Admired & Reviled

The Piper Malibu series has a checkered history and a rabid fan base. What its safety record can teach the rest of us

0

by Ken Ibold

Considered by many to be the flagship of the single-engine piston fleet, the Piper PA-46 is, in some respects, the worst best airplane you could imagine. Fast, pressurized and able to take on both in-flight icing and scorching summertime ramps, the appeal of the airplane is undeniable. At the same time, the airplane is complex, and some of the design compromises leave the airplane – and its occupants – exposed to risk not found in most other airplanes.

Together, these factors make the PA-46 – in its Malibu, Mirage or Meridian incarnations – an airplane that some owners hate to love. They pay the price in maintenance and insurance but are still subjected to risk that others might deem unacceptable.

Mention the Malibus accident record and many pilots wonder if Malibu owners are nuts. They have invested huge amounts of money, time and effort into buying the airplane and it stands to reason that a poor safety record would reflect badly on those investments. Malibu fans, however, point to the airplanes capabilities, comfort and handling and pass off everything else as a simple matter of risk management.

Make no mistake, when the Malibu works, its universally acclaimed as a delightful airplane. In order to keep it that way, the airplane demands strict attention to maintenance, systems knowledge and pilot proficiency.

We conducted a study of five years of accidents involving the three models of PA-46, during which we found 50 accidents. We found that over 90 percent of those accidents could be classified into five broad categories: engine failure, loss of control, mechanical failure other than the engine, weather and poor pilot judgment. Only four accidents did not fall into those broad categories – a bird strike, a runway collision with another airplane, an accidental gear retraction during taxi and an accident of unknown cause.

When assigning accidents to these categories, we applied some judgment. For instance, a power failure on initial climb isnt lumped in with engine failures when the pilot failed to sump the water out of the fuel tanks. Likewise, we dont blame the weather when the pilot tries to take off with the airframe encrusted with snow, ice and frost.

Finally, we want to make it clear that these numbers are based on episodes that meet the NTSBs accident criteria. Engine failures that result in successful deadstick landings and dont have other damage are not included – and there are surveys that purport that as many as 11 percent of all PA-46s have suffered at least one engine failure in flight. Also not included are landing gear failures that dont result in structural damage. So while an occurrence might seem like an accident to the pilot and the insurance company, its not included here unless the NTSB also considers it an accident.

Engine Failures
As in many airplanes, the engine is regarded as the primary trouble spot. Just how big a problem it is remains uncertain. In a safety study conducted by Aviation Safetys sister publication, The Aviation Consumer, about 27 percent of Malibu accidents from 1987 through the first half of 2003 involved engine failures. However, when we limited the analysis to the last five years, engine failures accounted for only 10 percent of Malibu accidentsThis huge discrepancy is likely the result of several factors. First, when the Malibu was introduced in the early 1980s, the book called for operating lean of peak at 80 percent power. Apparently many pilots were not comfortable with LOP operations, so they operated at more conventional rich-of-peak settings while still running book numbers for manifold pressure and RPM. The result was predictable: Very high engine temps led to catastrophic failures.

In addition, the airplanes twin turbochargers put added stress on the engine as well as adding to temperature problems. Power loss and engine compartment fires due to cracked exhaust components just downstream of the turbochargers have been chronic problems.

It appears, however, that Malibu operators have begun to get a handle on proper engine operations. Multi-probe engine monitors are found on virtually all Malibus and pilots are taught from the beginning of the importance of monitoring cylinder temps. Preflight inspections routinely include decowling the airplane to examine exhaust components and turbocharger condition.

Second, pilots have learned that engine failure must be considered a possibility, if not quite a likelihood. Many plan their routes within gliding distance of airports whenever possible.

The Malibus high aspect-ratio wing makes it a good glider, enabling it to cover 50 miles from a typical cruise altitude of 20,000 feet. Pilots also must put great stock in their ability to handle deadstick landings. Given the fact that the airplane tends to spend more of its time flying in poor weather, smart operators even practice deadstick instrument approaches.

Finally, the reduced rate of engine failure-related accidents indicates that engine maintenance has become a priority. Oil change intervals of 25 hours are not uncommon, with a simultaneous inspection of the other potential engine trouble spots.

Loss of Control
Like most airplanes, loss of control around the airport is the primary cause of Malibu accidents. During our five-year study, we found that 16 out of 50 accidents involved loss of control in the airport environment. Of those 16, five were on takeoff, seven on landing, two on missed approaches and two on go-arounds.

That loss of control rate is lower than most airplanes. The Cessna 172, for example, has a loss of control rate about five percentage points higher. While that is partly to be expected because of the relatively high level of flying experience most Malibu pilots enjoy, its also clear that Malibu pilots take some pride in proficiency.

During an informal query of Malibu pilots at a recent convention of the Malibu Mirage Owners and Pilots Association, about two-thirds of the roughly 200 pilots in attendance reported total times of more than 3,000 hours, and nearly all claimed more than 2,000 hours. About 90 percent said they held commercial certificates or better and more than half expressed confidence they would be able to pass a commercial certificate practical ride that afternoon.

Given that pilot profile, the runway loss of control issue becomes a bit more bewildering and warrants additional attention. Of the 16 loss-of-control accidents, three were in Meridians, which brings up the issue of low time in type and the challenges that come with the distractions of transitioning to a new airplane. In the case of the Meridian, thats multiplied by the move from piston to turboprop.

Four of the loss-of-control accidents occurred during go-around or missed approach. We have long held the rejected landing to be the most forgotten maneuver in the pilot repertoire, and this provides some ammunition to back that up. Whether the crash has its roots in loss of directional control due to uncountered engine torque, loss of situational awareness or spatial disorientation brought on by the acceleration and climb, these are among the most preventable of GA accidents.

The remainder of the loss-of-control landing accidents were garden-variety runway prangs, porpoises and failures to hold the centerline.

Mechanical Failure
The Malibu is a complex airplane, so it stands to reason that mechanical failure might come into play. There were seven accidents wed consider to be mechanical in nature, though three could just as easily go into the engine failure category.

Those three involved an engine fire due to the failure of a turbocharger clamp, an engine failure due to improper repairs to the turbine inlet temperature gauge, and a loss of power when a fuel delivery problem fouled the plugs. We put these accidents into the mechanical failure box because they are more closely aligned with proper – or, more precisely, improper – maintenance than with the design and application of the engines involved.

The other mechanical failure accidents were a fire resulting from an improperly repaired fuel line, the failure of the engine mount that also serves as the nose gear attach point, another landing gear collapse, and an apparent runaway trim during climb.

The important revelation when it comes to mechanical failure is that, while knowledgeable and conscientious mechanics are important for any airplane, they are doubly so for airplanes like the Malibu that are asked to give their all in extremely demanding conditions.

Under the Malibu cowling is a nest of hoses, tubes and wires that are packed into a very tight space that tends to operate at high temperatures. Proper inspection and routing of those items is crucial to the airplanes airworthiness.

Because of the demands of the airplane and its complex systems, Malibu specialty mechanics have sprouted. The high stakes of Malibu ownership have made these specialists popular among Malibu owners, despite the inconvenience involved with ferrying the airplane for maintenance. One Malibu owner we know, for example, ferries his airplane from Texas to Missouri every 25 hours for an oil change and engine compartment inspection. He reports his dispatch reliability has increased dramatically since he adopted this policy.

Weather
As an all-weather airplane, the Malibu gets its share of exposure to convective activity, icing, high density altitude takeoffs and instrument conditions. Perhaps surprisingly, we counted only four weather-induced accidents.

One involved clear air turbulence that resulted in the wings and horizontal stabilizer needing replacement. (The airplane landed safely.) One was an in-flight breakup after the pilot flew into a thunderstorm at FL260. One involved a runway loss of control when the runway was 85 percent covered in ice. One resulted from the airplane stalling at 10 feet agl while landing with an iced airframe.

In each of these cases, the pilots judgment could also be called into question. We lumped them into a weather category because not all weather risks can be identified ahead of time, and these appeared to fall into that category based on the accident reports.

Judgment
We saved the best category for dessert. While well stop short of calling these boneheaded pilot moves, these 14 accidents reflect serious breaches of what wed consider sound PIC judgment.

Some are particularly egregious. The pilot who took off uphill from a short runway in an overloaded airplane. Three dead. The one who carried ice into a thunderstorm when he had 21 hours time in type. One dead.

Then there was the pilot who hadnt flown the airplane in five months, yet didnt sump the tanks. On takeoff, the engine failed due to water in the tanks. The airplane crashed when the pilot attempted to turn back to the runway from 400 feet agl. Five dead.

Into this category we lump the uphill takeoff into the trees, several VFR forays into IMC, descents on instruments to below minimum altitude, tailwind landings and controlled flight into terrain.

Judgment accidents are somewhat immune from airplane choice. Its reasonable to assume that most of them would have been just as likely if the pilot had been flying a Cessna P-210 or a turbocharged Bonanza instead of a Malibu.

Paradoxically, judgment accidents often involve experienced pilots who wrongly count on their experience or superior pilot skills to get them out of jams. Of all general aviation accidents, judgment errors are the toughest to battle.

Add up the numbers and heres what you get: Poor stick-and-rudder skills and lousy judgment calls accounted for 60 percent of Malibu accidents during the five-year period we studied. While that may seem damning, you have to put it in perspective.

First off, judgment is easy to criticize in the harsh morning light but somewhat more difficult to assess in the heat of battle. And recall that Malibu pilots as a whole tend to be better prepared than most pilots in both the stick-and-rudder and judgment departments by dint of their greater experience and insurance-mandated recurrent training.

Just how the Malibus accident record meshes with the known problems with engine reliability is difficult to reconcile. Certainly the airplanes dispatch reliability suffers, as any owner will attest. Some owners report as many as half of their planned trips being affected in any given year, with some of those trips canceled. At the very least, flight planning and preflight inspections are seriously affected.

That owners defend the airplane is not surprising for a couple of reasons. First, because most copies of the airplane sell for a cool half-mil or more, denigrating the machine could come right out of the owners pockets if resale prices are depressed.

Second, the Malibu fills a sparsely populated niche. Competing models include the Cessna P210, with fewer than 600 registered, and the Extra 400, with only seven registered in the United States. To get similar performance and comfort, you have to step into a medium twin, with the concomitant financial burden involved with buying and supporting two engines and all of their accessories.

Finally, anyone who invests the time and effort necessary to buy an airplane will necessarily defend their decision as having been the right one for them. However, ask them if the airplane is safe and youll likely get some kind of confirmation that, while the airplane has its share of problems, its ultimately the pilot who determines if any given flight is safe or not.


Also With This Article
Click here to view “Structure Was OK, Training Was Not.”
Click here to view “By the Numbers.”

LEAVE A REPLY

Please enter your comment!
Please enter your name here