We Fly The Hornet

The Hornet’s critics refuse to believe that one aircraft, with one pilot, can adequately fulfil the role of two or more aircraft, often with two crew, which it is to replace.

After some three years of reporting the RAAF’s painfully drawn-out selection of the Hornet as its new tactical fighter, involving sitting through countless briefings and reading mounds of papers, I thought I understood it as well as any amateur pilot could expect, and had wondered how one man could possibly handle all those systems efficiently.

But it took a 1. 3 hour ride in aircraft 161257 behind Lt. Bob Stumpf of the VFA-125 Squadron at Lemoore, California, 10 show that I had not appreciated how well it all comes together in the cockpit.

The cockpit displays combine Hornet’s state-of-the-art radar and other systems to provide the pilot information as he needs it with a facility previously undreamed of.

It would be little exaggeration to suggest that any tolerably bright delinquent pouring his 20-cent pieces into those video games, would soon feel quite at home in a Hornet cockpit. In a relatively few hours, you could probably make him almost as much danger to an enemy as himself. Imagine then what a Hornet could do in the hands of a top pilot.

The main components of the cockpit displays are two cathode ray tubes, called digital display indicators (DDls), mounted either side of the up-front-control, or CNI panel, directly above which is the head-up display.

Directly below the CNI is another DDI which will be replaced on production aircraft with a moving map display.

Engine instruments appear in digital form over the pilot’s left knee. About the only conventional ’round dial’ instruments are a set of basic flight instruments, designated ‘standby’ instruments, above the pilot’s right knee.

The HUD has become the primary flight instrument, showing the pilot his attitude, airspeed, altitude, vertical velocity, angle of attack, Mach number and G forces, along with other information.

All this can be swapped between the HUD and any of the DDls, along with digitised displays from the radar, or other sensors or weapons systems.

‘We were intent on what we call situational awareness,’ lead engineer with McDonnell Douglas on Hornet cockpit development, Gene Adams, said.

‘It is very difficult for a pilot to keep in mind that the radar is looking at one thing, the FLIR at another, the EW is looking around and the HUD has its own section. All of these systems are on in their various modes and the pilot has to integrate all of these in his head.

‘It was important to us that he had as much information available without having to call it up.

‘To know what the FLIR is doing he just looks at it, instead of turning it on, calling up the display, removing whatever was there, and so forth.

‘We maximise the number of displays and make their format alike so they can be moved from one position to another in the cockpit.

‘The mapping system has symbols on it to tell the pilot where he is going, where his footprint is going, where and how long to go- so the mind does not have to calculate it- it just looks and absorbs.

‘In a multi-sensor attack- using radar and flir, the pilot wants everything up simultaneously.

‘This was all fine and dandy but the F-18 cockpit is very small and designers had to put in a lot of systems out of two cockpits which were unique to either air-to-air or ground-attack missions.

‘A strike fighter pilot needs a gunsight, radar and flight instrumentation, all combined on head up and head down displays with heading, speed and altitude on each, plus a pitch ladder so a pilot looking at any single display the entire instrument always has basic information available and need look nowhere else. ‘

The number of displays that can be programmed on the DDls is virtually infinite. Any time you press any of the 20 buttons on each DDI, theoretically, all 60 functions could change, and any one of those 60 could Call up a further 60, and so on – up to about 800, although there are less than 20 generic formats such as radar.

Except for armament, the pilot seldom has to go past two button pushes.

A mechanical flight instrument in an F-4 used to cost about $1500. In an F-15 they jumped to about $8000. They are very labour intensive and to get decent reliability you have to use jewel high-quality movements. When one fails, since they are sealed, they must be sent all the way back to the depot for repair. An altimeter took 11 square inches to give the pilot one number.

Digital indicators can give the pilot altitude in several places at once and it takes less than half a square inch.

COM/NAV Identification (CNI) functions really eat up a conventional cockpit. In the Hornet, two three-band radios including all navigation, instead of taking up acres of precious cockpit space, are operated on the upfront CNI control directly below the HUD.

If the pilot wishes, he can push menu and then engines and have all kinds of engine data details displayed on the DDI.

That is probably a $15,000 instrument, which combines 10 round dial instruments which would have cost two or three thousand dollars apiece, and a lot of space,’ Mr Adams said.

‘Had we known how good these engines are, we could have gotten by with a few lights that the engines have started or not, because, within a few seconds of the engines starting, the data can automatically be displayed in a lot more detail on the CRT.

‘The engines are so good that 20-20 hindsight leads me to believe we might have been able to use that space for something else. ‘

The lower central screen is a horizontal situation display onto which can be projected images from a 57 ft long 35 mm film colour driven by INS in whichever direction the aircraft happens to go. It is imaged on a ground glass with a beam splitter which combines it with the image from a DDI so that the DDI is actually drawing on top of the map.

The map moves as the aircraft does and the DDI can write anywhere in the circle, showing planned waypoints on the flight are, for instance, eight miles and 48 seconds away. It will also show known hostile anti-aircraft sites and their lethal radius according to the aircraft’s altitude. As long as the picture on the CRT overlays the map, or nearly so, the pilot knows that two independent navigation references agree.

In addition to many million square miles, the film has room for 200 pages from the pilot’s handbook on the film, or ship recognition information including high-quality reproduction of actual photographs or graphics of any sort.

The film is equal to 500 square feet of maps.

You could put on it all of Australia and Tasmania on one to two million scale, the 200 frames out of the handbook as well as 500 miles of the coastline of Australia at the high-resolution scale of one in 500,000.

In a combat situation, the pilot should never have to remove his hands from the throttles and stick. A series of buttons, toggle controls and triggers falling under his fingers and thumbs controls and sensors, armaments, and certain other requirements.

The system is designated HOTAS (hands-on throttle and stick).

Push your stick hand thumb forward and a Sparrow missile is selected, along with all the radar displays, for a medium-range attack, push it down for Sidewinders and pull it back for gun for close-in shoot-outs. Each time, the appropriate radar displays with all information appear automatically on the cockpit displays and HUD. The beauty of this is that the pilot can be looking back over his &J,oulder watching another aircraft as he selects systems.

Targets on radar can also be manually designed by the pilot placing a cursor over a blip with a thumb control on the control column.

Different modes can be selected at the press of another finger control and the target designator has over 100 modes.

Moving the thumb changes all kinds of radar parameters without the pilot having to even glance at the console or any display. In the gun mode, it even shows you how many rounds are left.

Our flight plan called for a climb to 19,000 feet then a flight for about 100 miles east to a restricted military area in the Owens Valley, near Mt Whitman, the highest point in the continental US.

To avoid noise complaints, the US Navy has bought up land for several miles around the base, which it leases to farmers – something which airport developers in Australia might find worth considering.

Strap-in and ejection seat arming is considerably different fr?m the Mirage and although it takes some getting used to, it will no doubt prove highly efficient. The US Navy face mask is much softer and more comfortable than RAAF issue and although there are minor differences in the oxygen supply system, it will be familiar enough to RAAF pilots.

The seats are allegedly filled with a material similar to some ski boots, which moulds to body contours after a few minutes’ exposure to body heat. USN pilots I spoke to said they found this hard to believe and the seats felt just as hard and uncomfortable as any other ejection seat.

Startup is very simple, using only the aircraft APU and no ground support equipment. Stabilising each engine at ground idle is virtually automatic and the whole engine startup requires only flipping one switch and then a push and pull on the throttle. The APU automatically shuts down once both engines are at idle and it has had time to cool.

Pretakeoff checks uncover a “stuck screen”. The rear cockpit where the pilot sits considerably higher and has a much better forward view than from the rear seat in a two-seat Mirage, has no HUD so the HUD display has to be placed on the left DDI, which in this case resolutely refused to have anything to do with it.

A request for a maximum performance takeoff and climb was denied. Afterburner on takeoff is vital for many combat aircraft but is considered by many to be excessive for the F-18. We use it for this takeoff, however, and liftoff at about 130 knots comes in less than 10 seconds.

A delay in going to afterburners makes the takeoff role longer than usual but we are off in well under 2000 ft with full internal fuel but no external stores.

We are well past the end of the runway before Stumpf pulls up into a near vertical climb and about 45 seconds from brake release, we level off at 7000 feet and pull the engines out of the afterburner.

Stumpf apologises for the takeoff being ‘nothing much’. The Hornet has an initial rate of climb at sea level of about 40,000 feet per minute which, although it is not a major tactical consideration, looks very good at air shows.

One does not select flaps up in the normal manner after takeoff. The flaps program themselves up as the aircraft increases speed and are not fully up until the aircraft reaches. 9 Mach. There is no discernible trim change to the pilot as this happens.

The ride is noted immediately for its smoothness and lack of drama. As we filter out through civil air traffic control, the radar automatically picks up and displays a variety of civil aircraft as potential targets.

One target is indicated at 13. 5 miles, 23,000 feet and . 8 Mach. A minute or two later the airliner crosses our nose, slightly high.

As we fly through a high saddle on the edge of the valley with less than 500 feet between us and the ridge at close to 400 knots, Stumpf rolls the aircraft almost inverted for what pilots call the ‘pulldown’. For a few moments, the mountain appears to be coming down on top of us, with the rocks rising on either side, before Stumpf rolls right way up again and we dive steeply down the valley.

Simply pushing the nose down as an aircraft climbs over a saddle would not be fast enough to keep it below searching radar and could lead to the dreaded negative G in which a rush of blood to the head can cause the pilot to ‘whiteout’.

Descending the valley, turbulence buffets the aircraft like a truck being driven at high speed across a series of railway lines.

Most straight-wing aircraft would be violently jostled in this situation but the F-18’s flight control systems effectively damp out most of the knocks.

Levelling out in the valley, Stumpf tries to acquire our ground target automatically by using the INS to show its position. We get a fair picture. Stumpf is not happy that the picture is not as crystal clear as it sometimes is.

Painting the dam from 6000 ft over the ground the lake can be distinguished and after a couple of tries the original picture is expanded so that the dam shows clearly as a straight line along one edge of the lake.

Weapons cursors can now be placed on this and should stay on the target even if the aircraft is forced to manoeuvre unexpectedly during the run-in.

At military power and 14,000 feet, Stumpf pulls back to four G and the F-18 pulls a tight loop and levels off again over 1000 ft higher than it started.

When I try, eyeballing the horizon, pulling four G, the F-18 slides lazily over the top inverted then pulls its nose up without the slightest fuss, making even a ham-fisted apprentice Cessna driver look good.

At 380 knots, a fairly typical tactical speed, Stumpf throws his stick to one side and we revolve 360 degrees in an aileron roll in just on one second. Dropping speed back he does one the other way with a little rudder which is even faster.

Next comes a maximum performance split S, rolling the aircraft on its back then pulling the nose through at the maximum pitch rate. In about two seconds we are pointing straight down until the aircraft is flying the right way, straight and level in the opposite direction.

This manoeuvre would be used in a dogfight to get an adversary almost directly below. In less than 2000 feet, pulling 4. 7 Gs, and 30 units angle of attack, in about 10 seconds. Most aircraft would stall the wings and ‘depart’ if you tried this.

While Stumpf plays electronics warfare officer and tries to get the displays to work I play pilot.

The F-18 proves ridiculously easy to fly with only the faintest tendency to pitch the nose up or down – which is probably feedback from me over-controlling.

Now Stumpf wants to show me some maximum performance turns.

By this time my voice on the intercom is starting to take on a slightly quavery quality as I beg for only one of each manoeuvre.

Stumpf slows the Hornet then banks steeply and pulls it into a tight turn at 320 knots and 10,000 feet, going to afterburners as we pass three Gs and the G meter climbs to nearly six Gs. In less than 15 seconds we have completed a turn of more than 360 degrees””. ith only about a 20-knot loss of airspeed and a slight gain m altitude. At 4 Gs, according to Stumpf, the Hornet can keep turning and climbing indefinitely.

This is an area where Mirage pilots will notice a big difference when they transition to the Hornet.

The Mirage is a 12,000-pound aircraft with about 6000 pounds of fuel internally with its single engine in afterburner giving about 13,000 pounds of thrust. The F-18 is a 24,000-pound aircraft with about 10,000 pounds of fuel and 32,000 pounds of thrust giving it close to 1:1 thrust.

A major benefit of this extra power is that hard turns in air-to air combat inevitably bleed off speed from any aircraft. Thrust helps to keep up the vital speed and energy.

The other advantage with this kind of power is being able to add speed when you want to. Anyone chasing you can cut across any wide turn you make and cut you off at the pass, so to speak.

If you add airspeed quickly with power and makes a series of really hard turns he cannot cut any corners.

The ability of the wing surfaces to mould to optimum shape and the LEX to take effect at low airspeed and the great big stab to bight into the air and move the nose allows you just to push that aeroplane around almost at will and move the nose where you want it without having to worry about stalling or departing controlled flight.

‘You have to do a phenomenal amount of hard work to get this thing out of control, including asymmetric thrust and wing loading, very slow and nose high,’ Stumpf commented.

With the radar in air-to-ground mode, Stumpf designates a target at random and the computer tracks it automatically while we manoeuvre then roll into a dive, flying a little aircraft symbol down a line on the DDI Until the bombs release automatically and we pull away.

Shortly after this a female voice from the computer warns that fuel is bingo so after a few more manoeuvres we ease up out of the valley for the return to Lemore.

On the way back to Lemore we finally get a contact and the intercept goes routinely and smoothly, just like the briefings and simulators.

Finally we get a target at 35 miles at 13,000 at . 4 mach until he appears on our nose at 23 miles.

As we drift closer to the field, the radar continues on track while scan, automatically locking up a number of targets by itself. At one stage it had three on the scope and switched priority from an earlier contact to the most recent when it determined that it was closer and getting to us quicker.

Closing on the field, we switch to air-to-ground radar and at more than 30 miles range, runways and hangars are clearly distinguishable on the DOI. The picture gets steadily clearer and more detailed as the range decreases.

Even if the radar is not having one of its better days, the display is still far clearer than any other radar I have seen.

At under 1500 feet we run through the pre-landing checklist on the screens while that woman calls ‘fuel low’ then we do a carrier-style approach, jockeying throttle to maintain a glideslope which puts us down on an imaginary third arrestor wire, for a go-around before the final touchdown.

Stumpf flew the three-degree glideslope right onto the deck with no flare and although he had warned me to expect a hard landing I heard rather than felt the reassuring thump as the wheels touched the runway.

That monstrous undercarriage soaked up the blow so smoothly that with a feeling of firm but gentle vertical deceleration, we settled down into the rollout with less waggle and rebound than you would expect from any half-decent airline landing. Without any excess braking, the aircraft slowed satisfyingly rapidly.

You could not land an F-15 like we land this aircraft regularly – you would break the gear. ‘ Designed for a 24 fpm sink rate but normal is only 10 fps. The landing role is routinely less than 3000 feet.

The outside temperature was 30 degrees Celsius during the flight and the barometric pressure 29. 81 inches.

Two-seat Hornets are in short supply so we remain strapped in for a ‘hot’ refuelling with engines running.

We then taxi back to the line and climb out with the engines still running, while another crew waits to climb in immediately. I try to mentally compare the Hornet to our Mirage and realise that the generation gap is of light years’ proportions.