7.2.1 Maintaining preparedness Flight planning When planning a cross-country flight some essential actions are required to minimise both the possibility of power loss and the consequences of such: Construct a safe route. Calculate the fuel needs. If using a GPS in flight planning be aware the GPS does not take into account the type of terrain or the height of terrain — the GPS indicated route might be over 'tiger country' (e.g. heavily wooded) or straight through a mountain. Warning: the GPS 'GO TO' function is an emergency use feature only — it should not be used as a substitute for proper route planning. Prior to take-off I suggest you review the groundschool module 'Take-off considerations' before continuing with this section. Check the stopping distance required. The pilot should know the distance required to reach flight speed and then bring the aircraft to a halt. It may be necessary to abandon the take-off shortly after lift-off, due to power failure or just doubtful engine performance or other event — this is particularly important in short field or 'hot and high' take-offs. If take-off and landing distance (over a 50 foot screen) charts are available then the total distance needed to take off, abort at 50 foot, land and bring the aircraft to a halt is just the sum of the charted density altitude take-off and landing distances required. If the distance available is insufficient to take off, reach 50 feet, land and safely bring the aircraft to a halt at the departure, destination and en route airfields, then maybe the planned flight is really not a good idea. Before taxiing ensure all extraneous objects in the aircraft are secured adequately so that they cannot foul the control lines or rudder pedals or become missiles in the event of an emergency landing. In addition you must ensure there is no possibility of anything becoming loose and wrapping around the tailplane, or passing through the propeller disc of a pusher-engined aircraft. Always check the fuel tanks for water, don't change tanks just before take-off, and taxi out and take off on the fullest tank. Always do an engine run-up before take-off which, as well as the usual engine checks, is of sufficient duration to ensure fuel is flowing properly throughout the system. Always plan to gain greatest altitude possible before reaching the airfield boundary, so take off into wind; don't do an intersection take-off; use all the distance available — runway behind you at the start of take-off is an asset stupidly thrown away. If the area outside the airfield boundary is rough, plan to climb out at Vx rather than Vy, and maintain full power until a good height and cruise speed is reached. The extra height gained with distance flown may be very handy if the engine fails. Whether operating from a familiar or unfamiliar airfield, you must have some knowledge of the terrain surrounding the airfield and the position, slope and condition of likely forced landing sites plus associated hazards. If the airfield is unfamiliar then you must ascertain escape routes, potential forced landing sites and hazards during the initial overflight or by ground inspection. After completing your take-off engine and cockpit checks, have a good look at the take-off path and rehearse your emergency procedure for any situation that may occur before you are established at a safe height. 7.2.2 Engine failure after take-off or a go-around Pilots should always be prepared for the possibility that the engine will lose partial or total power during the take-off and climb-out; or, for that matter, at any other time during flight. But, if there is even a suspicion something is not quite right during the initial ground run, the take-off should be abandoned immediately and the aircraft returned to the hangar area for a ground check. It is most unwise to continue the take-off if the engine falters and then picks up, or even if you are just not fully confident about its behaviour. When total or near-total power loss occurs after lift-off the cardinal rule is to 'fly the aeroplane!'; i.e. maintain control of the aircraft. This initially implies quickly getting the aircraft into the right glide attitude and waiting until the speed rebuilds to the appropriate glide speed, then fine trimming. (When changing from climb to glide attitude, the nose has to be pushed down through quite a few degrees, which might feel excessive — particularly if the aircraft was not trimmed to the climb speed.) In circumstances like this, some say the second and third edicts should also be 'fly the aeroplane!' and 'fly the aeroplane!'. During the climb-out the aircraft is at a high aoa, producing very high induced drag — particularly so if climbing at Vx — and when the engine fails, speed decays very quickly, and even more so if the aircraft has a high parasitic drag. The pilot may take three to four seconds to react and move the control column forward, and the aircraft will then take a few seconds to rebuild a safe speed. During these periods the aircraft will be sinking, and if height and airspeed are insufficient the pilot is locked into an immediate and probably very heavy 'landing'. More turn-back information can be read in 'The turn back: possible or impossible — or just unwise?'; also read Mike Valentine's article 'The turn-back following engine failure'. On-field landing If the aircraft is very low when the engine fails the only option is to keep the wings level and land more or less straight ahead — which is no problem if the airfield area ahead is clear. There is little time to do anything but fly the aircraft and close the throttle and also switch off the ignition and electrics. Airspeed is likely to be very low so keep the nose down and the wings level during the descent, using gentle control movements if necessary to change direction slightly. Lower full flap but be prepared for the associated attitude change. You must avoid the possibility of a wingtip striking an airfield marker, fence post or other obstruction — or getting caught in long grass — and causing the aircraft to 'cartwheel'; also the possibility of wheelbarrowing is high. You must also avoid tripping over the boundary fence while airborne, so just get it down (not nosewheel first) and use whatever reasonable means is available to decelerate. Long grass will help slow the aircraft but if necessary, groundloop it to avoid major or expensive obstructions, like a row of parked aircraft. The groundloop is induced by booting in full rudder (and brake) on the side to which you want to swing and will probably result in some wing tip, undercarriage and propeller damage, unless you impact something other than the ground. Off-field landing If some height has been gained but there is no possibility of landing on the airfield then an off-field landing is mandatory. Look for somewhere to put it down but don't immediately fix on the first likely landing site spotted straight ahead of you; there may be a more suitable site off to the side. You have to rapidly assess your height, airspeed (i.e. your energy level) and the turn possibilities available at that height; i.e. can you safely turn through 30° or 45° perhaps even 60° using moderate bank angles and still make it to that much better looking site? Will the wind assist or hinder? It has to be a quick decision because at best you have just a few seconds available to plan the approach. If any doubt, go for 'into wind'. Do not choose the site at marginal distance, even if it's perfect. Close by is better because the height in hand can be used for manoeuvring the aircraft into the best approach position. Because you have no power available you must always have an adequate height margin to allow for your misjudgements, adverse wind shifts, sinking air, vertical gusts and other unforeseen events — and you can dump excess height quickly by sideslipping. Remember that the rate of sink whilst sideslipping is high and the slip must be arrested before the flare. Apart from being clearly within range the choice of landing site is affected by: wind strength and direction ground run availability and direction; a short into-wind site may be preferable to a longer but crosswind/downwind site for an aircraft with a slow stall speed; the reverse applies for an aircraft with a high stall speed. It all relates to kinetic energy and stopping distance approach obstructions; final approach may require some diversion around/over trees, under/over power-lines plus avoidance of other obstructions. Can the near-ground turns be handled safely? Is there sufficient margin for misjudgement and/or wind gusts? ground surface and obstructions, including livestock, during the ground roll. Can you steer to avoid them? Are livestock or kangaroos likely to take fright and run into your path? the energy absorbing properties of the vegetation ground slope: the possibilities of landing downslope may range from difficult to impossible; moderate upslope is good if the pre-touchdown flare is well judged. There is a much greater change in the flight path during the flare; for example, if the upslope has a one in six gradient (about 15°) and the aircraft's glide slope is 10° then the flight path has to be altered by 25° so that the aircraft is flying parallel to the upslope surface before final touchdown. A higher approach speed is needed because the increased wing loading during the flare (a turn in the vertical plane) increases stall speed. If the wind is upslope then a crosswind landing may be feasible if a rural road is chosen can you avoid traffic, wires and poles, particularly in a crosswind situation? a final approach into a low sun should be avoided so that vision is not obscured. All of this is impossible to assess in the few seconds available, hence the need for prior knowledge of the airfield environs and a pre-established emergency procedure for any situation that may occur before you are established at a safe height. As height increases, the options increase for turning towards and reaching more suitable landing areas, making a short distress call and doing some quick trouble shooting. Trouble-shooting When trouble-shooting full or partial power loss remember the first edict — constantly 'fly the aeroplane!'. If the engine is running very roughly or died quietly (i.e. without obviously discordant sounds associated with mechanical failure) and time is available, then apart from the engine gauges, the obvious things to check or do are: Fuel supply: switch tanks (making sure you haven't inadvertently switched to the 'fuel off' position), fuel booster pump on, check engine primer closed. Air supply/mixture: throttle position and friction nut, throttle linkage connection and mixture control position. Apply and maintain carburettor heat (while engine is still warm), setting the throttle opening at the normal starting position. Apply carburettor heat or select alternate air to bypass the air intake filter — which could be blocked by grass seeds or a bird strike. Ignition: position of ignition switches — and try alternating switches in case one magneto is operating out of synchronisation. Or: reverse the last thing you did before the engine packed up. And then: try a restart. There is no point in continuing with a forced landing if the engine is really okay. Cockpit check prior to touchdown Pilot and passenger harnesses must be tight and maybe remove eyeglasses. Seats should be slid back and re-locked in place (if that is possible without adding to the risk) but be aware of the cg movement. Advise the passenger of intentions, warn to brace for impact and advise evacuation actions after coming to a halt. Unlatch the doors so that they will not jam shut on impact. If the aircraft has a canopy or hatch take similar safety action, if that is possible without the canopy affecting controllability or detaching and damaging the empennage. If equipped with a retractable undercarriage, leave the wheels down unless surface conditions indicate otherwise. To minimise fire risk turn the ignition, fuel and electrics off. Handling the approach Once the landing site is decided then choose the ground path for the landing run and select an initial aiming point up to halfway along it. (Once it is clear that the aircraft will reach or overshoot that safety point, then a second point located between the aircraft and that initial aiming point will become the touchdown target with the application of flaps/sideslip.) Continue tracking down the approach path, whilst correcting for any crosswind component, and watching the position and apparent movement of the aiming point relative to the windscreen. Avoid premature use of flaps — although partial flap does help low-speed manoeuvrability and reduces stall speed at the expense of a steeper descent path. At each stage of the approach the aircraft should be re-trimmed to maintain the desired airspeed — and keep it balanced. Watch the top of the highest obstacle along the approach path. If the vertical distance in the windscreen between the top of the obstacle and the aiming point is widening you should clear the obstacle, if it is narrowing you may not. You then have to decide whether you can: (a) accept to hit that obstacle; or (b) safely turn a little onto another landing path; or (c) lower full flap and/or start a full sideslip so that touchdown is made before the obstacle and into vegetation with more suitable energy-absorbing properties. Be aware that dead trees poking above the general tree level may be very difficult to see, particularly if the sun is in an unfavourable position. If the aiming point appears to be moving down the screen you are overshooting (too high) and will touchdown past the target. Lower first-stage flap or start a gentle sideslip and check the result. If you are still overshooting and will safely clear the approach obstacles use second-stage or full flap, or full sideslip (or both if necessary) to steepen the descent path. Prepare for flare and touchdown. If the aiming point appears to be motionless in the screen, the approach slope is good and touchdown would be close to the initial aiming point. At an appropriate position lower full flap, and prepare for flare and touchdown prior to the initial aiming point. If the aiming point appears to be moving up the windscreen you are undershooting (too low) and will touchdown before the initial aiming point. This is no problem if it appears that the touchdown point will still be within the target area — just continue the approach and lower full flap prior to touchdown. If, however, it appears that touchdown will occur before the target area, then lower full flap and head towards the softest vegetation or the most unobstructed area. Whatever you do you must hold the glide attitude. Do not raise the nose until rounding out and never think you can 'stretch the glide'; although ground effect (or water effect) can stretch the float a little. Make a firm touchdown to avoid floating and after touchdown keep the control column fully back. Very severe jolting will make it difficult to hold the feet on the rudder bar but try to maintain steerability, using rudder and brakes, to avoid the worst obstacles and preserve the occupant zone. If appropriate use maximum braking — but avoid locking a wheel — it may not ride over the smaller obstructions. Be prepared to evacuate the aircraft quickly and to grab the fire extinguisher. After evacuation keep well away from the aircraft until any fire risk has abated. If you have a handheld transceiver, broadcast that you are safe or need assistance. Activate your distress beacon if considered appropriate. Partial power loss 1. If loss of thrust is accompanied by extreme vibration or massive shaking of the aircraft (probably due to a propeller blade failure) it is important to immediately shut down the engine to avoid it departing from its mountings. 2. If the engine does not fail completely but is producing sufficient power to enable level flight at a safe speed, then it may be possible to return to the airfield. Make gentle turns, maintaining height if possible without the airspeed decaying, and choose a route that provides some potential landing sites in case the engine loses further power. It's a judgement call whether you should take advantage of a possible landing site along the way because the off-field landing is almost certainly going to damage the aircraft and possibly injure the occupants. But that must be weighed against the chance of further power loss before reaching the airfield, producing a much more hazardous situation; it is usually considered best to put the aircraft down at the first reasonable site. If there is insufficient power to maintain height then you must set up an off-field landing. Read the article 'Piper Worrier' in the January–February 2003 issue of Flight Safety Australia. 3. If the engine is producing intermittent power it is probably best to use that intermittent availability to get to a position where a glide approach can be made to a reasonable off-airfield site. Intermittent power negates the ability to conduct a controlled approach and could get you into a dangerous situation. So having achieved a position where you can start the final approach then shut down the engine by switching off fuel and ignition or, at least, fully close the throttle. Fully shutting the engine down early means the engine will be cold at touchdown, which reduces fire risk. 7.2.3 En route emergency procedure While en route at an appropriate cruising altitude you must maintain the habit of continually assessing wind velocity at cruising altitude and the best general areas for possible landing sites — taking into account the wind and glide distance and not forgetting to take note of what is right below. If the engine should fail, or give concern, first head directly to that general area at Vbg; or if it is very close then use Vmd and aim to make a spiral descent over that area. Trim to the chosen speed and maintain balanced flight; slip/skid increases drag. If you are more than 2500 feet agl you will have ample time available to make choices and the following procedures may be appropriate: Do the troubleshoot checks described above and configure the aircraft for minimum drag, i.e. flaps and wheels up. Ease the nose down a little when selecting flaps up to avoid stalling the aircraft. Try to stop a windmilling propeller, but if you don't succeed with the first attempt forget it. Change to fully coarse pitch (the minimum rpm position) if the propeller is adjustable in flight. Make a distress or urgency call and, if equipped, set the transponder to squawk 7700. Pick a first choice landing zone: something large, flat and firm, with few obstructions (which allows a circling approach and a multiple choice of landing runs) would be ideal. You will have to consider many factors and combinations thereof; for example, a site that provides a long ground run but which entails a downwind landing compared with a shorter, into wind and downsloping landing path, or an obstructed approach but clear landing path compared to a clear approach but obstructed surface. If you have been caught out in heavily treed hilly country the only options may be to: (a) land in a creek bed; (b) land along a ridge top; or (c) fly along a valley line then turn to land upslope onto the tree tops. In the latter case the airspeed would need to be greater than Vbg to provide sufficient energy to execute the turn and the subsequent flare to follow the upslope without stalling. Whatever alternative is chosen is high risk, but easily avoidable by not overflying such terrain at insufficient height to glide clear. Ground obstructions — stumps, roots, rock outcrops, boulders, termite mounds, ditches, potholes, old farm machinery, fences and power-lines — may not be visible until closer, so select an alternate landing zone nearby in case the first choice proves not so good. ('Single wire earth return' power-lines are near impossible to see — particularly if it's oxidised copper.) You can probably afford to change your choice once, but not twice! If landing in an obviously ploughed field try not to land across the furrows, particularly in a nosewheel aircraft; close to a fence the furrows generally parallel the fence line. If possible, avoid surface water. Estimate your height above the site by reference to the contour lines on your WAC or VNC and the altimeter. Airborne time available is height divided by the known Vbg descent rate, but flight into sinking air will reduce this. Decide on the general approach pattern and aim to fly as near a normal glide approach as possible, starting with the base leg. Do not plan to fly a normal square circuit; rather, plan a descending spiral that keeps you equidistant from the site. Decide on a base leg positioning location and aim to be at this location at a glide approach height that would allow one minute on a nominal base leg and one minute on final; say about 800 feet agl if your Vbg sink rate is 400 fpm. Avoid a long, straight final approach — it allows too much exposure to unfavourable atmospheric conditions, particularly sinking air and turbulence. Depending on height, distance and wind velocity (remembering the friction layer effect on the vertical wind profile) decide an approach to get down to that positioning location so that the landing zone is always in sight and always within easy reach — which allows the surface, the wind and final approach paths to be rechecked. The approach path should be planned starting with the ground run and working back. The approach path can be widened if far too high — otherwise medium S turns, flaps or sideslip might be used to descend to the positioning location, but flaps should be retracted before reaching there. Flaps probably won't be used again until well established on a final approach. In some aircraft S turns are not that effective in getting rid of excess height. If you feel you are in sinking air or battling a headwind, increase airspeed to a better 'penetration' airspeed above Vbg. Start the base leg from the positioning location and adjust the track and the turn onto final to compensate for the wind, height and/or misjudgements. While flying the base leg finalise the intended ground path for the landing run and select an initial aiming point about halfway along it. You may have to plan for a dogleg during the ground roll. Then carry out the final cockpit check, approach and landing as in 'handling the approach' above. The diagram below illustrates an approach pattern allowing multiple choice of final approach and landing run. The wind is estimated to be in the north west quadrant. Path A is the planned approach and landing run from a base leg positioning location, paths B, C and D show alternate paths which either delay or bring forward the turn onto final to cater for height, wind or positioning differences. Paths E and F show the possibilities for a turn onto a landing path if it is required to do so before reaching the base leg positioning point. Mike Valentine, the late RA-Aus Operations Manager, had a few very relevant comments: The turnback part of the (Coping with Emergencies) series is particularly timely in view of the Skyfox accident last October and the Bantam accident three weeks ago, both of which involved engine failures and attempted turnbacks. It is an old problem and seems to be one that won't go away. In view of this, I hope you don't mind if I offer a comment on a particular point in post-engine-failure training. My main background is in gliding (47 years), with about 30 years GA and 7 years ultralight instructing (Drifter, Gazelle, Skyfox) to add to the mixture. In gliding, we had a persistent problem with loss of control following a winch-launch cable-break and attempted turnback, a situation which is directly analagous to the problem which is plaguing us now. Most, if not all, such accidents were fatal. As Operations Director of the Gliding Federation of Australia, I had to try to address this problem and see if we could tame it. Rather than get involved here in a detailed analysis, I will just give you the bare bones of our efforts. In researching accidents of this kind over a 30 year period (world-wide, not just Australia), a couple of common threads emerged. Firstly, in many cases there was never any need to turn back — there was ample strip ahead and all the pilot needed to do was to establish a safe speed, adjust the approach path with spoilers/airbrakes and land ahead. This is a crucial point and is often overlooked. Secondly, and of equal importance, is the fact that, although a pilot may lower the nose after an engine failure, as briefed, the same pilot may not hold that attitude for a while and allow the speed to increase and stabilise. A glider in the full climb phase of a winch-launch is generally a fair bit steeper than an ultralight in the climb attitude, but the principle is no different (nor is the outcome, when the energy runs out). We did the trials in representative types of training glider, from the 400 kg Kookaburra (33 knot stall, 20:1 L/D) to the 590 kg IS-28B2 (35 knot stall, 35:1 L/D) and the results were remarkably consistent. From a full climb attitude at 55 knots IAS, the cable release knob was pulled, simulating a wire-break. As one pilot immediately took recovery action, using strong nose-down stick movement, the other pilot started the stop-watch. From the time the 'wire-break' occurred at 55 knots to the time 55 knots once more appeared on the ASI was a consistent 6 seconds. This is the amount of time needed before a pilot can make any attempt to manoeuvre the glider. In the types of glider we are talking about, 55 knots is about 1.5 Vs and is regarded by the GFA training system as a 'safe speed near the ground'. I have found that the above figures apply equally well to a Drifter. However, with gliders we then went one stage further. We did it because we were dealing with aircraft which were fully approved for spinning. We tried simulating a winch-launch in free flight by diving to 80 or 90 knots and pulling up to an approximate winch-launch angle, then when the speed fell to 60 knots we lowered the nose and immediately applied aileron and rudder to commence a turn. The result was consistent spin departures, not necessarily immediately but certainly before reaching 180 degrees of turn. All this means that lowering the nose after an engine failure is not the complete answer. If a pilot is not taught that the lowering of the nose should be followed by DOING NOTHING, just holding the new attitude and waiting for the speed to stabilise at the new figure before deciding what to do, he/she will not be protected from loss of control. All this led to a change in training emphasis in the GFA training system. (For an expansion of the foregoing read Mike Valentine's article 'The turn-back following engine failure'.) When preparing this module I asked the late Tony Hayes — a very experienced, enthusiastic and highly respected AUF CFI — a few questions. The following was his response: "I do not actually teach engine failures in the traditional sense of yank the power and "What are you going to do now?" type of thing. That is not teaching, it is checking correct response to something already taught. That is a bit of a non-event with my students as I expect the aircraft to be continually positioned so it has an escape route, if it is not so positioned then I work on the area via fundamentals of positioning rather than alarming and depressing demonstrations of why it is wrong! So my actual 'emergency training' happens in separate areas that include circuit planning, speed management, theory and practical glide appreciation. The whole lot revolves around one single concept that I would very much like the AUF to adopt as standard (it is standard in the gliding world) and that is 'safe speed near the ground'! In the theory area (which I do quite early as part of the fundamentals of control) I use the total drag curve rather than the more abstract polar curve. The interaction between parasite and induced drag is quite clear and the most energy efficient airspeed is clearly understood. To this is then superimposed the speed loss from an abrupt power failure and the average reaction time of a pilot at normal flying arousal levels. On a Thruster this is about 7 knots. 48 + 7 = 55 knots (which is also close to the aircraft's normal conditions approach speed). This is the 'safe speed near the ground' and I insist it is present at any time we are at or below normal circuit height. This is effectively an insurance policy. The aircraft may now sustain a total power failure and will automatically start returning to maximum efficient airspeed by itself, while the pilot wakes up, and so conserves height. This also ensures that there can be no loss of control. The alternative is a probable climb on the low speed side of the drag curve with increasing sink rates and decreasing glide angles. More to the point is that diving the aircraft to get airspeed back will dump height alarmingly fast. What I need to get across is a clear concept in the student's mind that the energy level in low-inertia, high-drag machines is equally as critical as positioning. A well positioned aircraft flown at the correct airspeed can recover. If flown too slowly at the point of failure, even though the angles and distance are right, the dive to recover airspeed will put the aircraft too low and may make recovery impossible! Those speed differences are not terribly alarming in themselves — just 5 or 6 knots is all it takes; which is probably one reason GA pilots get into trouble with ultralights. Once in the undershoot situation from a botched recovery then the scene is set for an attempted 'stretch the glide' and the consequent classic stall/spin. That is also important. Actual sink rates are only really apparent near the ground and the pilot is instinctively going to start pulling back to ease sink, still with a substantial amount of turning to do, and flying too slowly in the first place. The next major step after energy management is beginning to develop is a lot of passive instruction on circuit positioning via observation rather than being involved in actual circuit planning. I do a lot of control and direction refinement at a very early stage while flying the standard circuit pattern but not have the student even aware of what a circuit actually is. Once I come to circuit planning I can then quickly establish the reasons for distance/angle relationships for the type being used and the student is already well used to looking at them. Once we arrive at the point that engine failures are normally 'taught' then instead of teaching them, per se, I teach 'glide appreciation'. This validates the circuit pattern positioning. It is fully briefed on a whiteboard and the student is then pre-warned in the air. There is NO surprise element at all! The student then (with a clear mind) soaks in all the clues and retains them. Rather than becoming a sweaty terrified mess with a clear impression there is hardly any time to do anything, I find my students really enjoy putting their skills to use and everything clicks into place. Still not really finished yet though. When teaching circuit re-joins I instill the concept that while the prime interest is how to get down at a strange airfield (and we do take students to other local airfields 10 minutes flying away) they should deliberately do one extra orbit for the express purpose of looking at the 'way out' when they leave. And that, in my book, is the real key to emergencies – total situational awareness and then controlling the situation! Fly defensively (without huge effort but as a consequence of sound training so you do it automatically). Last year one of my students on 3rd solo had a major engine failure on climb out — which was bloody tough luck but underlines that it can happen. He was correctly positioned, at the correct energy level, and recovered back onto the airfield from a cross wind landing — no problems and no further damage! Knowing your aircraft, taking the time to consider conditions and study a strange airfield, having then a pre-prepared 'what if' game plan in advance will all result in pre-made decisions that only have to be refined if something does happen. This will control over 90% of engine failure drama. STRICT COPYRIGHT JOHN BRANDON AND RECREATIONAL FLYING (.com)
