DA50 same price as DA62 - How's this make sense?

Any DA50 related topics.

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Boatguy
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Re: DA50 same price as DA62 - How's this make sense?

Post by Boatguy »

lgrennlee wrote:
Thu Nov 18, 2021 3:02 am
Also the tanks rely on a transfer pump which can be left on and auto transfer but if forgotten the transfer rate is "only" 60G/hr. It's possible that one might not be able to put all of the fuel in the main tank before it runs dry if they forget. Also the pump could fail creating a fuel emergency very quickly.

Along those lines... and this is potentially important for a high performance aircraft. The Cirrus Vno is 176 KIAS, The DA40 is 152 KIAS. That is a pretty low value when I'm sure the plane is quite slippery. It will prevent "high performance" descents when it is bumpy out. It may also limit top speed when a bit lower to the ground.
I think there are a variety of the reasons why the DA50 may not be a successful airplane, but I do want to call out a couple of your assertions.

Most single engine aircraft require some fuel tank management. The DA40 and SRxx both require switching between R and L tanks at the appropriate times. My DA40NG requires the same fuel transfer from R to L as the DA50 and it's never been an issue. In the event of transfer pump failure, the engine becomes the transfer pump since it returns about 90% of the fuel pumped from the L tank to the L tank. Switching the fuel selector to the "Emergency" position causes the engine to draw from the R tank and then the engine will transfer fuel from the R tank to the L tank at about the same rate as the fuel transfer pump.

The DA40NG Vno is 130KIAS which you may have confused with the Vne which is 152KIAS in the NG and 178KIAS in the DA40 Lycoming. Perhaps your reference to 152KIAS is for the DA50? Or is there confusion between Vno and Vne?

The DA50 is much larger and more comfortable than a DA40 or SR22, but it is definitely lacking in range and speed to compete with the SR22.

Diamond is all about engineering, marketing and customers are an after thought at best. Cirrus is all about marketing and customers with very little innovative core engineering in the SR series (though the Vision Jet is clearly an engineering accomplishment). The introduction of the DA50 continues to underscore this difference between the two companies. You asked the right question which Diamond did not; who is the customer for this airplane?
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Re: DA50 same price as DA62 - How's this make sense?

Post by ememic99 »

lgrennlee wrote:
Thu Nov 18, 2021 3:02 am
I can only hope they find somewhere to put another 20 gallons of fuel.
DA50 is definitely duration and range challenged - to put it mildly. Besides that, it’s nose-heavy and not as easy hand-flying as DA42 or DA62, requiring constant trimming even in brief turns to ease the force against your arm.

Adding 20 gallons (or even better 30) would fix the range but the problem is MTOM which would exceed 2 tons which in European IFR operations means airway fees (approximately $100 per flight hour additional cost).
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Re: DA50 same price as DA62 - How's this make sense?

Post by lgrennlee »

Boatguy wrote:
Thu Nov 18, 2021 4:17 am

Most single engine aircraft require some fuel tank management. The DA40 and SRxx both require switching between R and L tanks at the appropriate times. My DA40NG requires the same fuel transfer from R to L as the DA50 and it's never been an issue. In the event of transfer pump failure, the engine becomes the transfer pump since it returns about 90% of the fuel pumped from the L tank to the L tank. Switching the fuel selector to the "Emergency" position causes the engine to draw from the R tank and then the engine will transfer fuel from the R tank to the L tank at about the same rate as the fuel transfer pump.

The DA40NG Vno is 130KIAS which you may have confused with the Vne which is 152KIAS in the NG and 178KIAS in the DA40 Lycoming. Perhaps your reference to 152KIAS is for the DA50? Or is there confusion between Vno and Vne?

The DA50 is much larger and more comfortable than a DA40 or SR22, but it is definitely lacking in range and speed to compete with the SR22.

Diamond is all about engineering, marketing and customers are an after thought at best. Cirrus is all about marketing and customers with very little innovative core engineering in the SR series (though the Vision Jet is clearly an engineering accomplishment). The introduction of the DA50 continues to underscore this difference between the two companies. You asked the right question which Diamond did not; who is the customer for this airplane?
Sorry, I meant DA50 not DA40... thank you!

Shame on me on the fuel system (I didn't read the whole section on the fuel system). There is an emergency valve so there will be no single tank issue. I don't understand why fuel needs to be transferred to the main tank. The normal swapping left to right should be sufficient no? From a systems perspective, providing a transfer pump seems overly complicated. I guess you can correct a fuel imbalance in flight with that design where it is not possible without burning it in the DA40 XLS.
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Re: DA50 same price as DA62 - How's this make sense?

Post by CFIDave »

lgrennlee wrote:
Thu Nov 18, 2021 12:03 pm
I don't understand why fuel needs to be transferred to the main tank. The normal swapping left to right should be sufficient no? From a systems perspective, providing a transfer pump seems overly complicated.
You may be missing an important element of the DA40NG and DA50 fuel systems operation: The approximate 90% of fuel that is not injected into the engine and that has to be recirculated back to the left wing MAIN fuel tank gets very hot as it goes through the engine's common rail. So unused fuel from the engine is first routed through the right wing AUX tank with plumbing that keeps it from actually mixing with AUX tank fuel -- to cool the unused fuel and keep the fuel in the right wing AUX tank warm. Then the unused fuel is routed back into the left wing MAIN tank. The right wing AUX tank acts as a big heat sink for the hot unused fuel.
N62DV DA62 62.056
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N811ET DA40 XLS 40.874 (sold)
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Re: DA50 same price as DA62 - How's this make sense?

Post by lgrennlee »

CFIDave wrote:
Thu Nov 18, 2021 2:29 pm
lgrennlee wrote:
Thu Nov 18, 2021 12:03 pm
I don't understand why fuel needs to be transferred to the main tank. The normal swapping left to right should be sufficient no? From a systems perspective, providing a transfer pump seems overly complicated.
You may be missing an important element of the DA40NG and DA50 fuel systems operation: The approximate 90% of fuel that is not injected into the engine and that has to be recirculated back to the left wing MAIN fuel tank gets very hot as it goes through the engine's common rail. So unused fuel from the engine is first routed through the right wing AUX tank with plumbing that keeps it from actually mixing with AUX tank fuel -- to cool the unused fuel and keep the fuel in the right wing AUX tank warm. Then the unused fuel is routed back into the left wing MAIN tank. The right wing AUX tank acts as a big heat sink for the hot unused fuel.
Yes indeed, very interesting thanks for that!
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Re: DA50 same price as DA62 - How's this make sense?

Post by lelievre12 »

I've been comparing the Diamond DA50 RG numbers to my Cessna P210N.

Top Speed DA50RG - 181KTAS @ 12K = 1.84 Nautical miles per pound of fuel. www.youtube.com/watch?v=JMQjAN8QirI
Top Speed P210N - 199KTAS @ 16.5K = 1.84 Nautical miles per pound of fuel www.youtube.com/watch?v=sqzC7RC9fzk

75% Cruise DA50RG - 170KTAS @ 12K = 1.93 Nautical miles per pound of fuel. www.youtube.com/watch?v=JMQjAN8QirI
75% Cruise P210N - 171KTAS @ 17.5K = 2.11 Nautical miles per poiund of fuel. www.youtube.com/watch?v=QUfY4ZrMfyw

Useful Load DA50RG = 1232# (5 seats)
Useful Load P210N = 1358# (6 seats)

Vs0 DA50RG = 57 KCAS
Vs0 P210N = 54 KCAS (RSTOL equipped)

Interesting to compare these two aircraft. I
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Re: DA50 same price as DA62 - How's this make sense?

Post by ememic99 »

Just two remarks regarding the above comparisons:
1. Why didn’t you use same altitudes?
2. 100LL in Europe is usually 2+ times more expensive than Jet A1 and it’s not as widely available as Jet A1.
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Re: DA50 same price as DA62 - How's this make sense?

Post by Boatguy »

photoSteveZ wrote:
Fri Jul 30, 2021 4:21 pm
I have only two complaints about the DA62 in a couple of hundred flying hours: it’s a runway hog, and the air conditioning is marginal.
The AC complaint is a long standing issue which seems like it wouldn't be that hard to fix.
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