MTOW increase?

[Charles]

Here's a naive question. I was reading the article about the Diamond Star XLS referred to in another thread ( http://www.planeandpilotmag.com/aircraf ... ml?start=1 ), and the following statement caught my attention:

Diamond has recertified the DA40 to a gross weight of 2,646 pounds, 111 more than the previous Star. As a result, useful load increases by about 70 pounds. Maximum landing weight remains at the old 2,535 pounds, so if you depart at gross, you’ll need to burn off about 19 gallons of fuel before you can return for landing.

Here's the naive part: does this recertification extend to older DA40s?

Charles

[Gary]

Here's a naive question. I was reading the article about the Diamond Star XLS referred to in another thread ( http://www.planeandpilotmag.com/aircraf ... ml?start=1 ), and the following statement caught my attention:

Diamond has recertified the DA40 to a gross weight of 2,646 pounds, 111 more than the previous Star. As a result, useful load increases by about 70 pounds. Maximum landing weight remains at the old 2,535 pounds, so if you depart at gross, you’ll need to burn off about 19 gallons of fuel before you can return for landing.

Here's the naive part: does this recertification extend to older DA40s?

Charles

This is actually a great question.

I had the gross weight increase done for my 2003 DA40. It increases both takeoff and landing weight and required two things:

1. OSB 40-25/1 New main landing gear struts. I think this cost me around $4,000. If you are serial number 40.350 or higher you should not need the new struts as this is when it became standard but please verify this first.

2. OSB 40-57/1 Increased takeoff mass to 1200. This requires replacement of an elevator bushing, some adjustments and some new placards and manual supplement. I can remember what it cost but it is at least a few hundred dollars. Serial number 40.822 and higher should already have it.

A list of all DA40 service bulletins is available on the Diamond website but you can also access them in the wiki section above.

Since the gross weight increases 111 lbs, the useful load should also increase 111 lbs since the modification does not add to the empty weight or what am I missing here? Newer DA40s are heavier than earlier models (as a general rule) so they end up with lower useful loads. My DA40 has one of the best (if not the best) useful load and full fuel (40 gal) payload of any DA40, 938 lb useful load, 698 lb full fuel payload.

[Rich]

Here's a naive question. I was reading the article about the Diamond Star XLS referred to in another thread ( http://www.planeandpilotmag.com/aircraf ... ml?start=1 ), and the following statement caught my attention:

Diamond has recertified the DA40 to a gross weight of 2,646 pounds, 111 more than the previous Star. As a result, useful load increases by about 70 pounds. Maximum landing weight remains at the old 2,535 pounds, so if you depart at gross, you’ll need to burn off about 19 gallons of fuel before you can return for landing.

Here's the naive part: does this recertification extend to older DA40s?

Charles

This is actually a great question.

I had the gross weight increase done for my 2003 DA40. It increases both takeoff and landing weight and required two things:

1. OSB 40-25/1 New main landing gear struts. I think this cost me around $4,000. If you are serial number 40.350 or higher you should not need the new struts as this is when it became standard but please verify this first.

2. OSB 40-57/1 Increased takeoff mass to 1200. This requires replacement of an elevator bushing, some adjustments and some new placards and manual supplement. I can remember what it cost but it is at least a few hundred dollars. Serial number 40.822 and higher should already have it.

A list of all DA40 service bulletins is available on the Diamond website but you can also access them in the wiki section above.

Since the gross weight increases 111 lbs, the useful load should also increase 111 lbs since the modification does not add to the empty weight or what am I missing here? Newer DA40s are heavier than earlier models (as a general rule) so they end up with lower useful loads. My DA40 has one of the best (if not the best) useful load and full fuel (40 gal) payload of any DA40, 938 lb useful load, 698 lb full fuel payload.

There's a clarification needed here. For some aircraft (mine is one), the maximum landing weight gets increased from 2407 to 2535 as a side-effect of doing both the above conversions. So currently, if I take off at the MTOW of 2535 lbs I would need to burn off just over 21 gallons of fuel to be within certified limits. That also implies I really can't take off with less than about 30 gallons on board.

Were I to get this total mod done, I get to have a higher MTOW, but would still need to burn off just under 19 gallons. My limits would be like Gary's.

In any case I need to figure on at least a two-hour flight to push to the MTOW limit, if I'm to keep to the Max landing weight limitation. (Of course, one need no worry about this except for the possibility of a ramp check or a hard landing.)

[Gary]

There's a clarification needed here. For some aircraft (mine is one), the maximum landing weight gets increased from 2407 to 2535 as a side-effect of doing both the above conversions. So currently, if I take off at the MTOW of 2535 lbs I would need to burn off just over 21 gallons of fuel to be within certified limits. That also implies I really can't take off with less than about 30 gallons on board.

Were I to get this total mod done, I get to have a higher MTOW, but would still need to burn off just under 19 gallons. My limits would be like Gary's.

In any case I need to figure on at least a two-hour flight to push to the MTOW limit, if I'm to keep to the Max landing weight limitation. (Of course, one need no worry about this except for the possibility of a ramp check or a hard landing.)

Yes, the maximum landing weight is lower than the maximum t/o weight. New MLG struts increase both. I don't understand why you need a minimum of 30 gallons to take off unless you have a CG issue.

[Charles]

Gary, great info, thanks. I have #231 so would need the modifications. And at around $5k, it might make a lot of sense to do it.

[Rich]

There's a clarification needed here. For some aircraft (mine is one), the maximum landing weight gets increased from 2407 to 2535 as a side-effect of doing both the above conversions. So currently, if I take off at the MTOW of 2535 lbs I would need to burn off just over 21 gallons of fuel to be within certified limits. That also implies I really can't take off with less than about 30 gallons on board.

Were I to get this total mod done, I get to have a higher MTOW, but would still need to burn off just under 19 gallons. My limits would be like Gary's.

In any case I need to figure on at least a two-hour flight to push to the MTOW limit, if I'm to keep to the Max landing weight limitation. (Of course, one need no worry about this except for the possibility of a ramp check or a hard landing.)

Yes, the maximum landing weight is lower than the maximum t/o weight. New MLG struts increase both. I don't understand why you need a minimum of 30 gallons to take off unless you have a CG issue.

Well, if you need to burn off something like 20 gallons, how little are you willing to land with? I typically plan for 10 gallons remaining.

[Gary]

Well, if you need to burn off something like 20 gallons, how little are you willing to land with? I typically plan for 10 gallons remaining.

Now I understand. When you stated "I really can't take off with less than about 30 gallons on board" I thought you were referring to a weight and balance restriction not simply good airman-ship. I also require 1 hour fuel reserve on landing. If you want to do a few touch and gos you could take off with as little as 15 gallons.

[Jean]

Well, if you need to burn off something like 20 gallons, how little are you willing to land with? I typically plan for 10 gallons remaining.

I also like to have 10 gallons in the tanks when I land. No stress.

[Rich]

Now I understand. When you stated "I really can't take off with less than about 30 gallons on board" I thought you were referring to a weight and balance restriction not simply good airman-ship. I also require 1 hour fuel reserve on landing. If you want to do a few touch and gos you could take off with as little as 15 gallons.

Sure, if you're below max landing weight to start (or are ignoring this restriction). I do it all the time on short flights at the typical weights I fly.

[Antoine]

I just saw on the Diamond Europe web site that they offer an upgrade for existing DA40 TDI to DA40 NG which includes the NG's landing gear and winglets. New MTOM is 1280 Kg.

What if we asked them for a quote to upgrade the DA40-180 to 1280 Kg MTOM and winglets? (1280Kg = 2822 lb).

The winglets would give us the additional climb performance to compensate for the extra payload, and the Lyco is more poweful than an AE-300 at take-off...

I think an extra 80 Kg of payload would be reaaaaaally great!
Who is interested? It would be much better if several of us wrote jointly

And by the way, if the stock DA40 XLS were upgraded to the same ex factory, I think they would sell quite a few!