Review: Iris Pro Series – Diamond Star XLS

The IRIS Diamond Star DA40 XLS is a reasonable model of this new style type of GA plane ie made from composite materials with radical design features.  It looks good and flies very well and it has its own sounds which are unique to this plane.  In general terms the instruments are good, being specially developed for the Iris DA40 they are clear and functional with a few minor niggles.  The DA40 has a range of over 700nm so it is quite useful for those 4 to 5 hour flights and at a cruise of around 150KIAS, it’s no slouch.  Being equipped with a “glass cockpit” ie the G100 it can be flown for both VFR and IFR flight.  In terms of performance, size and design you would have to compare the DA40 to the Cirrus SR20, the Columbia C400 (much faster) with the choice coming down to personal preference and how fast that you want to get there.  The Interior looks a little flat, I would have expected more detail in the seating but there are 2 interior colours available (as in the real deal).  As I have noted on several previous occasions, it does not have facilities for loading, maintenance or repair during use, and that would have made it a much better plane in my opinion.  This is the first GA plane developed by IRIS FSS and it shows great promise for the future.  In the words of Flying Officer KITE: “Jolly good show” (courtesy of the BBC).

The Diamond Star — A Brilliant Faceted Review

Background: (Courtesy of Wikipedia and DiamondAircraft)

The DA40 is a single engine, four-seat low-wing cantilever monoplane made from composite materials. It has a constant speed variable pitch propeller, a fixed nose-wheel landing gear and a uniquely designed T-tail.  The engine is usually a Lycoming IO-360-M1A 180HP which is an air-cooled, 4-cylinder horizontally-opposed piston engine slurping Avgas.  The propeller is a MT 3-blade composite constant-speed (with or without feathering), and the IRIS model also has a 2-bladed propeller version.  The latter appears to be a “cosmetic” modelling as there are no differences in performance etc between the IRIS 2- and 3-bladed variants in the sim.

In the Sim

Installation was painless with a self extracting “exe” file which installs in the correct FSX location.  The documentation i.e. the Manual, the paint kit and “bonus” features are installed in the \FSX\Iris Pro Series Seminole folder.

Settings: On my system in the Select aircraft menu in FSX under “Publisher” I was presented with the tab for “Unknown” and this allows the choice of all 8 models.  I found that to display the Aircraft in the publisher tab as IRIS FSS, I had to edit the aircraft.cfg (and each “fltsim.x” variant within the cfg file) and add this line below any “uixx” entry in the first section:  ui_createdby=”IRIS FSS”.  Similarly under “Aircraft type” tab you will find the IRIS DA 40 listed as “legacy”, so I changed this to ui_typerole=”Single Engine Prop”.  My flight control settings are full right — as realistic as you can get.  I did not experience any adverse effects on my frame rates.

The Guide: There is a manual of 37 pages, which is basically a checklist of operating limitations, aircraft specifications, normal ops, performance charts, and a series of pictures of the cockpit which have annotations showing what button, gauge, lever, etc does what.  These are well laid out and it is easy to find what the purpose of a particular gauge, etc is for.  Again, unfortunately, there is very little interesting background information on the DA40 or its aviation history.  The “main” instrument is the G1000 system and pilots are urged to read the information contained in FSX for the default G1000 unit.  However, as I discovered, the default FSX G1000 unit does vary (operationally and layout wise) to the Iris G1000 unit and these differences might have been better explained in the manual.

Bonus Features:

Found in: Microsoft Games/Flight Simulator X/IRIS Pro Series/Diamond Star XLS/Bonus Features/

I could not find any reference in the manual as to what the bonus features (which appear to be replacement textures) actually do.  However, this was posted in the forum: “If you run the file ‘Replacement Texture Installer’ it’ll reduce all the textures to DXT5 format which may save some graphics card memory.”  I did not test the bonus textures.

The Visual Aspect

Outside the planes appear quite realistic being very similar to the real deal and the whole package does have great eye appeal.  I have to admit that the Interior looked a little Spartan and flat to me, and I would have liked to see more detail in the seating, but again this is a minor observation. In the real world (and in the Iris DA40) there are two upholstery colours, Premium grey and Premium Tan leather, but in the Iris they appear to be more “cloth-like” than “cowhide-like”.  I like to see stitching!

Figure 2 Diamond DA40 Photograph Courtesy of Michael Priesch and Airliners.net

Figure 3  Diamond IRIS FSS DA40 XLS pretty close

As you can see in the pictures above the Iris DA40 closely resembles the real world variant good modelling.

Figure 4 IRIS DA40 Tan Leather Upholstery

Figure 5 Diamond Tan Upholstery, real world, Courtesy Diamond Aircraft

The Interior is well appointed showing the luxurious club seats available in this aircraft with slight variations in the positions of the seat belts.

The, handles, buttons, gauges, levers, lights and wheels all look realistic and are quite clear. Unfortunately, none of the gauges “pop-up” or increase in size when clicked (neither do they in real-life), so a TrackIR would represent a good investment. Shift + 2 Pulls up the Radio etc stack, which looks and operates like the standard FSX gauge.  The other gauges seem to be exclusive to the Iris Model.  There are no 2D panels and in 2D mode pressing “W” displays the standard FSX mini-gauges.  I did not use “DX10 Preview” in the sim, as it is posted on the forum that there may be issues with this model and DX10 preview.  In the default FSX C172 (G1000 Glass cockpit model), both the PFD and the MFD pop-up larger in front of the VC by using a “shift + number” key, thus making them easier to see and change in flight.

Figure 6 IRIS DA 40 VC Cockpit

Figure 7 Microsoft Games/Flight Simulator X/IRIS Pro Series/Diamond Star XLS Central Consol, Throttle, Prop, Mixture

There are 8 variants depending on the number of blades in the propeller and whether there is a wheel speed faring or not.  It would appear that these are apparently based on real-life aircraft and it would have been nice to know the history of those 8 planes and why they were chosen.

IRIS FSS DA 40 Models

Figure 8  IRIS DA40 N1275PB 3 blade prop, speed faring and tan upholstery

Figure 9  IRIS DA40 N349AF 2 blade prop, plain wheel grey upholstery

Figure 10  IRIS DA40 G-CEZE 3 blade prop speed faring tan upholstery.jpg

Figure 11  IRIS DA40 N975DS2 blade prop speed faring GREY upholstery

Figure 12  IRIS DA40 VH-BUG 3 blade prop NO speed faring GREY upholstery

Figure 13 IRIS DA40 G-BYVO 2 blade prop NO speed faring GREY upholstery

Figure 14 IRIS DA40 VH-DRB 2 blade prop speed faring GREY upholstery

Figure 15 IRIS DA40 VH-PYO 2 blade prop NO speed faring GREY upholstery

There are two opening doors, i.e. the front access door, and a port-side rear passenger door both of which open and close, and there is a “tread” strip on the wing allowing access to the plane.  The front door opens with a mouse click inside the VC, but the rear door does not.

Figure 16 IRIS DA40, main, passenger Door open and tread strip

Range:

The tank holds around 50 US gallons (usable — 53 USG max) and on *normal fuel usage (approx 10 US gallons/hr) you can fly for around 5hours, i.e. around 720 nm, (*engine setting of 75% and a 45 minute reserve).  One flight I had ran for 650nm and the fuel was definitely on the low side when I landed, not much room for error or a go around!

I did not see any significant drop in performance (frame rates) in FSX in this plane.

Instruments in the Interior:

There is only one cockpit layout for the 8 models (See Figure 6).  This layout depicts the usual avionics/navigation instruments which are exclusive to the IRIS DA40 plus a Garmin G1000 which although based on the default FSX G1000 is unique to the IRIS DA40.  The gauges excellent and readable but you do have to magnify the VC panel in order to read them and or change values, and that is tricky, particularly at low-level flying.  I found the easiest way in flight was to pause the sim, make the changes and resume flying.  A TrackIR would be an asset.

The IRIS DA 40 G1000 has more functions than the default FSX G1000 and of course these are not described in the IRIS manual, nor are they described in the FSX manual, so there is a little intuition needed in interpreting some of the functions.  I have to say that they are simple functions such as autopilot, Vertical Speed, etc so they are reasonably easy to deduce.

However, I believe that the default FSX G1000 has more functionality than the IRIS G1000, and is easier to use, particularly in flight.  The developer has posted on the IRIS forum that some of the functions in the IRIS G1000 do not work and an upgrade is promised to rectify the situation.  For example setting the baro key in the IRIS DA40 is non-functional at this time.  I spoke with the developer, David Birch, and posted some of my observations that I had noticed wrt to the IRIS G1000, and he informed me that many of the points that I had raised (see addenda) could be addressed in a forthcoming comprehensive upgrade.  Once these are implemented we will have a very nice G1000 system.

The instruments look good at night with clear illumination and excellent lighting.  The lights are controlled by the default key strokes, ie “L” turns on all lights including panel lights in the VC, Position and strobe.  There is a light switch panel in the VC (switches all of the lights on/off) which is much better than using the “L” key, and this can be configured to various joystick buttons (I used FSUIPC4 to set the lighting switches).  The landing and taxi lights have different intensities and are quite good with adequate illumination for the procedure, and it will be interesting to see a Shockwave Redux version, although the developer did inform me that the IRIS DA40 lights are based on the A2A Shockwave lights.

Figure 17 IRIS DA40 VC PFD

Figure 18  IRIS DA40 VC MFD

Figure 19  IRIS DA40 VC MFD TOPO Mode

In TOPO mode on the MFD the colours appear to be washed out, which is probably something to do with the backlighting in the VC.  The developer said that IRIS would look at making this view much clearer.

Figure 20 IRIS DA40 VC well lit at night

Figure 21 IRIS DA40 VC Light Panel Switch controls all lights

Figure 22 IRIS DA40 Landing, Strobe and NAV lights

The Payload

These are set within the Sim for a pilot, co-pilot and two passengers and baggage, so that reflects the payload of the real life plane.  The co-pilot is female and the two rear passengers are extremely light!

Figure 23 IRIS DA 40 Female Co-pilot as designated in the Payload

In the air

The engines can be started manually, or Ctrl + E will also work, unfortunately a step by step manual start procedure (other than the various settings to be adopted) is not outlined n the manual.  However, if you are used to GA planes it is a relatively easy procedure to follow without specific instructions.  I set all my controls in FSX to realistic ie to the far right.  The plane taxis well I use my Eclipse Yoke in conjunction with a Logitech G940 system, setting the “paddles” on the Eclipse as a “tiller” (via FSUIPC4) and this gives great smooth control on the ground, and reverts back to the rudder at 60 KIAS.  Some simmers have had issues with the nose-wheel steering but I did not experience any problems either when taxiing or rolling for take-off.

For take-off I followed the manual checklist, i.e. brakes hold, flaps/trim at T/O, throttles at idle, check manifold pressure, check gauges, release brakes, push throttles to full and rotate at around 60 – 65 KIAS I had now rolled about 1200’, so check your runway length!! (There was no noticeable torque effect on take-off.) I climbed at around 60KIAS @ 2400 rpm, retracted flaps at 500’, adjusted the trim for best climb at a the speed of around 75 KIAS at max power.  With these settings I was climbing at around 1,000’ ft/min, quite useful!  You need to adjust the mixture for best EGT (above 5,000’) for the plane to run smoothly.  The gear is fixed and does not retract. With a full load on board it to took me nearly 1800’ to take-off.

Figure 24  IRIS DA 40 Flaps set to Take-off

The ceiling of this plane is around 16,400’ restricted to 14,000’ in the USA, and it achieves this in less than 20 minutes depending on load, etc.  It cruises effortlessly at 150 KIAS with a prop setting between 1800 and 2000 rpm at around 75% engine power.  Having an autopilot coupled to the PFD makes it easy to maintain the correct height with optimal engine settings.  However, it is very easy to maintain level flight and a cruise speed by judicious use of the trim and throttle controls.

In terms of the four fundamental basic flight manoeuvres, straight-and-level flight, turns, climbs, and descents are all performed with aplomb by the IRIS DA40, and that makes it very easy to fly. In other word when you push the stick forward the nose drops, move the stick to the left and the plane turns left and so on, basic stuff but essential in flying the plane.

Although IRIS gives you a 2-bladed and a 3-bladed prop option, there is no difference in the flight characteristics in the sim.  The cruise and top speed figures quoted in the IRIS manual do not match those on the Diamond Aircraft (and Wikipedia) website, and this discrepancy may be due to the fact that the latest DA40 XLS are built with a 3-bladed prop and IRIS may have used the 2-bladed prop model for their specifications.  This is a minor detail and really doesn’t affect the flying performance.

Figure 25  IRIS DA 40 in full flight

Stalls

Inducing a stall was according to the “book”, i.e. above 3000’, no flaps, reducing the power to idle and trying to maintain level flight.  In the sim the stall occurs at around 70KIAS (real-life is around 50KIAS) the plane becomes very heavy, shakes a lot and wants to descend rapidly i.e. almost uncontrollable.  FS Force makes it very realistic with a huge amount of shake during the stall.  Recovery was also by the “book”, i.e. decreasing the angle of attack and advancing the throttle to full power, until I had full control back again.  I thought that stalls were well modelled in this plane.

Landing

As always (I’m predictable), I set up my approach at around 5 — 7 nm out by setting a rich mixture, and the prop at full rpm and setting the throttle to reduce speed and stabilising to around 100 – 110 KIAS, (with flaps set to T/O and trim down to maintain descent and speed).  I try to descend at approximately 500’/min and the plane was very responsive and easy to control at these settings.  By the time that I had reached the threshold I had reduced speed to around 70 – 75 KIAS, finally settling on the tarmac at around 60 — 65 KIAS.  The controls were good during landing, being both light and responsive and easy to control.  Cross wind landings were good, I maintained the crosswind at around 15 KIAS and the plane was reasonably easy to land using standard procedures. I only missed the runway a few dozen times during this part of the testing.  My opinion – this plane has very good landing characteristics in good and bad weather.  IFR flights are easy with G1000 system and it is very satisfying to complete a 500nm journey with little or no visibility for most of the way to finally come down on final through the clouds and see the runway dead ahead.

Sounds

I liked the unique sounds (they have to be from a real world aircraft); as usual they vary (as they should) from outside to inside and front to back.  The range is good thru’ idle, taxi, full throttle, etc — very rorty!!

Repaints

Repaint kit included.

Support: This was by email and forum.  I received very good responses on the forum and also by raising a support ticket.  I was also fortunate to have a long telephone conversation with the developer, David Birch, which answered many of my questions.

Upgrades

A version 1.2 is being planned and this will include a DA40 with an analogue panel as a turbo-diesel powered unit, plus various suggestions from users.

Summing Up:

This is a credible first GA plane from IRIS FSS.  It is quite speedy and you get from A to B pretty fast.  The plane handles beautifully and it looks very good.  It has a few niggles which are relatively minor but with the positive attitude the IRIS team have, I’m sure most of these will be fixed in the very near future.  I thought that the manual was adequate but needs a little more input to describe some of the functions, ie start from cold and dark, differences between the IRIS G1000 and the Default FSX G1000.  There was no facility for maintenance or repairs and it used the inbuilt payload function of FSX when it would have been good to see a dedicated load manager, and I have posted this request on the forum.  There is also an “annoying” post-it note on the VC panel, urging you to buy IRIS products but as the developer states, “the note is in dds format and can be edited and the words replaced with a picture or other words.  It might be better if it was removed all together.  On the positive side it handled very very well and the flight characteristics were excellent, being easy to fly with no vices.  It will be another good basic GA plane to park in your virtual hangar.

WOW Factor: 8/10

Peter Hayes, Australia, March 2010.

Supplementary:

Questions and Issues that I raised with IRIS which may be fixed in an upcoming patch:

Table of the Important Bits: