BeechTalk - BT

Username Protected · **Posted:** 08 Dec 2014, 02:33

Username Protected wrote:

Which requirement? Point out a FAR, section and subsection. I just don't see it in Part 23 below FL410. Are you referring to 23.841? If so, not the way I read it.

23.841(a) requires no loss of cabin altitude for any probable failure. Engine failure is a probable failure, happens all the time, so you have to keep cabin below 15,000 ft when the engine quits.

Basically impossible to do without a second source of pressurization.

23.841 is triggered when you seek a ceiling above FL250. The altitude was lowered from 33,000 ft to 25,000 ft in Amendment 23-49, which is why some SETPs got higher altitudes before they changed the rule. The change was prompted by the Europeans. Guess what, the two grandfathered popular SETPs are both made in Europe. Makes one wonder.

Given the recent depressurization accidents (TBM most recently), there's no going back on this rule and I would expect no leniency from the FAA on this. Body bags make policy, right or wrong.

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 02:42

Username Protected wrote:

"Probable" leaves a lot of wiggle room.

Actually, it doesn't. It is a very precise term in FAA certification language.

"Probable" means a failure that would occur, on average, 1 or more times during the entire operational life of each airplane. Mathematically, the FAA deems this to be a 1 in 10^5 hours chance, or one occurrence every 10,000 hours of flight.

Window failure: not probable.

Engine shutdown: probable.

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 02:47

Username Protected wrote:

Another way to meet the pressurization requirement is to have check valves in the system and outflow valves that are protected against going above 15000' incase of a normal mode failure.

Cabin leak down rates don't allow this approach.

It has been tried. In a tight airframe. Didn't work.

If such an aircraft ever did get certified, it wouldn't meet requirements very quickly after entering service. There are many leaks in the cabin, some intentional or unavoidable.

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 02:54

Username Protected wrote:

Another way to meet the pressurization requirement is to have check valves in the system and outflow valves that are protected against going above 15000' incase of a normal mode failure.

Cabin leak down rates don't allow this approach.

It has been tried. In a tight airframe. Didn't work.

If such an aircraft ever did get certified, it wouldn't meet requirements very quickly after entering service. There are many leaks in the cabin, some intentional or unavoidable.

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 02:59

Username Protected wrote:

Next, I spot checked four of them. All four had roughly half the flight time below 30K. That is pretty pathetic on a two hour flight....

Which flights?

The smallest jet (thus potentially most representative) was this one:

http://flightaware.com/live/flight/RSP7 ... K/tracklog

13 minutes below 30K on climbout, 17 minutes on descent below 30K, 104 minutes above 30K, or 78% of the time.

I'm not seeing what you are seeing. Specifics?

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 07:11

Username Protected wrote:

Next, I spot checked four of them. All four had roughly half the flight time below 30K. That is pretty pathetic on a two hour flight....

Which flights?

The smallest jet (thus potentially most representative) was this one:

http://flightaware.com/live/flight/RSP7 ... K/tracklog

13 minutes below 30K on climbout, 17 minutes on descent below 30K, 104 minutes above 30K, or 78% of the time.

I'm not seeing what you are seeing. Specifics?

Mike C.

Username Protected · **Posted:** 08 Dec 2014, 08:59

Username Protected wrote:

I don't think a window is part of the pressurization system. If it was then the wing, tail, fuselage, door would also be part of pressurization. You certainly need those components to have a pressurized airplane but you also need fuel and oil!

They have no intention of trying to meet the requirement. They are well on the final certification process with the sub RVSM limit. Why are you guys arguing about things that don't matter?

Username Protected · **Posted:** 08 Dec 2014, 09:06

Username Protected wrote:

Hey Mike. I think that after 39 posts on the subject, we understand that you think building a SEJ is a bad idea, destined to fail.

The SF50 is a SEJ. I believe it's too late for you to save Cirrus.

Can we move on with life now?

Amen! They are, in fact, going to build it. They have 3 planes flying testing now. Whether the presold 550+ planes all get built or not we'll have to see. But when you run a company, decide what you're going to build, get it financed, into the final stages of approval, have a factory and people hired to build it and hundreds of people standing in line to buy it it's probably going to work at some level.

Often things are a terrible idea until the day before they are successful. Is this going to be successful? Will people fly a slow jet? We'll know in 12 months more or less. Now it's for some folks to go check out the rest of what BT has to offer...

Username Protected · **Posted:** 08 Dec 2014, 09:18

Username Protected wrote:

Hey Mike. I think that after 39 posts on the subject, we understand that you think building a SEJ is a bad idea, destined to fail.

The SF50 is a SEJ. I believe it's too late for you to save Cirrus.

Can we move on with life now?

Amen! They are, in fact, going to build it. They have 3 planes flying testing now. Whether the presold 550+ planes all get built or not we'll have to see. But when you run a company, decide what you're going to build, get it financed, into the final stages of approval, have a factory and people hired to build it and hundreds of people standing in line to buy it it's probably going to work at some level.

Often things are a terrible idea until the day before they are successful. Is this going to be successful? Will people fly a slow jet? We'll know in 12 months more or less. Now it's for some folks to go check out the rest of what BT has to offer...

Username Protected · **Posted:** 08 Dec 2014, 09:55

Username Protected wrote:

That sucks, i had no idea they kept you so low on that route. Fl to nyc you can usually get up high flying the coast but the atlanta route sounds terrible. I would stab myself if stuck at 210 and consider a different mode of transport, maybe the MARTA goes us up there?

That altitude is no big deal in the PC12. I can file 270 and I'll get it but they bring you right back down. So to avoid all the time to climb I just file 210.

Username Protected · **Posted:** 08 Dec 2014, 09:58

Username Protected wrote:

Quote:

Still not following what "piston think" is.

Transferring piston experience to jets. An example is assuming a single jet is less cost than a twin jet.

Mike C.

That's the case with all other singles. Compare even a PC12 to a KA250-350

Why is the MU2 irreplaceable? I thought twins were less expensive to build? So canceling production of the MU2 had nothing to do with economics? The plane was a smashing success so they cancelled it?

Username Protected · **Posted:** 08 Dec 2014, 10:06

Username Protected wrote:

The CJ3 flew the same exact route & altitude as your PC-12? I recall the max altitude of the PC-12 as 30,000'. Since I'm wrong, as you've stated above, prove me wrong ... next time you're flying your PC-12, take a picture of your cockpit from 41,000' and post it in this thread. Upon doing so, I'll admit that I'm wrong. Until you do so, I will continue to believe you're wrong, and that you are unable to dispute the facts that I posted with anything but your non-fact based opinions.

I'm not sure why you're being so difficult. What's your motive?

We're discussing how ATC dictates altitude and speed on most of my routes and therefore a jet did not make sense for me. Flights into TEB are brought down low early to stay out of JFK, LGA, etc.. That's the only point I'm trying to make. This will be the case with any single pilot airplane.

Telling me to post a pic of a PC12 at 410 is not moving the discussion forward.

Username Protected · **Posted:** 08 Dec 2014, 10:08

Username Protected wrote:

Hey Mike. I think that after 39 posts on the subject, we understand that you think building a SEJ is a bad idea, destined to fail.

The SF50 is a SEJ. I believe it's too late for you to save Cirrus.

Can we move on with life now?

I haven't read where Mike has attacked anybody personally. I have seen Mike lay out some arguments that seem fact based. Not sure why we would want to try to kill the thread unless it's purpose is just a "feel good" thread for everything positive about Cirrus. People can choose to read or not...

Username Protected · **Posted:** 08 Dec 2014, 10:10

Username Protected wrote:

Everything will happen much faster. An SR22T pilot has to learn to think as those speeds.

If you depart a major metro area and you get at 10,000 ft, you are going 200 knots, climbing 2500 FPM, 20 nm from the airport, had 3 altitude assignments, had 4 frequencies, had 3 or 4 vectors, maybe had a reroute thrown in for good measure.

All in the first 5 minutes after liftoff. That's the busiest time for me in my MU2, by contrast an ILS to mins is serene.

Now add night, weather, schedule, etc. Whether that pilot has 1 or 2 engines is insignificant to his workload. Fail a generator and the SEJ pilot workload just shot up while the TEJ pilot has a minor nuisance.

Also, most SR22T pilots don't fly in the flight levels all that often. With the SF50, it will be almost every flight. It isn't that hard, but it far less tolerant than a piston fixed gear single for mistakes.

If SR22 pilots are the target audience, then the SF50 will likely be their first turbine, first jet, first retract, first pressurized, first air conditioned, first known ice, first flight level airplane. That's a lot to take in at once so I expect some tough love during their initial course and a hefty mentoring period, probably 50 hours or more. Some of those jet egos are going to get bruised.

Cessna doesn't think 182 pilots are ready for a Mustang.

Jets demand a type rating for a reason.

Mike C.

This is not a reason to not build the SF50. You're not the only guy who knows how to manage the flight levels. I never thought it was that big of a deal. Lot's of folks do it.

I think you have an axe to grind. This post is irrational.

Username Protected · **Posted:** 08 Dec 2014, 10:13

Username Protected wrote:

That's not true:

http://flightaware.com/live/findflight/kteb/kpdk/

I asked Flightaware tonight for ALL recent flights TEB to PDK. 9 came up, all business jets. The altitudes they got were:

C56X FL400
C750 FL430
C550 FL380
C680 FL400
CL60 FL340
GLF5 FL430
CJ3 FL430
C56X FL400
C560 FL400

The lowest one, FL340, was a CL60, filed for FL360, flew at FL340, perhaps a turbulence thing. It was the ONLY one where they didn't fly at or HIGHER than the filed altitude.

It isn't difficult to check these things out.

Mike C.

That's not the point. Where do they get dropped to 13K'? That's the point.

I'll get whatever altitude I file. The problem is "how long they keep me there".

Cirrus SF50