Robinson R44 helicopters are death traps, right up there with Mitsubishi MU-2s and Cirrus SR22s – at least that’s according to a lot of articles you read online. A dramatic headline in The Los Angeles Times late last year was the most recent example, warning residents of southern California that “Danger spins from the sky.” It’s a compelling story, and the newspaper even went so far as to calculate the numbers (something most non-aviation publications neglect). But does it tell the whole story?

In the spirit of Richard’s very popular “What’s wrong with Cirrus/Mooney/Bonanza pilots” series of articles, I’d like to offer a more nuanced perspective. This comes from my perspective as an R44 owner and pilot, but also as a longtime safety geek who reads a lot of accident reports. With one foot in the airplane world and one in the helicopter world, I’ve found some of the comparisons between the two quite revealing.One important similarity is that, as Collins repeatedly found in his articles, the “problem” is usually with the pilots and not the design of the aircraft itself. That may seem like a dodge, but it’s simply what the statistics show. Certainly some models are more forgiving than others, but better training and operating habits seem to correct for most of those weaknesses, as the rapidly improving accident record for both the MU-2 and the SR22 have shown recently.

Os números

I will also focus only on fatal accidents. While a non-fatal accident can ruin a day or a career, it’s the fatal ones that most pilots focus on and rightfully so. This restriction also makes for simpler comparisons, since (unlike in airplanes) many very minor helicopter mistakes become accidents. If you taxi a 172 into the side of a hangar, you’ll replace the wing cuff and face some embarrassment. It probably won’t even show up as an incident, much less an accident. On the other hand, if the rotor blades on your R44 clip a hangar, the helicopter might be totalled. This skews the data when comparing accidents and incidents in airplanes vs. helicopters.Let’s start with a look at the statistics, which is not as easy as it might sound. I will restrict my analysis to US accidents, since the NTSB typically shares more complete information and the accident causes are consistently reported. Comparing an accident report from Brazil to one from the US is not always helpful, or even possible. Doing this excludes a number of accidents, since the majority of R44s are flown outside the US, but there are enough aircraft in the US to get a fair read on safety trends.

Finally, the numbers below include total fatal accidents and fatal accidents per airframe. Many safety studies use accidents per 100,000 hours as the key rate, and it’s a valuable number since it considers the exposure. Unfortunately, it’s very hard to accurately track hours flown by model and that’s especially true for helicopters. I don’t put much stock in the estimates that are published.

One number that is easy to calculate is how many fatal accidents have occurred. Here are the total number of fatal accidents in the US for the R44 over the last 5 years:

  • 2018 – 3
  • 2017 – 2
  • 2016 – 2
  • 2015 – 1
  • 2014 – 5

That’s 13 total over a 5 year period, not exactly a staggering toll, and with 1622 registered in the US that means that 0.8% of the US fleet has been involved in a fatal accident in the last 5 years. For comparison, the Bell 206 series had 12 fatal accidents in that period and a rate of 0.8%. The Eurocopter AStar also had 12 fatal accidents in that period and a fleet rate of 1.3% over the last 5 years.

Comparisons like this are unavoidably apples and oranges – both the 206 and the AStar probably fly more hours per aircraft than the R44, since they’re used by a lot of air ambulance and law enforcement operators. But they are also typically flown by much more experienced pilots and they both have turbine engines. It’s at least interesting that the percentage of the fleet involved in a fatal accident over the last 5 years is as good or better for the R44 compared to two stalwarts of the turbine helicopter fleet.

One final comparison. The Cessna 172, a somewhat similar performing aircraft in the fixed wing world and one known for its good safety record, saw 59 fatal accidents in the 2014-2018 timeframe. With a US fleet of 19,678, that leads to a much lower 0.3% fleet fatal accident percentage. If anything, these numbers show that helicopters in general have a worse safety record than airplanes.

Causes

The raw numbers are directional, but the causes of the accidents and the stories behind the crashes are much more revealing. Here’s a quick recap of those 13 R44 accident causes:

  • Hit wires shortly after takeoff from a field
  • Crashed shortly after takeoff due to unknown reasons (there are implications about poor maintenance but the NTSB report is not final)
  • An IFR training flight crashed in the waters off Hawaii in good weather, but the wreckage was not found so no cause was determined
  • A low-level flight impacted terrain in a remote area; the pilot had no helicopter rating
  • Crashed after descending from cruise (maybe with a tail rotor issue, maybe a low pass gone wrong)
  • Crashed on takeoff – and the pilot was drunk
  • VFR-into-IMC in the mountains
  • Improper maintenance led to a control rod detaching and in-flight loss of control
  • The pilot had a heart attack and crashed trying to land while doing external load practice (a very demanding type of flying)
  • A crop duster hit wires while flying between fields at low altitude
  • Midair collision with an airplane in the traffic pattern at a towered airport
  • Improper maintenance meant a pitch link was not re-attached properly
  • Crashed after taking off at night from an unlit area and hitting trees

Reading these accident reports, it’s hard to find a consistent problem with the helicopter. Two involved pilots flying illegally (one drunk and one without a rating) and one involved pilot incapacitation. Three involved hitting obstacles at low altitude, and the VFR-into-IMC accident proves that helicopter pilots are not any more immune to this temptation than Bonanza or 182 pilots.

Three trends do jump out. First, private operators have a much worse record than other pilots. That is true in these accidents, across helicopters in general, and even in the airplane accident record. While accounting for roughly 10-15% of estimated piston helicopter flight hours, personal and business use without a crew accounts for the majority of accidents. R44s in particular are often flown by low time pilots – in fact, it’s the only helicopter of any real popularity that is flown by private owners. The typical pilot is completely different from a Bell 206 or an AStar.

The diversity of operations is also unique. From crop dusting to external load flights to law enforcement, R44s are often working machines, rode hard and put away wet (watch this if you don’t believe me). Sure, Cessna 172s are used for a lot of different operations, but nothing like the variety of a helicopter. That means different risk exposures, as the accidents on takeoff from remote locations prove quite dramatically.

Finally, while maintenance is a given, it can introduce the possibility for fatal mistakes in a helicopter. As two of the above accidents demonstrate, the post-maintenance flight is particularly risky. There are certain parts of any helicopter that simply must be installed properly or there’s nothing the pilot can do to recover. Good maintenance and methodical preflights are table stakes for helicopter operators.

Digging deeper

A deeper reading of the accident record (including some non-US reports) shows many accidents that will seem familiar to airplane pilots. There are plenty more examples of VFR-into-IMC accidents and a depressing number of reckless flying mistakes, both of which are hardly unique to the R44.

One issue that does seem to be more common in R44s is post-crash fires. A number of serious but survivable crashes have become fatal accidents because the helicopter caught fire and killed the occupants. The problem stems from a decision by Robinson in the 2000s to use “wet tanks” instead of fuel bladders. This increased the fuel capacity but left the tanks susceptible to post-crash leaks and fires. Beginning in 2009, Robinson switched back to bladders on all new aircraft and incentivized owners of older models to replace the old tanks, so at least the number of aircraft in this camp is declining.

While some law firms have sprung up to focus on this issue, it’s worth remembering that the fuel tanks didn’t cause any of these accidents – they caused them to become fatal. A minor point perhaps, and no comfort for the families involved, but it shifts the focus to crashworthiness rather than aerodynamics or performance.

Inevitably, the discussion about R44s turns to that longtime villain: mast bumping. This topic takes on an almost mystical tone with some non-aviation writers, but it is mostly a matter of physics and it is not unique to the R44. All semi-rigid rotor systems (two-bladed) are susceptible to catastrophic in-flight breakup if the helicopter experiences low G conditions and the pilot does not recover properly (Vertical Magazine published a thoughtful analysis of the issue if you want to read more.)

But mast bumping isn’t really a design defect, it’s simply a fact, whether you’re flying a Huey or an R22. The solution is to avoid low G situations (no pushovers with the cyclic) and practice proper pilot technique if you find yourself in one. That technique is still evolving, too, with some instructors now emphasizing reducing the collective in addition to the traditional aft cyclic. The theory is to reduce the tail rotor thrust and main rotor torque, which will reduce the right rolling tendency.

Speed also matters. Robinson is increasingly emphasizing that pilots should slow down in turbulent conditions: “A pilot’s improper application of control inputs in response to turbulence can increase the likelihood of a mast bumping accident.” For significant turbulence, slowing down from 110 knots to 60 or 70 knots may be required.
Reputation meets reality.

Much like the Cirrus, the R44 has been a revolutionary aircraft for personal aviation. In both aircraft, the accident record shows machines with lots of performance being flown by pilots without lots of experience. An R44 can carry four passengers 250 miles at 110 knots – and then land in a 50 ft x 50 ft spot in the forest. That’s an impressive list, but you can earn the certificate to fly that mission in as little as 40 hours of flying. If ever there were a “license to learn,” the Private Pilot – Helicopter is it.

Both the NTSB and FAA have reviewed Robinson helicopters over the years (as they did for the MU-2). The results are telling: the helicopters were found to meet all certification standards, but the FAA wrote SFAR 73 to mandate type-specific training for Robinson R22s and R44s. The organizations were effectively admitting that safety rests with the pilot.

While the lawyers argue over fuel tanks and the engineers argue over mast bumping, helicopter pilots (and safety advocates) should focus on some very practical tasks. For a start, owners must expect and demand good maintenance, and take post-maintenance flights very seriously. Pilots should be rated, rested, and well-trained. That’s obvious, but bears repeating given recent history. This is not the place to pinch pennies or cut corners; if that’s your style then helicopters are not for you.

Pilots should fly above 500 feet if at all possible, and plan off-airport landings very carefully. The helicopter can almost certainly make it into that tight spot, and your passengers will love you for it, but can you as the pilot make it? Researching off-airport sites before getting in the right seat – perhaps including driving to the location for inspection on foot – and wide safety margins are essential.
A cultural change about weather minimums is in order too.

The FARs grant helicopters broad latitude to fly VFR in truly scuzzy weather, as low as one half mile and clear of clouds. Many operators take those limitations as recommendations and spend very little time considering the weather before a flight. Unfortunately, the results speak for themselves: even among professional helicopter air ambulance pilots, VFR-into-IMC accidents are common.

I am hardly an expert helicopter pilot (90% of my time is in airplanes), but I have owned and operated an R44 for over 7 years. It is a reliable, capable performer, and I’ve flown it on both long cross countries and on short local flights to tight landing spots. It’s the most fun I’ve ever had flying, but it’s also the most demanding thing I’ve ever done. Because they can do so much, helicopters can lure you into situations without many escape routes. It’s easy to say, “I’ll keep flying even though the visibility is bad, and if it gets worse I’ll land in a field.” That flexibility is great, but are you really disciplined enough to land in that farmer’s field if it’s required?

Helicopters are incredible machines, but they are terribly unforgiving. As the most popular model in the civilian world, the R44 may simply be a notable example of this adage.

Reputation meets reality

Much like the Cirrus, the R44 has been a revolutionary aircraft for personal aviation. In both aircraft, the accident record shows machines with lots of performance being flown by pilots without lots of experience. An R44 can carry four passengers 250 miles at 110 knots – and then land in a 50 ft x 50 ft spot in the forest. That’s an impressive list, but you can earn the certificate to fly that mission in as little as 40 hours of flying. If ever there were a “license to learn,” the Private Pilot – Helicopter is it.

Both the NTSB and FAA have reviewed Robinson helicopters over the years (as they did for the MU-2). The results are telling: the helicopters were found to meet all certification standards, but the FAA wrote SFAR 73 to mandate type-specific training for Robinson R22s and R44s. The organizations were effectively admitting that safety rests with the pilot.

While the lawyers argue over fuel tanks and the engineers argue over mast bumping, helicopter pilots (and safety advocates) should focus on some very practical tasks. For a start, owners must expect and demand good maintenance, and take post-maintenance flights very seriously. Pilots should be rated, rested, and well-trained.

That’s obvious, but bears repeating given recent history. This is not the place to pinch pennies or cut corners; if that’s your style then helicopters are not for you.I am hardly an expert helicopter pilot (90% of my time is in airplanes), but I have owned and operated an R44 for over 7 years. It is a reliable, capable performer, and I’ve flown it on both long cross countries and on short local flights to tight landing spots. It’s the most fun I’ve ever had flying, but it’s also the most demanding thing I’ve ever done.

Because they can do so much, helicopters can lure you into situations without many escape routes. It’s easy to say, “I’ll keep flying even though the visibility is bad, and if it gets worse I’ll land in a field.” That flexibility is great, but are you really disciplined enough to land in that farmer’s field if it’s required?

Helicopters are incredible machines, but they are terribly unforgiving. As the most popular model in the civilian world, the R44 may simply be a notable example of this adage.

by John Zimmerman

Crédito por artigohttps://airfactsjournal.com/2019/01/whats-wrong-with-robinson-r44-pilots/