for the benefit of passengers and cabin crew. We have also been visited by the charming cabin crew with both liquid and solid refreshments, but in the short sector between the two cities, there is practically no spare time. ATC requests a speed reduction in lieu of holding, to 250 kts, and Ted sets this on the auto-pilot. The PDCS now shows Mach 0. 713, Dest Elev. 20′, wind 35, Distance 124. We are now requested to descend to FL 190 and the descent on the VSI shows a descent rate of 1500 feet/minute. Further descent is requested to FL 11o. The aircraft flies at 1° body angle down on descent and 3° up in cruise.

CZP is now requested to call Approach on 127. 0 at 30 miles and to descend to 5000. Descent is now through the cloud and the city appears to be mainly under the cloud as we break out. . begins to form on the windscreen, so Ted selects engine ant1-1ce on as a precaution.

As the aircraft descends on approach the speed decays and flap 1 is selected at 21O knots, then 5° at 190, 15° at 170, 25° at 150 and at 140 kts, 30° flap, reducing to approach speed of 133 knots + 5 knots = 138 knots = V ref 122 + gust additives.

Runway 07 straight-in approach is our Approach controller’s request and we are to call the Tower at the NOB on 120. 5.

Zero Seven appears in the distance and as we approach, Ted increases the power a little to maintain our correct descent, and as we approach the flare point with 27 feet altitude shown on the radio altimeter the auto-throttles retard. CZP touches down with very little flare. Ted selects thrust reverse and our V ref speed of 124 knots is quickly decayed.

The time is 7. 05 p. m. and we have landed. CZP is pulled up opposite the Ansett hangars, thrust reverse cancelled, and we take the next taxiway left and head for Bay 4 at the Ansett Terminal.

On taxiing into the bay care must be taken not to damage the pilot heads which are on the side of the fuselage and easily knocked by the ramp. On the DC-9 the pitot heads are up on top of the nose out of harm’s way. As soon as the green arrow disappears in the slot of the guidance indicator, the brakes are applied and CZP is stopped.

The crew now carry out their parking checks, and Ted books a few minor snags on the maintenance release.

In comparison with the DC-9, the 737 is wider and has the same body width as the 727 and 707. Passengers generally would be unable to tell the difference between the 727 and 737. Engine starting is fully automatic on the 737. The 737 has six settings of flap for takeoff providing greater short field capability. The DC-9 has two flap settings which perhaps makes things simpler. The flight controls on the 737 are hydraulic and provide greater response and the aircraft is light and positive to handle; in transitioning from the DC-9 it is easy to over-control the 737. The 737 has more powerful engines, hence the JT8D-15s give a greater rate of climb. The 737 has a control wheel steering mode which works off the auto-pilot and enables auto-pilot use just after takeoff and in the circuit. In the area of stalling the 737 handles more conventionally than the DC-9 and is fitted with a stick shaker. According to Captain Walters, the 737 is more thrust sensitive in the pitching plane than the DC-9 because of the lower thrust line of the wing-mounted engines, and on the final approach, the aircraft is very speed-stable and responsive. The DC-9 requires a little more attention to maintain an accurate approach speed. Landing is straightforward with the 737 and its behaviour near the ground is more predictable than the DC-9. The 737’s thrust reversers are very effective and little braking is required after touchdown; even on a wet runway, the 737 will stop within the certified wet runway distance using only thrust reverses. In the cockpit area, the obvious differences are the 737’s superior electronic and navigation equipment, and computer.

Special thanks to Captain Ted Walters for his assistance in the air and on the ground.