Airtest – Mitsubishi Marquis

It is a courageous venture, launched in the midst of a recession. But Interair are convinced that they have the product, the enthusiasm and expertise to offer the Marquise to a market where brand loyalty is taking second place to bottom-line economics.

The Marquise, sold in Australia, New Zealand, New Guinea and the South-West Pacific by lnterair, represents perhaps the front runner of a new breed – an aircraft designed from the metal up as a turbo-prop, not an old airframe equipped with new engines.

The basic design concept was started more than 20 years ago . . .

Through the years Mitsubishi engineers refined, embellished and improved the basic airframe and wings until today the Marquise stands at the front of its line.

The aircraft type has a number of telling things going for it: toughness – the fuselage is designed on two I-beam keels running the entire length of the airframe which is itself covered with chemically milled heavy gauge 2024 aluminium.

Machined circular frames are mounted to the I-beams to provide maximum strength at stress points.

The wings are double-spar and with a high loading of 65 lbs/sq. ft. , house five integral tanks in a wet wing configuration. Fuel management is as simple as feeding the tip tanks, or the outers, to the main tank.

A beefy undercarriage main assembly is a direct copy, built under licence, of the military F-104 J undercard – which was itself built to take all the shocks and stresses of Service requirements.

When the main wheels are in the retract position, having gone up and forwards, they project fractionally from the wheel wells giving good insurance – along with the wheel pods and tough I-beam structure and two-foot clearance between four-bladed props and the ground – against damaging the aircraft or its occupants seriously in the event of a wheels-up landing.

State-of-the-art systems embodied in the Marquise include spoilers instead of ailerons, and big double-slotted Fowler flaps which extend and retract in small increments on command from the cockpit, giving insignificant pitch changes. The primary control system is mechanically connected to the control surfaces by push-pull rods, quadrants and cables.

The control surfaces are operated by conventional motion of the wheel and rudder pedals, while elevator and rudder trim systems are manually controlled by control knobs, actuators and cables.

All this reflects Mitsubishi’s basic design philosophy- incorporating into the Marquise the most efficient systems to give ease of operation hand-in-hand with a high degree of reliability.

Which brings one to the Marquise’s next strong point- maintainability. Many parts and components have an unlimited life, including the spar and pressure hull.

Continued development and refining have gone on throughout the type’s evolution; one noticeable mod. has been the addition of two yaw strakes under the tail assembly. This has, as was proved during the Australian Aviation’s evaluation sortie, improved low-speed stability.

Speed is another strong point of the Marquise – becoming known in most regions of Australia, with typical down-under wit, as the Rice Rocket.

Payload/range figures work out very satisfactorily in most cases. Mitsubishi Aircraft International claims that the maximum range at 31,000 feet, take-off at a gross weight of 11,575 pounds, covers 1395 nautical miles including reserve.

Cruise speeds are exciting; maximum cruise at 16,000 feet with 98 per cent rpm, 650 degrees EGT or 100 per cent torque, is listed at 308 knots using a mid-weight of 10,200 lbs.

Normal cruise is 295 knots at Flight Level 200, using settings of 96 per cent rpm, 650 EGT or 100 per cent torque, again at 10,200 lbs.

Interair told AUSTRALIAN AVIATION during our evaluation that the old pilots’ gossip about the Mitsubishi Marquise being a hot ship in terms of steep rates of descent, high approach speeds and a Vmc of 99 knots with 20 degrees of flap out, is not valid.

The aircraft needs positive handling, yet a gentle touch not found in other turboprop twins we’ve tested. But there is no suggestion of a hot ship. Far from it; we flew the aircraft in fairly tight sequences with wheels and full flap down during our evaluation and found no vices coming up behind us as long as we kept the IAS steady on about 11O knots indicated.

Single engine rate of climb is listed at 41O fpm with a weight of 11,575 lbs. (max. take-off), and 675 fpm weighing in at 10,200 lbs. Not spectacular, but it’s a rate of climb nonetheless.

The solid construction and almost military specifications of the Marquise can be found in high gear and flap extension speeds (175 knots for undercard and first stage flap to 5 degrees).

Total usable fuel – in tip and wing tanks-is given as 403 US gallons – 186 in the tip tanks, 70 in the outers and 159 in the central tank.

The cabin volumes compare more than favourably with other types slotted into the corporate/charter sector is where the mighty Marquise is elbowing its way through sheer product excellence.

Cabin length is pegged at 21 ft 6 in, impossible when one views this portly little type from the outside, but proven when one gets in and wanders about the seven-options seating arrangement.

The cabin width is 4 ft 11 in, and the designers have used every inch of that width to tell effect. Cabin height could be pointed at by the purists as being small at 4 ft 3 in, but even the legendary Bill Lear maintained that one doesn’t have to stand up in a Mercedes while travelling in it . . .

In short, taking into account the length of stages needed by your average corporate/charter passenger, that point seems irrelevant to us unless one has a board member of mobility akin to that of Young Mr Grace in Are You Being Served?

lnterair Marketing and Sales Manager Chris Grimm followed up his company’s philosophy in the Australian marketplace while we waited for Chief Pilot Phil Larnach to pre-flight the evaluation aircraft at Sydney Airport.

Four Marquises have been sold against stiff opposition since interior began in January 1981. One Solitaire has been sold and is now operated by lnterair: and a Diamond I is on order.

Interair operates, as we have mentioned, on an all-working team concept, with no idle members apparent. Managing Director Lyle Copley has an efficient organisation at Essendon, catering for parts, tooling, servicing and warranty activities. On warranties – Chris told us that Mitsubishi Aircraft International have put a two-year warranty on the Marquise-and they won’t be a party to a customer taking delivery of his aircraft unless he, or his designated pilot, has been thoroughly trained in safety procedures.

The intermarriage between Japanese and US organisations in the Mitsubishi organisation has progressed to the degree where the type is about 70 per cent US-assembled and 30 per cent Japanese-assembled.

In detail, the aircraft assemblies and sub-assemblies are made by the Nagoya Aircraft Works of Mitsubishi Heavy Industries Inc. , in Nagoya, Japan, and shipped to Mitsubishi Aircraft International inc Plant in Dallas, Texas for final assembly, roll-out and flight testing.

We talked about engines and as we walked out, VH-MIU was waiting. Mitsubishi has been using the trusted Garretts for so long, said Chris, that engine refinements are second to none. The Qarrett TPE 331-10-501 turboprops have been flat-rated at 715 showpiece and can be both removed from the wings in two hours, thanks to careful design work. It takes about 3-4 hours aside to replace the Garretts.

Each engine nacelle has three big access doors giving excellent accessibility to power plants, for inspection and maintenance.

With that 715 shp used for maximum continuous and take-off power, revs per minute are limited to a no-compromise 100 per cent of 41,730. Max. cruise is given as 98 per cent-49,859 rpm, and recommended cruise power at 96 per cent (40,100 rpm).

The big Hartzell four-bladed props have a 98 in diameter, and clear the ground by 2 ft 2 in, clearing the fuselage by 11 in. They turn slowly – prop take-off and max. Continuous are given as 1591 rpm, max. cruise at 1559 rpm and recommended cruise at 1527 rpm. No wonder the Marquise is a quiet ‘good neighbour’ type welcome at most airports and airfields after curfew . . .

Looking at the aircraft on the ground at once confirms the high wing loading. With an area of 178 sq ft, the wing spans a seemingly short 39 ft 2 in, has a MAC (mean aerodynamic chord) of 5 ft 1 in, and a 7. 71 aspect ratio.

Dihedral is zero, as one would imagine. For those interested NACA figures, Mitsubishi gives the root section as NACA 64A415, tip section NACA 63A212 (modified).

The Fowler flaps, when down to their full 40-degree deflection cover a massive 42 sq ft, and make possible that docile stall speed of 76 knots on the clock.

Spoilers, remarkably efficient and with military undertones, each have an area of 2. 9 sq ft, and can be deflected up to 60 degrees. ft: crisp roll rate_, even in a fully-dirty condition, proved the point in our eqaluation, and made for an over-correcting 1nitla. l phase in cruise once we thumbed out the Sperry, such is the spoiler sensitivity. ·

One had to look hard to see where the 266 in pressure capsule ended aft, such is the cleanliness of design and the benefits of heavy-milled skinning.

The Marquise might look as if it’s built like a brick you-knowwhat but it has been designed to last long after Brand X has come apart or become unglued through rough strip usage or continued high utilisation.

Outside inspection showed that the Marquise boasts three and a half windows each side in the passenger compartment half is a small window aft of the main cabin, about level with the capacious 44 cu ft usable volume baggage compartment.

Interair say one could carry up to ten passengers in the aircraft – including one in the certified-seat loo and one in the righthand seat forward. The type is certified for single pilot operation.

The test, aircraft was fitted out with unusual seating arrangements – We. have had many customers asking us what the executive seating and high-density seating look like,’ said Chris Grimm. So we put one side up in the normal arrangement the other side in executive style.

The cabin itself is very VIP; one loses the sensation of sitting inside a cigar as soon as one is settled in the seat.

In the cockpit, the atmosphere is one of easy professionalism. The black-backed panel sits high but does not intrude unnecessarily. The main annunicator panel squats down low on the pilot’s left flight instruments in front-the centre section of the evaluation aircraft was shared by an RCA colour weather radar, engine and fuel management gauges and Comm. Phil Larnach had at his command a Collins VLF/Omega box – the black box itself sat in the rear bay, along with radios and elevator controls.

A hast of options can be fitted on the panel; standard equipment includes a Sperry SPZ-500 Integrated Flight Command System giving Flight Director, Air Data and auto-pilot operation.

The IFCS provides heading, nav, approach, back course, and VOA approach lateral modes. It also gives altitude hold, and altitude preselect! Vertical speed hold (as we found out on approach to Sydney later in the piece), IAS hold and standby modes.

The whole lot comes in a Collins/Sperry standard avionics package. Dual VHF comm transceivers; dual Collins VOR/ILS; ADF; DME; transponder; and dual Sperry C-14A compass systems, to name a few.

The copilot has a Garrett cabin pressurisation and a Hamilton Standard air-conditioning system to play with. The pressure differential is psi, using_ air bleed from the engines. An air cycle refrigeration system is used for ground and in-flight cooling.

The overhead features switch for anti-ice, lighting and panel lights, among other electrics.

The entire cockpit is professional, refined to its ultimate efficiency and simplicity. The arrangements were so faultless that were surprised at finding ourselves inwardly criticising the high placement of the right armrest!

We had been cleared for a climb to FL 250 on a radial east of Sydney for air work. With four on board, our ramp weight was 4789 kg, take-off weight was computed at 4764 kg.

The starboard Garrett off and running after a relatively simple start drill, we could already feel the power in hand from the engine, flat-rated from its 1000 shp to 715 shp. And we began believing the claim that the Garretts give maximum performance over a wide range of operating conditions and heights.

Ground handling, even with only one of the two turboprops running, was smooth and direct. The twin nose wheels are controlled by mechanical linkage to the pedals, and travel 25 degrees left to 21 degrees right. An automatic disengage is activated when the gear retracts.

Incidentally, operators can inflate their main wheels from 40 to 74 psi, depending on the type of surfaces used during operations.

Testing the brakes during run-out to the holding improved the hydraulics can really put on the anchors using single discs and nine spot-type brakes.

With the port engine off and running, we turned onto the duty runway and departed with brisk and quiet acceleration. Our take-off was noticeable by its silence within the aircraft, and we rotated at 105 on the clock, climbing initially at 3000 fpm. Undercarriage was selected and we timed the sequence at about seven seconds with a slight vibration feeding in during cycling.

A minimal ‘tickle’ was felt through the controls during our evaluation, but proved a non-event when it came to distraction. Flaps came up in increments, giving minimal pitch changes during retraction as we set altitude selection and armed it, activated Omega and settled into a steady cruise climb around the 2600 fpm mark. Outside air had been + 20 on take-off – and the barometric pressure was a not-often-seen 1035.

Readouts during the initial climb phase included 100 per cent rpm, fuel flow at 430 lbs/hr/side, 100 per cent torque and EGT (exhaust gas temperature) steady at 580 degrees.

We were indicating around 156 knots at transition height, climbing at 2000 fpm with 86 per cent torque showing. Fuel flow was already coming back to 365 lbs/hr/side.

Control forces – before we switched in the auto-pilot – were light and positive. Back in the cabin, we could clearly hear the ‘passengers ‘ chatting away, from where we sat in the front office.

We made it exactly 20 minutes before the altitude select bell sounded off and we levelled off at Flight Level 250. Phil advised that another 200 feet wouldn’t hurt, to get the Marquise on the step. And get on the step it did . .

We were indicating 175 knots (TAS was around the 282 kts mark) in minus 30 degrees. Torque read out at 67 per cent, EGT 640 degrees, fuel flow back to 250 lbs/hr/side and rpm down to 96 per cent, as per the book.

The black boxes told us we had a wind of 282/45, which gave us a ground speed of a very healthy 326 knots. What a way to travel.

We concentrated on slow-speed work during this evaluation, just to prove claims that the Marquise is a docile aircraft in that phase and give the lie to that ‘hot ship’ label pinned on it by pilots who hadn’t flown it.

Bringing power well back, we selected first stage flap and undercarriage down at 175 knots, in this rarified upper air, and put the aircraft into some steepish manoeuvres. There was a slight buffet as the Fowlers came down on their first-stage travel, and a slight pitch as the mains and nose-wheel came down.

We followed Phil’s instructions to keep 115 showing on the ASI during our evaluation at this stage, lowered the big Fowlers all the way through their double-slotted travel to 40 degrees – and the Marquise took it without a murmur or even a twinge.

Control response through the spoilers was a delight, the roll rate being crisp enough to satisfy anyone who needed to put the aircraft through such ungentlemanly manoeuvres. We initially lost or gained up to 100 feet in the turns, such was the sensitivity of the aircraft’s control system; Phil told us that most pilots went through an over-correction phase on initial contact with the Marquise – which made us feel a little better.

Slow-speed evaluation over and proved, we milked up the flaps, retracted the F-104-type mains and nose-wheel and began the descent back to Sydney, power back to Flight Idle.

Not above 220 knots, advised Sydney. With a decent rate of 2000 fpm, this was easily accomplished by commanding the Sperry SPZ-500 IFCS to ‘hold’ at that speed, sitting back and remarking to Phil (who had already commented on it all being too easy) that one day we’d find ourselves wearing technicians’ white coats instead of normal flight deck clothing.

Through the transition layer, we were cleared to 5000 ft DME 30, from Flight Level 120 to 5000 feet.

Just short of the coast at a cleared 3000 feet, we turned to 330 degrees, cloudbase scudding along above the cockpit.

A last readout showed torque at 46 per cent, EGT 480, fuel flow 280 lbs/side/hr and 172 showing on the IAS. Cabin depressurisation was easy on the ears.

Undercart was selected down at 160 knots with first-stage flap, as we continued on a coupled ILS approach to Sydney.

The only thing we had to do was monitor and adjust speed with power . . .

Twelve hundred feet, 20 degrees of Fowler out in the slipstream, 140 knots IAS, and auto-pilot was thumbed out at 1000 feet. Speed was bled back to 120 knots, and at decision height (400 feet) the last stage of the flap was selected. 105 knots. . . 100 over the fence, a slight flare and the Marquise sat down quietly on the bitumen. Beta selected and the aircraft stopped as if it had contacted a rubber wall. In fact, we had to increase power to get to the turnoff.

We shut down the port engine during taxi back to Flight Facilities – and that was that. We left Chris and Phil to refuel for a run to Brisbane where they had a customer waiting and recapped on the aircraft, its potential, its undoubted efficiency in all departments, and its place in the corporate and charter sectors in Australasia.

The answer is five stars to all those points. With increasing selectivity by corporate and charter operators, the Marquise looks set to hold its own in an increasingly comprehensive market by virtue of sheer product excellence, durability and being built from the outset as a true turboprop machine