Airplane Review: Diamond DA-40


(Photo courtesy of Diamond Aircraft)

I don’t usually care too much what plane I fly, so I have only been flying Diamond DA-20s in Canada to keep my proficiency. They cheap, fairly new, fun to fly, beautiful, and have unbeatable safety record. They don’t fly very fast or very far, but I don’t really care about those because it’s just the plane I fly locally every few weeks to not forget how to fly.

But I thought it would be nice to also get checked out on a 4-seater, because it would be nice to be able to carry a few more people once in a while.

Cessna 172 is out, because I hate Cessnas with a passion. I have flown Cessnas a few times, and every time I felt like I was flying a school bus. And school buses don’t fly very well.

Sure, they are very stable and very forgiving, but they also don’t do very much. Plus, the visibility from the cockpit just plain sucks, with an instrument panel that blocks 3/4 the view.

So no Cessnas.

There aren’t many other 4 seaters available at Boundary Bay Airport where I fly out of, but the FBO I fly with happen to also have a Diamond DA-40, which is the “bigger brother” of the DA-20 I am used to, so I decided to give that a try. That’s quite possibly the second best decision I ever made in my life (after not doing drugs).

It’s a very modern design based on glass fibre (but pilots don’t really have to worry about that much – that’s the maintenance guy’s job), T-tail, otherwise fairly standard.

The Numbers

On paper, this plane is fairly respectable –

Maximum cruise at 140 kt (85% power at 2000 ft density altitude), and apparently can go up to 150 kt at 100% power – and the powerplant is rated for continuous operation at 100% power.

800 lb useful load – just slightly lower than Cessna 172’s 840 lb, but 800 lb is enough for 3 medium sized people (150 lb each), 50 lb bags, and full fuel (50 gallon).

~1100 ft/min climb at sea level.

All from a 180 hp Lycoming engine drinking standard 100LL avgas.

Compared to C172 SP, which also has a 180hp Lycoming engine, the much higher performance shows how much more efficient this plane is (sorry I just like to diss Cessna, no offense to people who like them :P).

Glide ratio 13:1. I’d almost call it a glider. I have seen how well the DA20 glides, and it looks like the DA40 is no different. This is amazing. Most airplanes of this class have glide ratios in the range of 7-10:1.

Exterior and Preflight


(Photo courtesy of Wikipedia)

When I saw her getting bigger and bigger as I get closer, it was orgasm. I have never seen a plane so beautiful. If you tell me to pick my favourite plane based on looks alone, this guy would definitely be the first.

Very smooth and “flowy” design (which happens to also help a lot with airplane performance), with very very long high aspect-ratio wings. Aspect-ratio of wings is the ratio between wing length and the average chord (“width”). It’s one of the big tradeoffs in airplane design – low aspect-ratio = higher maneuverability at high speed, high aspect-ratio = lower cruise performance but better low speed handling and gliding. I like the design choice they make here, because I like planes to be forgiving at low speed, and don’t mind losing a few knots at cruise.

The T-tail design is somewhat uncommon in this class of aircrafts as well. Less prop wash on the tail means changing power will have less effect on pitch, which is pretty nice. One disadvantage according to Wikipedia is that if a T-tail plane is put into deep stall, the wings can mask the elevator, and recovery may be impossible due to little pitch authority. Just don’t go into deep stalls?

The doors are absolutely amazing. All doors open up, and passengers have their own door, too, which is pretty uncommon but very convenient. Stepping on the wing to get into the airplane takes some getting used to, but it’s pretty fun.

Preflight is fairly easy and standard. Draining fuel is a little weird but that’s a common problem with low wing airplanes. You have to get below the wings to do the draining. Pretty short checklist.

Controls and Instrument Panel


(Photo courtesy of Diamond Aircraft)

Central stick design. I like to fly planes with sticks because they feel more natural to me, but the major downside is you can’t really fly with a map or notebook on your lap… because that’s where the stick is.

Most of the panel space is taken up by the 2 huge screens of the Garmin G1000 avionics. The left screen (primary flight display) shows important things like airspeed, altitude, attitude, turn rate, heading, etc, while the right screen (multi-function display) shows the map, and also engine parameters.

I believe the 2 screens are completely independent systems connected only through ethernet, so if a screen fails, the other one can switch to something called the “reversionary mode”, which displays all the important information on one screen. This mode can also be activated manually, which is useful if the right seat pilot/passenger wants to fly (and see those numbers).

The airplane has 3 batteries in case of alternator failure – main battery which will power the whole plane for about 20 minutes, then a backup battery that will only power the G1000 for another 90 minutes, and then ANOTHER backup battery that will only power the backup analog instruments (on top of the G1000) for another 90 minutes. Not sure why anyone would keep flying for hours after an alternator failure (which would give a big fat obnoxious warning on the G1000)… but hey, that’s nice.

One thing I love about the G1000 is the situational awareness it brings. It continuously monitors engine parameters (oil pressure, oil temperature, CHT, EGT, fuel etc) and will give the pilot a big fat visual and audible warning if any of them go into yellow or red. That significantly reduces pilot workload in instrument scans and significantly increases safety margin. I believe it can also give out terrain proximity warnings, but I don’t know how that works.

I don’t know if this is standard for DA40, but the one I flew also has active TCAS WHICH IS SUPER AWESOME. It shows all nearby transponder-equipped aircraft in vicinity on the map, and will issue audible traffic advisories if they get too close (“traffic 1 o’clock, 2 miles, low”). It’s not 100% reliable, though, especially in bad weather. It will pick up reflections and things like that and show false targets sometimes. It DOES send out interrogation signals, so it works even if there are no ATC units nearby interrogating transponders (this is not true for many low end traffic advisory systems). Of course, this does not replace visual scans, because there ARE actually still people out there flying without transponders, or have broken transponders. The system is only designed to aid in visual acquisition of other aircrafts.

It also has a 2 axis (HDG and ALT) autopilot with heading and altitude pre-select, which is very awesome. Altitude pre-select = choose a target altitude and a climb/descend rate, and AP will try to climb/descend to the target altitude and maintain it. Heading = choose a heading or NAV target on G1000, and AP will do standard rate turns to that heading/target. 4 ways to disconnect autopilot – AP button on the autopilot panel, red missile firing button on the stick, black button on the stick (temporary override), and if all else fails, pull out the autopilot fuse.

In the center is throttle, prop speed (variable pitch), and mixture (G1000 assisted-lean is pretty cool). As well as parking brake, defrost, and fuel tank select (no “both” :(:(:().

Flaps have 3 positions – up, take-off, and landing. Fully electronic. Just need to flip a switch.

Trim is also pretty cool. Electric trim, not actually connected to the elevator. It’s just an electric motor that will apply a fixed force on the stick based on trim.

Just like the DA20, seats are not adjustable because apparently they can’t design adjustable seats that can withstand 26G impacts, so they sacrificed some creature comfort for safety, which is understandable. Rudder pedals are adjustable, though.

Taxi-ing and Take-off

Taxi-ing may be weird for people not used to castering nosewheels. Steering is by differential braking only, which is quite different from planes like C172. It feels like the DA40 has much higher moment of inertia, and will keep overshooting when turning.

I didn’t have any problem with it because I am used to taxi-ing tailwheels, which are much worse, but I heard many nosewheel pilots have trouble taxi-ing the DA40 straight.

Run-up takes a little while mostly because of mixture leaning (if using G1000 assisted-lean, which requires leaning VERY slowly).

Take-offs are pretty simple. Flaps in T/O, mixture rich, prop pitch full fine, throttle full, rotate when “R” comes up on the G1000 speed tape (which also shows Vy, Vx, etc). Fairly significant left turning tendency, but still easy to control. Rudder authority is awesome.

This little girl climbs FAST!! The flight manual quotes 1125 fpm (I think), and I was seeing something close to that. I wasn’t even climbing at Vy (maximum rate of climb speed). Vy is around 70 kt, and I was going at 85 kt (according to the instructor, if I climbed out at Vy, the plane will climb so fast that it would be dis-orienting). Still, the ground just went WHOOSH and was nowhere to be found. Combined with a fairly short take-off distance, this is reassuring.

The most critical phase of the flight, I think, is the take-off, where if the engine fails, there may not be many possible places to land, and climbing fast helps to minimize this window.

Cruising, Maneuvering, and Landing

Definitely counts as an easy airplane. Controls are responsive, but the plane is still relatively stable. Not quite as fun as the DA20 (flying the DA20 feels like flying a fighter jet), but a lot more interesting than C172.

The highly efficient design means it can accelerate pretty fast. Throttle in and the speed picks right up to ~110 kt (at around 50% power, didn’t try to go faster because we only stayed in the pattern for this flight).

On the other hand, slowing down the plane without flaps is relatively difficult. T/O flaps can be deployed at 108 kt, though, so it’s not really too bad.

Even with the high cruise speed, the stall and approach speeds are still pretty low (50 kt stall in clean configuration, and 70 kt normal approach), which is nice. Just like the DA20, I like to land with T/O flaps because landing flaps significantly increase rate of descent, which would require a very strong flare which is kinda scary. So I only use landing flaps when I screw up the approach and end up way too high.

With T/O flaps and approaching at the right speed, landings are very easy. Don’t know what to say about that… just easy. Standard round-out, fairly shallow flare.

Many pilots say landing Diamond airplanes are hard because they like to balloon a lot. From my experience, that’s not true if you do the speed management right, and use at least T/O flaps. They land just as easily as any other airplane I have flown… but maybe that’s because I’m used to flying Citabrias which are notoriously hard to land since they are tailwheels with no flaps.

Sure, you can’t dive at the runway and expect to bleed off all the speed before touchdown like you can with a Cessna, but that’s because Cessnas are flying school buses. Not supposed to do that anyways. Pitch for speed, power for altitude, and flaps if too high, forward slip if WAY too high.


Extremely happy with this airplane! Good performance, forgiving, yet still fun to fly. Also, sexy.

It also happens to be very safe due to benign flight characteristics. The DA40 has 0.35 fatalities per 100,000 flight hours, which is 1/8 the average for general aviation, and the lowest of all GA airplanes! From what I have seen, most DA40 accidents were instrument approaches into very bad weather, and stupid stuff like buzzing. No stall/spin accidents because stalls are very gentle – no dropping wings or nose (well, barely), with very low tendency to spin.

Only gripe – fuel tank select. Need to remember to switch tank every half hour. Why can’t they just have both feed the engine all the time?! Many planes do that, and it would be one less thing to remember.

Would be nice if useful load is slightly higher, but not many planes can take 4 people + full fuel, and 800 lb is still plenty I think.

At $195/hr it’s definitely not a cheap airplane, but when bare-bone 30 years old C172s are asking for $150, I think that’s a reasonable price. Probably won’t fly her by myself because I’m not made out of gold, but for carrying a few people, it’s actually not too bad, especially since she is fast, so $/distance is lower.

BTW, this is where I’m renting from

Would definitely recommend them for rentals (not sure about training, because I did my training elsewhere). They are upfront about everything, and no membership fees, fuel surcharge, etc. What you see is what you pay. Online booking system is pretty crappy, but the planes are good.

I would definitely not recommend this airplane for flight training, though. G1000 is very nice when you already know how to fly, but if you are still learning to fly, it would just be @#$@#%@# information overload.