A friend’s recent tangle with a vehicle brought home to him the realization that bad things don’t always happen only to other people. Bad things and bad situations sometimes land foursquare at our feet with no consideration for our schedules- our demands or our stations in life.Back to Articles
A friendâs recent tangle with a vehicle brought home to him the realization that bad things donât always happen only to other people. Bad things and bad situations sometimes land foursquare at our feet with no consideration for our schedules- our demands or our stations in life.
When maladies happen weâve really no choice but to cope as best we can and work toward the best outcome possible. If itâs a health issue- our best preparation may be no more complicated than having good health insurance. If itâs a mechanical problem with the home or vehicle- our best-laid plan may be little more than the right phone number for ringing up the appropriate technician to fix the issue.
When itâs a problem in a hollow tube- miles above the Earth and hurdling through the sky at 10 miles a minute- well- weâd better be prepared to take care of ourselves. What we do and how we handle such a crisis can make the difference between an ultimate safe arrival back on Terra Firma â with a great Hangar Flying story to tell â and becoming the subject of a news story about the unhappy ending we suffered.
Turbine engine makers can accurately boast hundreds of thousands of hours between unplanned shutdowns â nonetheless- it stands to reason to realize that once every few hundred thousand hours- a turbine engine will - uncharacteristically - need to be shut down or fail somehow in-flight.
Avionics today employ highly reliable components and displays capable of working for thousands of hours without malfunctioning. Sadly- the hardware systems â largely robotically built â and the supporting software all originate from human minds and human hands. And so it is that in the most-human of traits- once in a while something in them will fail somehow.
With this in mind- letâs look at five situations that can contribute to accident stats- as well as a quick primer on avoidance and mitigation techniques.
Relax. Todayâs modern aircraft fairly bristle with back-up or redundant systems â equipment and procedures that exist primarily because a failure once happened without a fallback position- and in the aftermath- enterprise or regulation created an alternative.
THE RAREST OF ACCIDENTS?
The chances are great that youâll get through an entire career of flying without exposure to any of the scenarios covered in this story. General aviationâs long-time reputation for being safer relative to the risk from driving to the airport particularly resonates for business aviation.
Overall- turbine-level business aviation enjoys a strong safety record- with corporate and owner-flown operations both better than the overall average for the group. Owner-flown operations had a fatality rate under 0.4 per 100-000 flight hours in recent years- with a rate of about one accident per 100-000 hours. Within the corporate-operated community of business turbine aircraft- the fatal rate comes in considerably better â under 0.1 per 100-000 hours; the total rate being about 0.3.
Overall- business turbine aviation has a per-100-000-hours rate of about 0.5 for fatal accidents- 1.5 overall. Better than general aviation overall- not as good as the airlines â and overall low enough to render as a rarity any particular pilot or passenger becoming one of those stats. Recent years have shown that the business aviation community continues to improve. In 2009- business turbine aircraft accidents fell about 33 percent according to Robert E. Breiling Associates in Florida â to 43 from 64 in 2008. That drop far exceeds the drop in flight activity gauged in 2009 â about 20 percent â meaning lower exposure and better flying helped the yearâs safety record considerably. Yet still- things do happenâ¦
FUEL SYSTEM PROBLEMS
At the lower-end of general aviation fuel supply accidents stand among the most common of causes behind accidents and incidents; in business aviation- mismanaging fuel and fuel-contamination problems are both less prevalent â but still play an occasional role in the altered outcome of a flight.
Among the causes of fuel management-related problems are Flight Plan changes â whether due to changes in weather or a diversion for other reasons beyond the aircraft crewâs control. A runway closed by an accident or incident would be an example of that. From first hand experience- be advised that few scenarios create more cockpit tension than finding that airport youâve struggled through weather to reach became unavailable just a few minutes before you planned to land there.
Hardware failures in the fuel system play a role in other fuel-starvation or supply-restriction events. Learning that insufficient pressure or flow volume means restricting power â or worse â is not a moment of high joy. So whatâs a body to do? No pilot wants to arrive at the start of an approach with fuel enough for only one shot; but it happens â not often- but often enough.
The existence of conservative fuel-reserve guidelines like those of the National Business Aviation Association came about precisely because of the wild-card influence of changes like those just mentioned. And with the sophistication of todayâs modern business turbine flight deck- the lack of fuel is more often than not one of a series of errors â avoidable when those tools are heeded.
So are there solutions for those instances where the sufficiency of fuel is in doubt? If you know youâre going to be short- try to make the shortage as minimal as possible:
â¢ Lower power settings typically save fuel â but not hugely.
â¢ Flying to an alternative destination at a lower speed may increase the time needed to arrive in the pattern with margins still uncomfortably low â but this counter-intuitive solution does mean arriving with more available fuel still in the tanksâ¦ fuel to power other options. â¢ Ask ATC to keep you higher to keep fuel consumption lower.
â¢ Confess and communicate â donât just commiserate with the people in the plane with you.
â¢ Tell the controller youâre in a fuel-criticality crisis. (That controller may be able to help with a different altitude- a much-needed direct-to clearance and a traffic-free lane to the approach).
Instances of mechanical failure mean first falling back on any instructions in the pilot operating handbook (POH) to deal with failureâ¦ maybe cycling a breaker- maybe manually activating a boost pump- maybe a change in how fuel is fed. A mechanical failure may impose constraints on engine power â and those constraints may prevent further problems.
Any pilot type-rated and receiving worthwhile recurrent training in a business turbine aircraft should be able to start the appropriate emergency procedures even as the Second-in-Command or non-flying pilot finds the appropriate page of the POH.
HYDRAULIC SYSTEM FAILURE
A loss of hydraulic-system function presents less of a problem for some systems than it used to. The increasing use of gear systems that allow the trucks to free-fall into place means the system needs no fluid to push down and lock the wheels â only to raise them.
But depending on the aircraft- the lack of a functioning hydraulic system can leave you with no way to force down the landing gear- and hydraulic-system problems can pose a problem for other systems â brakes- flaps- steering control- possibly even flight-control system operation- depending on the aircraft.
Whatâs your course of action? For the crew- thereâs that POH to reference first and communication with ATC; in the meantime- the goal is to determine the potential for reversing the failure while looking at available airports for diverting.
The electrical breaker position should get checked and- maybe- cycled off and back on before pump function is again checked. If the aircraft has a hydraulic accumulator- be sure to check its pressure- and any valve-alignment issues involved in using its reserve pressure.
Determining what remains in the way of flight-control or lift-control device control is critical â and then make the arrival choice appropriate to the situation. For example- if the hydraulic-system failure impacts brakes or flaps- alternative runway calculations are in order. Thereâs no sense aiming for a field that just works with normal brake and flap functions â not when you canât land as slowly or stop as quickly.
How quickly you make the field should be an issue only when thereâs a question about the integrity of other systems. And remember: be stingy about using any action available only once for whatever reason â such as non-renewable accumulator pressure or the lack of fluid reserves.
ELECTRICAL SYSTEM FAILURE
The inventory of equipment dependent on the continuous flow of electrons through the miles of wires in business aircraft runs fairly long these days. On the flight deck- where most of the rest of the plane is controlled- youâll find scores of breakers and switches â graphic testimony to the power-hungry nature of modern cockpits incorporating navigation and communication radios; ATC-surveillance gear; flight-management systems; autopilots; electronic flight and navigation displays; and lighting- both interior and exterior.
In the out-of-sight parts of the aircraft lurk others: pumps that pressurize hydraulic systems- maybe even elements of the flight-control architecture or ground-steering system depend in part on that steady supply of electrons- along with motors that aid in trimming the aircraft- flushing the toilet or moving around fresh air. So- itâs not indulging in hyperbole to say a loss of electrical power equals an in-flight crisis.
Fortunately- most modern aircraft employ at least one standard form of back-up electricity: battery power- available to keep the panel alive â for a while- at best- and part of it- at least. The steps to survive are fairly straightforward- fortunately- and they begin before a crisis: knowing (a) the failure points of the electrical system- (b) the loads of major components- (c) the battery capacity and (d) a sense of how to shed- or reduce- electrical demand to preserve battery power for as long as possible.
A quick scan of any critical systems at risk of malfunction should battery power end is also advisable. For example- if parts of the landing gear- flaps or trim system depend primarily on electricity to function properly- a generating-source failure could warrant extending gear and flaps as soon as airspeed allows â even when many miles and many minutes earlier than normal.
Thereâs no point in arriving at the normal gear-down point in an approach and finding that a landing-gear malfunction â caused by a drained battery â has compounded the already worrisome crisis of a generating-system failure.
Reducing electrical load â from two radios to one (for example)- and shedding all the lights- even in favor of flashlights at night â can help you keep alive enough panel power to execute even a taxing ILS approach through the clag. The passengers in the back will- of course- need to be advised of the end of their phone- internet or television feeds and of the need to power off lights- galley gear- etc.
Many of todayâs newer avionics systems offer - or arrive - with their own stand-by power systems- usually with an integral battery of an installed auxiliary battery to power critical avionics and instruments. Some aircraft sport their own back-up power solutions â maybe a wind-driven turbine- maybe a back-up alternator or battery-and-bus combination.
Nonetheless- these systems typically carry limits on their ability to power components â limits that still require pilot action. IN NO CASE should the existence of stand-by electrical power be considered a reason to continue a mission far beyond a first-alternative point in the flight plan.
PRESSURIZATION SYSTEM PROBLEMS
Remember that earlier line about the âhollow tube- miles above the Earth and hurtling through the sky at 10 miles a minute?â For the occupants of that tube to survive requires aircraft pressurization â or some other pressure source. And as these systems function- a running engine generally guarantees a supply of air which pressurizes the tube for our breathing comfort â as well as for our survival.
A variety of issues can render the pressurization system inoperable- however- and when that happens- need we say we have a problem? A potentially insidious one at that? Intercooler inlets may ice over and threaten the radiator with overheating â which can lead to a breach of the pressure system. A regulator valve may fail. A supply line may breach. Regardless of the cause- any and all of these can literally leave passengers and crew gasping for air â sometimes so quickly that only correct action almost instantly can assure survival...of the crew.
The inability to keep the fuselage pressurized means all the humans will need both supplemental oxygen and a trip to below 15-000 msl as quickly as it can be safely achieved.
A rapid- near-instant loss of cabin pressure above FL180 can inflict rapid loss of consciousness; above FL300- unconsciousness can occur in scant seconds; above FL400- the lapse can occur so quickly that passengers and crew may not even get their masks on before loss of consciousness. Go higher and the window shrinks even more and succumbing can occur almost instantly.
For these reasons- the remaining flight crew must wear a pressure mask during any absence of a second crew member â and is why single pilot jet operations carry altitude limits on the solo pilot. Alarms and instrument readings should give flight crew ample warning of a slow loss of pressureâ¦but a malfunctioning alarm could undercut that safety system. Hence- modern pressurized aircraft sport stand-by oxygen for the flight crew- and for most turbine aircraft- all passenger seats.
For passengers- any pressurization loss scenario means extinguishing all smoking gear â cigars- cigarettes or pipes (yes- some operators do still allow smoking)- and putting on the available supplemental system- as well as following any other instructions from the crew.
Perhaps the least-complicated to deal with of all the available in-flight crises is engine failure- as it means one thing right off the bat: the airplane is coming down! Even a multiengine aircraft canât keep flying on one- and getting down ASAP is the rule. The interim issues are âWhy did it fail?â- âCan that failure be reversed on the way down?â and âWhat needs to happen before the clock and altimeter run out on us?â
Two engines dominate the business turbine landscape- though single-engine turboprops have gained ground in the last decade â and single-engine fanjets are in the pipeline. For the multiengine crew- loss of one engine is a very rare event â one which leaves the crew with that second engine for maneuvering to the closest available runway.
A loss of both is a statistical rarity of lottery-winning long-shot odds â but it has happened. Lose one of two and the options and flexibility grow considerably. While the crew busies itself with an emergency declaration â and an engine loss- whether all or one of many- is an emergency- no question â the passengers should be busy preparing for the inevitable touchdown. That means stowing any and all loose items as quickly as possible- belting in tightly- and preparing to assume the brace-for-impact position.
Meanwhile- the crew will work the problem trying to relight the fire- checking fuel-system integrity- pump function- and more. Fortunately- a business jet without power will definitely fly â it just wonât fly indefinitely. Keeping speed at the appropriate pitch â depending on whether the crew is trying to maximize mileage or time aloft â can usually be left to the autopilot or FMS; keeping the aircraft clean of gear and flaps until the last possible moment can help assure an arrival.
Flying final approach as slowly and gently as possible is critical to lessening the impact of an off-field touchdown â and that touchdown may be best achieved with the gear still stowed.
Interestingly- the injury and fatality record for single-engine aircraft actually exceeds that for multi-engine aircraft overall â but the numbers improve when only multiengine turbine aircraft are examined; better- but not equal.
BRACE FOR IMPACT
Regardless of the emergency- passengers must heed the instructions and guidance of their flight crew. Any off-field or forced landing will likely prompt the crew to order passengers to assume a crash position and to brace for impact. The crash position is straightforward: pillows to cushion head from knees; arms crossed- on knees- head on pillows. Knowing how to use oxygen masks- familiarizing yourself with available exits- the location of fire extinguishers and first-aid kits â these are all part of your job as a passenger.
âBeing busyâ or âIâm just a passengerâ are poor excuses for failing to take part in assuring your own welfare in a crisis. Yes- the crew is responsible for passengers â but first- the crew is responsible for ensuring the safe arrival of the aircraft- the best insurance for the safety of the occupants.
For example- if the incident involves fire or visible flames in the cabin- donât wait on the flight crew! Step up and into the role of firefighter with the on-board extinguisher â as youâre screaming for help. While rare- all of the above incidents do occur- and you should know how best to react should one of them occur on a flight you are making.
Just as the best safety system on the airplane is a well-trained flight crew- one of the best safety enhancements to that crew is a well-informed- well-prepared passenger!