I began this post in November 2015. The NTSB report has since been released. Accident Report. It turns out the copilot was flying and apparently stalled the airplane.
Day before yesterday two pilots killed themselves and their seven passengers when they flew their airplane into the ground while trying to land at an airport in Ohio. I know the airport; I’ve been there a few times during my flying career. It’s one of those old airports that was originally a city airport but has since been replaced by a much larger airport a few miles away that was built primarily to attract the airlines. Such airports now are used by “general aviation,” a catch-all term that the aviation industry and the FAA use to describe all civilian aviation that doesn’t involve scheduled commercial operations. Because they’re not intended to handle large transports, the runways at general aviation airports are usually only a few thousand feet long and the instrument approaches are often “non-precision,” meaning they are something other than the Instrument Landing System found at large airports and which provide both directional and glide path information to the pilots.
The general public – and some aviation professionals who came from military backgrounds and have never been a part of general aviation – are under the false impression that airline airplanes are better equipped than the “small” jets and turboprop airplanes used by corporations and non-scheduled commercial operators. In fact, the opposite is often true and, furthermore, the equipment installed on corporate jets is identical to that used on airline airplanes. Not only that, all airplanes with a maximum gross takeoff weight of 12,500 pounds or more are built to the same standard, a standard that guarantees that the airplane can lose an engine on takeoff and continue the takeoff and fly. Pilots of such airplanes have to be type-rated by the FAA to fly them and they have to be able to demonstrate that they can lose an engine during the takeoff roll and continue the takeoff if the airplane has reached the published “decision speed” for the gross weight and atmospheric conditions existing at the time of takeoff. In short, “large” airplanes, meaning any airplane certified under CFR Part 25, are designed so that they will fly after the loss of an engine; they are designed to be safe – and they are. Accidents in the United States involving Part 25 airplanes are infrequent almost to the point of being rare. When one is involved in an accident, the question is always “why”.
Although it’s commonly believed that if an airplane loses power it will fall out of the sky, in reality even if all power is lost and the proper airspeed is maintained, they’ll glide. The higher they are, the further they’ll glide. Depending on the glide ratio and altitude, an airplane may glide for close to 100 miles. Part 25 airplanes are required to continue flying after the loss of an engine, regardless of whether they have two, three or four engines. (Naturally, the loss of the engine on a single-engine airplane means it’s going to come down. In short, engine loss on a Part 25 airplane is not going to cause an accident as long as the pilot flies the airplane in the manner in which it was designed to be flown.
By far, the majority of aircraft accidents are what is known as “controlled flight into terrain”, or CFIT for short. Furthermore, such accidents are always caused by some kind of pilot or crew error. The error can be an improperly tuned navigational aid but in many cases it’s due to the pilot’s failure to observe proper actions, particularly published instrument approach procedures. Instrument approach procedures are either precision or non-precision, with the difference being whether or not there is an electronic glideslope as part of the approach. ILS approaches use two transmitters, one to transmit a signal to line the airplane up with the runway and another to provide a glide path. ILS approaches normally take the airplane to 200 feet above the runway but with the proper equipment and crew training, some may take the airplane to 100 feet and some are certified to take the airplane all the way to the runway. Non-precision approaches do not have glide path information. Consequently, instead of having a “decision height” at which the pilot decides either to land or miss the approach, they take the airplane down to a “minimum descent altitude” or MDA. MDAs are established to keep the airplane clear of terrain and obstacles.
The “why” in aircraft accidents is why did the crew do what they did that resulted in the accident. Why, for instance, did they continue their descent below the published MDA and fly into the ground? At this point, the NTSB has issued a preliminary report http://www.ntsb.gov/investigations/AccidentReports/Pages/cen16fa036_preliminary.aspx which does not speculate on a probable cause. However, it does state that a single-engine Piper Warrior on an instrument training flight shot the approach and landed just before the Hawker crew started the approach. As they exited the runway, they radioed that they had broke out “right at minimums” which means they came out of the clouds right at the published minimum descent altitude or MDA. This leads me to believe that instead of flying a normal descent path, the Hawker crew rushed their descent to the MDA in an attempt to get below the clouds so they could see the airport. A normal descent is predicated on a descent rate of approximately 500′ per minute, which will put the airplane at the MDA at a point where the pilots should be able to see the runway and land safely. Since the airplane impacted the ground some two miles short of the runway, the crew obviously went below the MDA although why they did has yet to be determined. It is likely it was a deliberate act.
Sadly, many accidents involving flight into terrain are the result of deliberate actions on the part of the crew. Others are due to improperly set avionics, meaning the crew had one navigational aid set in their navigational equipment when they intended to use another aid. Since the approach the crew was flying at Akron is a localizer approach, one would think they were using the proper frequency but it is possible that they were set on a VOR frequency. Since the measured visibility at the time of the crash was 1 3/4 miles and the airplane impacted 1.8 miles short of the runway, it is unlikely that the crew had the runway in sight. Normal procedure on a non-precision approach is to descend to the MDA then maintain that altitude while remaining on the approach until the airplane is in a position to land or until the missed approach point is reached, at which point the pilot initiates a missed approach. Don’t be surprised if the accident report reveals that the pilots descended too rapidly in an attempt to get below the clouds and simply flew into the ground.