M & D jet receives EASA Type Certificate

On Thursday, December 3, 2015 at 2:36:48 PM UTC-5, wrote:
On Thursday, December 3, 2015 at 6:28:10 AM UTC-8, wrote:
http://translate.google.de/translate...html?news=1991

Interesting announcement. Let the retro fits begin!


What is the maximum range of the JS1 with that engine, and what cruising speed achieves that range?

On https://translate.google.ca/translat...e/&prev=search there is a pilot report, in part "He is strong and has sufficient fuel (Diesel) from 100 to 200 km, depending on usage patterns on board." I imagine you can go a shorter distance faster, or cruise economically longer (and higher).

On Thursday, December 3, 2015 at 8:32:48 PM UTC, Dan Daly wrote:
On Thursday, December 3, 2015 at 2:36:48 PM UTC-5, wrote:
On Thursday, December 3, 2015 at 6:28:10 AM UTC-8, wrote:
http://translate.google.de/translate...html?news=1991

Interesting announcement. Let the retro fits begin!


What is the maximum range of the JS1 with that engine, and what cruising speed achieves that range?

On https://translate.google.ca/translat...e/&prev=search there is a pilot report, in part "He is strong and has sufficient fuel (Diesel) from 100 to 200 km, depending on usage patterns on board." I imagine you can go a shorter distance faster, or cruise economically longer (and higher).

The most recent range estimates from JS that I have available, using 40 available litres fuel from the 43 litre tanks, show:

around 100Km level flight @ 210pkh (114 knots) at 95,000 rpm full power

around 150km level flight @ 150kph (80 knots) at 75,000 rpm

around 200km single climb at 2m/s cruising @ 138kph (75knots) and full power, then gliding at best LD.

By my reckoning these estimates are rather conservative based on a fuel flow of 67 litres per hour at full power that I see indicated on the control unit in flight and the fact that the performance and climb rates seem to match well with the claims. For the climb and glide scenario that should give 80km range while climbing 4000m and a further 200km in the glide at 50:1

On Thursday, December 3, 2015 at 2:36:55 PM UTC-7, wrote:
On Thursday, December 3, 2015 at 8:32:48 PM UTC, Dan Daly wrote:
On Thursday, December 3, 2015 at 2:36:48 PM UTC-5, wrote:
On Thursday, December 3, 2015 at 6:28:10 AM UTC-8, wrote:
http://translate.google.de/translate...html?news=1991

Interesting announcement. Let the retro fits begin!


What is the maximum range of the JS1 with that engine, and what cruising speed achieves that range?

On https://translate.google.ca/translat...e/&prev=search there is a pilot report, in part "He is strong and has sufficient fuel (Diesel) from 100 to 200 km, depending on usage patterns on board." I imagine you can go a shorter distance faster, or cruise economically longer (and higher).

The most recent range estimates from JS that I have available, using 40 available litres fuel from the 43 litre tanks, show:

around 100Km level flight @ 210pkh (114 knots) at 95,000 rpm full power

around 150km level flight @ 150kph (80 knots) at 75,000 rpm

around 200km single climb at 2m/s cruising @ 138kph (75knots) and full power, then gliding at best LD.

By my reckoning these estimates are rather conservative based on a fuel flow of 67 litres per hour at full power that I see indicated on the control unit in flight and the fact that the performance and climb rates seem to match well with the claims. For the climb and glide scenario that should give 80km range while climbing 4000m and a further 200km in the glide at 50:1

Assuming, of course, that it actually starts!

Mike

44 all successful starts so far for me Mike.

4% oil is added to the fuel.

Does anyone have a performance chart for this jet engine showing what the max altitude is one can reasonably expect it to fire up?

On Friday, December 4, 2015 at 2:03:10 AM UTC-7, wrote:
44 all successful starts so far for me Mike.

4% oil is added to the fuel.

I just remember one jet failure leaving a JS-1 in unlandable terrain in the middle of the Navajo Nation last year!

On Friday, December 4, 2015 at 8:55:24 AM UTC-6, Mike the Strike wrote:
On Friday, December 4, 2015 at 2:03:10 AM UTC-7, wrote:
44 all successful starts so far for me Mike.

4% oil is added to the fuel.

I just remember one jet failure leaving a JS-1 in unlandable terrain in the middle of the Navajo Nation last year!

It was actually this year, Mike. And I wouldn't call the terrain unlandable, the glider and the pilot did not have a scratch.

Further to my earlier performance posting I have today received from M+D a copy of the approved certification version of the engine manual. It is only in German which I can't read but I can make out a couple of significant differences to the earlier draft versions from JS.

1) 2% oil mix instead of 4%

2) Max rpm 97000 rpm but only for 5 minutes. Fuel use 77L/hr. (Fuel consumption and thrust seem to be exponentially related to the rpm.)

3) Max continuous rpm 80000 (= 58% thrust).

The introduction of the maximum time for full thrust is going to reduce the potential range because previous predictions for the JS1 were that the best range would be a single max power continuous climb then glide. I am not sure what the best climb rate or speed for best climb at 80,000rpm are so I can't make a good estimate of the resulting range but I seem to maintain level flight at around 70knots at 67,000 so it must be climbing at 80,000 rpm.

On Friday, December 4, 2015 at 8:33:49 AM UTC-7, wrote:
On Friday, December 4, 2015 at 8:55:24 AM UTC-6, Mike the Strike wrote:
On Friday, December 4, 2015 at 2:03:10 AM UTC-7, wrote:
44 all successful starts so far for me Mike.

4% oil is added to the fuel.

I just remember one jet failure leaving a JS-1 in unlandable terrain in the middle of the Navajo Nation last year!

It was actually this year, Mike. And I wouldn't call the terrain unlandable, the glider and the pilot did not have a scratch.

Excuse my memory - I am already in 2016 mode! Yes, the pilot in that case showed extraordinary skill in landing in what I would regard as unlandable terrain! I had always though the simplicity of the jet made them more reliable than conventional IC engines (at least the retractable ones used in gliders). Do we have actual data on reliability?

Further to my earlier performance posting I have today received from M+D a copy of the approved certification version of the engine manual. It is only in German which I can't read but I can make out a couple of significant differences to the earlier draft versions from M+D.

1) 2% oil mix instead of 4%

2) Max rpm 97000 rpm but only for 5 minutes. Fuel use 77L/hr. (Fuel consumption and thrust seem to be exponentially related to the rpm.)

3) Max continuous rpm 80000 (= 58% thrust).

The introduction of the maximum time for full thrust is going to reduce the potential range because previous predictions for the JS1 were that the best range would be a single max power continuous climb then glide. I am not sure what the best climb rate or speed for best climb at 80,000rpm are so I can't make a good estimate of the resulting range but I seem to maintain level flight at around 70knots at 67,000 so it must be climbing at 80,000 rpm.