We have compiled some relevant information below. There are links to full articles and GAPs here too, and you will find more information on the CAA website.
Many occurrences result in fatalities or serious injury because pilots lose control of their aircraft after an engine partial power loss, especially in the takeoff phase of flight.
A partial power loss is where the engine is providing less power than that commanded by the pilot, but more power than idle thrust. This presents a more complex scenario to the pilot than a complete engine power loss.
With a partial power loss, there are strong influences working against you, simply because the engine is still providing some power, but this power may be unreliable. For example, in the takeoff phase, this may lead to a strong desire to return the aircraft to the runway rather than land ahead.
As occurrences of partial power loss occur three times more often than a total power loss, your pre-flight planning should consider a partial power loss event as much as a total power loss.
By considering the many factors involved in the takeoff, such as wind strength and direction, runway direction, terrain and obstacles, and landing options on and off the airfield, you will reduce the mental workload required to handle a loss of power. This can also help you with decision-making under stress or a high workload in an emergency.
Pre-flight Checks and Inspection
Ensure the engine starts easily and runs smoothly, and allow an adequate warm up time.
Conducting a thorough engine run-up is an important step. Testing fuel flow from the selected tank (fullest or takeoff tank), checking for correct operation of the carburettor heat control, and checking and comparing individual magnetos for a specified RPM drop range is vital. Engine oil temperature and pressures, fuel pressure, and other engine or systems gauge indications should be within accepted aircraft operating limitations.
Fuel starvation, exhaustion or contamination also rate highly as causes of partial power often leading to total power loss. The following checks may help prevent this happening:
- Know your aircraft fuel system and how and when to operate associated controls such as fuel caps, fuel drains, fuel primer, fuel pumps, fuel selector and mixture control among others.
- Always ensure there is sufficient fuel quantity for your flight, including reserves and diversion allowance and that you use the dipstick to visually check fuel levels.
- Understand what your dipstick is telling you.
- Have a fuel plan even when operating in the circuit.
Induction icing can occur at temperatures of -10°C to +35°C and above 50 percent humidity. Also, know your aircraft systems, especially the use of carburettor heat or alternate air for fuel-injected engines in the case of restricted induction airflow.
All single-engine aircraft pilots, just like multi-engine aircraft pilots, should ‘self-brief’ prior to each and every takeoff. It helps you keep ahead of the aircraft, and keep control.
Here is an example of a self-brief:
“Engine failure before rotation point; I will abort the takeoff, close the throttle and stop on the remaining runway. Engine failure after rotate; runway remaining, I will lower the nose, close the throttle, land in the remaining runway available. Engine failure in initial climb; I will lower the nose, close the throttle, select the best option, and execute trouble checks if time permits.”
After rotation and in the initial climb, any partial engine power loss that degrades performance to the extent that you cannot maintain height can be treated as a complete engine failure with a potentially extended glide distance.
At a reasonable height, and with power that is sufficient to maintain height, a turn back to the recently departed runway may be an option but it has a number of considerations attached. Your overriding thought should be that the engine could fail at any time.
Accidents occur when control is lost, especially when the pilot attempts to turn back to the runway at low level and low speed, or does not maintain control in the glide.
Related Vector article on partial power here.
An emergency landing is one you weren’t planning to make. You have no choice, you are landing whether you want to or not, and often somewhere that is not ideal. Half of all engine failure occurrences are as a result of non-mechanical issues that were directly influenced by the pilot.
The survival of you and your passengers is the top priority – the state of the aircraft is secondary. It is okay to sacrifice the aircraft to save yourself.
Think ahead, so you have a plan for the most common emergency situations. Think about what actions you will take in the event of an engine failure or communications failure.
Have the right mindset; an engine failure could happen at any time, so continually look for options. Say to yourself as you fly along, “if it happened now, I could go there.”
If you experience a partial engine failure, never count on the power level you currently have to make it to a landing area. Choose a spot that you could reach if the engine stopped right then.
Successfully handling an engine failure, or partial power loss, requires decisive pilot action combined with well-rehearsed forced landing cockpit drills.
Excess Speed to Height
At the first sign of engine trouble convert any excess airspeed above the best glide speed, to valuable height. Trim for best glide speed and apply the appropriate rudder to remain in balance.
Carburettor Ice and Fuel Checks
Carburettor heat or alternate air should be applied as soon as possible, but do not let this distract you from finding a landing site.
Confirm Wind Direction
Wind direction and speed can be determined from many cues: smoke, dust, tree or crop movement, wind lanes or wind shadow, cloud shadow, local knowledge, aircraft drift, weather reports.
Select a Landing Site
The area of likely landing sites must be within easy gliding distance before any other selection criteria are applied. The considerations are listed in order of importance: size, shape, slope, surface, surroundings, stock, sun, and close to communication.
Plan Your Approach
Plan your approach from the ground up.
Select an aiming point approximately one third of the way into the landing site and estimate elevation.
This should preferably be lefthand, so the pilot in command has the best view of the landing site.
1000-foot AGL area
The 1000-foot area should be at 90 degrees to the landing site threshold and about three quarters of the normal circuit distance out.
1500-foot AGL area
The 1500-foot area is at the upwind end of the landing site and helps you to position yourself correctly at the start of the downwind leg. This area can pivot out if high, or closer in over the field if you are low, but maintaining the same gliding distance from 1000 feet.
Now determine how you get to 1500 feet. Circle down if too high, curve towards or glide straight towards if you have limited height.
Assess Your Approach
Cross-check your visual height judgement with your altimeter and estimate the distance-to-run to achieve each reference point. If too high you should not orbit to lose height, it is better to make a series of S-turns.
- Engine trouble-check;
- Fly the plane;
- Emergency radio call;
- Fly the plane;
- Passenger briefing;
- Fly the plane; and
- Downwind checks.
The final actions are to carry out the ‘off checks’ and to land the aircraft using techniques that will produce the best possible result.
Judging Final Approach
Do not extend downwind or you will run the risk of undershooting the landing site.
When you are absolutely certain that you can achieve your aiming point, then you can use flap (or sideslip if permitted) to touch down earlier than your aiming point. If necessary, touchdown as close to the threshold as possible.
Assuming that you have chosen a reasonable landing site, put the aircraft on the ground intact.
Another Vector article about forced landings in difficult terrain here.
VFR Above Cloud
If you encounter a lowering cloud base while on a cross country flight, it can be tempting to climb up through a hole and fly VFR above cloud or ‘on top’, particularly if the weather at your destination is clear. This is a risky decision, however, given the changeable nature of New Zealand’s weather.
Pilots create at least three major problems for themselves by flying VFR on top. First, you compromise your ability to navigate accurately. Second, you lose situational awareness of where terrain is below you, and third, if you have an engine failure, you will be forced to descend through the cloud layer – a terrifying situation to be in.
Given the changeable nature of New Zealand’s weather, there is no guarantee a hole will exist to enable you to get below a cloud layer again if you opt to go over the top. Even if you establish that a hole exists at your destination before deciding to fly on top, by the time you get there it could very easily have closed in.
Descending through a cloud layer is not an option without appropriate equipment, training and experience. This is incredibly dangerous due to the risk of spatial disorientation, and because you will have no way of maintaining terrain clearance. Not to mention that it is also against the rules.
Civil Aviation Rules set the minimum safety standard. Aircraft on air operations are not permitted to fly VFR on top.
The rules for private operations are less prescriptive. The VFR meteorological minima in Part 91 do not preclude private flights above cloud – however good airmanship does. If you get into a situation where you cannot find a hole or have an engine failure, and descend through cloud, then you will be breaking the rules.
How to Avoid Getting Stuck on Top
Think about the weather and the suitability of your route given the conditions on the day. If you are unsure about whether you can make it through a mountain pass given the cloud base, pre-plan alternative routes before you depart. With this in mind, plan to have enough fuel on board to go the long way if necessary, without using your reserves.
Helicopter pilot Keith McKenzie is based in Taumarunui and has 36 years' flying experience.
“The best piece of advice is – don’t do it. If you do, it could be the longest flight you can remember – if you live. Holes seem to close extremely quickly and open very slowly. The weather can change so much, so quickly, that it can lead to an emergency situation almost instantly.”
In order to make the best possible decisions en route, always obtain up to date weather information from an ATS unit and other aircraft.
Gavin Wills of Glide Omarama talks about getting stuck on top of cloud on the West Coast.
What to Do if Stuck on Top
Most importantly, don’t panic. Fly the aircraft, and establish communications early with those who can help. Do some quick fuel and daylight calculations to establish how much time you have available to make a sound decision on how to proceed.
Seek help – make a MAYDAY or PAN call and squawk 7700. Talk to other aircraft in the area – they may be able to direct you to a hole.
Use any and all navigation equipment at your disposal (if you know how).
Climb to be above the Maximum Elevation Figures shown in each fifteen minute quadrangle on the Visual Navigation Charts.
Fly higher – you will be able to see further, but remember there is a trade-off between gaining height to see further, and requiring more power to maintain straight and level flight at higher altitudes.
Adjust your power to fly at best range speed.
Do not, under any circumstances, descend through cloud. The five hours of instrument time required for a fixed wing PPL (or 10 hours for a CPL) do not equip you with the skills to descend through a cloud layer, because of the dangers of spatial disorientation.
To get below a cloud layer again, find the biggest hole you can to minimise the angle of bank required to descend through it. Reduce your speed to minimise your turn radius, but caution is required due to a possible reduction in margin above the stall.
Position the aircraft at the edge of the hole and make a coordinated descent, anticipating the aircraft’s position in advance.
Descending through a hole in a cloud layer is an emergency manoeuvre. In order to successfully complete this you must be competent in handling your aircraft. If you are not trained in, or competent in, carrying out a steep gliding turn, it is essential that you pick a hole big enough to make a straight descent through – with no angle of bank required.
How does a GA aircraft with two experienced pilots on board crash? Does the plethora of expertise in the cockpit actually increase the risk? If so, what can be done to reduce the uncertainty over who is in charge? Many pilots regard flying with an aviating mate one of the most pleasurable journeys they can make.
While two-pilot data is not collected by the CAA, American research indicates that about 12 per cent of GA (General Aviation) accidents happen to aircraft with at least two experienced pilots on board.
Without data or voice recorders, it’s impossible to know exactly how that can happen. But it does.
There are plenty in GA who say it is precisely having two pilots in a GA cockpit that heightens the risk of an occurrence.
Terry Curtis, who’s been a training captain for many years, and used to supervising others of equal rank, says often those dynamics are a function of the pilots’ personalities.
“If I’m not the pilot-in-command (PIC), I don’t touch any controls, unless I’m asked to. I might make suggestions, if something concerns me, but I don’t touch anything.
The opposite can also cause problems, says CAA Aviation Safety Adviser, Carlton Campbell.
“You can have a PIC who’s intimidated by the person sitting in the right-hand seat. And the person sitting in the right-hand seat knows it.
“That can lead to difficulties if there’s a flying incident brewing. The PIC defers too quickly to the other pilot, or the other pilot is too quick to question and overrule what the PIC has chosen to do.”
Peter Hendriks, chief pilot and owner of Wanaka’s Classic Flights, says a planeload of experienced pilots can be the ‘worst case scenario’.
“No-one wants to say anything, even if they’re worried, for fear of losing face, or causing offence.”
At the root of the problem is the lack of standard operating procedures as used by airlines, to remove the ambiguity about who does what, should the plane fly into trouble. Or who does what, full stop.
The airline sector has agreed phraseology – part of its Crew Resource Management – for the first officer to use to persuade the captain to desist from their course of action.
Terry Curtis, who flew in the left hand seat for Mount Cook Airlines for 20 years, says first officers, who become uncomfortable with the decisions the captain is making, would start by saying something like, ‘I’m not entirely happy with this’ and progress through to ‘Captain, you must listen to me!’ which is the agreed-upon phrase for the captain to desist immediately from his or her course of action.
He agrees that in GA, two flying mates need to come up with a similar statement.
“‘I have control’ is pretty effective,” Terry says, laconically.
Terry has had to use it a couple of times, once when the PIC was so involved with other things, he forgot to ‘fly’ the plane.
Terry says the two pilots should be talking all the time.
“Discussing how the trip is going, and listening to one another. The PIC needs to realise that while the final decision about what to do rests with him or her, the ‘passenger pilot’ might have flown that route before, or seen similar weather.”
Peter Hendriks says there should be a clearer indication of who will do what before the GA flight begins.
“Radio, for instance, and in what circumstances the non-flying pilot’s opinion will absolutely have to be taken notice of.”
Carlton Campbell says he’s conscious of making the roles explicit because he often flies with pilots with as many flying hours as him.
“So while there may be two people who can rightfully have control, generally one will be more qualified to be PIC – perhaps more experienced on type, for instance.
“If I’m getting into a cockpit with someone equally qualified, I’ll say ‘you’re more current and more experienced in this aircraft. If there’s an emergency, I’m not going to do any taking over. I’ll sit back, and offer suggestions, but that’s all’.”
Full Vector article here.
CRM for the Single Pilot
The most common factors in general aviation accidents and incidents are poor judgement and poor decision making. Adapting CRM for the single pilot can give pilots the tools they need to apply good judgement and improve their decision making skills, as it has done in the airline sector.
The critical lesson in CRM is to use all of the resources around you. Operating single pilot may make you feel on your own, but in fact, there are plenty of resources at your disposal. The most obvious, and unfortunately most underused, is air traffic control. If you have a problem, let them know - they can’t help if they don’t know. And if they don’t know, they may end up contributing to the problem.
Keep people who need to know in the loop. Updating your passengers or other non-flying crew members during normal and abnormal operations will lead to an improved information flow. You may need that critical piece of information they have.
An important element of SOPs are checklists. As a single-pilot operation you are reliant on checklists to replace the ‘challenge and response’ element of a crew environment, so checklist discipline is critical. Just as important is the time at which you execute a particular checklist. Take some time to consider and develop some cues for when you would carry out particular checklists, and challenge yourself to use the checklist properly every time.
You must firstly take good care of yourself and secondly make sure you are fit to fly. Using the “I’M SAFE” checklist is a good idea.
While in flight, if you feel unwell, do not press on, get on the ground at the nearest suitable airfield and make use of all the available assistance.
This is the most important element of single-pilot CRM. You can only process a certain amount of information at one time, so being aware of your workload and preserving some mental capacity is important, but even more important is being well prepared.
Know your aircraft – what are the system failure indications, what are normal operating parameters, what are the emergency drills you must know off by heart? Spend time thinking about the ‘what if’ scenarios. Then, when ‘what if’ becomes ‘right now’ you have already considered what you will do.
Just as important as workload management, is maintaining excellent situational awareness. You should be constantly updating your mental picture with all the new information you receive.
Threat and Error Management
Aviation is an environment filled with threats. Threat management aims to identify the potential threats to your operation, and to manage them so they do not impact negatively on your flight. Some threats can be anticipated, others will happen without warning.
Take some time before the flight to consider the particular threats you may face on today’s flight.
Pilots make errors. We may never be able to eliminate errors completely from the aviation system – it is, after all, run by people, but we must be able to admit those errors, manage them, and above all learn from them.
There are only a few situations in which you have to act immediately, and your actions in those cases should be second nature, but in all cases fly the aircraft. Otherwise take time, while making sure you fly the aircraft, to make a proper diagnosis, take the appropriate actions, while flying the aircraft, and then at an appropriate time evaluate the information you received and the actions you took, to make sure your decisions were correct.
Operating as a single pilot means you do not have the benefit of feedback from another crew member – therefore, you need to continually self-reflect and learn from your own experiences.
Full Vector article here.