Flying Training

Lesson 27: Practice Forced Landings

Sunday 4 June 2006, 3.00pm with Kerry Scott in Citabria VH-WKM

Weather: Broken cloud at 3500 feet. 12 knot wind from the south on takeoff. Cloud cleared and wind dropped during the flight.

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Forced landings are a rare event in general aviation these days, but they do happen, so this is a pretty important lesson. I prepared by reading Kerry's briefing notes, and the relevant chapters in the Flying Training Manual and Emergency Maneuver [sic] Training, and learning the checklists off by heart (CFMOST to attempt to restart the engine and WOSSSSSET to check a likely field for suitability). I turned up early (around 2pm) to give me time to check my student file to see what the expectations were for this lesson (on the right) and the next.

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The lesson was booked for 2.30pm but the first half hour was taken up with filling up WKM following its previous flight (to 110 litres, which Tim thought a little generous), and then Kerry managed to fit in a preflight briefing while eating a late lunch. She seemed happy with my preparation and knowledge of the procedures following an engine failure, so now it was time to go and try it in practice.

WKM is the oldest Citabria in the Curtis fleet, and the one with the most instruments. It has some oddities. I spent ages looking for the Hobbs meter (which measures student hours) before finding it on the right hand side of the cockpit forward of the door. The nose fuel drain is inaccessible from the outside, and in fact I still have to find out where it is. Instead of wingtip strobes it has a rotating red anti-collision beacon which looks as though it was lifted from a 727.

Anyway, we started up and taxiied for the run-up area for runway 24 while I battled with getting the ATIS from the extremely unfamiliar ADF. The rationale for this is that you can listen to the ATIS using the ADF, while still having your VHF radio (COM1) tuned to the tower frequency. It's done by flicking a switch at the top of the control panel, and then tuning the ADF (to 281kHz for Camden) in a completely different location underneath. I think I need to spend some time sitting in this aircraft on the ground without a clock running to learn all its foibles.

Since we had a quartering tailwind on taxiing, I held the stick a little away from the wind, and the elevator neutral (remember "Climb into the wind; dive away from the wind"), and turned the aircraft into the wind in the run-up bay rather than facing the taxiway. Checks done, I taxiied to the runway 24 threshold, waited for an aircraft ahead of me to enter the runway and made my call to the tower. After a Tiger Moth landed we were ready to line up and take off.

The crosswind blew me across the runway somewhat, and after takeoff I dipped a wing into the wind to attempt to keep straight on the centreline. Roll on the lesson on crosswind takeoffs and landings, because I need the practice!

Kerry had briefed me on the various height limits in the control zone and the training area. Basically we were going to depart to the north, so as we passed Oran Park we were free to climb to 3500 feet. In some corners of the training area the lower limit is 2500 feet, and to the west it's 4500 feet (so good for aerobatics).

As we left the Camden Control Zone Kerry had me tune the radio to the Sydney Radar frequency - 124.55MHz.

We cruised up to the northern limit of the training area (basically the water pipeline from Warragamba Dam to Prospect Reservoir) and Kerry ran me through the various stages of the engine failure procedure. In order of importance (and following Emergency Maneuver Training) these can be summarised as Speed, Spot, Set-up. As the speed drops, progressively raise the nose to preserve height, trimming as you go so you end up trimmed for a 60 kt glide, and look around for a suitable landing area.

Once trimmed in a glide at 60 knots, follow the engine restart procedure, which is CFMOST:

  1. Carby heat HOT
  2. Fuel ON, and fuel in tanks (check the gauges).
  3. Mixture - FULL RICH (in a real engine failure, cycle through the range first).
  4. Oil temperature and pressure in the green. (If in the red, there's not much point trying to restart the engine).
  5. Switches - ON (try each magneto in turn, in case one is faulty).
  6. Throttle - through the range and back to 1/3 (so you can tell if it restarts, but not so much as to cause problems if it suddenly surges back to life on short final).
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With these checks out of the way, and assuming the engine has not restarted, the next step is to estimate the wind direction and speed, and look for a suitable landing spot. Kerry showed how it's possible to use ripples on dams to judge the wind direction - the water surface will be smooth on the edge where the wind is coming from. There weren't any other obvious cues, but we already knew that the wind was coming from the south, and in a real cross-country flight it's a very unaware pilot who wouldn't already know the wind direction.

At first sight there seemed to be many landing spots, but on closer examination many were made unusable by power lines, fences, trees or hills. As in all aspects of flying, there's a checklist for potential landing spots - WOSSSSSET:

  1. Wind - smoke, water, flags, ATIS.
  2. Obstacles - power lines, fences, trees, high ground.
  3. Size - at least 500m long. Is it wide enough?
  4. Shape - try to find a straight runway shape.
  5. Surface - hard and smooth. Look for ruts and holes. Ploughed (brown) is no good.
  6. Slope - preferably land uphill. Use creeks and dams to get slope.
  7. Sun - try not to land into a setting sun.
  8. Elevation - to estimate high key/low key altitudes. Camden is 230 feet; The Oaks is 900 feet, so high key, 2500 feet AGL, is 3400 feet AMSL. Round off to the nearest 500 feet.
  9. Terrain - surrounding terrain may change the approach. Watch for wind shear.

Click to enlarge One useful landing spot is at the north-east corner of the training area, right beside the water pipeline. It's a private airstrip, where the boys and I attended a Zonta-sponsored fly-in some years back. The strip runs more or less east to west, sloping up towards the east. It's visible in the picture to the right, but you'll need to enlarge the photo to make it out. There are power lines on the approach, but not so close as to cause a drama as long as you spot them and stay clear. (There was also a Cessna O-2 parked by the hanger. Wonder if it's a permanent resident there?)

Kerry ran through the procedure and then let me do it myself. Having identified the landing spot (at least 1/3 of the way into the field), plan your approach and identify a High Key position 1500-2000m upwind of the spot, and a Low Key position 600-800m abeam of the spot. The aim is to reach the High Key position at a height of about 2500 feet AGL, and the Low Key position at a height of about 1500 feet AGL.

As you manouevre towards the High Key position, make a Mayday call, eg: "Mayday, Mayday, Mayday, Citabria Whisky Kilo Mike, Whisky Kilo Mike, Whisky Kilo Mike, engine failure 5 nautical miles north of Camden airport, 2 people on board, attempting landing on private airstrip by pipeline.". Then brief your passengers. Reassure them that the plane glides well and you will get them down safely, then ask them to make sure they have no sharp objects in their pockets, to remove their glasses and tighten their harness.

In a real emergency, if time permits, you might run through the trouble checks at this point - CFMOST - and try a restart if the engine doesn't restart itself during the checks. During a Practice Forced Landing lesson, you will warm the engine by increasing the rpm to 2000 while holding in right rudder and forward stick to prevent the nose from rearing up to the left. Count to 4, then back to idle.

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During the practice, at a height of no lower than 500 feet AGL, go around. Carby heat to cold, throttle up (not necessarily to full, remembering our good neighbour policy) and hold the nose on the horizon. As you pass through 1000 feet AGL, increase the rpm steadily to full throttle and establish a climb.

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We must have done this four or five times, at various heights and locations. Following the private airstrip, the next target was a feedlot. We got down low enough to see that it was actually quite undulating, though still suitable, before climbing out and heading west towards the Blue Mountains. It was hard not to be distracted by the surroundings. The sun was low over the mountains, sending rays of light towards us, and Kerry was good enough to fly the aircraft for a few minutes while I took the pictures you see here.

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The business of identifying possible landing areas added new interest to the surroundings, but it was possible to be misled. On the third or fourth occasion, we were at 3500 feet when Kerry pulled the throttle, and a very tempting green field presented itself to the south. I carefully trimmed for 60 knots and watched to see whether the field was rising towards the horizon (bad) or falling under our nose (good). It seemed bang on, so I aimed towards it and ran through the trouble checks, briefing and Mayday calls. Unfortunately after a couple of minutes it became obvious that we were not going to reach it, and would instead have to make a very dodgy approach to a field on the nearside of the original target, which was short and had trees on the approach. Lesson learned - beware of the effects of gliding into a headwind. At my request, Kerry pointed out some more suitable fields to the right at the foot of the hills.

For a bit of variety, one of Kerry's "Oh, we've lost power" comments came when we were still only at 1500 feet. This meant a quick trim for 60 knots and a very cursory glance around to find a field that we would probably have made as long as we could squeeze through a gap in a row of trees on the way in. Probably a good lesson in not blithely manouevring around at low altitude.

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Towards the end of the lesson we headed south to The Oaks, taking in the view of Lake Burragorang to the west. By this time the sky had cleared, and it was a pleasant run south. I didn't have a chart with me (must fix that next time) but I remembered that The Oaks township had a very square appearance when seen from the air, and I had no difficulty picking it out, then confirming its identity with the grass runways to the west of the town.

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We aimed for a High Key position to the south of the runway, and made a right turn. Although this was a practice, the circuit direction when landing to the south is right, to keep away from the town, so I made a normal right-hand gliding circuit while Kerry made the radio calls on the CTAF frequency - 126.7MHz. It was clear that there were two parallel grass runways running more or less north-south, and aircraft were using the westmost runway, which was interesting because there were aircraft parked alongside it. An east-west runway at the southern end is not in use as it has sheds on it.

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I'm afraid I was guilty of being distracted again as one of the planes landing appeared to be a Mooney, and I haven't seen too many of those, but I made what I believe was a nice, stabilised glide approach and was just thinking about setting up for a landing when Kerry called for a go-around. Perhaps one day I'll actually land at The Oaks and take a look around.

So, time to return to Camden. First tuned the standby radio to 125.10, checked the ATIS and noted that runway 24 was still in use, and the code was now Hotel. Then, I can't believe it, I stuffed up both the initial inbound call, and the call as we approached the circuit. On the inbound call I forgot to add, "with Hotel" but I knew the call needed something else, so I added, "Request permission to land". Where did that come from? Kerry says she's heard stranger things on the radio but it's still excruciating. As we approached the airfield I forgot to report my height. Guilty as charged - I boned up on everything to do with practice forced landings and forgot to revise the procedures for departing and rejoining the circuit. Well, next lesson I have to describe accurately the circuit departure and arrival procedures, the radio procedures and the training area boundaries, altitude limits and restricted areas, so there's a challenge.

Kerry planned to sit back and enjoy my landing but it wasn't my best. Speed too high on base and stick back insufficiently on the flare. I was probably still thinking about the lesson and not concentrating enough on the task in hand.

Before I finished the lesson there were a few more questions, like what to do once on the ground after a forced landing. I gave a fairly complete answer: evacuate the aircraft, help passengers out if necessary and meet at the rear of the aircraft. Make sure it's chocked so it doesn't roll away(!), and go for help, leaving someone with the aircraft if possible.

Next lesson has the brief title "Advanced Turning and Sideslipping", but it includes the aforementioned circuit arrival and departure procedures, radio procedures, training area boundaries, restrictions and height limits, then steep level turns at 45° and 60°, steep descending turns at 45° and 60°, steep climbing turns at 30°, recovery from a spiral dive (throttle closed, level wings, ease out of the dive), stall recovery from developed and incipient stalls in left and right-hand steep turns, state G loading and bank limits from the flight manual, and finally sideslips in a straight line and a turn. Plenty there to keep me occupied - probably just as well it's two weeks away, as it will allow plenty of time for practice.

Here's Whisky Kilo Mike after the flight:

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