Archive for May, 2007

9 - Stalling over Oxfordshire

Monday, May 21st, 2007

Hours on this day: 1h 0m

Hours so far: 12h 30m

Today, I had my first lesson back at PFT in Oxford, after returning from Jerez yesterday. The weather looked overcast and threatening, but in fact the cloud was few (very few) at 3500 ft, overcast at 5000 ft, and the wind was 10 knots close to the runway - quite benign conditions. So after a thorough briefing (quite a contrast with some of the FIS instructors!), I went out to re-acquaint myself with a PA28. How different everything seems now, compared to my first lesson here a week last Friday! There is a faint but unmistakable sense of familiarity starting to emerge. Following the walk-around, we taxyed out on the grass for runway 03, and followed the power checks from the checklist. All very straightforward.

Takeoff in a PA28 on grass is rather different to a C172 on 2000m of tarmac. A rotate speed of 65 knots is chosen to give plenty of safety margin, so the elevator control on takeoff is a balance between unweighting the nosewheel to prevent the bumpy grass from hammering it too hard, and preventing the aircraft from rotating airborne before the desired airspeed has arrived. I followed the instructor through on the new technique, but it seems fairly simple. Once airborne, the instructor promptly handed me control, and the interesting process began of applying my newfound skills to the novel environment of the PA28. The controls seemed a bit more responsive, but perhaps it was just the different geometries and response rates leading to that impression: general wisdom is that the Cessna 172 is a bit more responsive than a PA28.

I made a reasonable job of maintaining the trimmed 75 knot climb to the target altitude of 3500 ft, whereupon we made some turns to position ourselves for a stalling exercise. For the level cruise, power of 2350 rpm is applied, and trim for level flight results in about 95 knots. Visibility was good, and with a few stray wisps of cloud around our altitude, my well-coordinated turns with a panoramic spread of Oxfordshire at 30 degrees across the windshield as we skimmed wisps of cloud reminded me what an absolute joy it is to be flying. I found that I was starting to make automatic rudder control and balance adjustments, from visual detection of tiny yaw changes in my peripheral vision - which given the mystery and difficulty which obscured the use of the rudder just a few days ago, was very pleasing indeed. The instructor never once pointed out a lack of balance to me.

The aim of the lesson was stalling, in a variety of configurations: clean with no power, with 1700 rpm and with 1200 rpm, then with flaps 25 at the glide and at 1500 rpm, and finally with flaps 25, 1500 rpm and a 30-degree turn: the latter to simulate a grossly-mishandled turn to final. It’s much easier to perform the standard stall recovery in a graceful and co-ordinated manner in a PA28 than in a Cessna 172, especially with flaps deployed, because the application of full throttle does not hurl the nose skywards as it does in the Cessna. I assume it’s because the thrust line is more closely aligned with the centre of drag in a PA28. I’m starting to understand why my instructor in Jerez expressed a preference for the PA28 over the Cessna, citing the Cessna’s pendular stability.

I felt my recoveries were OK if a little uncoordinated, but the instructor was very happy with them. The crucial point is that adding power reduces the stall speed and height loss, and adding flap also has a similar effect. Stalling with power and flap allows the best recovery performance, with only about 100 feet of height loss. My control of the pitch and yaw attitude is moderately instinctive now, regardless of the aircraft configuration. The stall in the turn was much more benign than I expected: I was expecting a hefty wing drop, but the aircraft just maintained its angle of bank and pitched downwards. Recovery was simple indeed, with little rudder needed.

My big weakness at the moment is attention to detail in the checks. For example, I kept forgetting to add carb heat before stalling, and remove it after. I forgot to raise the 25-degree flaps after the final stall in the turn, and I didn’t notice until the instructor pointed it out to me, half-way back to Oxford. The instructor didn’t make a big deal of it, but I think it’s a really serious matter: too many AAIB reports indicate carburettor icing as the cause of premature death. More generally, I keep on omitting things from checks. I need to find a way of methodically improving my attention to detail. This doesn’t come naturally to me.

I brought us into an accurately-flown 75-knot glide descent, to join right downwind for 03. Salient features of the local area and circuit were shown - particular care is needed to avoid Weston-on-the-Green. Parachute zones rightly have zero tolerance of airspace incursions. Established in the downwind, checks were made - I need to learn these - then we turned base just beyond Yarnton, and configured the aircraft for a 75 knot descent at 1800 rpm with flaps 25. Turned final, and maintained the approach accurately with little difficulty. It seems that all the practice in Jerez of approach flying at precise speed and altitude in bumpy air has handsomely paid off: tight speed control with elevators/trim and descent control with throttle is almost second nature. At about 100 ft from the runway, a sharp downdraft caught us, and the instructor took control to land - handing it back to me to taxi us over the grass and park.

This was a profoundly satisfying lesson, because it demonstrated the huge development of my skills achieved in Jerez. I feel almost like a different person now. The next lesson is the circuit: which I expect will be a substantial challenge, and I just can’t wait!

Unspanish weather

Sunday, May 20th, 2007

Today is my last day in Jerez, and the fine weather has broken. On the one hand, the absence of high-thirties heat is a refreshing change. On the other hand, the veering 15+ knot winds, low cloud base and impending rain showers pretty well rule out flying. Sigh. Back to Oxford tonight, and a lesson booked there tomorrow… and the weather there is looking quite feasible.

In the meantime: back to the Gorila bar! Cheers.

8 - Failing to fall out of the sky, when the plane stops flying

Sunday, May 20th, 2007

Hours on this day: 1h 35m

Hours so far: 11h 30m

Today was the perfect flying day. My instructor and I, the nice English lady again, had decided that the best course of action would be a very early start, to get some good time in before the air got too thermal and the airport too busy. So we taxied off at 0730 UTC, 0930 local, into the cool and crisp morning. Just beautiful in the soft light and still air of the early morning - a real sense of “the way aviation should be done”.

Did a little better with the radio, managed to get the taxi clearance and acknowledge it correctly, and once we reached the hold for the runway, we were cleared for an immediate takeoff before the approaching 737 landed. A pretty good takeoff, too: could hold the centreline better, but not bad. After a rapid left turn to clear the centreline for the approaching 737, which landed a few seconds later, we departed towards Echo and settled down, said goodbye to Jerez Tower and called up Seville Approach, before climbing to our operating altitude of 4500 ft for the exercises. At this point, it became clear that I wasn’t concentrating properly, with pretty hopeless co-ordination of the attitude and rudder for the climb. I think I’d been distracted by concentrating on the radio calls, and forgot how to fly the aircraft. Incorrect priorities!

Today’s exercise was stalling. At 4000 ft or more, the exercise starts with the HASELL check:

Height - enough to recover no less than 3000 ft AGL, and a power-off stall recovery loses about 500 ft. We were starting at 4500 ft to 5000 ft, so no problem there.

Airframe - settings flaps, trim, and other airframe bits if the aircraft has them.

Security - make sure that all loose items in the cockpit are stowed or secured

Engine - check carb heat, check mixture rich, check temps and pressures

Location - not near airfields, built-up areas, cloud or controlled/restricted airspace

Lookout - the exercise is immediately preceded with at least a 180-degree level turn with about 30 degrees of bank, with a very thorough lookout to ensure that the area the aircraft will sink into upon stalling is clear of traffic. This later proved to be very helpful, when the clearing turn revealed a PA28 converging onto our course 1000 ft beneath us - and climbing! At which point, I decided the abort the manouevre and swiftly make a 180 degree turn in the opposite direction.

So, the stall. Kill the throttle, and hold level flight by pulling back harder and harder on the elevators. As the ASI sinks below 50 knots, it takes a lot of effort to keep the nose pointing upwards. The stall warned starts blipping, and there’s a bit of vibration in the airframe… now the stall warner is a constant note… the VSI is over 500 fpm descent despite pointing the aeroplane at the sky… and everything has gone eerily quiet… then the nose breaks downwards rapidly, and maybe a wing drops.

The recovery is simple: gently release the back-pressure on the elevator (airspeed increases very quickly indeed), to get about a 20-degree pitch-down attitude, and simultaneously apply full throttle. Once the airspeed is over 60 knots, gently pull back to bring the aircraft into a climb.

It’s a simple description, but good execution is more subtle. As the stall is approached, aileron authority is lost, but it is of paramount importance to neutralise yaw with the rudder, while maintaining the ailerons in the neutral position. The big skill I learned today was steering the aircraft in yaw with the rudder, with respect to a reference point on the horizon. It’s not difficult, but if you’ve driven a car for any length of time, the brain is hard-wired to compensate visual yaw with arm and wrist movements. This must be unlearned. Getting this rudder steering right is immensely satisfying, though.

Once the nose has dropped, the next subtle skill is co-ordinating the pitch control with the throttle control. Once the nose has assumed a modest downwards attitude, it’s time to apply full throttle. Naturally, right rudder is needed to compensate for the resulting yaw. But if the throttle advance is done suddenly, the thrust impulse can cause a substantial upwards pitch moment - and when you’re only a few knots above the stalling speed, that’s bad news! In fact, when the aircraft is in such a delicate situation, any sharp impulse is bad news: so the throttle must be opened gently over a few seconds. And a substantial forward elevator pressure is needed to correct the upwards pitch moment. I guess this upwards pitch moment may be exaggerated on high-wing types (like the Cessna 172 I flew today with flaps extended), since the thrust line is a long way below the centre of drag.

So the nose has dropped, the throttle applied, the attitude maintained steadily and the airspeed is now rapidly rising: time to arrest the descent to minimise the height loss. Clearly, it is necessary to maintain airspeed well above the stalling speed, to avoid going back into the stall, so I thought “well, need to avoid losing height, so pull back as hard as is necessary to quickly get to a climbing attitude without losing too much speed.” WRONG! In a dive with rapidly increasing airspeed, pulling back hard can induce a high-speed stall, due to the high wing loading from the G-force. So the pull-back must be started as soon as possible (as soon as 60 knots is reached in the recovery), and executed very gently, reaching a level attitude after perhaps five seconds, and entering a climb thereafter. The real skill in the stall comes with the finesse to make all these actions co-ordinated, such that the manouevre is smooth and gentle.

In-between stall manoeuvres, an abbreviated version of the HASELL check is carried out: then HELL check. It’s self explanatory. Next, we started variations on the theme. The main one was recovering from an incipient stall with 30 degrees flap: an attitude that is likely to be encountered in a final approach going seriously wrong. The stall warner is the cue, but in case the stall warner isn’t working, airspeed falling towards 40 knots and buffetting are together a good clue. As soon as the condition is identified, execute the standard stall recovery: keep straight with rudder, release back-pressure, gently apply full throttle, compensate for yaw and pitch, and as soon as 60 knots is achieved, gently start to level off. The height loss from this is very small, perhaps only 100 feet.

With a little bit of practice, my recoveries were good. I really like the stalling exercises: it’s a gentle and fun manoeuvre. Perhaps it’s also the quietness, the sense of hanging in the sky, that I like. Anyway, my concentration was faltering a little, so it was time to head for base. Set up a descent for Echo VRP, successfully made and acknowledged the hand-off call from Sevilla Approach to Jerez Tower, made the “inbound at Echo to land” call to Jerez Tower, and nearly managed to acknowledge the clearance - I got all the information correctly. Good progress. Entered the downwind, and we could see a big jet on about two mile final, so we made three orbits on the downwind until Tower gave permission to proceed. Once more, I flew the approach, and received a pearl of wisdom from the instructor: use aileron to maintain wings level, and steer with the rudder. It worked brilliantly, and made the final approach so much easier. Once again, I was surprised at how easy it was to line up with the runway and get the descent profile correct. Aiming for the ILS touch-down zone (incorrect, I should have aimed for the numbers), everything was going perfectly, until the control reversal switch in my brain flicked, and I hit right rudder when I meant left… and at a hundred feet, we were pointing significantly right of centreline… “I have control” was the response in my headset. Not bad, though. If conditions are benign, there’s a fighting chance that I’ll get it onto the tarmac next time.

7 - Push To Talk

Saturday, May 19th, 2007

Hours on this day: 1h 30m

Hours so far: 9h 55m

The weather’s getting quite warm in Jerez now. It’s at least mid-thirties today. I had another instructor, a very nice English lady. While all the instructors are individually pretty good, in their own distinctive ways, the duplication and discontinuity that is resulting from so many different methods and people in such a short time is a little irritating. Still, it’s all good flying practice - and unlike the people who book x days off work in which to obtain their PPL, there’s no rush for me. On the plus side, I get many different assessments of my flying, and learn many alternative techniques, so perhaps it’s broadening my training.

The New Thing for today was the radio. Having scribbled my calls on a crib sheet, making the initial call was very simple. With remarkably little trepidation, I pressed the PTT:

“Jerez Ground, Delta Echo Alpha Romeo Uniform request taxi VFR Echo.”

What was less simple was the clearance:

Ground (thick Spanish accent and readability 3/5): “Delta Romeo Uniform, taxi to Runway two zero hold short at Tango two wind is mumble mumble seven knots QNH is one zero one three squawk two mumble mumble four.

Me: <scribbles furiously, realises I haven’t got it, looks pleadingly at instructor who has written down the clearance correctly… thinks hard… >

<some time passes… perhaps a tumbleweed blows across the apron… as I copy from the instructor’s kneeboard and think hard>

Me: “Taxi to Tango two for runway two zero QNH one zero one three squawk two three two four, Delta Romeo Uniform.”

Hooray.

Release the parking brake, and we’re away. I can steer and all, now.

Making simple responses on the radio was simple too…

Tower: “Delta Romeo Uniform, hold position.”

Me: “Delta Romeo Uniform, holding position.”

Although of course, in the response, I should have put the callsign at the end not the beginning. I need to pay attention to that. Inbound at VRP Echo at the end of the flight, still trying to stabilise the aircraft at 1000 ft (only about 700 ft from the ground) after the descent, I put the call in: but was in absolutely no mental condition to understand the clearance beyond “left downwind runway two zero”, let alone repeat it! I guess that will come with time. Still, I got the important bit.

Anyway, the bulk of yesterday’s lesson was revising and practicing turns and setting particular climbs and descents, then we started practicing approaches. Spotting the point where we will meet the ground, given a particular descent configuration, seems to be fairly easy. I don’t know how I do it, since it’s such a subtle thing, but it seems instinctive. Perhaps my brain is subconsciously doing the “identify the point not moving on the windshield” trick in a very very sensitive way: looking at a point five or eight miles away, from 3000ft at 70 knots, the movement must be tiny. Handling the configuration changes as the flaps go down also seems pretty straightforward: 10 degrees on downwind, 20 degrees early on base, 30 degrees late on base or early on final. Obviously, more throttle is needed to maintain the touchdown point as more flap is extended, given a constant 70 knot airspeed. It’s also important to be swift and accurate with the trimmer, so that the yoke can be held with a gentle touch - a firm grip against a couple of kilos of backpressure wipes out the aerodynamic feedback through the yoke.

Compared with the previous lesson, it was much less demanding - although my concentration and performance was still flagging after an hour or so of exercises, so the instructor was clearly doing her job! So once again, inbound at Echo to land, flew the approach with little ATC delay, and was “joined on the controls” at about 200 ft for the final touchdown, though it was really more down to the instructor than myself.

6 - Visual flying

Friday, May 18th, 2007

Hours on this day: 1h 40m

Hours so far: 8h 25m

My latest flight was with the same instructor as the day before. I made sure he understood that nausea had been a big limiting factor in the previous lesson, and confirmed his opinion of the correct procedures and configurations for landing. He’s not big on briefing, but flying lessons are so much easier with a modicum of preparation.

So we taxyed out to the holding point, waiting while the infinitesimal speck on the horizon that had called final when five minutes from the threshold inched towards the airfield. Finally, we were away. The takeoff was as straightforward as yesterday, though I must be quicker with the rudder when applying the power so I stay on the centreline. Once airborne, we headed out east again, with minor threats of physical assault from the instructor if I persisted in failing to use the rudder when turning. I resented that, since I had made an attempt to use the rudder, but I merely got it completely wrong. We embarked upon the banking exercise that had made up so much of yesterday’s lesson, and the instructor’s abuse continued. I was completely failing to understand what I was doing wrong, so I stopped and asked for an explanation. He demonstrated: and then it clicked. It’s all about the position of the nose relative to the horizon, as the nose banks from side to side. By keeping focussed on a spot on the horizon, and maintaining awareness of the position of the nose in my (slightly) peripheral vision, everything fell into place. Suddenly, the instructor was telling me I was getting it right.

Brilliant. And once it had clicked, it seemed fairly instinctive.

Next, we started the climbing and descending turn exercises, and I had great difficulty getting the airspeed right. So the instructor told me to fly straight, put his chart over the dials, and asked for 70 knots climb. I knew exactly what he was getting at, but since I’d only been flying for about five hours and I’d never had the opportunity to learn attitudes visually, I had no idea. So the rest of the lesson comprised learning attitudes visually. The horizon positions can be remembered by reference to objects around the windshield:

100 knots straight and level: horizon is half a compass-height above the top of the compass.

80 knots straight and level: horizon is half-way up the compass

70 knots full power climb: horizon is a little way below the top of the combing (only visible on either side of it!)

100 knots glide descent: horizon is about half-way up the windshield

100 knots 500fpm descent: horizon is double the compass-height above the combing

And there were others, which I can’t remember, so no doubt I’ll have to revise them in the next lesson! The other part of the equation, of course, is the power setting. I wasn’t really watching the engine speed but going on feel and engine note. Which may turn out to be the best approach - after all, the whole exercise is about flying without constant reference to the dials.

Eventually, my brain failed: I persisted in doing the exact opposite of what the instructor asked, despite his increasingly insistent assertions, and I failed to notice that I was doing the opposite of what was requested. He insightfully noted that I appeared to be confused, and thus it was time to go home. It was quite remarkable, witnessing the way my brain failed to respond correctly to a simple instruction (in a stressful and unfamiliar environment). Stuff like that might kill me one day.

We flew back towards the zone entrance VRP, visible from about 20 miles away, and the instructor asked me to choose the point at which to set up the 100 knot 500 fpm descent from 3000 ft to the zone entry height of 1000 ft. A quick bit of mental arithmetic: 2000 ft at 500 fpm is four minutes. 100 knots (110 mph) is just under two miles a minute, so four minutes is about seven miles. So I estimated seven miles, entered the descent, and sure enough, it all worked perfectly. Just as we approached the VRP, the instruction came to hold: asking the instructor for guidance, he asked me to use my initiative and figure it out. so a gentle 360-degree turn followed, and then we were cleared into the zone. The circuit was extremely busy, with inbound heavy traffic and numerous PA28s circuit-bashing, and a most circuitous succession of orbits and holds followed that had the instructor nearly as baffled as me. I just maintained 100 knots at 1000 ft through the bumpy thermal air, and steered the aircraft where the instructor told me: I was very pleased to discover how easy that now seems. Finally, we were downwind and number two: downwind checks from my kneeboard crib-sheet, comfortably controlled the flap extensions and re-trimmed, set up the 70 knot 500 fpm descent from base, and made a pretty good turn to final. These aspects of the approach seem so much easier than when I was doing it in flexwings a couple of years ago. On short final, with a 90 degree crosswind at 11 knots reported, the instructor grabbed control and took us in: at first, I wondered why, since he only does that when I’ve screwed up and I had everything just right. Then I realised: he reckoned the wind was gusting 20 knots! A very interesting, impressive and asymmetric landing followed.

I concluded the lesson by taxying back, and parking the aircraft neatly and precisely! A good result.

5 - Co-ordinated rudder

Wednesday, May 16th, 2007

Hours on this day: 1h 50m

Hours so far: 6h 45m

My lesson today was with a different German instructor. He has a slightly more laid-back approach than the previous one, but the biggest problem is that his English isn’t really fluent, which was a bit of a problem at times. Nonetheless, his lesson was extremely useful - albeit very demanding.

So today, I did my first takeoff. In the benign wind conditions, it was extremely simple: hold the elevator back such that the control lock hole in the yoke shaft is one hand-span withdrawn from the panel, hit full throttle, keep the centreline, and sure enough it rotates at 50 knots and unsticks around 60 knots. Once it’s positively unstuck and a couple of metres in the air, ease forward a centimetre or two to let the speed build, then the nose comes up into the climb attitude, and away we go. Simple!

We climbed out towards the east today, instead of heading for the coast. The air was fairly smooth as we started out, since it was only about 11:15 local time. The first exercise was deceptively simple: swiftly bank left, then bank right, and repeat - holding the heading. This implies co-ordinated rudder to go with the aileron inputs: and the movement is too swift for the balance ball to be any use! So for the first time, I started to properly decipher the great mystery of the rudder. Get it right, and the aircraft does not yaw at all with the aileron input: the nose remains glued to a fixed point on the horizon for at least a couple of seconds (if it is held longer, the lateral component of lift starts to take effect and pull the aircraft into a turn). Together with maintaining correct pitch with the elevator, it was really very tricky, and purely a matter of feel. It was substantially compounded by the huge asymmetry in the rudder response, due at least partly to the propellor slipstream: left rudder rarely needs more than a gentle dab, whereas right rudder usually needs a very hefty shove. And then everything was complicated by the onset of nausea after a few minutes of vigorous swaying left and right - very distracting and uncomfortable, and once it started, it didn’t really go away until after I’d landed. This made the rest of the lesson very hard work.

After a few runs back and forth, practicing the banking at 100 knots and at 80 knots, I got it nailed perhaps 70% of the time. I told the instructor I wasn’t feeling very well, and so we turned around and tried a different exercise: climbing and descending turns - with correct and co-ordinated rudder, of course! Starting at 2500 ft, we set a 100 knot 500 fpm climb, and established a 30 degree constant turn, turning for a while in one direction then in the other. Rudder co-ordination was the main difficulty again here. If the nose is raising while turning in, it indicates that more rudder is needed, and vice-versa. Once the angle is established and the aircraft is in balance, the nose attitude (and resulting rate of climb) is a consequence of the elevator input. Doing this exercise accurately was very demanding, maintaining numerous different parameters correctly at the same time: angle of bank, rudder co-ordination, elevator input for nose attitude and rate of climb, and airspeed (a factor of elevator and throttle). Descending was very similar, except that instead of needing to hold-off the bank with aileron, the bank needed to be positively held-on. I was expecting this effect from the briefing in my books, but compared to the difficulty of co-ordinating the manoeuvre, it’s a trivial detail that is resolved entirely intuitively.

After a couple of turning climbs and descents from 2500 ft to 4500 ft and back again, we cruised to an area south of the Jerez zone through some increasingly bumpy and thermal air, then did more turning climbs and descents but at 70 knots. But distracted by the nausea, my concentration was faltering and my performance was deteriorating, so we called it a day. We made the lengthy and bumpy (but scenic!) trip back to the zone, and I retained control as we entered at 1000 ft and followed the circuit joining instructions for a left downwind. The instructor asked for the downwind checks, which I didn’t know having never done them or briefed for them before, so I had to dig out the checklist and read it, working through the checks while I attempted to maintain 100 knots at 1000 ft in the bumpy thermal air (I’ve only ever flown the aircraft in a circuit once before), while putting flaps down and re-trimming the aircraft accordingly. Not ideal - an impossible workload, and when the instructor called the base turn, I lost it completely… “I have control” has never sounded so sweet in my headset! Established on base, I retook control, and tried to set the aircraft up for the requested 70 knot 500 fpm descent. Well, having never set up descents at specified rates before today’s lesson, it was a bit of a struggle, but I sort-of got it… coped with 20 degrees flap fairly well (not bad considering the trouble I was having with adjusting for flap the day before yesterday), and then the turn to final came up. Speed control was tricky, but I was roughly right: the speed kept dropping too much, and mindful of the consequences of insufficient speed on final, I was paying a great deal of attention to it as full flap was lowered. In retrospect, I did a reasonable job of my first ever final approach, getting a pretty good line onto the runway at roughly the right speed despite the modest crosswind. The final approach was steep, and at about 100 ft, it became very alarmingly steep as the aircraft dropped out of the sky at about 60 knots! “I have control” sounded again with some urgency, as the instructor completed the landing. As with the instructor the previous day, he was at pains to demonstrate holding off for as long as possible, to land the aircraft in the stall. I get the message.

After the landing, the instructor gave back control for the taxi back to the apron. I’ve almost got the hang of taxying now, and even managed to park the aircraft. 3/10 for taxying accuracy, but 10/10 for failing to damage anything along the way.

There wasn’t much to talk about in the debrief, but on reflection, I don’t properly understand why the aircraft fell out of the sky just before the flare. Inadequate airspeed and wind shear, perhaps? The stall warner is unserviceable in this aircraft, so I don’t know whether we were at a quasi-stall. I’ll ask the instructor tomorrow.

4 - Circles in the sky

Tuesday, May 15th, 2007

Hours on this day: 1h 30m

Hours so far: 4h 55m

Another perfect CAVOK day here in Jerez, 28 degrees and 7 knots 30 degrees off the runway. I flew again mid-afternoon, continuing with the “Straight and Level” exercise and adding climbing, descending and turning. My taxying is improving slightly - I’m not fearfully resting on the brakes all the time, now I am familiar with their rather vague response. This business of controlling direction with my feet rather than the steering-wheel-like object in front of me is starting to come a little more naturally!

After the take-off and once settled into a climb, I took control as we headed back out west towards the coast. Very bumpy in the thermals today around 3000-4000 ft: settled comfortably in a gentle cruise climb, the VSI suddenly took off northwards over 1500 ft/min, accompanied by a gentle wafting sensation like a lift in a skyscraper! Once over the sea at 5000 ft, the turbulence subsided and we settled down for the exercises. First was climbing, and the glide descent. Climbing is quite familiar after yesterday: starting at a 100 knot level cruise, look out, full power (needs right rudder to hold straight), pitch up to hold 80 knots, and trim. On achieving the desired altitude, pitch forward to level flight (at 80 knots, the horizon is at the top of the compass on the glare shield), and keep increasing the pressure and dropping the nose as the speed builds, to maintain constant altitude. At 100 knots, pull the throttle back to 2400 rpm, and trim.

To make the glide descent from the 100 knot S&L cruise: look out, then pull the throttle to idle but don’t let the nose drop: compensate with left rudder (needs practically no rudder on this aircraft, since there’s a constant right-rudder trim!), and maintain attitude. As the speed falls, this needs more and more back pressure - until 75 knots, at which point pressure is released to drop the nose and maintain 75 knots. Trim once it’s settled. Levelling out is similar to entering the climb: full throttle (with right rudder), bring the nose up to the S&L position, and push it back down to maintain level flight as the speed builds. At 100 knots, throttle to 2400 rpm and trim.

Next was turning, level with 20 degrees of bank, doing a 360 in one direction then the other. I’m starting to get the hang of the rudder now: even at low power settings, this aircraft never needs more than a featherweight touch on left rudder, while right rudder needs constant pressure to maintain balanced level flight! I’ve got out of my bad habit of watching the VSI, and I track a combination of the horizon position and altimeter to maintain level, which needs constant attention in the turn. Although turning in itself is simple, the workload to turn accurately is quite high:

check horizon picture…

check airspeed…

check horizon…

check altimeter…

check horizon…

check bank angle on AI…

check horizon…

quick lookout scan…

whoops! I’ve lost 100 ft and gained an extra 10 degrees of bank…

so correct it…

check horizon…

damn! Now I’ve overshot the roll-out heading! Must look at DI too…

But after a few goes, I was pretty well nailing it. The instructor requested 10 degrees of flap (which I controlled pretty well, having drummed the response into myself after yesterday’s lesson), then we repeated the turns at 80 knots with flaps. Not a great deal of difference, except that the controls are slightly more mushy.

And so we headed back to the field, establishing a gentle descent with 1500 rpm as yesterday. Lots of fun controlling the aeroplane through the rollercoaster thermals as we crossed the coast! I considered it an opportunity to learn how to control the yaw with rudder, but this isn’t the done thing since the yaw is always a consequence of roll in these thermals: aileron and elevator is adequate. We levelled off at 2000 ft, then descended again to 1000 ft for the zone entry. This time, I levelled out in a controlled manner at the desired low altitude, and successfully flew the aircraft through the fast and bumpy downwind and base, until the instructor took over for the landing.

That was a great lesson. Nailed pretty much everything, and everything makes sense. The instructor is presenting at exactly the right pace for me, with a workload that is high but not too high. Tomorrow, I’m going to fly with the CFI. Let’s see what that holds for me!

Fly-in-Spain: first impressions

Tuesday, May 15th, 2007

I’m spending a week in Jerez, for some solid flying training to get my PPL under way without the usual UK ratio of weather cancellations. Today’s METAR: 01009KT CAVOK 24/08 Q1020. It was like that yesterday, and it’ll be like that tomorrow! FIS is run by a bloke called Hans, and he’s a pleasant enough chap. The overall atmosphere is laid-back, perhaps one might even say slack: I was hanging around for three hours yesterday after the time Hans told me to arrive at the office, before I finally got to briefing with my instructor. But the standard of flying operations appears good, possibly due to the presence of highly-experienced CFI Brian Mellor, who is a very nice guy and whom everybody speaks of in reverential tones. I was hoping to have a really concentrated course of flying here, getting 15-20 hours in one week, assuming that the limiting factor would be my stamina and concentration, but I’ve quickly been disabused of this notion. The limiting factor is actually the availability of instructors (FIS are very busy right now), so I’ll get one flight per day of about one and a half hours. This means I should get 10-11 hours over the week, and a solo is unlikely although I should get into the circuit. So my week is rather more chilled-out than I expected! After all my lesson preparation, blogging and revision, I still have time to wander around the town, or maybe drive over to the coast.

I’m staying in an apartment that Hans has, for a very modest weekly rate. It’s shared with other students and instructors as they come along, although I’ve got it to myself at the moment. It’s in the middle of Jerez, which is convenient for the amenities, and so I’ve rented a little car to get me to the airport a few km north of the town. The apartment is comfortable and quiet at night, but most of the appliances are broken (including the fridge - Hans assures me it will shortly be repaired) and there’s a nasty smell from the drains. Oh well. It’s cheap.

3 - First flight at Jerez

Monday, May 14th, 2007

Hours on this day: 1h 25m

Hours so far: 3h 25m

Today, I had my first flight with Fly-in-Spain at Jerez. Perfect weather here: low 20s, 6-10kt wind at a fair angle to the runway, visibility 50km+, and a few small cumulus (indicative of some rather bumpy thermals, according to another student circuit-beating) in the middle of the day which disappeared before I finally got airborne at 1715 local time. The aim of the lesson was to revise Exercise 4 (Effect of Controls), and proceed with Straight and Level Flight.

The lesson started with the flight plan (mandatory for VFR to/from a controlled airfield in Spain) and endurance/weight/balance sheet - paid attention as I’m doing it myself for tomorrow’s lesson. We then went out to the German-registered Cessna 172 - it’s rather tatty-looking and has a couple of minor unserviceable items, but I’m assured the important bits are in fine working order. Doing the checklist was new to me, but pretty self-explanatory. The instructor took care of the radio, and with a taxy clearance, we were off.

I’m still having difficulty with taxying, and especially accurate control of the individual toe-brakes at the same time as the rudder control. I guess I just need more practice to find the technique that works for my rather odd-shaped feet. After a lengthy wait at the hold, the instructor took control and got us airborne, departing the airport zone to the west and heading for the coast.

The first exercise was a recap of the primary effects of elevator, then of aileron, then of rudder. All straightforward, although it was useful to practice with the rudder some more. Next followed an investigation of the secondary effects - again, familiar and straightforward. We then moved on to the “straight and level flight” exercise. Holding straight and level at a constant speed is not difficult, especially in the still and smooth air this afternoon. This was followed by maintaining straight and level while changing speed from 100 knots to 80 knots, and back again. To reduce speed, the throttle is cut from 2400 rpm to 2100 rpm, and the height maintained by increasing the pitch attitude, then re-trimming. To increase speed by 20 knots or more, full throttle is applied, with forward elevator pressure to maintain altitude (avoid a climb), and when cruise speed is attained, cruise power (2400 rpm) is set and the pitch is trimmed. I discovered that the VSI is misleading and useless for maintaining altitude inthis exercise! Instead, the movement of the altimeter and the physical sensation seem to be much more reliable indicators of vertical movement. This exercise was repeated with smaller changes of airspeed (100 knots to 90 knots, and back again), and only a 200 rpm change in power was required.

The most tricky part of the lesson was controlling the attitude of the aircraft when lowering and raising ten degrees of flap. Despite being able to correctly describe the effects of flap on aircraft attitude when quizzed by the instructor, I found it difficult to recall whether to expect a pitch-up or pitch-down when I actually moved the lever. For the sake of my small brain, the correct answer is:

lower flap: aircraft pitches up, so apply forward elevator pressure

raise flap: aircraft pitches down, so apply backward elevator pressure

The elevator pressure required can be quite strong. From a straight-and-level 100kt cruise, lowering 10 degrees of flap causes a pitch-up, and if this is controlled to maintain constant attitude (and height), the speed reduces to about 80 knots. After the aircraft has stabilised in this configuration, raising the flap causes a pitch-down, and if this is controlled, the speed gradually increases again to 100 knots.

It took me a few attempts to get this right, but I nailed it in the end. At which point, the lesson concluded with a shallow descent (1500 rpm, 75 kts) from 4500 ft to the approach altitude of 1000 ft. It was a lovely opportunity to take in the scenery as we slowly sank through the smooth air towards Jerez. Levelling off at 1000 ft, everything suddenly became incredibly busy and bumpy… and the instructor took over for the join on right downwind, approach and landing.

2 - Flying at last!

Saturday, May 12th, 2007

Hours on this day: 1h 0m

Hours so far: 2h 0m

Sixth time lucky! I finally managed to get off the ground at Oxford on Friday morning. It’s breezy and turbulent cold-sector weather in the middle of a very unsettled spell, with a stiff south-westerly breeze and scudding cumuli amongst the showers before the next front comes in this afternoon. Still, the lowest base of the scattered cumulus is well over 2000ft, and with 10kts only about 10 degrees off runway 21, this morning was eminently flyable.

I was introduced to the PA28-140 through a brief walkaround and a trip to the fuel pumps, then we were away. Steering while taxying was still rather counter-intuitive thanks to my previous flexwing experience, but on nice smooth tarmac and with some concentration, I happily failed to cock it up.

The instructor took control for the power checks, magneto and carb heat checks, then we were cleared for takeoff. Climbed up through the rather bumpy and turbulent air underneath the cumuli, with a right turn to head north-west towards Stow and Moreton-in-Marsh. In straight and level flight at cruising speed (95 kts), the horizon is about four-to-five finger-widths above the glare shield. So time for the first exercise: pitch control. All very straightforward: back-pressure on the elevator until the nose is just above the horizon, causing a drop in airspeed (to about 80 kts) and an increase in altitude. Returning the nose to the straight-and-level attitude, some significant elevator back-pressure needs to be maintained because the speed has dropped, until the speed has risen back to the trimmed cruise attitude. With downwards pitch, the reverse is true: forwards pressure needs to be maintained after levelling off from a brief descent, until the aircraft has regained its trimmed cruise speed.

Next up, ailerons for roll control. The instructor demonstrated 30 degree left and right turns, with a little back pressure to prevent the nose dropping, and I noted the following attitudes to establish the bank angle without looking at the AI: in 30 degrees left bank, the horizon intercepts the inner lower corner of the windshield and forms a 30-degree angle with the top of the glareshield. In 30 degrees right bank, the horizon intercepts just below the inner top corner of the windshield, and just grazes the rounded edge of the windshield. All very easy and intuitive.

Rudder control was pretty much as I recalled from my lesson at Land’s End last year, a yaw producing a secondary effect of roll and ultimately a spiral dive (which is fun to recover from!). If the roll is counteracted with aileron, a side-slip is entered, out-of-balance and with reduced airspeed. This is all simple and makes sense, but I really don’t have a feel for using the rudder to maintain balance. I failed to notice that whenever I turned the aircraft, I didn’t touch the rudder, so it was interesting to note how busy the instructor was with the rudder when we were on final approach.

Throttle control, with the associated changes in airspeed and/or altitude, was again familiar and straightforward. What was new was the change in attitude resulting from the torque and slipstream when making a sudden change in power. Sharply applying power causes pitch-up and left yaw, and this must be compensated with elevator-down and right rudder. Sharply reducing power causes pitch-down and right yaw, requiring elevator-up and left rudder. I was trying to get this in order in my head, but trying it for myself, I found that the compensating responses were instinctive to keep the nose pointing at the same piece of horizon. The instructor thought it was fine - but looking back, I think I was using aileron instead of rudder to compensate for the yaw. I must practice this again, and more generally get the hang of using the rudder.

The lesson concluded with a scenic flight back to Oxford, and the instructor took over for the circuit and landing. A good opportunity to have a good look at the airfield and circuit, and also listen to RT. I’m getting 50% of it. I failed to note that the aircraft on the threshold as we turned for final had been cleared for take-off - we reached 1/2-mile and it still hadn’t moved, so the instructor went for a go-around. I was also slightly frustrated that in the perfect visibility I couldn’t spot the Seneca on a straight-in approach, that was six miles when we were on downwind. But at least I knew it was there! I finally spotted it passing over the threshold as we were late downwind on our go-around.

And so, we landed.