Small helicopter crashes at Chandler Airport

[barnstorm2]

http://www.azfamily.com/news/homepagetopstory/stories/chandler-local-news-041609.de9b7c26.html

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CHANDLER -- Two people were able to walk away after a small helicopter went down near Chandler Municipal Airport Thursday morning.

Investigators say what is believed to be an A600 Talon helicopter was doing some training exercises with an instructor and student on board. The chopper reportedly was hovering at 15 to 20 feet when it dropped and landed on its side.

There was some damage done to the rotors and the body of the chopper.

Investigators are looking into whether it was a mechanical problem or pilot error that caused the accident.

The Talon helicopter is a two-seat homebuilt kit. It can cruise up to 100 miles per hour and climb up to an altitude of 10,000 feet.

[animal]

I still have not figured out why so many of these Exec style Rotorway helicopters seem to roll over so much.

I just know I don't want one.

[Vance]

I often see helicopter pilots and even instructors ignoring the height velocity curve.

I have not seen the height velocity curve for the Rotorway helicopter.

I would postulate that when hovering at 15 to 20 feet it would be difficult to manage a successful autorotation if the power was interrupted in a Rotorway helicopter.

Speaking with the owners suggests to me that the Rotorway helicopters are somewhat maintenance intensive.

I agree that Rotorway helicopters seem over represented in rollover incidents.

I have peered at the Hobbs meter on nearly every Rotorway I have had access to and the hours seem low to me. If this is the pilots first helicopter experience that would suggest to me some very low time pilots are flying these helicopters.

Low time pilots seem overrepresented in helicopter rollover incidents.

Thank you, Vance

[brett s]

From what I've seen Rotorways have limited cyclic authority compared to many other helicopters, that doesn't help either. The point at which a dynamic rollover becomes unrecoverable is quicker to reach...

Hovering at 15-20' isn't a great idea in just about any helicopter - there are a few that could successfully land from there with an intentional power chop that the pilot is expecting, but probably not from a unexpected one. That second or two delay while you figure out what just happened is enough to make a difference!

[animal]

Brett and Vance ,you are both correct, and even when I was on the Rotorway owners group forum I read many times of emergency landing,where the pilots autoed in just fine,only to roll over on touch down.

[Vance]

The story of a successful autorotation to the ground followed by a dynamic rollover may be exaggerated by the pilot in command to obfuscate responsibility for the damage to the aircraft.

It is my understanding that the autorotation is not successful until the rotor is no longer turning and you are able to reuse the aircraft without repairs.

I find a hovering autorotation challenging from 3 feet. I cannot even imagine the challenge from 15 to 20 feet. The impact may be above the design limitations for the skids.

Thank you, Vance

[Wannabe1]

An instructor on board and hovering at 15'-20'? Why would he/she be allowing that?

I did enjoy the comment that "there was some damage done to the rotors". Only some damage? Must be pretty good rotor blades!

[scott heger]

The biggest problem is the lack of inertia in the rotor blades of homebuilt helicopters, and to some extent R-22's. This is because they don't make much power,and bigger blades require much more power to turn, a design compromise, and not a good one in the smaller types. You can chop the power on a Bell 47 or Jet Ranger, and have almost three seconds before it sinks. Plenty of time to recognize a problem and prepare for the touchdown in the next few seconds. Loose power in a R-22, and you are hitting the ground in three seconds. From what I understand, Rotorways are even worse, but have no personal experience to say for sure. Most of these accidents are not true dynamic rollovers, but the skids collapsing, or loss of control with sideways drift from basically running out of RRPM to control (and lift) resulting in a crash landing. I do 15 foot hovering autos in my Bell helicopter monthly, normally with a little wind and they are always non events. At the Bell school, my instructor did one from about 40 feet with no wind! Timing is a little more important at that height.

Why you would ever get a small helicopter in 20+ feet of height and in a no airspeed hover as a instructor teaching a student,..... well you are dancing with the helicopter devil......guess who won that day. Glad no one was physically hurt.

I know a pilot who lost a engine in a Sikorsky S-58 at 110 feet with a sling load over the roof of a new industrial building. The engine started to burp and lost power, he went nearly straight down, but forward of his rooftop crew below, and only put one wheel into the top of the plywood roof. The helicopter was basically undamaged. That is what hundreds of pounds of blades and rotor head buy you in safety. Size definitely matters with rotor blades.

Scott Heger, Laguna Niguel,Ca N86SH

[Al_Hammer]

I think the lack of inertia in small helicopters can be explained by this post from Frank Robinson.

FRANK ROBINSON ON ROTOR INERTIA VS DIAMETER
At this point, many helicopter pilots ask "why not just add some blade tip weights to, say, a Robinson R22 helicopter, to make it into a high-inertia system?"

"It's not as easy as that," says Frank Robinson, the R22's designer. "Rotor blade tip speeds are similar for all helicopters regardless of the size of the machine, because they are all limited by the speed of sound in air. The stored energy of a tip weight is only dependent on tip speed, therefore, a one-pound tip weight added to the 50-foot diameter rotor of a large helicopter would store the same energy as a one-pound tip weight added to the 25-foot diameter R22 rotor. However, the centrifugal force produced by a tip weight is inversely proportional to the rotor diameter, so the one-pound tip weight would produce twice as much centrifugal force in the R22 rotor as it would in the larger helicopter rotor, even though it would not store any more energy. The increased centrifugal loads carried by the blades, the pitch change bearings, and by the rotor hub would all be twice as great. Clearly it is very difficult to engineer a small helicopter with a high-inertia rotor."

It may seem counter intuitive that the centrifugal force gets larger as the diameter gets smaller. it does if you keep the tip speed constant. The typical gyro prop experiences greater centrifugal force than the rotor due to the same effect.

[barnstorm2]

Now the 'neighbors' are upset. Or at least a few have-nothing-else-to-do busybody housewives on a mission to solve a problem that does not exist.

What about student car drivers? What about auto accidents?

%$#%#^%@ !!

No one was even hurt!

Perhaps she should have considered this BEFORE buying a house near an airport!?!?

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http://www.azcentral.com/news/articles/2009/04/20/20090420cr-helicrash0422.html

Chopper crash worries Chandler airport neighbors

Neighbors around Chandler Municipal Airport have complained to city officials for years about noisy helicopters and seemingly dangerous maneuvers by student pilots over their homes.

Since a helicopter carrying a flight instructor and a student crashed at the airport Thursday, two of the most vocal neighbors say they're more disturbed and frightened than ever.

"We're waiting for the big one," said Barbara Smith, who lives east of the airport in Peterson Farms.
"A helicopter will crash into a neighborhood sooner or later; it's just a matter of time. It's a scary thought, but these are students and what they do is take-off and land, touch down and circle."

Dirk Matthews has been sending e-mail complaints about helicopter noise and traffic to airport officials for years.

In the most recent one, written less than two weeks before the crash, he called their attention to a student pilot who appeared to be struggling to control a helicopter in high winds and questioned why the airport would allow "such dangerous flying."

"I saw it coming down Gilbert Road right over residential areas; it scared the crap out of me," Matthews said.

In response to his complaint, Airport Manager Greg Chenoweth said no on at the airport witnessed the incident and "we do not have a standardized policy for closing the Chandler Municipal Airport due to weather conditions."

Chenoweth also said because the airport is a public facility it can't deny use to helicopter pilots and students.

Most of the residents' complaints over the years have focused on Quantum Helicopters, a training school based at the Chandler Airport.

However, Thursday's accident involved a RotorWay helicopter in which an instructor and student were practicing hovering. The helicopter flipped on its side and was seriously damaged, but the student suffered only minor injuries and the instructor was unhurt. RotorWay is based in west Chandler at Stellar Airpark.

Calls to that facility were referred to RotorWay owner Steve Dupont in Van Nuys California.

Dupont said the helicopters are built for non-commercial use and sold as kits assembled by buyers. He said the company and safety of its craft have "a very solid reputation . . . the majority of accidents that happen are caused by pilot error."

Thursday's accident is under investigation by the Federal Aviation Administration and National Transportation Safety Board. Matthews said he hopes the findings will spur tougher regulation of helicopter flights over neighborhoods.

However, FAA spokesman Ian Gregor said determining the probable cause of an accident "is not going to trigger an investigation into flight patterns or noise."

[brett s]

Gotta love it - idiots...

If the sound of aircraft bother you, don't live near an airport!

[scott heger]

The Chandler airport was built when there was nothing but farm fields around it. The houses (and people) are the ones that have encroached. Don't want airplanes falling out of the sky near you, or hearing the preexisting noise ? Move.

Scott Heger Laguna Niguel,Ca N86SH