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Diamond anounced two day ago that the DA50 will come in two version: the DA50 SuperStar and the DA50 Magnum with the AustroEngine AE300 powerplant. This is not hot news, but what Diamond added is that the DA50 Magnum will be pressuzried !

Even if you’re not an IFR pilot, this probably makes it even more attractive. Pressurization means getting to higher altitudes without need for supplemental oxygen, and less ears problems. For IFR pilots, this makes a major difference.

The maximum altitudes we can use without pressurization are in the 10 to 12′000 feet range, and these are the worst place to fly: most of the icing layers are found below 15′000 feet. Getting a pressurized aircraft does not mean that you can fly in icing conditions, but if you encounter them, that will not be at cruising altitude, and clibming through is an option.

This is particularly enjoyable when descending is not possible beause of high grounds. Another advantage is the possibility to fly high-speed approaches (particularly as these planes will be damn quick) without having to sustain the rapidly chaning pressures, which can lead to sever ears trauma.

Apart from the Cessna P210, there are not a lot of pressurized single engine airplanes around. Piper offers a turbo Saratoga with built-in oxygen, but if you want a pressurized Piper, you’ll have to buy a Mirage or a Meridian, which is clearly not adressing the same market as the 210 or the DA50.

Once again, Diamond seemd to have heard what pilots are expecting: the decision to add pressurization is the direct outcome of requests from customers who booked a DA50. I must admit that if I had the money (the prices are not yet anounced…), that would probably be my aircraft of choice.

Links:

Diamond press release about the pressurized DA50 and the AustroEngine (including pictures)

Comment from AOPA on the same topic

More on ear trauma and pressurization

As I don’t fly pressurised aircraft (yet), I spent most of my flying time at altitudes between mean sea level and 10′000 feet. I never flew below mean seal level (a trip to the Netherlands would make it possible), but I popped above the 10′000 feet limit occasionally when flying over the Alps.

The airspace at and below 10′000 feet is like my flying home. It’s not always an easy place to fly, but I like it. Most of the icing is there, as air-temperature above is too cold for that. Thermal and orographic (caused by wind over mountains) turbulence occurs below 10′000 feet.

The view from there is much better as from FL300 (sorry jet guys), and there is much less traffic there than where the airliners, business jets and turboprop do fly. And descent planning is much easier when there is only 3′000 feet to loose to the IAF.

When I read that “sustained flight below 10′000 feet is not recommended“, I did not like that - particularly as it was part of Boeing check-list. If it is not recommended for airliners to fly below 10′000 feet, what about light aircraft then ? Shall I always request Flight Level 110 ? Shall I buy an oxygen bottle and cannulas ?

Well, let’s have a closer look. It all started with a an aircraft which flew for 10 hours with a cracked windshield. The cracks were small, the windshield shown no deformation, this incident was a non-event. In the forum discussions on this incident, the procedures to apply in case of cracked windshield for various type of aircraft were exposed.

Most of these procedure include a descend, aiming at reducing the pressure difference between the cabin and the outside air. If the windshield is seriously damaged, the pressurization could break it, leading to more serious trouble. Most Airbus checklist require a initial descent to 23′000 feet, and lower if required.

As often, the Boeing procedure is less… academic, and probably easier to follow: descend to 10′000 feet or the minimal safe altitude, whichever is higher. Here comes the note at the origin of this post, extracted from a Boeing 777 abnormal checklist: “Sustained flight below 10,000 feet is not recommended due to greater risk of bird strike”.

So what ? Not only my favorite place has most of icing, extra turbulence, and moreover we have most of the birds ? Even if Boeing thinks that sustained flight below 10′000 feet is not recommended, I like to do it, and I’ll continue !

There are no elegant, or smart aviation accidents. Loosing someone is always tragic, whatever the circumstances. I don’t want to judge anybody, my aim is simply to highlight how quick and silly accidents can be.

A KingAir 200 was back from a short test flight after maintenance. The pilot reported some noises, and the mechanic decided to board the plane while the engines were still running. You think he’s got hit by the prop ? Missed. This already happened, but not this time.

This accident occured when the mechanic opened the door. The reason is not yet clear, but the cabin was still pressurized, and the door violently hit the mechanics head. He died after being transported to the hospital.

The causes will be established by the investigation team, and could range from human error to technical deficiency in the pressurization system. I don’t want to speculate here, but there is something that makes this accident slightly different from others: I can’t imagine the usual series of events leading to it.

Most accidents have multiple causes, and preventing any of the causes could have avoided the fatal ending. This is the famous theory of the cheese slices: only when all the holes are lined-up, the accident happens. Even the most unexpected engine failure in a single engine aircraft gives the pilot some time to react and try to land. But this accident was so sudden that there was simply no possibility for a corrective action when the problem became apparent.

This could compare to an airframe falling apart in-flight, leaving the aircraft totally out of control. Such sudden and unavoidable accidents are hopefully extremely seldom, thanks to good application of the safety principles.

I don’t know if the KingAir is fitted with an pressurization indicator that is visible on the door itself. Some airliners have that incorporated in the door window. A red light illuminates if there is a pressure difference, so when someone wants to open the door - be it from inside or outside - he knows that there is a danger linked to pressurization.

It’s probably not frequent that KingAir doors are opened by someone else than one of the pilots… may be the recommendations of the investigation report will go in that direction. Whatever, the Murphy’s law has been verified one more time…