The Planes of Fame Northrop N9M crashed shortly after takeoff from the Chino, California, airport on Monday, killing the pilot. This N9M, the last remaining flying-wing, third-scale prototype used to develop the B-35, was being flown in preparation for the upcoming Chino Air Show. Local authorities have confirmed that the sole occupant of the aircraft was killed. Photos on social media depict the crash site adjacent to a state prison in Norco; the N9M appears to have suffered a comprehensive post-crash fire.

Update: The pilot has been identified as David Vopat, 51, of Chino. ATP-rated Vopat was a volunteer at the Planes of Fame Museum. The museum says the N9M was being prepared to fly in the upcoming Chino Air Show, and has published a tribute to Vopat on its website.

This particular N9M was restored by the Planes of Fame Museum starting in 1981, and completed its test flying in 1996. It was one of four third-scale prototypes built by Northrop in the 1940s to test design concepts that would eventually yield the B-35 flying-wing bomber. The B-2 Spirit bomber also traces its lineage to the N9M. Powered by two 300-HP Franklin eight-cylinder engines buried in the wing, the N9M had twin pusher props and advanced flying-wing features like leading-edge slots.

According to the Planes of Fame website, “The primary mission of the N9Ms was to provide flight test information from which the maneuverability, controllability and performance of the XB-35 could be predicted. It was flown at Muroc Army Airfield (later Edwards Air Force Base) by well-known pilots including Robert Cardenas, Russ Schleeh, John Myers, and Bob Hoover.”

Reuters is reporting that Boeing is telling airlines that “it is targeting U.S. Federal Aviation Administration approval of its software fix as early as the third week of May and the ungrounding of the aircraft around mid-July.” Boeing said it made the final test flights of revised software last week and is expected to submit it to the FAA soon.

As previously reported, the changes will center on the authority of the MCAS (Maneuvering Characteristics Augmentation System) to move the horizontal stabilizer and the number of times the system, which is supposed to prevent the 737 from stalling at high angles of attack and power, will activate. Boeing will also tie the system to both left and right angle-of-attack (AOA) vanes; previously, the system relied on the input of just one AOA sensor.

Whenever the new software arrives, the FAA will doubtlessly take great care vetting the solution. And yet this will not be the final steps for Boeing, as it still has to revise and have approved training materials for the 737 MAX’s MCAS. Then it, along with the FAA, needs to convince foreign aviation authorities to lift their flight restrictions, though this is not likely to be a certain thing based on the positions taken publicly by China and the European Aviation Safety Agency. This is in addition to the multinational review committei looking into how the software was initially approved.

The continued grounding impacts Boeing and air travelers alike. Previously, United Airlines said it would cancel all 737 MAX flights through July, while American has canceled flights through Aug. 5. The aircraft has been grounded globally since March 10. Boeing's stock closed Tuesday at $374 per share, down from $440 a share on March 1.

As if Boeing’s pasting in the public eye over the 737 MAX wasn’t enough, reports are surfacing that the company could be cutting corners at its Charleston, South Carolina, plant that builds the 787 Dreamliner. According to an exhaustive report in The New York Times, Boeing management has been accused by former and current employees at the plant of overlooking manufacturing issues to speed production and drive efficiencies.

The Times reviewed “hundreds of pages of internal emails, corporate documents and federal records, as well as [conducted] interviews with more than a dozen current and former employees” that “reveals a culture that often valued production speed over quality.” Over the weekend, Brad Zaback, general manager of the 787 program, said that the report “paints a skewed and inaccurate picture of the program and of our team (at the plant).”

Where the 737 MAX debacle has led to speculation that Boeing pushed ahead quickly with a substantial redesign of its evergreen jet, in lieu of creating an entirely new aircraft to battle Airbus, the revelations by employees in Charleston suggest a company trying to reduce production times and cost. According to the report, line workers have found evidence of “foreign objects” left from the manufacturing and assembly processes. “Tools and metal shavings have routinely been left inside jets, often near electrical systems. Aircraft have taken test flights with debris in an engine and a tail, risking failure,” the Times said. Dreamliners have taken off on test flights with loose hardware in the engines, and acceptance pilots for major airlines have reported finding their own examples of FOD (foreign object debris) on board new aircraft.

It’s worth noting that the 787, aside from the grounding after battery fires early in its service history, has not had an accident. More than 800 Dreamliners have been delivered while Boeing is reporting a current order book of nearly 700 aircraft to be built.

For the second year in a row, FlightSafety International has been named one of Forbes' “best mid-sized employers.” It is one of 500 companies with more than 1000 employees to be named, and just one of eight in the aerospace and defense industry to receive this accolade.

“We are pleased and honored that FlightSafety has been named by Forbes as one of America’s best mid-size employers again this year,” said co-CEOs David Davenport and Ray Johns. “This is directly attributable to our focus on teammates and our culture of quality and customer service. We are committed to provide a positive work environment and family atmosphere that recognizes and rewards achievements, offers opportunities for advancement, and encourages open communication.”

The Forbes survey asks employees if they would recommend their company to friends and family. FlightSafety also said that “when respondents were asked to recommend and evaluate other organizations in their industry, FlightSafety was more positively evaluated than 80% of all companies on the list.”

Topping the Forbes list for 2019 is TripAdvisor, which has 1646 employees. El Segundo, California-based R&D firm The Aerospace Corporation, with 4000 employees, was the top-ranking mid-sized company in the aerospace and defense category. FlightSafety was number 461 on the overall list.

Cirrus recently announced the second generation of its SF50 VisionJet. In this video shot at Aero in Friedrichshafen, Germany, Adam Hahn gave AVweb a tour of the new cabin improvements.

Bob Barrows, who designed the Bearhawk line of experimental aircraft, suffered a landing accident on approach to Holly Ridge/Topsail Island Airport (N21) on Monday. According to reports, Barrows clipped power lines on approach and the Bearhawk LSA impacted the turf runway in a strongly nose-down attitude.

Photos of the aftermath show the airplane crumbled right to the firewall. According to Bearhawk’s Mark Goldberg in a forum posting on Tuesday morning, “Bob has a broken leg and broken foot, and was in surgery last night. And is bruised up. I heard the extent of his injuries late last night after surgery but no updates yet today.”

Holly Ridge airport, 28 statute miles northeast of Wilmington, North Carolina, has a single 3600-foot-long turf strip that’s bordered on both ends by power lines. The weather was good at the time of the accident, with light winds at the nearest reporting station.

Goldberg also posted that “some of the BH community nearby are offering to go get his LSA and take it home. One lesson learned is that the steel tube structure Bob designs in his planes—is a really good thing. An aluminum airplane would not have protected Bob as well.”

The Bearhawk LSA is a two-seat tandem taildragger with a Continental C-85 engine. Cruise speed is listed as 115-125 MPH with a landing speed of 30 MPH.

Almost from the beginning of our flight training, pilots are drilled on simulated engine failures in every phase of flight. Once we’re introduced to dealing with engine failures, we practice and perfect them, and then revisit them to ensure proficiency. This training is necessary because, although generally reliable, small airplane engines do still fail, especially if they are piston engines. Good inspection and maintenance practices plus proper operation help minimize or eliminate the risk. However, the likelihood (probability) of an engine failure and even its severity (consequences) can be managed ahead of time so that a failure might be less likely and, if one does happen, you might be in a better position to land without injury and maybe without damage.

So...What’s The Risk?

Before taking steps to minimize the risk of engine failures, we probably should try to quantify it. Thanks to the way U.S. aviation mishaps are cataloged, it’s safe to say that engine failures happen more often than the data reflect. The sidebar below about the Aircraft Owners and Pilots Association Air Safety Institute Nall Report goes into greater detail, but it’s safe to say engine failures that don’t result in substantial damage, serious injury or death aren’t part of the data. In fact, the NTSB’s definitions specifically exclude “[e]ngine failure or damage limited to an engine if only one engine fails or is damaged....” The punchline is that official data underestimate the actual and unknown engine-failure rate. Personal experience bears this out.

So, we can presume the actual engine-failure rate—and our risk— is greater than demonstrated. That’s the bad news. The good news is we also can presume that some number of engine-failure events didn’t result in substantial damage, serious injury or death. If we’re going to have to deal with an engine failure, what can we do to wind up in the “uninjured, no-damage” category? A lot, it turns out.

Basic Strategy

First, pay heed to what you learned in primary training and should be practicing regularly. An actual engine failure may be unlikely, but it is still possible. Staying proficient with emergency procedures and forced landing techniques is still vital. However, as when dealing with any hazard, a more comprehensive approach to managing engine-failure risk could lead to better outcomes.

Our basic strategy to managing the risk of engine failure starts with our familiar risk management matrix, reproduced at the top of the following page. Once a risk is identified—engine failure in this case—we must analyze it in terms of its likelihood (probability) and its severity (consequences). This will allow us to see the total risk and then point the way to mitigating actions. The objective is to mitigate unacceptably high risks down to lower risk by reducing risk likelihood and/or severity.

What’s an unacceptably high risk? Any high risk (red) must be mitigated to lower either the likelihood or the severity of the risk to produce a lower overall risk level. What if the risk is “merely” at the serious (yellow) level? Good practice and professional standards dictate that this risk also be mitigated. If you look at any airline or corporate flight department, you will find that risk management is ingrained in both aircraft certification standards and operating procedures such that most risks end up being mitigated to the low (white) level. You should always be striving to reduce risk, but as a general aviation pilot you have discretion to accept some risks that our commercial cousins always mitigate.

Managing Risk Likelihood

Let’s start by analyzing how we can manage risk likelihood for engine failures. An engine failure in a single-engine piston aircraft, while unlikely, is still possible, so the likelihood is firmly in the “remote” line. An engine failure in a turbine-engine single, on the other hand is highly unlikely to occur, hence “improbable.”

Does this mean that you can’t control risk likelihood in your piston single? No. Obviously, you can move the severity needle anywhere within the “remote” bucket so that you are closer to the “improbable” category than you are to the “occasional” level.

Most of us can’t afford the jump to turbine equipment, so what are some actions you can take to reduce engine failure risk likelihood? The following list is heavy on maintenance actions with some operational actions added.

Frequent oil changes. Make sure that the oil filter is inspected for metal and other contaminants and take an oil sample for lab analysis.

Top end inspection. Compression and borescope inspections should be done at least at every other oil change.

Frequent engine inspection. Depending on your level of activity, you might want to conduct detailed engine inspections, using the 100hour engine checklist for your make and model, more often than at the annual or 100-hour inspection. For example, I fly my Mooney about 160 hours per year. I do oil changes at 40-hour intervals and a 100-hour engine inspection at 80 hours. This event includes compression and borescope inspections. I am now also doing these at the 40-hour interval as the engine approaches its time between overhaul (TBO).

Engine monitoring. Think seriously about having one in your aircraft and using it to evaluate the health of your cylinders and valve train.

Other engine instruments. Even rudimentary engine instruments can be used to detect changes and trends. Is your oil pressure lower than normal and your oil temperature higher? Time to ground the aircraft and investigate.

Managing Risk Severity

Is there really a way to manage the level of risk severity? Of course. Your primary objective is to prevent fatalities and injuries, with saving the airplane as a secondary objective. In other words, use mitigations that avoid a catastrophic outcome and aims for “negligible” consequences. Here are some key mitigations that could save your life and maybe even the aircraft.

Be proficient. Prevention may be your first line of defense, but this could be your last line of defense. Practice simulated engine failures and know your emergency procedures cold, especially techniques such as best gliding speed.

Maintain situational awareness. Spotting an incipient engine failure in the early stages can allow you to execute a precautionary landing or better position yourself if the engine quits before you’re on the ground.

Install shoulder harnesses. Most aircraft now have them, but if yours doesn’t, install them. Airbags are also available for retrofit on some aircraft.

Fly higher. Altitude buys you time and distance if the engine dies. I typically operate my Mooney between 9,500 to 12,500 feet. From two miles up and a 13:1 glide ratio, I have a 25-mile radius to find an airport or suitable landing spot.

Airframe parachute. This may sound like an ad for Cirrus, but 82 of them have deployed their CAPS chutes within the system’s limits and all the occupants have lived to regale their friends with the story.

Avoid/limit certain profiles. Concerned about operating at night, in IMC, or over or around inhospitable terrain, wilderness, urban areas and water? You should at least factor these into your risk management planning, as described in the next section.

Hazardous Profiles

Transportation utility is certainly why I own an airplane, but we should consider what hazards and risks we face from potential engine failures in certain extreme and not-so-extreme settings. Below are a few settings that I consider during my preflight planning and in-flight risk management. Your assessments of these settings may vary from mine, and that is part of your prerogative, if you do so consciously.

Night. Night operations have historically been more hazardous than daylight flights. From an engine failure perspective, the likelihood doesn’t change, but the ability to mitigate risk severity is compromised because of restrictions on seeing potential landing sites. My own mitigation is that I will not initiate a night flight in a single-engine piston, except under the most benign conditions (good visibility, full moon, favorable terrain). I will continue a flight into darkness if conditions are favorable, but will fly high to increase the chance of reaching an airport if the engine fails.

Low IFR/IMC. In a piston single, I will initiate a flight into low IFR if the IMC is localized. I will also continue a flight into low IFR if it only exists around the destination or in scattered areas along the route. I won’t initiate a flight where the flight path is totally within a low-IFR system.

Inhospitable terrain. When flying over poor terrain, I will try to fly as high as practical, such that my “rocky footprint” is eliminated or minimized. That is, I would be able to glide to an airport or suitable landing area in the event of an engine failure.

Water. Most single-engine aircraft can be ditched in a manner that will usually not injure the occupants. The risk comes from being able to escape the aircraft and then surviving in a water environment until rescued. I have made three trips to the Bahamas carrying only life jackets, but I would no longer do such a trip in a single piston unless I had a raft, signaling gear and other survival equipment.

Wilderness. Even if over terrain where a forced landing or ditching could be made without injury, these operations demand full survival gear and training on how to use it. The main problem is not being near any rescue options. In two trips to Alaska (one in a Mooney and the other in a Bonanza), I’ve followed all three common routes: the Alaska Highway, the Trench and the coastal route. I had full survival gear and knew how to use it. On any future trip, however, I will stick to the Alaska Highway route when operating a piston single.

Urban environments. Many large city cores are almost exclusively hostile to a successful forced landing (ask Sully for confirmation). Many pilots are based in dense urban areas where the airport itself is surrounded by houses and other buildings and obstacles. I’m not based in an urban environment, but when flying to such locations, I try to do a little additional risk management planning. For example, is there a different airport that I could use with a longer runway?

In nearly 10,000 hours of flying, I have never had an engine failure. Hopefully, that will continue and your experience will be the same, but it’s always better to be prepared.

Two Kinds Of Engine Failures

You will be way ahead of the risk management game if you can avoid all the pilot-induced reasons that engines stop. These include fuel exhaustion and fuel starvation, carburetor icing and other causes where the risk can be mitigated through better preflight planning, checklist use and other procedures. We also can talk about regular inspection and maintenance, and proper operation. From experience, if the engine’s healthy, keeping it that way isn’t much of a problem. Get to know your engine monitor—you do have one, right?—and learn to manage your engine. For some additional details, see the article beginning on page 12.

Once we eliminate the easy stuff, we’re down to actual mechanical failure of some powerplant component. In these cases, the extent of powerplant failure depends on which component fails. For example, catastrophic failure is the usual outcome for piston-engine crankshaft, connecting rod and oil pump failures. Fortunately, such failures are extremely rare. On the other hand, failures of pushrods, magnetos, pistons and rings are more likely—but still low—and may only cause a power reduction.

The Aircraft Owners and Pilots Association (AOPA) Air Safety Institute (ASI) recently published its latest annual Nall Report, analyzing fatal and non-fatal general aviation accidents. The 2018 Nall Report looks at NTSB data beginning with 2006 through 2015. It breaks down accident causes into three major categories: pilot-related, mechanical and other or unknown (top right). The data shown are for 2015 alone.

In 2015, mechanical reasons were ascribed to 15.7 percent of non-commercial fixed-wing accidents, earning them a distant second behind the pilot-related category. Of them, 82 (54 percent) involved the powerplant. Only nine (11 percent) of the powerplant failures during 2015 were fatal, meaning we basically have a one-in-ten chance to survive an accident resulting from an engine failure. As this article’s main text explains, however, some unknown number of engine failures do not result in a reportable accident.

Risk Assessment Matrix

Likelihood

Probable: An event will occur several times.

Occasional: An event will probably occur sometime.

Remote: An event is unlikely to occur but is possible.

Improbable: An event is highly unlikely to occur.

For ease of analysis, the risk assessment matrix has only four “buckets” of likelihood or severity. In reality, an event’s outcome occupies a continuum of infinite levels of both likelihood and severity.

Severity

Catastrophic: Results in fatalities or total airframe loss.

Critical: Severe injury or major damage.

Marginal: Minor injury or minor damage.

Negligible: Less than minor injury and less than minor system damage.

What’s Your Approach To Managing The Risk Of Engine Failure?

All pilots have different tolerance for risk and are permitted to exercise discretion when operating under Part 91. Nevertheless, there are certain ground rules we should always follow to mitigate potential engine failures.

• Always conduct risk management for all flights. In complex situations, use a flight risk assessment tool (FRAT) to identify, assess and mitigate risk.
• If any identified risk is assessed as high (red) and cannot be mitigated, don’t launch until it can be mitigated.
• If any identified risk is assessed as serious (yellow), then make every effort to mitigate it to lower levels. If you cannot mitigate a yellow risk and still decide to launch, remember that you must consciously accept the elevated risk on behalf of yourself, your passengers and possibly those on the ground.
• Even medium (green) or low (white) risks should be mitigated where possible.

Robert Wright is a former FAA executive and president of Wright Aviation Solutions LLC. He is also a 9800-hour ATP with four jet type ratings, and he holds a Flight Instructor Certificate. His opinions in this article do not necessarily represent those of clients or other organizations that he represents.

This article originally appeared in the November 2018 issue of Aviation Safety magazine.

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AVweb’s General Aviation Accident Bulletin is taken from the pages of our sister publication, Aviation Safety magazine. All the reports listed here are preliminary and include only initial factual findings about crashes. You can learn more about the final probable cause on the NTSB’s website at www.ntsb.gov. Final reports appear about a year after the accident, although some take longer. Find out more about Aviation Safety at www.aviationsafetymagazine.com.

January 13, 2019, Adrian, Mich.

Piper PA-32R-300 Lance

At 1746 Eastern time, the airplane was substantially damaged when it landed short of the runway after its engine failed. The airplane impacted a fence and terrain; the solo private pilot received minor injuries. Visual conditions prevailed.

Post-accident examination of the Lycoming IO-540-K1G5D engine revealed a crankshaft gear bolt, p/n 13S19649, was fractured. The engine logbook stated an AN8-14 bolt had been installed. The illustrated parts catalog and a mandatory service bulletin specified an AN8-14A bolt.

January 13, 2019, Port Hadlock, Wash.

Beechcraft B35 Bonanza

The airplane collided with trees at about 1400 Pacific time following a loss of engine power. The solo commercial pilot received minor injuries; the airplane was substantially damaged. Visual conditions prevailed.

The pilot reported that shortly after takeoff the cockpit door opened, and that while turning onto left downwind to return to the runway, the engine lost power. The pilot subsequently initiated an off-airport forced landing, during which the airplane struck a stand of trees.

January 15, 2019, Salt Lake City, Utah

Piper PA-28-140 Cherokee 140

At about 1050 Mountain time, the airplane landed hard on a road following a partial loss of engine power during a go-around. The solo commercial pilot was not injured. The airplane sustained substantial damage to its landing gear and right wing. Visual conditions prevailed.

While on final approach, the airplane was high, so the pilot initiated a forward slip to lose altitude. He reduced the throttle but instead of decreasing, engine rpm increased. The pilot opted to initiate a go-around to troubleshoot the problem, retracted the flaps and added full throttle control. The engine would only develop about 1500 rpm, however, which was not sufficient to maintain altitude. The airplane continued beyond the runway and subsequently landed on the road.

January 17, 2019, Ellensburg, Wash.

Piper PA-23-250 Aztec

The airplane impacted terrain at about 1645 Pacific time. The solo commercial pilot was fatally injured and the airplane was destroyed. Visual conditions prevailed.

A witness about 2300 feet from the accident site reported observing the airplane about 200—300 feet above the ground, “diving down sideways.” Another witness reported seeing the airplane at about 300 feet AGL and heard the engines “gunning.” He observed the air plane impact the ground at about a 45-degree angle, right-wing low.

January 18, 2019, Beechwood, Wis.

Piper PA-24-250 Comanche 250

At about 1520 Central time, the airplane was substantially damaged during a forced landing after a partial loss of engine power. The solo private pilot sustained minor injuries. Visual conditions prevailed.

The pilot was cruising at 3000 feet MSL when he noticed the carburetor temperature gauge moving through the yellow arc (cooling) toward the red arc (getting colder). About the same time, the engine began to lose power and rpm was dropping. The pilot performed remedial actions and, after applying carburetor heat, engine roughness worsened. With only partial power, the pilot selected a field for a gear-up forced landing.

January 19, 2019, Keshena, Wis.

Stinson 108 Voyager

The airplane impacted trees and a road at about 1130 Central time during a forced landing. The pilot and one passenger sustained serious injuries and two passengers sustained minor injuries. The airplane sustained substantial damage. Visual conditions prevailed.

While in cruise, the engine experienced a momentary and substantial loss of rpm. The pilot enrichened the mixture, activated the carburetor heat and switched fuel tanks. The engine recovered and the pilot left the carburetor heat on for about three minutes, then slowly turned it off. About two minutes after the carburetor heat was turned off, the engine ceased producing power. The pilot reported that once the engine stopped, it did not “windmill” and the starter would not engage. An asphalt road with trees on both sides was chosen for a forced landing. During the landing, the airplane impacted the trees and bounced on the road, coming to rest upside down on a snow-covered embankment.

January 21, 2019, Kidron, Ohio

Douglas DC-3C

At about 0912 Eastern time, the airplane was substantially damaged during a takeoff attempt. The captain and first officer were fatally injured and the airplane sustained substantial damage. Visual conditions prevailed for the positioning flight.

A witness observed the airplane lift off about a third of the way down the runway. Soon after it became airborne, white smoke was seen coming out of the left engine. The airplane began to veer to the left and did not climb normally. The witness watched the airplane descend over a building until he lost sight of it. The airplane struck power lines and trees before impacting the ground and came to rest about 200 yards beyond the runway’s departure end.

This article originally appeared in the April 2019 issue of Aviation Safety magazine.

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