Some pilots refuse to fly piston-powered helicopters, insisting instead on turbine-powered machines.  Turbine engines, their argument goes, are much less likely to fail in flight than piston engines. Though more expensive to purchase and to operate, the reliability of turbine-powered helicopters makes them safer than their piston-powered counterparts.

Does that mean the new Robinson R66, with its Rolls-Royce turbine engine, will be a safer helicopter Robinson R66 (Turbine engine)than Robinson’s R44, with it’s Lycoming piston engine? 

Not according to Robinson.

In fact, for years Robinson has taken a contrarian view, suggesting that pilots are in fact safer in piston-powered helicopters.  Though the large turbine engines used in airliners are incredibly reliable, the small turbine engines used in helicopters are not.  According to Robinson, accident statistics favor piston helicopters. 

Tim Tucker, a Robinson factory pilot, caused a stir when he published the data supporting that argument in a 2003 issue of Rotor and Wing magazine.  Unfortunately, his article, ("Turbine Reliability: Fact or Fiction") is no longer available on the internet (or at least I can’t find it). But Robinson R44 owner and flight instructor Philip Greenspun sums up the substance of  the argument pretty well:

Turbine engines have a reputation for extreme reliability, but physically small turbines, such as those that go into low-power helicopter engines, are subject to a lot of thermal stress and are not nearly as reliable as the turbines in an Airbus. Piston engines have a reputation for unreliability, but that was earned when the engines were operated at 100 Robinson R44 (Piston engine)percent power. The R44 is a demonstration of the most reliability that you could ever get from a piston engine; the Robinson R66 and similar light turbine helicopters demonstrate the least reliability that you could ever get from a turbine engine. . . 

The Robinson factory stops short of saying that the turbine engine makes its new R66 more dangerous than the R44.  But it’s not saying that it makes it any safer either. Deftly avoiding the issue, the company president told AOPA Pilot magazine (December 2010 issue): 

The decision to use a turbine engine really had nothing to do with reliability.  Data has shown the Lycoming 0-540 installed in the R44 to be extremely reliable.

But If Robinson believes small turbine engines are less reliable that the piston engines, then why is Robinson introducing a turbine-powered helicopter at all? 

According to Robinson, the market wants a helicopter with improved performance at high altitude and a better power-to-weight ratio.  It also wants a ship that can use jet fuel, since avgas is in some parts of the world becoming harder to come by. Only a turbine-powered helicopter can meet those demands.

Fair enough.  Just don’t think that shelling out the big bucks for the R66 ($790,000 for the R66 vs. $415,00 for the R44) is going to buy a greater extra margin of safety.  In fact, if you believe what Robinson has been saying about small turbine engines for the past 10 years or so, the R66 should prove to be less reliable, and thus less safe, than Robinson’s cheaper piston version.

Why does the public accept the EMS helicopter industry’s horrible safety record? Because the industry has sold the idea that it’s critical to deliver trauma victims to a hospital within the first “golden hour” after an injury.  While the industry acknowledges that the EMS helicopter accident rate is high, it argues that many more lives are saved by EMS helicopters than are lost.    

The logic is appealing.  But it doesn’t wash. Here’s why.

  • The Need for Speed.  Though helicopters are fast, when it comes to getting the patient to a hospital, a ground ambulance is often faster. At least in urban areas, ground ambulances are more widely distributed than EMS helicopters. That means a ground ambulance is more likely to be stationed closer to the trauma victim. A well-positioned ground ambulance can often get to the trauma victim and deliver him to a nearby hospital quicker than a helicopter can. By and large, a helicopter’s speed advantage is limited to rural environments, where ground ambulances are fewer and farther between. The helicopter’s speed advantage is overrated.
  • “Life Flights” That Aren’t.  At 12 year-old was airlifted from summer camp to a hospital in Austin, Texas after she hit her head in the shower. The bill for the flight was $16,000. Upon arrival at the emergency room, she was treated, and then sent back to her summer camp.  Such stories aren’t unusual.  In fact, some studies show a third of all patients delivered to emergency room by helicopter are released without ever being admitted to the hospital.
  • Pricey Shuttles.  Many EMS helicopter flights are inter-hospital transfers merely shuttling patients between hospitals. Operators love these profitable gigs. One calls the transfer patients “golden trout,” and encourages pilots to “hook” every one they can, regardless of how bad the weather conditions. No matter that, since the patient is already at a hospital, these transfers seldom classify as “emergencies.”

This is not to say that EMS helicopters never make a difference for trauma victims.  But much less often then the industry would have us believe.  One study showed that, at most, only 22% of those transported by EMS helicopter to Silicon Valley hospitals could be considered to have "possibly" benefited from the air ambulance. Other studies suggest that, even in cases involving serious trauma, helicopter transport improves the patient’s outcome less than 5% of the time. That means that 95% of the time the helicopter exposes the critically injured patient to an unnecessary risk. 

The industry has oversold the need for EMS helicopters. The benefits simply do not outweigh the risks.

The EMS helicopter was returning to Shenandoah Valley Regional Airport in Virginia, having dropped off a patient in nearby Charlottesville.  Reports differ on whether the Cessna was departing the airport or returning to the airport for landing.  The Cessna and the helicopter collided.  Though the helicopter landed safely, both occupants in the Cessna were killed.

No Control Tower

There’s no control tower at Shenandoah Airport. The primary means of preventing collisions at airports like Shenandoah is called “see and avoid.” That means that pilots are supposed to look out their windows, see other aircraft, and avoid them. 

Helicopters and Airplanes Don’t Mix Well

Though the "see and avoid" method may sound primitive, over the years it has worked well, and mid air collisions are relatively rare.  But helicopters don’t mix well with airplanes in a "see and avoid" environment.  Helicopters tend to fly slower than airplanes and, because they have a small cross section, they are hard for airplanes to spot — especially when viewed from directly behind. 

Because of that, when near an uncontrolled airport, helicopter pilots are supposed to "avoid the flow" of airplane traffic.  In other words, as best they can, helicopters are supposed to stay out of the way of airplanes.  Sometimes that’s easy enough. For example, if the airplane traffic flies on one side of the airport (see below), the helicopters generally should fly on the other side. Or, the helicopter can fly at an altitude that is lower than the altitude at which the airplanes are flying.

 Fixed wing traffic pattern

The above diagram depicts a left-hand traffic pattern for fixed-wing (airplane) traffic similar to the pattern used at Shenandoah Airport.  Airplanes typically fly the traffic pattern at 1000 feet.  To avoid the flow of that traffic, helicopters might fly a right-hand traffic pattern on the other side of the runway, and fly no higher than 500 feet.

One question will be whether the Cessna was operating within the "flow" of fixed wing traffic when the collision occurred and, if so, why the EMS helicopter did not avoid that flow. 

Cessa Crash Site

I often write about the NTSB’s "party system." That’s the NTSB’s practice of asking airlines and manufacturers for help in determining an accident’s cause.  If you ask me, it’s a bit like asking the fox for help in figuring out what happened to the chickens. The party system allows industry participants to bias NTSB probable cause findings in their favor.

The NTSB allows party participants to handle evidence and perform certain engineering tests.  But one thing the NTSB insists on doing all by itself is downloading the data from an aircraft’s black boxes.  The NTSB’s labs in Washington DC are well equipped for that job, and it doesn’t require any "help" from the airlines. 

But when it received the black boxes from the American Airlines 757 that ran off the runway at Jackson Hole, the NTSB quickly figured out that one of the black boxes had already been tampered with. The culprit turned out to be the trusted "party participant," American Airlines:
The Safety Board learned that the recorders were flown to Tulsa, Okla., where American Airlines technicians downloaded information from the DFDR. . .
That was too much industry "help" for even the NTSB to tolerate.  So the NTSB kicked American off the investigation.
Because maintaining and enforcing strict investigative protocols and procedures is vital to the integrity of our investigative processes, we have revoked the party status of American Airlines and excused them from further participation in this incident investigation.
Revoking a participant’s "party status" is the NTSB’s equivalent of the death penalty.  It is the harshest punishment the NTSB has the power to dole out. Still, it doesn’t seem like much of a deterrent for next time.
 
Narrated video of landing shows spoilers, thrust reversers failing to deploy: 
 

https://youtube.com/watch?v=blFw4Y1dtps%3Ffs%3D1%26hl%3Den_US%26rel%3D0

Emergency Medical Services helicopters don’t get paid for being on call. They earn money only when transporting patients. But, when they do transport a patient, they are paid well — up to $20,000 per trip.

The business model has worked out well for the industry. In fact, the number of EMS helicopters in service has quadrupled since 2002. But since an operator doesn’t get paid unless the helicopter carries a patient, there’s an incentive to fly the mission regardless of how adverse the conditions. And because operators are paid the same rate no matter what equipment they use, operators tend to use older helicopters, and to run them as inexpensively and as ill-equipped as possible.

Not surprisingly, the EMS helicopter fatal accident rate is, when compared to other forms of commercial N502MT - EMS Helicopter Crashaviation, off the charts.  In fact, with a crash rate that is 6000 times that of commercial airliners, flying an EMS helicopter is the second most dangerous job in America. Only working on a fishing boat is riskier.

Some of the reasons why EMS helicopters crash: 

  • Weather.  Inadvertent flight into clouds or fog can cause the pilot to become disoriented and lose control of the aircraft. Thunderstorms can bring a helicopter down in seconds. While accurate weather information is available for airport destinations, it is a rare commodity for the off-airport locations that EMS helicopters typically service. The lack of accurate weather information, coupled with economic pressure to complete the mission, takes a toll.
  • Unprepared Landing Sites. Helipads are designed so that there are no wires, trees or other obstacles for the helicopter to hit during landing or takeoff. The ground is firm and level so that the helicopter won’t roll over when it touches down.  But when responding to a call, EMS helicopters accept landing sites that have been neither surveyed for hazards nor otherwise prepared for helicopter traffic.
  • Terrain.  EMS helicopters crash into mountains, ridges, and hillsides with some regularity. Most of those accidents happen when it’s dark, foggy, or cloudy. “Controlled flight into terrain” is a leading cause of EMS helicopter crashes.
  • Mechanical Failure.  Rotor blades come off, engines fail, and pilots lose control of EMS helicopters due to defective parts or maintenance.

In Part II ("Golden Hour and Other EMS Myths"): With names like “Angel Flight,” “Mercy Flight,” and “Life Flight,” the EMS helicopter companies market themselves as indispensable life-savers. Is this just marketing hype, or are the benefits of helicopter transport really worth the risks?

Steve Wilson argues that there are safety issues with Cirrus airplanes. First, Wilson feels that the Cirrus is more prone than your typical Beechcraft to crashes in which the pilot loses control of the aircraft while maneuvering. Second, Wilson feels that the Cirrus is more susceptible to crashes involving inadvertent encounters with icing conditions.

Of course, the NTSB chalks up both of these types of accidents to pilot error, not to a fault in the

Continue Reading Steve Wilson: “The Cirrus Airplane Has Serious Problems”

Robinson Helicopter Company has long touted the crashworthiness of its helicopters. An excerpt from Robinson Safety Notice SN-10, which dates back to 1982:

The R22 and R44 have demonstrated excellent crashworthiness as long as the pilot flies the aircraft all the way to the ground . . .The ship may roll over and be severely damaged, but the occupants have an excellent chance of walking away from it without injury.

That’s turned out to be not quite true. Sure, occupants may survive the initial rollover without injury. But because of the way it is designed, the helicopter is prone to catching fire and burning the occupants before they have a chance to get out.  There has been a string of such R44 N2153Saccidents, the most recent being the September 16 Robinson crash at Mammoth, California.

The R44 helicopter involved in that accident, N2153S, experienced a problem on takeoff.  The pilot "flew the aircraft all the way to the ground," just as he was supposed to. When the helicopter touched down, it rolled over.  As advertised, the two occupants survived the rollover uninjured.  But almost immediately, fuel rushed into the cabin, a fire erupted, and both occupants were badly burned.

As I explained here, there is no reason for an occupant to be burned in that sort of mishap. Technology has existed since the 1970’s that can almost completely eliminate post-crash fires in otherwise survivable helicopter accidents.  The technology is not particularly expensive, fancy, or heavy.

In the case of the Robinson helicopter, the biggest problem is the aircraft’s transmission. In any type of rollover accident, the transmission can puncture the fuel tank. The fix is simple: replace the rigid fuel tank with a soft bladder tank that won’t rupture. 

Robinson has known about the problem for years.  But instead of fixing it, Robinson tried to dodge liability by putting the problem back on the owners. While continuing to tout the aircraft’s crashworthiness, in 2006 it posted on its website a "safety notice" No Nomex On Robinson Websiteadvising that anyone flying in one of its aircraft should wear fire retardant clothing head-to-toe.

To reduce the risk of injury in a post-crash fire, it is strongly recommended that a fire-retardant Nomex flight suit, gloves, and hood or helmet be worn by all occupants.

Robinson didn’t seriously expect any occupants to wear that kind of clothing.  It’s hot, uncomfortable, and generally inconvenient.  The "strong recommendation" was strictly a "CYA" move.  If Robinson was serious about it, it wouldn’t have posted on its website pictures of people flying Robinson helicopters in shorts and t-shirts. (One such picture right.)  Rather, it would show everyone wearing head-to-toe Nomex. But that sort of "advertising" would kill sales.

The unnecessary burn injuries continued. Finally, in December 2009, Robinson conceded that there was indeed a better way and announced that all new R-44’s will be equipped with bladder tanks.

In a continuing effort to improve the R44 fuel sytem’s resistance to a post-accident fuel leak, current production R44s now feature bladder-type fuel tanks, flexible fuel lines and other modifications.

Great news. But what about the thousands of Robinson helicopters produced before last December without bladder tanks?  They are, without a doubt, defective.  The defect has caused, and will continue to cause, needless burn injuries.  The defect and the resulting injuries are Robinson’s responsibility.

 In 1996, a ValuJet MD-80 went down in the Florida Everglades, killing all 110 on board.  The cause of the crash was ultimately traced to oxygen generators, which had been removed from service and improperly secured and loaded into the plane’s cargo hold. 

The FBI became involved early on. Various players were charged with, among other things, criminal conspiracy to falsify records and violations of regulations concerning hazardous materials.

That turned out to be a bad idea. As soon as the FBI came on scene, witnesses clammed up. Many refused to talk unless granted immunity from prosecution. The NTSB’s work came, to some extent, to a standstill.  

The lesson learned from the ValuJet crash was that, after an accident, determining the cause of the crash so that others can be prevented should be paramount. Meeting that objective requires a free flow of information.  Except in the most egregious cases, aviation accidents should not be the subject of criminal proceedings.  

On Monday, a French court convicted a US mechanic of involuntary manslaughter in connection with the July 2000 crash of the Air France Concorde. The details of the charges against the mechanic are here. Regardless of whether it sticks on appeal, the guilty verdict will negatively impact aviation safety for years to come. 

The verdict will result in no additional compensation for the Concorde families. Nor will it bring about any additional improvements in industry maintenance practices. As discussed here, those improvements happened long ago as a result of the civil lawsuits. All that the guilty verdict will do is cause those involved in future aviation accident investigations to assert their 5th amendment right to keep mum for fear of criminal prosecution.  That will make it only more difficult to determine the cause of an aviation accident, and to bring about the changes necessary to prevent similar accidents from happening again.

The NTSB hasn’t yet released its probable cause finding concerning the Pilatus crash at Butte, Montana that killed the pilot and his 13 passengers.  But it has just made public its “docket.”  The docket sheds some light on what may have been happening in the cockpit in the minutes leading to the crash.

The flight was bound for Bozeman. Suddenly, the pilot diverted to Butte, which was only marginally closer.  Though the pilot never explained the reason for the diversion, the docket suggests that the

Continue Reading Pilatus Crash at Butte: New NTSB Reports Show Pilot Under Stress

We’ve filed suit against Los Gatos real estate broker Karen Trolan (pictured), her husband Steve Trolan, and their company, Trolan Enterprises, as a result of the September 2009 plane crash that left the Trolans’ passenger, 14 year-old Marilyn Mitchell, seriously injured. 

The Trolans were headed from Truckee Tahoe airport to San Jose. They needed very littlKaren Trolane fuel for the short flight. But fuel was a few pennies per gallon cheaper in Truckee than in San Jose.  The Trolans decided to fill the tanks of their single-engine Cessna 206 to the tops.

When departing a high altitude airport such as Truckee, that’s a very dangerous thing to so. As discussed here, the combination of thin air and a heavy aircraft can dramTrolan Plane Wreckatically compromise the aircraft’s ability to climb. After takeoff, the aircraft will ride briefly on the cushion of air that exists between the plane’s wings and the runway, and then crash.  And that’s exactly what happened.

The NTSB’s preliminary report confirmed that the Trolans’ tanks were indeed full when they attempted to take off.

The crash was caused by pilot error, plain and simple.  Yet, the Trolans have turned their back on Marilyn and her family, leaving them to fend for themselves. The Trolans have yet to pay any of Marilyn’s medical bills, which continue to mount.