Skycatcher DA

denverpilot

denverpilot

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So reading about the first operational Skycatcher crash, I'm seeing that the *engine* manufacturer has placed an 8000' DA limit on the powerplant and it's being added as a factor to the "pilot error" preliminary NTSB report.

Actually the wording sounds like it's not a limitation but that the "chart stops" at 8000' DA. So?

Never seen the NTSB throw that one out there as causation for "pilot error" before. Plenty of older DA charts don't cover, say... Leadville on a warm day. One must extrapolate.

If they'd said they found no evidence the pilot calculated the effects of DA, that's a lot different statement than saying he was "off the chart".

No calculation clearly indicates the pilot was at fault, the "off the chart" stuff insinuates that the engine manufacturer doesn't *want* the engine operated above 8000' DA to a non-pilot reading the report.

Looks like a new NTSB trend that could make the Skycatcher wildly unpopular here at 6000' MSL if one can't extrapolate to calculate performance.

Anyone else notice this subtle circumstance/wording?
 
Odd... reading that report, it sounds like choosing the wrong direction for takeoff was the real problem.
The weather observation facility located on the field reported that 3 minutes before the accident the wind was a left quartering tailwind at 5 knots, while shortly after the accident the wind was a left quartering tailwind at 22 knots, gusting to 32 knots with respect to the airplane's takeoff runway direction
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I'd love to know if the POH says, "Don't try to take off over 8000' DA" or just doesn't show it on the chart. There's a big difference there, in my admittedly inconsequential opinion. Betcha he'd have had better luck with a quartering headwind, though.
 
Looking at the Cherokee charts from Piper, the takeoff altitude stops at 7000 ft MSL.

I'm still waiting to fall out of the sky when I'm at Leadville, merrily toodling down the runway for takeoff - with no problems.
 
Yeah that's the weird part. Downwind is not smart but flying "off the chart" especially Part 91... Who cares?

Apparently the NTSB does now. Weird.

Are they sending a message to the manufacturers ("Extend your lame charts"), or pilots ("Don't fly off the chart").

They need to clarify that greatly in the final report.
 
Limitations are clearly stated as such in the POH or placards/instrument markings. The fact that you run out of chart above 8000 DA does not by itself constitute a limitation. However, it does mean that in order to comply with 91.103, you must have "other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature." Not too sure where such information may be found for a Cessna 162 above 8000 DA other than by experimentation.
 
Ron Levy said:
Limitations are clearly stated as such in the POH or placards/instrument markings. The fact that you run out of chart above 8000 DA does not by itself constitute a limitation. However, it does mean that in order to comply with 91.103, you must have "other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature." Not too sure where such information may be found for a Cessna 162 above 8000 DA other than by experimentation.
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Well put Ron.....
Extrapolating numbers is a risky deal in itself. Sometimes the calc is linear but most times it ain't.:hairraise:..... Exploring that side of the performance curve basically makes you a "test" pilot... Be careful out there kids.:yesnod::yesnod:.

Ben.
 
Reading the report, I don't think they are referring to "flying off the chart" seems to me there is a sentence in the POH that says something along the lines of "Do not attempt to takeoff when density altitude is at or above 8,000'" I see a cirrus has similar verbiage that states "Maximum Takeoff Altitude: 10,000'" It also says "recommended". Im going to chock this up to somethign along the lines of "maximum demonstrated X-Wind component"
 
Reading that report, I think DA was a relatively minor contributing factor. The pilot's attempt to takeoff before a passing storm was the primary factor. I'd bet that if it was turbo-charged airplane the result would have been just as bad.....if not worse!
 
DaleB said:
Odd... reading that report, it sounds like choosing the wrong direction for takeoff was the real problem.
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What airport was he departing, I don't see it referenced in the link.

Taking off with a 5 kt tailwind is not necessarily a big deal, especially at many high altitude airports with one way, or at least preferred direction runways.

Trying to beat the passing storm was most defiinitely a poor decision.
 
Just found the rest - it was Rawlings, WY (RWL). It doesn't say which runway, but my guess is that he was trying to takeoff from rwy 4, heading away from the mountains and storm which just happened to overtake his airplane as he was lifting off.

I don't see how you can blame performance charts here.
 
DaleB said:
Odd... reading that report, it sounds like choosing the wrong direction for takeoff was the real problem.
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If there's a DA restriction, that might be contributing, but a 50kt rotation speed that suddenly turns into 30kts thanks to a big gust will ruin anyone's day.
 
Precisely. I wasn't saying a 5k tailwind would necessarily be a show-stopper... but 22 or more definitely would be. So you see a storm approaching, and you just assume the wind isn't going to change quickly and without warning? Not smart.
 
The report strongly implies that an increasing tailwind was the cause. It does not mention anything about leaning for that DA; I wonder if that was a factor, too?

Dan
 
Dan Thomas said:
The report strongly implies that an increasing tailwind was the cause. It does not mention anything about leaning for that DA; I wonder if that was a factor, too?

Dan
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At that density altitude they'd be getting what.... 50% of their sea level horsepower? Probably less? Failing to lean would surely cost them 10% (or more) of what little they had left... I'm amazed they even got it into ground effect before turning it into a Cessna Groundcatcher at the end of the runway.

If they were looking at their groundspeed on the GPS they might have even been encouraged for a minute there. Looking back at the airspeed, maybe not so much.
 
I read something else recently that implied that operating off the charts was considered outside of the manufacturers limitations. I can't remember where I saw that though. Piper's charts are pretty weak for flying in CO. I believe the charts say "Extrapolation beyond 7000 not valid". I'll check the exact wording when I get home.
 
Section 3 (Operating Limitations) of the 162's POH has no mention of altitude limits for takeoff or landing, in written or placard form.

There is no reference to the words "density altitude" in the POH; all references are to pressure altitude. Those related to the topic at hand are as follows:

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And here are the performance charts under discussion, with 8000 being the highest value listed; certainly not a defined operational limit:

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Manufacturers don't like providing us with good data out here in the Rockies, but we're used to it. ;)
 
The B-1 was limited for departure operations at extremely high temperatures. The AF did not purchase the TOLD (Take Off & Landing Data) for temperatures above 100F. That may have been rectified after I retired.
 
BillTIZ said:
The B-1 was limited for departure operations at extremely high temperatures. The AF did not purchase the TOLD (Take Off & Landing Data) for temperatures above 100F. That may have been rectified after I retired.
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I spoke with one of the B-1 pilots at Ellsworth (during the Dakota Thunder 2011 Awesomeness) about takeoff and he said that full AB is SOP. But the tables include data for power settings lower than that.

So the AF paid for power setting data that they don't use, but not for temperatures which are common throughout the US and many places that a B-1 could be deployed to.:dunno:
 
So the TO distance charts for my PA-32-260 show TO distance vs density altitude. The maximum DA on the chart is 7000'. In the Denver area the DA is over 7000' whenever the temp is above about 70 def F. Further the chart has the following note "Extrapolation of chart above 7000 feet is invalid." Nowhere in the POH does it tell you what to do for DAs over 7k.
 
TangoWhiskey said:
Section 3 (Operating Limitations) of the 162's POH has no mention of altitude limits for takeoff or landing, in written or placard form.
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Troy,
Where did you find that link, and are there links for other Cessna POHs /Pilot Information Manuals there?

Edit:
Found it. On Cessna.com -> Aircraft -> Propeller Aircraft, select the model of interest, then Brochures and Documents :
http://www.cessna.com/single-engine/skyhawk/skyhawk-documents.html
http://www.cessna.com/single-engine/skylane/skylane-documents.html
 
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COFlyBoy said:
I read something else recently that implied that operating off the charts was considered outside of the manufacturers limitations. I can't remember where I saw that though. Piper's charts are pretty weak for flying in CO. I believe the charts say "Extrapolation beyond 7000 not valid". I'll check the exact wording when I get home.
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For the PA28 D,E,F,G models (180 HP) the Takeoff vs DA chart only goes to 7000 MSL and there's no caveat. The Altitude Conversion chart goes to 16000, the Rate of Climb v DA goes to 15K, and the Range v DA goes to 11K.

However, in various places there are comments about crusing above 10K, ceiling at 16K, etc. In fact for my D model, Service Ceiling is 16.4, and Absolute Ceiling is 19K.

For the Archer II the Takeoff v DA chart is more detailed but still only goes to 7K MSL with no caveats.
 
COFlyBoy said:
So the AF paid for power setting data that they don't use, but not for temperatures which are common throughout the US and many places that a B-1 could be deployed to.:dunno:
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Welcome to DoD acquisition management...it's a career field in itself!
 
COFlyBoy said:
So the TO distance charts for my PA-32-260 show TO distance vs density altitude. The maximum DA on the chart is 7000'. In the Denver area the DA is over 7000' whenever the temp is above about 70 def F. Further the chart has the following note "Extrapolation of chart above 7000 feet is invalid." Nowhere in the POH does it tell you what to do for DAs over 7k.
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Found something in the Archer III POH:
"Warning: Performance informat ion derived by extrapolation beyond the limits shown on the charts should not be used forflight planning purposes."

The Takeoff chart does go up to 8K Pressure Alt.
 
murphey said:
However, in various places there are comments about crusing above 10K, ceiling at 16K, etc. In fact for my D model, Service Ceiling is 16.4, and Absolute Ceiling is 19K.
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Hey! You've cracked the code!

We don't do takeoffs up here. We just start at the cruise climb checklist! ;)

(Performance-wise, it's kinda true even if I am really just joking.)
 
denverpilot said:
Hey! You've cracked the code!

We don't do takeoffs up here. We just start at the cruise climb checklist! ;)

(Performance-wise, it's kinda true even if I am really just joking.)
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I like it....I am usually just as concerned with calculated climb rate at the given DA as I am with takeoff distance. Just because you can generate enough lift to leave the runway in a given distance doesn't mean you can continue flight!
 
COFlyBoy said:
I spoke with one of the B-1 pilots at Ellsworth (during the Dakota Thunder 2011 Awesomeness) about takeoff and he said that full AB is SOP. But the tables include data for power settings lower than that.

So the AF paid for power setting data that they don't use, but not for temperatures which are common throughout the US and many places that a B-1 could be deployed to.:dunno:
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The US Air Force shortsighted? Never!
:rofl:
 
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