NSTB Prelim on ANC 206 crash: At least 658 pounds over gross

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Overloading likely cause of fatal 2010 plane crash, board says

By CASEY GROVE
casey.grove@adn.com

Published: March 17th, 2011 01:01 PM
Last Modified: March 17th, 2011 01:51 PM

Severe overloading caused a plane to plummet from the sky after takeoff from Merrill Field in June 2010, according to a probable-cause report from the National Transportation Safety Board released today.

"Two witnesses said that just before it took off the airplane was loaded so heavily that its tires looked almost flat," the probable-cause report said.

Police at the accident scene identified the father and pilot as Preston Cavner, 34. The crash and resulting fire killed Cavner's 4-year-old son, Miles, and burned Cavner and three others inside, the NTSB said.

Cavner's wife, Stacie Cavner, 32, son Hudson, 2, and 16-year-old Texas resident Rachel Ziempak survived with critical injuries.

The Cessna 206 was bound for Port Alsworth and packed with construction materials, groceries, luggage, plants and other items for a family lodge, according to the NTSB.

Investigators estimated Cavner had overloaded the plane by at least 658 pounds. The amount of cargo impeded rescuers trying to get to victims inside the plane, the report says.

That weight estimate is a conservative number, said Jim LaBelle, chief of the NTSB's Alaska region.

"In 26 years of aviation accident investigation, both as an investigator and as a manager, I have never seen an aircraft involved in an accident that was that much overweight," LaBelle said.

The NTSB also faulted Cavner for using the plane's flaps outside of recommended limits, which caused increased drag, and for allowing the two younger children to ride on other passengers' laps, a violation of federal air regulations that require kids to be strapped in.

On the day of the accident, the plane took off and climbed to an altitude of about 150 feet. Witnesses said the engine was loud and the plane, its nose at a high angle, was struggling to climb, according to the report.

The crash occurred about 5:05 p.m., police said. The plane fell yards away from the busy intersection at Sixth Avenue and Ingra Street.

Brian Caton, a former manager of the nearby Ingra House hotel, recalled Thursday witnessing the plane crash and subsequent rescue.

"It hit the top of our building, spun around, and crashed into the building across the street," Caton said. "It was pretty mangled."

A small fire broke out under the crumpled plane, and 15 to 20 people ran toward the scene, some with fire extinguishers, Caton said. They worked to get the door open and pulled out the four survivors just before the plane exploded into flames, he said.

The plane had hit a small, empty building located on a defunct used-car lot. The building also caught fire.

Firefighters had the blaze under control by about 5:30 p.m, police said.

Reach Casey Grove at casey.grove@adn.com or 257-4589.
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Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Google is my friend. The Cessna site says the MTOW is 3600lb. This guy was not the brightest crayon in the box. What made him think he could carry 658lb more than the POH said he could?

To put this into perspective, the 172SP has a MTOW of 2550lb. That's the equivalent of trying to take off in a 172 weighing 3016lb:dunno:
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Seriously why do we learn weight and balance computation in our private pilot training? Why his family had to suffer for his ignorance... utter shame. He may have deserved it, but not his family.
 
TopGunn said:
Seriously why do we learn weight and balance computation in our private pilot training? Why his family had to suffer for his ignorance... utter shame. He may have deserved it, but not his family.
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I will say that Cessna Salespeople always hinted that the gross could be over by 10% and be ok if CG was near center. I would never do it but they would say it was the lawyer CYA.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Overgross operations are incredibly common in Alaska depending on the operation. Not right but incredibly common 600+ lbs overgross doesn't really surprise me, especially if they were going to a lodge.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Beeing overgross when you are by yourself, tanked up to go somwhere far is one thing. But with people on board, nah, not acceptible. I remember talking to a guy who used to ferry Mooney's to Australia. When he'd take off, he'd get 150-200FPM out of it. But he was by himself, full of gas.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

The way things should be
v.
The way things are.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

I think he was more of on a suicide mission here.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

mshunter said:
Beeing overgross when you are by yourself, tanked up to go somwhere far is one thing. But with people on board, nah, not acceptible. I remember talking to a guy who used to ferry Mooney's to Australia. When he'd take off, he'd get 150-200FPM out of it. But he was by himself, full of gas.
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Well...there's a big difference between what you should do, and what some guys are willing to do. Some guys...well, I guess they're better than I am, or at least have bigger balls than me. Let's just say that its not uncommon to see a 207 loaded (to the point where you'd have to jump in and start it to get it to come off the tail ) with 5 people, full fuel, and all their baggage crammed in. The pressure to do this sort of thing varies from company to company, the bigger the company, the more likely it is that the company is reputable. At smaller companies there is the chance that you will get on the "uncool" list by not carrying overgross loads, or by not flying in absolutely dog-poo weather. Most companies leave it up to their pilots though, and will let you do whatever you want - especially if it makes them some extra money. Other companies will reign you in if they think you're going overboard (you want to try to work for these companies as they tend to be a lot more conservative and won't push you). Maintenance is typically outstanding (though the airplanes don't look pretty), but the pressure to fly as a test pilot can be pretty stupendous at some places.

There are also old timers that have been flying their airplanes WAYYYYY overgross for years and won't hesitate to insinuate that you're a • for not flying with an extra 300lbs, there are other oldtimers that know better and will be mentors. Try to find those guys, you'll probably live longer if you do.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Proclaiming "renegade pilot" every time a light aircraft goes down will not improve our safety record. Why a pilot flies overweight, not that a pilot flies overweight, is the underlying problem. What fault in the system invites this sort of risk taking? It's human factors, and everyone here happens to be one of those...
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

TopGunn said:
I think he was more of on a suicide mission here.
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Not really, I've seen planes blast off with loads like that, and barely climb for miles and miles and miles and miles...

It depends on if the pilot knows what he's doing, and realizes he's going to die if he gets too slow. Chances are this guy was didn't think this through. Ignorance + complacency in this one. I heard a "war story" (so take that with a grain of salt as it was mostly beer induced BS-ing) of a dude who got overloaded by 1000lbs in the 80s in a 207 and he was still around to tell it. Apparently the rampies loaded 2 or 3 carts of mail into his plane instead of only one, and he didn't think anything of it. Turns out, instead of loose leaf mail, one of the carts was phonebooks in bags...so, those got loaded in on the bottom, with the loose leaf on top. He didn't know what was up until he was airborne dodging rocks.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Well.... overgross in Alaska happens. I feel for the family and the wife who lost a husband and a child.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

TopGunn said:
I think he was more of on a suicide mission here.
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Not really. As has been pointed out, the airplane WILL fly with 600 extra pounds. However, AT THE MINIMUM low speed handling, climb performance, takeoff performance, and landing performance will be degraded. Also, especially if loaded out of CG (which is pretty much a given in this case, I don't know that it's very easy to get 600 extra pounds in a 206 and still be in CG), there are stability/handling aspects that could be a problem. The thing is, you know that these will all be issues, but since you're essentially a test pilot, you don't know HOW MUCH of an issue. Could be no big deal, could be "OH HOLY MONKEYS, THE PLANE DON'T WANNA FLY!!!!". Now, there are a lot of people up here who regularly fly a set amount over gross-say, 300 lbs in a 206. They've been doing it for years and know how the airplane handles and performs when loaded like that. Are they still really test pilots? Well, they can and do make the flight safely. However, the airplane under those conditions PROBABLY does not meet it's certification requirements. Is it right? No, not really. Does it happen? Yes, every day. Does it occasionally bite someone? Yup. Part of life up here, unfortunately.

Another thing to think about in over-gross operations is the cumulative effect on the airplane. Your typical Alaska plane (206, Cherokee 6, Navajo, Caravan) has basically an infinite fatigue life when maintained in accordance with the manual and ADs, and operated in accordance with the limitations. However, start over-grossing the airplane and that may or may not hold true. Do it once, and the airplane doesn't notice. Do it 10 times, still no. Do it day in and day out for years on end, while flying in turbulence (common with the mountains in many parts of AK), and you can end up with some...unusual...structural problems. Surprisingly, very few airplanes up here break up in flight. My shoot-from-the-hip theory on that is that airplanes operated in this way tend to crash and be rebuilt before the cumulative effects of fatigue manifest themselves in anything other than little cracks. Also, as Pat mentioned, many of the 135 operators are very very conscientious about MX in part due to the demands placed upon their aircraft.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Sad story. All because of too much weight.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

I wish somebody would flight test and publish official performance charts for over gross operations.

As has been pointed out, Cessnas fly notoriously well in over gross configurations. I think this lulls pilots into a false sense of security. They push deeper and deeper beyond the "limits" until the real limits jump out and bite them. It would be nice to know what the real limits are from the start. Unfortunately, ignorance is not bliss in this case.

The main reasons I don't fly over gross are fear of enforcement action and simply not wanting to set a bad example for new pilots. But not because I think it's unsafe. Those are probably lousy priorities. I believe it's a result of not having adequate information beyond the envelope of the current charts.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Roger said:
Not really. As has been pointed out, the airplane WILL fly with 600 extra pounds. However, AT THE MINIMUM low speed handling, climb performance, takeoff performance, and landing performance will be degraded. Also, especially if loaded out of CG (which is pretty much a given in this case, I don't know that it's very easy to get 600 extra pounds in a 206 and still be in CG), there are stability/handling aspects that could be a problem. The thing is, you know that these will all be issues, but since you're essentially a test pilot, you don't know HOW MUCH of an issue. Could be no big deal, could be "OH HOLY MONKEYS, THE PLANE DON'T WANNA FLY!!!!". Now, there are a lot of people up here who regularly fly a set amount over gross-say, 300 lbs in a 206. They've been doing it for years and know how the airplane handles and performs when loaded like that. Are they still really test pilots? Well, they can and do make the flight safely. However, the airplane under those conditions PROBABLY does not meet it's certification requirements. Is it right? No, not really. Does it happen? Yes, every day. Does it occasionally bite someone? Yup. Part of life up here, unfortunately.

Another thing to think about in over-gross operations is the cumulative effect on the airplane. Your typical Alaska plane (206, Cherokee 6, Navajo, Caravan) has basically an infinite fatigue life when maintained in accordance with the manual and ADs, and operated in accordance with the limitations. However, start over-grossing the airplane and that may or may not hold true. Do it once, and the airplane doesn't notice. Do it 10 times, still no. Do it day in and day out for years on end, while flying in turbulence (common with the mountains in many parts of AK), and you can end up with some...unusual...structural problems. Surprisingly, very few airplanes up here break up in flight. My shoot-from-the-hip theory on that is that airplanes operated in this way tend to crash and be rebuilt before the cumulative effects of fatigue manifest themselves in anything other than little cracks. Also, as Pat mentioned, many of the 135 operators are very very conscientious about MX in part due to the demands placed upon their aircraft.
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I just did a W&B for a 206H model at 7200 pounds (600 over weight). I spread the extra weight out evenly and it was still easily within CG at about 46.5 inches, just obviously out of the envelope due to the weight.
 
Re: NSTB Prelim on ANC 206 crash: At least 658 pounds over g

Let's all loose 50 pounds so we won't fly overweight! Or don't eat that heart attack burger before flight.
 
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