Thanks Allen

Nice way of saying he's a lost cause nerd!

It’s been awhile since I flew with a Williams powered plane and forgot what the parameters on the motors were, dang they sure crank those things up, 107 N1 and 825 ITT. I know 4 guys with Williams powered planes, and saw an additional two here on BT with significant engine events. Good thing your all on TAP.

John what was your block fuel burn and weight on that flight.

Gary

Running at 107 I bet they have problems.

Andrew

Do you find cockpit dist max a good setting to keep things warm up front, does it effect the back?

I sometimes click it one notch to help.

Andrew

Running at 107 I bet they have problems.

Andrew

As I said its been awhile since I flew a Williams plane. Interesting that the red line is at 107% and 825c. Since as you said the max operating is 102.4% unlike the JT15D that the red lines ARE the max operating parameters. Any thoughts on why that is?

With the JT15-D at max operating 104% we are <600c on our temps at 430k.

Gary

Metal is metal and the Williams seem to run and start significantly hotter than their Pratt powered brothers. This is something to think about. The little Eclipse Pratts run similarly hot and have had some issues that the JT-15s don't seem to have.

You can't compare temps from one engine to the next since where and how temps are measured vary considerably even when the actual peak temperatures in the engine are similar.

That being said, the Williams engines do operate at higher compression ratio, so they will be hotter, but they are built from newer materials designed to handle that, too, so metal is not always the same metal. The higher compression ratio is why they are more efficient.


Give the PW600 series 50 years of service history and they won't be having issues either.

I'm sure the JT15 had its share of teething problems, they just happened so long ago that there are few remember them.

Mike C.

I'm not totally convinced on the Williams or the Pratt 600 fuel economies compared to the JT15.

Mustang: seems to burn about 90 GPH up high (1,300lbs thrust)
Klingon 501: about 120 GPH up high (2,200 lbs thrust)
Williams Klingon: about 110 GPH up high (going a tad faster so maybe its real world thrust is more than 2,200 lbs)

These fuel burn spreads seem to come out in the wash for the thrust produced.

It’s been awhile since I flew with a Williams powered plane and forgot what the parameters on the motors were, dang they sure crank those things up, 107 N1 and 825 ITT. I know 4 guys with Williams powered planes, and saw an additional two here on BT with significant engine events. Good thing your all on TAP.

John what was your block fuel burn and weight on that flight.

Gary

Do you find cockpit dist max a good setting to keep things warm up front, does it effect the back?

I sometimes click it one notch to help.

Andrew

You set power on the CJ2 with this chart or using the N1 calculator in the panel. MCT is 102.4



Williams leaves some headroom between MCT and the N1 that begins to cause damage.



Here are the ITT Temp limits.

If I missed it in this thread, I apologize, but has anyone calculated the ALL IN cost of flying a 500 vs 525 vs a V for a set number of miles per year? Ignore cost to acquire, as that is unique to each buyer and their capital situation.

I think the initial perspectives on differences between the planes are interesting, but it is probably splitting hairs in the end. I think you fly any of these planes with frequency, they are easy to fly. You drop down to 100 hours per year or less and it is tricky to stay 'truly' current and sharp. I am also on the younger end of the people who end up flying these things, and I am sure my perspective would be different in 20 years.

Its a harder comparison than it seems. On one side you have service center pricing and new parts and on the other you've got guys fabricating parts in their garage.