Aircraft Accidents - Page 5 Aviation Articles

Beechjet Landing Gear-Falling Into Place

Specific Repairs for Proper Beechjet Landing Gear Operation

Brian McKenzie-Elliott Aviation Accessory Shop Manager

Image of Repaired Bushing

A Beechjet is a unique airframe as it does not have a pneumatic blow down for landing gear. It primarily relies on airspeed and gravity. When the landing gear and trunnion have been maintained and repaired properly, this is never an issue. However, if the trunnion bearings are not aligned properly a slow wear eventually causes it to bind requiring repair to the trunnion bearing journals of the main landing gear.

Last year we had an AOG situation with a customer located in Caracas, Venezuela, that required this repair. The customer ran an approach to Miami and did not have all three landing gear down and locked. They cycled the landing gear a couple of times with no luck. They declared an emergency and proceeded to land anyway. As they taxied to the FBO, the line service technician noticed the left side main landing gear was not locked. They brought the aircraft in for swing tests and discovered that the left side landing gear was not swinging freely, in fact, it would fall only 7/8ths of the way down and not lock.

The aircraft was ferried back to its home base to trouble shoot the landing gear. They found that the landing gear would not pass the free fall test and removed the affected landing gear from the aircraft. During inspection of the trunnion, they found the forward trunnion bearing was seized and needed to be replaced. In this particular instance, there was an initial repair of the trunnion bearing journals where the bore was not reamed correctly and an oversized bearing was installed. This caused a misalignment, which ultimately caused the bearing to seize and the landing gear to not fall freely.

In this instance, the customer was very lucky. In these situations, the landing gear can collapse on landing or turns. In order to provide on our core values of Unmatched Quality, Uncompromising Integrity and Unbeatable Customer Service, I traveled to Venezuela amid political turmoil just days after Hugo Chavez’s death to make the repair. The aircraft was returned to service in less than five days and I returned two days before the Venezuelan Presidential election.

Another instance where this repair applies is when the factory bearing bore is enlarged due to repeated landings. If the bearings do not have an interference fit, this repair must be done in order to prevent further damage to the airframe.

At Elliott Aviation, we have seen this issue occur at least a half a dozen times in Beechjets. Properly repairing this requires pinpoint accuracy of lining up the bearing bore to the opposite side and our specialized tooling is centered between both pieces. In fact, we have developed a special tooling system that includes a series of reamers, specialized bushings and NDT capabilities to ensure the repair is handled correctly.

Brian McKenzie started with Elliott Aviation in 2007 as a Quality Control Inspector and led the development of Elliott Aviation’s Accessory Shop in 2011. He received his A&P in 2004, IA in 2009 and ASNT NDT Level III in 2010. Brian started his career in the US Navy where he was part of the fixed wing and rotor wing maintenance and aircrew. He has maintained airframes and components on a diverse number of aircraft including Beechcraft products, Gulfstreams, Citations, Falcons and helicopters. Brian has also worked for Aero Air, Evergreen International, Flightcraft and Jet Services Inc.

Elliott Aviation is a second-generation, family-owned business aviation company offering a complete menu of high quality products and services including aircraft sales, avionics service & installations, aircraft maintenance, accessory repair & overhaul, paint and interior, charter and aircraft management. Serving the business aviation industry nationally and internationally, they have facilities in Moline, IL, Des Moines, IA, and Minneapolis, MN. The company is a member of the Pinnacle Air Network, National Business Aviation Association (NBAA), National Air Transportation Association (NATA), and National Aircraft Resale Association (NARA).

Why You Could Land at the Wrong Airport, Too: Confirmation Bias in Pilots

Photo © Scott Scheiffer/Twitter

As humans, we tend to see what we want to see and believe what we want to believe. It's a psychological impediment known as confirmation bias, and it leads us to subconsciously seek information that affirms our beliefs and neglect information that might disprove the decisions we've already made.

We're all guilty of it, whether we know it or not. In fact, you're probably reading this right now with a hint of confirmation bias, seeking out the words and sentences on the page that confirm the thoughts or opinions you may already have.

It might sound like a lot of psychological babble, but it's a huge problem for pilots. Pilots trust in automation even when it's wrong because time after time, it works perfectly. Pilots land at the wrong airport even when the visual cues are there to tell them they're in the wrong place because they believe they're in the right place and look for indications that support that belief.

On two different occasions recently, aircraft have mistakenly landed at the wrong airport. Additionally, many aircraft accidents and incidents can be partially attributed to confirmation bias. Here are a few examples:

  • In 1989, a Boeing 737 operated by British Midland Airways crashed after encountering engine problems Both pilots incorrectly identified the engine that was malfunctioning and shut down the incorrect engine. When the perfectly good engine was shut down, the vibration lessened, confirming the pilot's belief that they chose the correct engine to shut down. The pilots then chose to ignore various other indications regarding the affected engine, like the engine instrument system (EIS). Confirmation bias was studied as a result of this accident.

  • In 2006, a CRJ-100 operating as Comair Flight 5191 crashed during takeoff from the wrong runway at Bluegrass Airport in Kentucky. Though there were many contributing factors in this accident, confirmation bias was listed in the NTSB findings.
  • In November 2013, a Boeing 747 Dreamlifter landed at Jabara airport, a small uncontrolled field in Wichita, instead of their intended destination, McConnell Air Force Base.

  • In January 2014, a Southwest Airlines crew landed at the wrong airport with a Boeing 737 full of passengers. The runway length at M. Graham Clark Downtown Airport, where the 737 landed, is just over 3,700 feet and the Boeing 737 stopped with just a few hundred feet to spare.

    The investigations for these incidents of airplanes landing at the wrong airport are incomplete, and I'm no investigator, but it's very possible that confirmation bias played a role in both of these incidents, causing the pilots to see and believe that they were on approach for the right airport while ignoring important visual cues such as runway lights, heading and instrument indications, which could have given them a reality check.

Preventing Confirmation Bias:
It's easy to fall into the confirmation bias trap, and general aviation pilots are not immune. In fact, confirmation bias is especially dangerous for GA pilots, who often fly by themselves. And we don't know when we're doing it, so it's a difficult problem to fix.

The FAA recommends that pilots make a conscious, unbiased effort to make decisions and remain cognizant of how reality might differ from our perception. A second person in the cockpit can help with this since two minds are better than one, but the accidents and incidents mentioned above tell us that confirmation bias can affect us, even with two or three people in the cockpit.

Another method for avoiding confirmation bias involves constantly looking for reasons to disprove your beliefs or decisions. If you see more reasons faulting the decision than supporting it, it's time to reevaluate.

While there is no absolute solution for confirmation bias, being aware of it is a step in the right direction. Knowing it exists might just help you evaluate - or think twice about - your decision making process.

Unforecast Icing Conditions: How Would You React?

Unforecast Icing Conditions
Photo © UCAR

Winter usually means great flying weather, but the cold weather also brings its own set of challenges: Snowy runways, cold preflights and dangerous icing conditions. For general aviation pilots, one of the biggest risks of flying in cold weather is the possibility of structural icing.

According to AOPA, aircraft structural icing was the cause of more than 150 accidents over a recent period of 10 years. Icing can be present, even when it's not forecasted. As pilots, it's important to know about weather patterns and what to do should icing begin to develop on your aircraft in flight.

I read an accident case study recently that I think serves as a good reminder to stay alert for icing conditions, even if icing is not in the forecast. You can view the details of this particular accident case study, in which a pilot of a Cirrus SR22 en route from Reno/Tahoe International Airport (RNO) to Oakland, California encountered inadvertent structural icing conditions and crashed into mountainous terrain, here.

By all accounts, the pilot performed his preflight preparation responsibilities normally. According to AOPA's accident analysis, he spent time reviewing the weather, including a full weather briefing, which stated that there were no AIRMETs or SIGMETs or precipitation in the area. The Cirrus SR22 was even quipped with an icing protection system, although it was not approved for flight into known icing. So what went wrong?

The NTSB's probable cause report states that the cause of accident was the pilot's loss of control due to an inadvertent icing encounter. Interestingly, the report also cited an inaccurate weather report from the NWS Aviation Weather Center as a contributing factor.

While there was a low probability for icing conditions according to the NWS, there were a few red flags that may have changed the outcome for this Cirrus pilot if he took notice and reacted. For example, the weather briefer indicated a low freezing level of 6,000 feet and approaching precipitation, although it was dry at the time. Additionally, as the Cirrus departed, an incoming Southwest Airlines 737 reported unforecasted moderate rime icing at 17,000 feet. The weather report also stated cloud tops were between 17,000 and 20,000 feet - well above the service ceiling of the Cirrus. This should have alerted the pilot that climbing above the clouds wasn't an option.

This accident is testimony that as pilots, the more we know about weather and icing conditions, the safer we'll be. While forecasts are helpful, the lack of forecasted icing conditions doesn't always mean that we're in the clear. Below are a few reminders and tips for winter flying.

  • Know your aircraft systems: There's a difference between de-icing and anti-ice equipment, and there's a reason that many aircraft with anti-ice systems are still not approved for flight into known icing conditions. Research and learn about your aircraft's specific systems and how it will react in icing conditions.

  • Know your weather: There are a few items to pay close attention to in the weather briefing, such as cloud tops, freezing levels, and of course AIRMETs, SIGMETs and PIREPs. But a good review of weather theory is helpful in determining the effects of incoming weather systems and fronts, as well as certain areas like over mountains or near water, where icing is common.

  • Know when and where icing occurs: Icing usually forms when the aircraft surface (NOT the outside air temperature) is below freezing AND where there is visible moisture. Icing can also occur inside of a "wet" cloud - a cloud with super-cooled liquid water droplets in it.

  • Know what to do when you encounter icing: You have three options if you encounter icing in your aircraft: Climb, descend or turn around. Which one of these you choose will depend on the cloud height, temperatures and your location and terrain. (FYI: Contrary to what many people are told, climbing is not always the best option, as the case study above demonstrates!) If there's even a small chance that you'll encounter icing conditions on your flight, it's best to fully prepare beforehand with multiple exit strategies. Know the cloud tops, the temperatures and the locations of alternate airports. And always communicate to ATC immediately if you find yourself in an icing situation. The pilot in the case above failed to notify ATC when he experienced icing. Instead, he spent 10 minutes trying to trouble shoot on his own. Perhaps the controllers could've helped route him into a warmer, cloudless area had they known more about his situation.


For more tips and tricks about how to prevent icing and what to do if you encounter it, check out AOPA Safety Advisor: Aircraft Icing.


Aircraft Accident Prevention: Getting Uncomfortable

Photo © Phil Ostroff/Flickr

As pilots, we do a number of things to prepare for a safe flight: Pre-flights, checklists, flight planning and a proper weather review. But are we too comfortable with our safety measures?

For those of us in the aviation industry, safety is the number one priority. It's instilled in us (hopefully) from the first time we step foot into the airplane. I don't know of a single pilot who would categorize himself as anything but safe, but even pilots with the utmost regard for operational safety can find themselves in an emergency situation without recognizing it.

There's an old theory that a person is better off flying with a brand new pilot than one with thousands of hours. There is both absurdity and truthfulness in this single statement. With experience comes knowledge and of course, the right knowledge can keep us from danger. But that same knowledge also brings a certain level of ease into our every-day flying habits, and this comfort can lead to a casual disregard for safety.

Instead of simply following the safety protocols we find in checklists and ops manuals, we need to be on the lookout for an accident-worthy chain of events. We need to change our mindset from "I follow the rules, so that means I'm safe" to "what decisions do I face that present a risk?" Pilots need to remain uncomfortable.

The moment we get comfortable is the moment we begin to ignore the warning signs of an impending emergency.

Aircraft emergencies aren't usually the result of a single wrong decision. Instead, accidents tend to occur after a series of ill-fated events, so it's important that we weigh the risk and value of each and every decision we make - even the small ones. If the decision doesn't bring us toward a safer flying environment, is it leading us toward risk? How far will we allow ourselves to venture from accuracy and perfection in flight? Are we comfortable with a certain decision because it's a habit or because we thoroughly weighed the risk? How many red flags do we come across before we change our course?

Take Air Florida Flight 90, for example. Flight 90 crashed into the Potomac River during takeoff as a result of icing conditions, but the investigation provided insight into a long chain of events that occurred before the accident: corporate culture problems, departure delays, taking off with icing, failure to use anti-ice, failure to reject takeoff, failure of the first officer to speak up and limited crew member experience, to name a few. Had one of the pilots interrupted that chain of events somewhere, the accident may have been prevented.

We won't fly perfectly every flight. But if we keep ourselves from getting too comfortable in our flying operations, we can work to remove as many unsafe decisions as possible in an effort to prevent the downward spiral of events that could lead to an accident.

Remember, removing a single link from a chain of unfortunate events can prevent an accident.

Why Did The FAA Send Me A Request For Re-Examination?

As you may know, if the FAA discovers evidence that leads it to reasonably question an airman’s qualifications to exercise the privileges of the airman’s certificate, the FAA may issue a "request for re-examination." The "evidence" is usually a situation or circumstances involving the airman and his or her operation of an aircraft. And, unfortunately for airmen, it doesn't take much for the FAA to have a reasonable basis for requesting the re-examination. As long as the FAA can show that an airman's lack of competence or qualification was a factor in causing the situation, then the request will be considered reasonable.

So, what types of situations may result in a request for re-examination? Here are a few, in no particular order:

  1. Running out of fuel.

  2. Landing with the gear up.

  3. Landing or taking off in a manner that results in damage to your aircraft (e.g. prop strike, tail strike, scraping a wingtip on the ground, striking runway lights etc.).

  4. Continuing a VFR flight into IMC.

  5. Getting caught on top of an overcast layer of clouds when you are not instrument rated or equipped.

  6. Taking off or landing on a runway at a tower controlled airport when you have not received take-off or landing clearance.

  7. Taking off from or landing on a taxiway.
  8. Getting into an accident with your aircraft.

  9. Getting caught operating your aircraft over gross.

  10. Landing at the wrong airport.

  11. Entering Class B, C or D airspace without first establishing communications with ATC controlling the airspace.

  12. Colliding with another aircraft in flight, or on the ground.

  13. Operating an aircraft on a flight without appropriate or current charts necessary for that flight.

This is only a partial list of some of the more obvious situations that may trigger a request for re-examination of an airman by the FAA. The list can, and does, go on.

Hopefully this will never happen to you. But if it does, it isn't the end of the world. Pilots survive, and even learn from, requests for re-examination all the time. For more information and tips on responding to requests for re-examination, please read my article: The 709 Ride.

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