crashed

[Ron Moore]

It's important to remember that the posted G limits are symmetrical. If he was rolling and pulling, inducing assymetrical G's, the aircraft's G tolerance is greatly reduced. While we won't know until the NTSB finishes the investigation, it appears much more likely that it's pilot error, he pulled a wing off, versus an aircraft mechanical failure.
The aircraft I flew until recently had Flint tip tanks. They are required to have (approximately) 12 gallons unitl the aircraft's gross weight was reduced (I don't remember the numbers). My technique was to fill the tips, put in the fuel required for the leg in the mains. I would burn the mains until they were about to go below 20 gallons per side, then transfer the tips to land with about 20 gallons per side, well in excess of the 45 minutes required.

[hharney]

Pressurized G model POH states:

The airplane is certified in the normal category. The normal category is applicable to airplanes intended for non-aerobatic operations. These include any maneuvers incidental to normal flight, stalls (except whip stalls) and turns in which the angle of bank is not more than 60 degrees. In connection with the foregoing, the following maximum certificated gross weight and flight load factors apply:

Gross Weight:
T/O Wgt ........................................4700 lbs.
Landing ........................................4465 lbs.

Flight Load Factor:
*Flaps up ......................................+3.8 -1.52
*Flaps down ..................................+2.0
*The design load factors are 150% if the above, and in all cases, the structure meets or exceeds design loads

Maneuvering Speed .......................155 MPH
*The maximum speed at which you may use abrupt control travel.

Never Exceed ................................230 MPH
Maximum Structural Cruising Speed .190 MPH

Most modifications will not adjust the operating limitations. Way too much expense involved. Although the extended fuel cells increase gross weight (normally not for landing but take off and cruise) the operating limitations remain as published by Cessna.

By speculation of the events, one would conclude that the pilot exceeded the operating limitations but don't rule out that there was some kind of damage or deterioration that was already present and the timing was not on their side.

[Ron Moore]

Understood. But, 3.8 is symmetric G's; there isn't a published unsymmetric (rolling) G limit. All that is known is that it is less than the symmetric G tolerance, the aircraft is not stressed for to withstand 3.8G's in a rolling pull.
If he was at red line and pulled up abruptly, he clearly exceeded the airframe limits. If he did a rolling pull, he exceeded them to some unknown additional extent.
It will be interesting to see the investigation results. He could have easily pulled the wing off a aero time airframe....

[Roger]

In fact isn't the whole idea behind a screaming dive down to the runway with a last minute pull up, done in a manner to exert G-forces on the passengers? It's like a roller coaster ride.


"watch this"

[hharney]

Just for a visual, here is the location of Station 177. It is 46 inches from the end of the wing not counting the wingtip.

[WebMaster]

It is way out on the wing, and the strut held. This should be an argument against the SID, at least the strut inspection.

[Roger]

I was discussing this today with a friend who is a chief metallurgist for P&W, and he mentioned something that puts this into perspective, ie. apparently the bobsleds running at the olympics are pulling 5.2G's going 90mph in a lateral turn.

Think about that for a moment, and then consider that for this crash the guy was doing over twice that speed and his G inducing pull was vertical ! I don't know the math on this, because we can't calculate the "unknown pull-up" but I can certainly see how easy it would be to snap a piece of wing off given what we believe occured.

Anybody want to bet a $100- burger that the word corrosion never comes up in the final report?

"watch this"