BeechTalk - BT

Username Protected · **Posted:** 02 Nov 2018, 23:04

Username Protected wrote:

Charles and Jerry,
Another datapoint. My PT6, prop and TBM were struck by lightning and never stopped running.....

Wow!

Username Protected · **Posted:** 03 Nov 2018, 01:49

Username Protected wrote:

Basic physics of flight stuff:
- Drag is proportional to speed squared.
- Power required is proportional to speed cubed.

So:
- Speed increase = 320kts/275kts = 1.16 (16% increase)
- Drag increase = 1.16 ^ 2 = 1.35 (35% increase)
- Power required = 1.16 ^ 3 = 1.58 (58% increase)

So to make a PC12 go 320 kts without changing the drag coefficient significantly would require an engine/prop combo to make 58% more power than now. That's a pretty big bump! Range would go to hell since for a turbine fuel flow is proportional to power, too.

Appreciate the correction, Jon! It's even worse than in my incorrect calculations! :thumbup:

Username Protected · **Posted:** 03 Nov 2018, 07:16

Username Protected wrote:

The gear box photo above is from a PC12 that experienced sudden in-flight engine seizure.

Larry,
I have not heard about this one. Can you give us the rest of the story?

Username Protected · **Posted:** 03 Nov 2018, 10:02

I’m guessing this is it (no fatalities or injuries):

https://www.smh.com.au/national/bolts-c ... -v8ow.html

Username Protected · **Posted:** 03 Nov 2018, 10:04

Username Protected wrote:

I’m guessing this is it (no fatalities or injuries):

https://www.smh.com.au/national/bolts-c ... -v8ow.html

Almost 10 years ago.

Legacy PC12... who knows how old it was at the time of the incident. Or how many hours on it etc.

Happened in Australia, who knows what kind of service this plane received.

Quote:

New overhaul procedures were introduced by Pratt & Whitney in January 2009.

I bought mine in 2013.

Username Protected · **Posted:** 03 Nov 2018, 13:56

It wasn't service - the bolts in the PT6 gear box were not manufactured correctly. Pratt subsequently took another PC12 out of service in australia and as I recall, other PT6 made with the same lot numbers in other aircraft.

My only point being - powerplants do sometimes fail. Even the PT6.

Single engine aircraft have to take that into account during their design process, and that's why the regulations say 61kts or less for singles. I'd have to pull up the regs and read them, but I think that only applies to aircraft under 6000lbs. It doesn't apply to experimental either.

I think for good reason.

It's the same thing that really holds back the SF50. It is really hard to build something fast that can land and take off slow.

Username Protected · **Posted:** 03 Nov 2018, 15:09

SF50 does 300 knots on 65gph. What’s the problem?

Flying doesn’t have to be hard to be effective.

Username Protected · **Posted:** 03 Nov 2018, 17:00

Username Protected wrote:

My only point being - powerplants do sometimes fail. Even the PT6.

Power-plants do quit, but even when they do quit, you still have outs. Combine the low likelihood of a failure with the low likelihood that you will NOT have an out and the risk of fatality is non-existent. Which, thus far, no fatalities due to engine failure in the PC12 in over 7 million fleet hours. There are other risks for me to address before a powerplant failure. I'm certainly not trying to convince anyone that they should fly a SETP over METP, it's purely an emotional decision.

Username Protected · **Posted:** 03 Nov 2018, 20:52

One thing in aviation never changes...the singles vs. twin debate! :deadhorse:

I wonder if there is an industry that clings to its OWT's and antiquated thinking any more vigorously than aviation?

Back when twin engined airplanes were first developed it was because PISTON engines were so unreliable that it was thought having 2, 3 or more was a good safety move. It probably was. But as piston (not to mention turbine) engines gained in reliability it doesn't seem that any of this was reconsidered much. The data certainly is clear. And now we drag these antiquated arguments into the modern era and try to extend it to turbines which are completely different beast. Emotion, tradition and flawed logic continue to make their arguments.

Yes, turbines do fail occasionally but as Chuck and others have made clear it's not a statistical relevance in consideration of other safety issues (like pilot inability to handle an inadvertent loss of one of two engines for example). Luckily, for the next 20 or 30 years anyway there will be choices for those who prefer two over one.

I believe I'd pick the P100E over the other choices. :pilot:

Username Protected · **Posted:** 03 Nov 2018, 22:08

As always, how did PC-12 or SETP get in the subject line?

Username Protected · **Posted:** 04 Nov 2018, 09:17

Username Protected wrote:

As always, how did PC-12 or SETP get in the subject line?

You've been around here long enough to know better...troublemaker! :hide:

Username Protected · **Posted:** 04 Nov 2018, 09:33

Username Protected wrote:

When you look at the all in costs of three airplanes, particularly new which I assume is the choice given the paucity of used examples on the market, and compare them to a fairly late model CJ2 or 3 they don't make much sense to me. A lot of expense and a lot less capability.

I think you're missing the most obvious advantage here, Tony...

A CJ2 or CJ3 would also free up (3) more letters in your 'Aircraft' list on BT:

TBM850WacoUMF5Decath

becomes

CJ2WacoUMF5Decath

The possibilities are endless on what type you could add to your list:

182, S2C (Pitts), CC (Carbon Cub), B17 (Staggerwing), T28, AT6, E75, L39...

Username Protected · **Posted:** 04 Nov 2018, 09:41

Username Protected wrote:

When you look at the all in costs of three airplanes, particularly new which I assume is the choice given the paucity of used examples on the market, and compare them to a fairly late model CJ2 or 3 they don't make much sense to me. A lot of expense and a lot less capability.

I think you're missing the most obvious advantage here, Tony...

A CJ2 or CJ3 would also free up (3) more letters in your 'Aircraft' list on BT:

TBM850WacoUMF5Decath

becomes

CJ2WacoUMF5Decath

The possibilities are endless on what type you could add to your list:

182, S2C (Pitts), CC (Carbon Cub), B17 (Staggerwing), T28, AT6, E75, L39...

Username Protected · **Posted:** 04 Nov 2018, 10:18

As I and others have mentioned the CJ2 is a real move up over the baby jets. And although one isn’t bathed with the luxury of a G1000, they still can be had with GTN750’s which now offer Vnav. They don’t offer fuel planning like the Universal which seems quite capable. HOWEVER, sit in one first. I’m 6’3 and felt like I had been pried into a tuna can. The CJ3 and 4 offer much more room. And I hear the mustang is comfy.

Username Protected · **Posted:** 04 Nov 2018, 10:35

Username Protected wrote:

As always, how did PC-12 or SETP get in the subject line?

I think where it happens, and being one that has looked at all these as candidates to serve my current and desired missions, you quickly get to the realization that the SETP's can do pretty much every mission a VLJ can do, just slower and lower, but the converse is not true. That is where my romance keeps flaming out, every time I look at one of these. For that 700-900 nm nice runway to nice runway milk run, the VLJ is a rockstar. But flying a mix of long, short, high, hot, contaminated missions, if you get the jet, you pay more to go a little faster... if you don't have to stop for fuel ;-)

but are left with some compromises. I think this is one of the reasons that the SETP's year over year continue to outsell the light jets. I think my solution is keeping my SETP for my day to day typical missions, and finding a dry lease in a light jet to check that box, and for that occasional straight line 862.5 nm mission, when I don't need a true IFR alternate

I think that is why the thread drifted, but apologies if I contributed to that.

Phenom 100E , Cessna M2 or Hondajet?