Archive for the Further Training Category

Night Rating: Part 2 (Failures)

Monday, December 22nd, 2014 | Permalink

You could also call this lesson “emergencies” but most of the things we’d be doing were more about getting experience with landing the plane under an acceptable failure condition (e.g. loss of approach lights), rather than a genuine fully fledged emergency (e.g. engine failure).

In my PPL training I was swapping instructors almost every lesson, but it was pretty normal to be back flying with a familar instructor again every other month or so.   I was now swapping instructors for my night rating and to my slight amazement, I had to actually go back several pages in my log book to find when I’d last flown with this instructor – even though they’d been instructing me right to the finish of my PPL.   Goes to show how many flights I’ve done in the year I got my PPL, it’s been a good year 🙂


PAPI lights

PAPI lights

We’d go fly some circuits, the first one would be completely normal just to settle down into things (flying can be a bit like stage fright, you can do it, but in the hours before turning the key you do sometimes find yourself wondering “Can I remember how to fly?”).

Then it would be a progressive set of challenges:

  • Landing without the PAPI lights
  • Landing without the approach lights
  • Landing without the airplane landing light
  • Landing with none of the above.

Check the Fuel and Oil and lets go

My training has drilled me to check everything, even if an instructor has just landed the plane and swears it’s all good – I’ve been drilled to check it anyway, if you go on any flight safety training lecturers the old and the wise (pilots who are one, tend to be the other) they will also stress to check everything.

This all sounds great in text books and it’s good safe, sensible stuff.   What it also means though is that when I try to deviate or short circuit around blocks of the check list, I find it all gets into a starting up muddle.

You find stupid things happen, like you jumped past the pre-startup internal checks and you’re now trying to start the plane – but wait, turning the master switch on was on the previous page, so you haven’t done that, so you have no electrics.   Switches get missed, flaps get left down etc.  and as you try to untangle the “must change state of” items from the “just check” items, you begin to feel surrounded by an aura of feeling like you should know how to do this……and yet you’re messing up!   You’ve done it hundreds of times before, feels surreal therefore that an 80+ item checklist isn’t engraved into your memory (hmmm, strange that!).

So I sort of hate doing the “lets just jump in the plane and go” approach.  I can do it at farms & places I’ve just landed, but I can’t seem to do it when I’m getting in a plane that someone else has flown before me – I’ve found on too many occasions that the previous hirer has left the radio on approach instead of tower, or the lights set weird or the fuel selector set wrong!

After a little bit of awkward faffing about and looking like a student all over again, the engine was running, ATC had cleared me to taxi out and we were away – the nerves could begin to calm down now.

Circuits :  Lights On, Lights OFF

Approach Lights, PAPI's & Runway Lights

Approach Lights, PAPI’s & Runway Lights

The wind at night is a strange thing, it can seem like the calmest day and then you get up 1,000ft and find it’s 20 knots crosswind to the runway.

On my first circuit I turned downwind and was quickly finding myself getting pushed more and more towards the runway.   There’s a good roundabout reference at the end of the downwind leg which is an excellent guide for both ensuring you fly a sensible sized circuit and going just beyond it, a good turn point for turning base.   I found that by the time I got there I was left of it, meaning my circuit was tight and the wind was pushing me in – no surprise then that when I turned left on to base leg, the crosswind became a tailwind and made matters worse.

I could lose the height ok, though my groundspeed was feeling pretty rapid in which to do so, but I found I had to turn on to final approach sharpish and while still trying to lose the height.   If you do all this to close together your nice rectangular circuit pattern starts to look like a military style continuous turn.   That’s ok, but I’d overshot the centre line of the runway and had to correct it to get it all lined up on final.

Other then the overshoot, the height was good, the speed was good and everything came together in the end for a nice enough landing.

Do it again without the PAPI’s

What the PAPI’s give you are a visual guide on your height, you want 2 red and 2 white, this means you’re on an approach angle of 3 degrees, keep the PAPI’s looking like this all the way down and they’ll guide you gently in over the runway at a nice casual approach.   More red then white equals low, more white then red equals too high.

One interesting point, typically GA aircraft in daylight don’t do 3 degree landings, they tend to do 3 white, 2 red and come in at a steeper approach angle then a jet would.   At night though, 3 degrees is what I’ve been told to fly.

Without the PAPI’s all you have are the approach lights and the runway side lights and you have to use these to judge your approach angle manually.   Which isn’t as easy as just following 4 lights in blind faith that they’re set right 🙂

Farms, Farms and Farms……..I love farm strip flying, I can’t encourage you enough to get an instructor to teach you how to do it and then go get some practice doing it.   My landings got better when I started farm strip flying, nothing I’ve done has improved my landings more.

So without the PAPI’s, there’s a pretty simple way to ignore all that text book stuff about runway perspective or trying to lean on your local knowledge of what the runway looked like the last 20 times you circuited on it etc.    Remember that the book says “Constant bearing, constant danger”, well the same rule applies to landings:   If you keep a point (e.g. the runway threshold lights) held constant at a position in the window all the way down – you will/can land there!    Of course if you have too much speed on at that point you’ll go into ground effect and float for another 150m but that’s your airspeed control going to hell, you’ll still be given every possible opportunity to flare it and make a good landing on the runway.   PAPI’s or no PAPI’s.

All you need to focus on therefore is that you want your airspeed in check around the same time as your landing point out of the window begins to stabalise its position.   Once you’re doing 65 knots, with the runway threshold held constant out of the window, your approach angle is going to be about right.

I found myself again getting blown in like crazy, again overshooting on the turn on to final.   However, the lack of PAPI’s really didn’t come as any bother at all.   I found I made a whole bunch more minor adjustments on the throttle and elevator as I point and powered my way to the landing point, but it was still a pretty well controlled landing.

No Approach Lights

This is stranger to fly then not having the PAPI’s, there’s something quite welcoming about the approach lights leading you to the runway.

Still you have the A14 and A1303 as visual references and the green strip of threshold lights at the near end of the runway.  So the main thing the loss of the approach lights does is make the runway/airport feel much, much smaller.

I messed this landing up a bit, as I touched down my left foot slipped and tapped the brake causing the unwanted sound of the tires to screech.   The touch down speed was slow and we hadn’t landed with the brakes on but the rolling speed was too high to be touching the brakes without them making noises about it.    There’s a good reason that ‘feet clear of the brakes’ is on the pre-landing checklists, if you were to land with your brakes on during a skills test – you’ll very likely fail for a dangerous landing.  The fear being that if you touch down at speed, brakes on, if both are on then the wheel that touches first will want to rotate the plane, or both will touch down and the tires might quickly want to give up the game.  With only one brake on you’ll be at risk of flipping the plane as it rotates around the differential braking.  Not a great idea.    This was nothing quite so serious, but I totally accept the principle it’s a bad thing to be doing, so I wasn’t thrilled with myself on this landing.   Still, you’re always able to learn from events.

No Landing Light

If you’ve ever seen a light aircraft come into land at night, you’d be forgiven for wondering why bother with that landing light anyway – it’s hardly illuminating anything.   True until about 30ft, when it is quite effective at illuminating the runway surface, critically what it provides is depth perception.

With the landing light on, those last 30-50ft before touch down can be done watching the runway come “up” to meet the plane (I know technically the plane is coming down to meet the runway, but it appears the other way around as you fly it in).

So without a landing light, getting the plane down to 50ft and over the runway should be easy enough, but judging when to flare it and estimating when the main wheels will be touching down on the runway becomes tricky.

Making sure my heals were on the floor and my toes were handling the rudder this time, I got it about right.   I was off maybe a couple of foot on the last few feet of height in the flare so a little flat, but not bad for a first go without a landing light.

All the lights (except runway lights):  OFF

The rule is you cannot land and must go around if the runway lights fail.   The reason is that without them, you’ll just be aiming for a now black centre line, somewhere in a sea of blackness.   It’s really not a safe idea!

Everything else is desirable, but not essential to the safe landing of a light aircraft, so time to see if I could put the plane down without any of the other lights.

Getting down to the runway I found easy enough, but again the real decider on whether I could pull off a perfectly smooth landing or with a slight thump seems to be the lack of a landing light.   Without it, it’s just hard to estimate those last few feet of where the main wheels are relative to the runway.

Still other then the one in the middle, all my landings I’d been happy with.


Again not a lot to be said really, everything seemed to up to a sufficient standard to keep progressing.

The plan for the next lesson would be to get the Navigation done, before the weather really turned on us.   This could be any route of my choosing as long as the flight took 1 hour and covered at least 27 nm (I can’t imagine how you do a one hour flight and fly less then 27nm to be honest, but the distance is a CAA criteria – I’m sure someone has a good rational for why there’s a distance requirement).

Night Rating: Part 1 (Night Familiarity)

Wednesday, December 17th, 2014 | Permalink

The night rating is one of the easiest ratings to add to a license, so as winter is now well and truly here and any hope of farm strip flying would now be the reserve of the incredibly lucky or foolish (generally I like to think I’m neither of those).  Seems like a good time to go get another stamp on my license 🙂

Why get a Night Rating?

Everyone’s reasons will vary, I’ve already given one of mine above but here’s a few more:

  • Escapism:  Want to escape into that childhood fantasy of getting into a bomber and taking off in search of finding a dam?    Just turning a Cessna 172 on at night with a red torch in hand is fun.
  • November – February in the UK:   It’s typically damned cold at 8:30am, during my training I quite enjoyed taking a broom to an aircraft’s wings on several frosty winter mornings.  However, if you’ve done it three or four times, you’ve probably done it enough.   Flying later on in the day is typically warmer (but not by much).
  • If a city looks nice during the day – it looks better at night.
  • You might not want to do loads of night flying, but from October-Feb, a flight taking off at 2pm is going to be at risk of coming back in the dark and if you have to divert, then what?   A night rating will keep it legal.

What’s involved in getting one?

No exams, just five hours of flight training, to include:

  • Three hours duel instruction
  • One hour (at least 27nm) Navigation
  • 5 solo full stop landings.

For more information, see the CAA website.

Lesson One:   Night Familiarisation

To get used to the essentials of night flight:  From airport lighting and how taxi speeds will appear very differently (out of the front window you’ll feel you’re going slow, now try looking left!).  To what cities look like and gain an appreciation of just how far out you can see at night.  A town you wouldn’t normally see straight after take off in the day, can be instantly visible at night – which can be disorientating.

Now technically I’ve sort of done this lesson before, but that was so early into my PPL training it’d be good to repeat it.

Satisfactory handling, must learn to land before continuing.

That is what I’m told it says in my training record for that first night flight – gives you an idea of how long ago it was!   Since then my landings have come a long way.

Checklists at night

Pilots love check lists, if you don’t I’d suggest strongly that flying isn’t for you – checklists, charts, plotting routes and manual calculations are all part of the ground fun that should be an aid to building the anticipation of next going flying.

Checklists in the day are one thing, at night with torch in hand, an array of instruments & switches before you.   It doesn’t get much better, at least not on the ground.

The Route

The plan was a pretty leisurely local area flight, we’d take take-off and then turn around to fly north to Newmarket.

From here we’d do an orbit of the town, before heading back to the airport.   Ask them for a zone transit (to allow us to fly through their aerodrome traffic zone [ATZ]), to get more familiar with the lights of the airport and when you can/can’t see them.

Head north west towards Bar Hill, getting familiar with the A14 at night and then turn it around and come back to Cambridge for a few circuits and get familiar with landing it at night (remember the last time I did a night flight I’d NEVER landed a Cessna 172 – I’ve done it hundreds of times since, but this would still be the first time an instructor had ever let me land it at night).

……even when you have your license, the first times can just keep coming.

Clear Skies – amazing views & almost incredible distances.

No sooner had we took off, you could immediately see Newmarket and the A14 leading the whole way.   I did find myself feeling a little unsure of what I was seeing and where things were for sure.   When you have the background noise of a Cessna 172 engine and you’re so used to seeing the day time landmarks etc.   It suddenly is a bit weird for example to not be able to see the wind farms to the east of Cambridge, but instead be able to see the bright lights of Newmarket & the runways of Mildenhall / Lakenheath.

Some great views of the town centre while orbiting, at only 2,500ft I sort of wonder how it looked from the ground 🙂

Sandy Transmitter Mast

Sandy Transmitter Mast

Heading back to Cambridge Airport we were cleared for a zone transmit, not above 2,500ft, as they had a fast jet coming in at 3,000ft.   Suddenly 2,500ft ceiling sounded very wise, the last thing we need is to go arguing with a fast jet – the approach speeds of a light aircraft flying at 115+ MPH and a fast jet doing 250+ MPH alone will make your mind boggle.

There is a big transmitter mast near Sandy, in the day it’s quite impressive to fly past (and will make you think twice about any low flying ideas you might have!).   Normally you cannot see this mast until you’re within a few miles of it.   However, at night because it’s over 300ft above ground level, it is lit by a red beacon light.   This makes it visible from Cambridge!  (20 miles away).

Heading north to Bar Hill we could hear on the radio that another club student, also getting their night rating, clearly had an instructor on-board who liked the idea of the route we were doing and was copying us.  Normally you wouldn’t know, but they also had to get a zone transit to follow us.

On the way out I got some top tips on just how dark the dark parts of the world were and a reminder on the idea of trying to land at an unlit runway was just going to be impossible.  You can really see why, from 2,000ft you just have black and bright light.   Who knows what is in the black parts – sure it could be a field, it could also be a house with its lights turned out!

Coming back to Cambridge:  Engine Failure

The plan was to come back to Cambridge and do a couple of circuits.  We joined the circuit and followed a PA-28, which rather tediously seemed to then go and do the worlds largest circuit!  🙁   As we were number two I had to entertain trying to follow them round, they were so wide that their base leg was pretty epic and to try and give them some time on final I told my instructor I was deliberately going to extend the downwind leg.

As I turned onto final, I was pretty pleased with how well my separation plans had worked out.   There was no reason they wouldn’t be able to land and taxi clear and then we could get clearance for our touch and go.   What could go wrong?

Cambridge Tower:  We’ve had an Engine Failure on the runway.

You’ve what!?!?   On the what?!?   How the what?

Go Around

It was followed by an immediate call to go around from ATC, the training drilled into me, kept me going here – but my brain was still racing to figure out what had happened to the PA-28.

They were landing, in fact they HAD landed!   So how had they had an engine failure?   Is that even possible?   Like I said, you can have first times – even after you have your license.

Whatever the cause, they were stressing air traffic control out, you can understand why.   They now had their only runway blocked by a plane, with two Cessna’s destined for Cambridge in the local area and a fast jet a few miles out.   Now this is a fully fledged & night licensed airport, so they can shift a plane – but having to, while managing a load of other circling planes isn’t going to improve their day.

Best theory in our plane was that they’d landed, brought the throttles back to idle and the PA-28’s idle setting had been set too low and this had just let the engine stall.

This theory was, very likely, soon confirmed as while we were getting back on to the downwind leg for another go as if by magic the “failed” engine had been restarted – bet that did wonders for their avionics 😉


I don’t mean to sound grumpy about it, but their little antic on the runway cost me a touch-n-go, so I would have rather they not have had the issue.   Sometimes these things can’t be helped though and one day it might be me having the awkward moment, so I try to sympathize.

Got a nice approach, brought the Cessna 172 down over the threshold and touched down just past the numbers so I was pretty pleased with the landing.

Still a bit unfamiliar with the lights leading off to the taxiway, it’s one thing to know the theory, it’s another getting real experience, so a few words of advice for where to turn off and some local knowledge that ATC wouldn’t ever ask me taxi past Charlie as Delta isn’t lit.

Nothing significant to be said in the debrief, think all in all the instructor was generally happy with my flying.

Next lesson would focus on landing the plane with various failures, both at the airport and within the plane.

Farm Strip Skills: Part #3 (Completed)

Monday, November 3rd, 2014 | Permalink

Farm Strip #3 Chart of route

Farm Strip #3 – Chart

The general scheme for this course is 1 hour revision, 1 hour land-away and finally an afternoon of land-aways.   Part #2 got scrapped due to weather, but thankfully the instructor said we could progress to the final part, do the afternoon of challenging farm strips and if I had no issues with them, he’d consider it a done deal and I’d be free to go fly farm strips on my own.   Time to impress then!

The weather was looking great, so no excuses.

Briefing and the Afternoon Plan

No PLOG for this trip, everything on the map again, general plan of attack was to fly up to White Fen farm (not even on the chart!) for a full stop landing, but we wouldn’t get out, then up to Sempringam Fen Farm for a touch and go and a full stop landing.

Neither strip is very big, ~470m x 16m

What makes farm strip flying interesting to me is if you crack open the C172 SP Pilot Operating Handbook a little bit of math will tell you that the plane won’t stop at full weight and zero wind in anything under ~580m.   So you can count these places out if you plan to tank up and take the family, to get into them less fuel is good and fewer passengers, even better.

White Fen Farm

Because this blog post is much delayed, I can tell you that farm strips aren’t always easy to find even with the advances of Google Earth.   Even now I find it essentially impossible to pin point you to where this place is.  Probably a good thing.

With about 2 nautical miles to run I finally spotted the place from the air.   East Anglia is flat and a shade of green/yellow almost everywhere that isn’t a town.  So spotting ~500m of straight grass amongst a sea of grass is harder then it sounds!   That said, I can think back to when I first started to learn to fly and instructors would ask if I could see Cambridge from 7nm out, forget it!   Today I’m so used to the shapes of airfields I look back wondering how I ever missed it, but experience teaches you what to look for.

Making radio calls on a safety com frequency as we joined “the circuit”, to no reply, I really focused on making sure I got my downwind/pre-landing checks in and then really put the effort in to ensure a good circuit, good height and to not turn on to the base leg until I was sure I’d have enough distance on final to get it down in one go.   They were kind enough to let me come and land at their farm, the last thing they need is a C172 buzzing the house on go-arounds if I could avoid it.

My top tip is to not turn base until the runway threshold is just about to disappear out of the rear side window.  If you fly a circuit of about 0.5nm (1km), this should give you, rough numbers, just under 0.5nm final approach which should work, without buzzing the next village down the road etc.   Any sooner and you’ll be trying a military continuous circuit and your workload will sky rocket, any later and as I said you’ll probably just upset the owners neighbors and never be invited back 🙁

Taking care to not come in short, but also not hit the tree on the right it was a pretty nice touch down.  I think if I could do it again I’d like to have touched down maybe 50m sooner, but I was happy with my airspeed control and the landing was controlled and not slammed.   Tick in a box.

We taxied down to the far end and due to the light winds take-off direction was much of a muchness, so just spun it around at the other end.   10 degrees of flap for best short field performance, brakes on and throttled up to 2,000 rpm.   One last check the instructor was happy, then release the brakes and charge down the grass strip.

Airspeed Indicator comes alive, now it’s about judging how fast the airspeed indicator is increasing relative to how much grass we have left.   By a quarter of the runway gone, we were well on our way to rotation speed, so it was looking good.   55 knots, rotate and climb away at best angle (Vx) of climb rather than best rate (Vy) – we care about not hitting the trees, not how fast we can get to 1,000ft 🙂

Onwards to Sempringham Fen Farm Strip

Spotting this one was probably going to be harder and worth remembering that my dead-reckoning and wind calculations were all done on the Chart with Max Drift estimations so weren’t going to be spot on. What I knew from my map was that I’d have Spalding on the right, if I overflew it I was too far right of track, if it was somewhere off to the right in the distance, I’d be to far left.   I also knew that there was a railway line that came out of Spalding and curved round to the west, if I overflew that then I’d gone too far north – I didn’t think the instructor would let that happen, but I was trying to come up with a plan to narrow down the big flat world outside.   Being really optimistic I knew the route crossed South Forty Foot Drain running north/south – I was hoping I’d spot that, if I spotted the crossing for that drain, Sempringham would be on my left.

Of course all best laid plans……I knew I was ball park in the right area, but ~4nm out I couldn’t see it, with hindsight I think I was a little fixated on the idea that it would be in front of me (being a bit optimistic about flying a perfect heading perhaps!).    The instructor asked if I gave up and wanted him to point it out to me?   Ok I give up.

Pointing to the left, about 4-5 nm away was what to me at the time looked like the thinnest strip of grass ever.  You’re joking that’s an airfield right?    It was straight and with a house & barn at the end it was the right sort of shape, but as we got closer, from 2,000ft it still looked incredibly narrow – even if we forget the length!

Impress or fail, we’d have our answer in a few minutes.

Setting up the circuit, I saw a good north/south ditch type thing to the east of the strip that I decided to use as a reference for the base leg.    I didn’t want to fly a silly sized circuit, but I didn’t want to turn and find myself halfway down the grass strip at 600ft either, this ditch seemed like a good sized compromise to a reasonable circuit shape.

On approach my eyes and brain were working overdrive on airspeed and watching the window.   Window, Airspeed, Window, Airspeed.   I took one comment from the instructor to just keep my airspeed up a little as I went through 60 knots – wind consideration here is critical, light winds need as much consideration as gusting etc.   Even so, I was really trying my hardest to put this plane down right at the very start of the strip.

Just going through 50ft the plane sank, I jumped on it and applied a little throttle to counter, caught it beautifully and it corrected just nicely enough to be able to take it back off again and touch down only feet from the start of the runway.   I couldn’t have been happier with it.

Full power, tons of runway left, which is saying something as it’s only 460m end to end!

Another circuit and again I really wanted a spot on landing for the full stop, just to show it was no fluke.

I used the same circuit points as before, they seemed to work out nicely and again went for ensuring I was totally in control of my airspeed on the approach with a constant picture out of the window.   Pointing the plane at just a few feet before the start of the strip for where I wanted the plane to go and using the throttle to keep the airspeed in check – I was still getting the hang of point and power technique, but having done only a few landings using it, I can assure you that post learning, it’s really the way to do it if you want accuracy.

Touch down, nice and soft and right where I wanted it to go at the beginning of the runway, we were down to taxi speed with around half the strip to go.

I chalk this one up as probably the best landing I’ve ever done.

G-MEGS:  Landed at Sempringham Fen Farm Strip

G-MEGS: Landed at Sempringham Fen Farm Strip

The best places to land involve those places that have coffee and cake, with much thanks, both were on offer.   Flying, cake and coffee – I see your hobby and raise you, it doesn’t get any better then this 🙂

Back to Cambridge

Another short field take off and it was off for a really quite pleasant flight back to Cambridge, funny really that some months ago Spalding/Cambridge was a route on one of my first solo Nav’s and I must have concentrated soooo hard to not miss Spalding.   Now I was just glancing at the map, spotting the land marks and really flying with my eyes out of the window just enjoying the views and a casual chat on the way home.

Great day to be flying.

Back on the ground at Cambridge the chief flying instructor said he was happy with my flying and didn’t need to see any more.   My training record now shows I’m cleared to fly the club aeroplanes into farm strips!

Farm Strips:  I’m hooked, more!

It’s been one of the best courses, different to when you’re trying to be formally taught how to fly.  Yet challenging and I really feel I expanded by skill set from doing it.   Not just in terms of flying, but also increasing my confidence to try find and go into shorter strips on my own, with the right training to be able to do it safely.

Hand on heart, I find myself completely hooked on flying farm strips now.

I’ve done a bunch of big runway landings, I trained at one etc.  Big airfields bring different things to the party, lots of radio work, procedural joins and accurate circuit flying being critical etc.  but for the challenge of the landing and even the challenge of finding some little patch of grass in the middle of nowhere. I found myself wanting to just get out there and do more farm strips – I started to wonder who might let me come land in their garden if I asked nicely enough 🙂


Farm Strip Skills: Part #2

Tuesday, October 21st, 2014 | Permalink

PLOG on the Chart to Marshland

PLOG on the Chart to Marshland

On arrival this looked like it was going to be a good day, but the longer you looked up, the worse the clouds became.

Obviously then the answer was to stop looking up and go get on with it!

All the planning on the Chart :  Wiz Wheel, forget it.

I’d been told not to plan this trip out to Marshland, we’d do it on the fly.

Now to learn a few more notations & symbols for drawing a PLOG on to a chart.   If it’s good enough for the military to have all their planning & radio frequencies on their chart, it’s good enough for me.

Normally you’d work out the wind corrections on a wiz wheel (Flight Computer), then work out heading corrections from that.  Very accurate, so long as the wind forecast is accurate.   However, you can’t do this easily if you’re diverting, so there’s a good case for learning to fly using Maximum Drift and some rules of thumb.

Maximum Drift

A quick calculation will give you a pretty accurate Maximum Drift (due to wind) you might experience on a flight:

Step 1 :  Calculate the max drift if the wind was perpendicular to the route being flown.

Max Drift = (60 / True Indicated Airspeed) * Wind Velocity Forecast for the Altitude being flown

Math in an aeroplane is actually harder then it sounds, even for math you’d find easy on the ground.   This is because you’re now traveling at ~100+mph, have people talking on the radio to you or have to listen in case they start, are trying to maintain a heading and altitude (and don’t forget to keep looking out the window!) – the constant ‘buuuuur’ of the engine also doesn’t help concentration.

For a Cessna 172, with a typical indicated airspeed cruise of ~100 knots, you can optimise step 1 further by saying 60 is close to 50 and IAS (Indicated Airspeed) and TAS (True Airspeed) will be close enough at cruise speed:  so 50 / 100 equals 0.5.

Now our equation becomes:

Max Drift =   0.5 * Wind Velocity Forecast for the Altitude being flown

Sure you now have a bit more error in the system, but here’s an example, lets say the Track we want to fly is 080 Degrees and the Wind is forecast to be 165/25  for our flight altitude.

If we do the equations above, with TAS = 100 knots.

Accurately  :      (60 / 100)  *  25   =   15  degrees

Estimate     :      25 / 2  =         12.5  degrees.

So with the wind at 85 degrees to our intended track and a reasonably high wind of 25 knots, rounding up, the quick estimate is out by 2 degrees.

Over a 10-20nm leg of journey, this error is going to be very negligible (i.e. With 2 degrees error, after 60nm, you’ll be 2 nm away from where you thought, so over a typical 10-20nm leg the crude method would put you, out by 0.3 – 0.6 nm).    If you still don’t like that small amount of error, remember that TAS here has been approximated to the Indicated Airspeed cruise of 100 knots.   TAS will actually be higher by a few knots, at 2,000ft AMSL in a Cessna 172 with IAS of 100 knots, flaps up and in level flight TAS will be very close to 104 knots.   Do the accurate math above using a calculated TAS, but use only the IAS 100 knots for the crude method and you’ll find that now the error is under 2 degrees.  It’s pretty good and probably more accurate then the error and danger of going eyes down while you get a flight computer out and start remembering equations and how to do division on the thing!

Step 2 :  Using the clock rule system, adjust as applicable for the angle you’re flying relative to the above wind (you might be flying straight into/with the wind).

Take the difference between the track on the chart and the forecast wind direction, multiply the number from step 1.  by

  • 1/4  if the difference is up to 15 degrees,
  • 1/2  > 15 and <= 30 degrees.
  • 3/4 if up to 45 degrees.
  • For anything else assume Max. Drift (e.g. multiply by 1).   This will give you a slightly pessimistic outcome.


If Step 1 gives us a Maximum Drift of 15 Degrees, then using the details from the above (Track we want to fly is 080 Degrees and the Wind is forecast to be 165/25 ).

165  –  80  =  85  Degrees difference, so we can just assume that we’re going to get the full 15 degrees of drift.

If we changed our track later on in the flight to say 140 degrees, then

165 – 140  =  25  Degrees Difference, so   15 * 0.5   (Multiply by a half as it’s greater than 15 Degrees, less than 30)   = 7.5    Degrees of drift.

If you’re still feeling bitter about my approximation method on step 1 above and have a desire for accuracy, it might be worth noting now that in the above condition with 25 degrees of difference, the drift error between the approximation and the precise calculation is less than 1 degree!


Lets go flying ………even if those clouds do look a lot darker.

The briefing was far shorter then your typical PPL training briefing, but even so by the time we got out to the aircraft, dark clouds on arrival, were looking lower and darker then they were before.   We discussed going again, was it worth it, should we go have a look anyway or not?    I elected we just go have a look.   In my heart I knew this was being optimistic, but the CFI wasn’t going to say yes if it was entirely pointless or unsafe and even if we just went up, turned round and came back, it would still be valuable experience of the weather with the proper instruction available etc.

A wall of darkness

As we set heading over Point Alpha, it didn’t take very long to know we could scrap this 🙁     Already at 1,700ft and being pushed down with every minute flown, the north of Cambridge looked like a wall of darkness and cloud – maybe, just maybe, if we dropped to ~1,000ft and pushed on past Waterbeach, maybe it’d clear.

The instructor asked what I wanted to do?   While on the ground I was of the view that there’d still be some things I could learn by going up in less then ideal starting conditions with experienced instruction.   Now I just felt this was more a question of “but should you carry on” rather than “Do you want to”.

I saw no point, it was a lot of maybe’s – that might not come true and if they didn’t how bad would it be when we gave up and tried turning round?   Even if they did come true, we’re aiming for a grass strip in the middle of nowhere, when we get there we’ll have no idea of the surface winds and even if we can get a rough idea of them, probably it’ll make for a hell of a challenging landing and I’ll come away from it feeling rubbish and like I’d forgotten how to land.   That would add no value to this objective.

I elected to call it a day and turn back for Cambridge.

Air Traffic heard our call to return and asked if there was a problem, this is a pretty normal response if you call to return only ~5nm from take-off.   I reassured them that it was just a return due to weather and they let us come straight back in on a Right Base join, which was helpful both for the deteriorating weather and to keep my costs down 🙂

Epic Wind shear:   Falling at ~3,000ft/Min

As I lined up on final approach there was a crosswind and you could feel it gusting hard on the controls.   I’d had worse on the way out to Calais, where almost full opposite aileron control was required to keep a Cessna straight, but now we were trying to land and there’s a big difference between keeping it straight at 2,000ft and keeping it straight at 500ft.

Still I was happy I was on it for this landing, the instructor wasn’t asking for control so they still had faith too 🙂

Then as we passed through 250ft, we just fell!    In ~2 seconds we dropped from 200ft to 100ft, 50 feet a second (or 3,000ft per minute!!)

Throttle Fully open, the Cessna managed to get lift again.

The window outside went from a happy picture, to the runway filling the screen in milliseconds – we’d just dropped out of the sky, for that second or two there was no flying involved, we’d just fallen straight down.    It’s a moment like this that makes you appreciate being in a C172 and not something with less power.  However, Cambridge is a mile long runway, so once recovered and flying again, the CFI said I could just re-land it a bit further down the runway – it meant we had to back track after landing but, still better than a full go around.

Back on the Ground Safely

Once safely back on the ground with time to reflect, the CFI said that the natural reaction of trying to pull back on the controls with only a little power would have been absolutely no good and we’d probably have just slammed the tail of the plane into the runway – he also said it was probably the worst wind shear he’d been in, I take that as meaning it was about as bad as it can get.

Still, it was recovered, we landed safely and I felt I took some good things away from it all – even if we didn’t reach our destination, the real skill in aviation is to know when to quit, rather than just press on regardless 🙂

Farm Strip Skills: Learning to Land (again)

Friday, September 19th, 2014 | Permalink

This is short (4 hours) course the club runs for Post-PPL members, focusing on improving short field take-off/landing & cross-wind technique at the little grass (often unlicensed) farm strips that are scattered all over the country.

Marshland Farmstrip

Marshland Farm Strip

Three big reasons I wanted to do this course:

  • I’ve landed on Grass runways at Cambridge & Sywell, but I’m not sure I’d be confident to even attempt to find a grass strip like Marshland – let alone try landing there!
  • There’s < 15 concrete runways in a 60nm Radius.   At 1-2/month, I’ll have visited them all within the year. Having the skill set and confidence to go to the ~30+ farm strips in the same radius will keep things much more interesting – then I can go back to the ones I like, as I like, not just because I’ve ran out of ideas.
  • Everyone I’ve spoken to who’s done it said it’s great fun.

Lesson 1 :  Revision at Cambridge (Grass)

I’d expected the briefing to be a drilling on how well I knew my 172SP Pilots Operating Handbook and associated performance facts and figures.   I’d done some brush up revision just in case, but actually the briefing was considerably better and all round more interesting then I’d imagined possible.

Some interesting facts & history about why even spotting a farm strip from the air can be hard (Windsocks might be considered an “invitation to land”, that can lead to all sorts of insurance issues.  Or you might actually dare use it for wind information, but what if they’ve tied it down for the day?).   Remember most of these places are unlicensed, they’re not required to have a windsock, if they have one there’s nothing stopping them tying it down to a post.   Runway centre lines & other such markings are optional :-\   you get the idea!!   If not just look at that picture of Marshlands again:  Runway or someones’ back garden?

Landing Technique:  Point and Power

I was taught the following landing technique, I suspect 95% of all PPL students were taught the same:

  • Power controls ALTITUDE
  • Attitude controls AIRSPEED.

So if you look low, add some power.   If the airspeed drops below 65 knots, point the nose at the ground more – if that makes the picture look low, add some power.

What does this mean in practice?    More often then not, you’ll find you’re landing with all the power OFF maybe 200-500ft above the ground with about the same distance to run.   Now if you’re still high, what can you do about it?   Nothing!    In Control Theory speak, you’re now technically out of control.

Not quite true, you might argue with me that you could side slip – fair enough, but perhaps go back and read the Flight Performance (PPL4) book again, one major risk with side slipping is your airspeed indicator will begin to read significant error, not entirely ideal, especially if you need to land on a specific point and therefore fly an accurate airspeed to that point.

Point and Power Technique reverses this idea:

  • Power controls AIRSPEED
  • Attitude controls Altitude (point the nose where do you want the plane to touch down).

Now the idea is to point the nose at the landing point and keep that point constant, if that stays constant, you will touch down there.  If pointing the plane at that particular angle causes the aircraft to lose airspeed, add power to get the airspeed back.   Now we’re in control of where the plane lands, we could theoretically point the plane quite considerably at the ground, so it’s less likely we’ll run out of elevator control then it was in the previous technique that we’d run out of power control.   If we find we don’t need power any more, the plane must still be aiming at the point we want it to land.

Point and Power is the technique used by all airliners, it becomes obvious why when you remember that fast jets use Auto Throttle:  Set an airspeed on the computer and all your left with Elevator control to point the jet at the bit of runway you want it to land on.   The computer will do whatever it takes to ensure through all your pushing/pulling, airspeed stays at the set final approach speed.

If Point and Power Technique is so good……then why isn’t this taught to all PPL students first???

Browse google and you’ll find a rare few instructors pondering the same question, but I’d draw your attention to the fact the same thought is asked in PPL Book 4, Descent and Landing Performance.  There the authors offer 4 explanations why PPL students are taught to use Attitude to control airspeed first:

  1. If airspeed is critically low, pitching nose down is a safe option as it reduces wing loading (therefore reducing the stall speed – and thus increasing the safety margin to the stall while increasing the airspeed).
  2. Aircraft can stall irrespective of power setting.   They stall because the Critical Angle of Attack has been exceeded… reducing the Angle of Attack by pointing the nose down, takes you further away from the risk of a stall.
  3. In the event of Engine Failure, the control column becomes your only means of controlling airspeed.   In an emergency humans revert back to the training drilled into them – in a student PPL’s case, this would then be to control the airspeed of the approach with the control column.
  4. At slow airspeed, pitching nose down remains consistent with the training for Standard Stall Recovery.

Essentially:   For an inexperienced pilot, it’s safer, but at the expense of accuracy.   As landing distance available gets closer to landing distance you require, you could argue that a precision landing becomes a safety requirement.   No points for avoiding the stall, but floating down the runway and crashing at the other end!!

Almost all the Grass Runways

Cambridge has 2 Grass runways (4, if you count them in both directions):

  • 05/23 Grass  :  899 m  (2,949ft)
  • 10/28 Grass  :  699 m  (2,293ft)

The POH for a 172SP says on an average day, landing on grass at ~1000ft elevation, you’ll need ~2,260ft from 50ft above the runway.   So being 50ft over the 28 runway numbers is going to be cutting it a little thin!!   However, only 870ft of ground roll is required, so if we touch down ON the 28 numbers, we should half the runway left when we stop – that sounds a lot better.   Perhaps that gives a real world example for when accuracy of landing technique & touch down point becomes as important as not stalling it at 50ft.

Plan of attack was to go do a couple of touch and goes on 05 Grass, then if that was ok and the cross wind would allow try 28 Grass.

If the wind gods really played fair, possibly even try 10 Grass, but that was looking unlikely with the wind.

Practice doesn’t hurt

To avoid embarrassing myself too much, I’d recently flown 05 grass solo.   If nothing else this helped my confidence and didn’t leave me flapping on the first circuit wondering when to turn and worrying about finding the runway.

It’s been months since I’ve taken instruction while landing a plane, so that was a little bit strange.   I’ve got quite used to my passengers going quiet at this point and just focusing on the task of landing.   Now I was working to land it while not looking like I should never have been granted a pilots licence!, listening to the instructor and trying to best apply a new landing technique.   It wasn’t as close to the numbers as I’d have wanted, but it was a decent enough grass landing with a good touch of cross wind technique required for good measure.   My one mistake I wanted to correct was that I’d not fully appreciated the wind on the turn on to final, as a result I’d turned a little to soon.

A mistake I’d occasionally found myself making on my solo grass circuits, was forgetting to raise the flaps on the climb out (Yes it’s on the checklist).   The reason for this is that on the main runway, you’d raise the flaps fully while on the ground roll, on the grass you raise them to 10 degrees – the grass runway also has a lot more going on in the ground roll, the bumps, re-setting the flaps, getting the power back in a much shorter distance.  I made sure to correct this now,  above 200ft with a positive rate of climb :  Flaps up.

Under careful instruction, I was flying the final approach a lot closer to the stall speed then I’d ever allow myself.   I fly final approach at 60-65 knots.   Now I was aiming to fly an accurate 50 knots (172SP POH says with flaps down it stalls at 48knots, so you get the idea!).

28 Grass :  The very under used runway.

Another acceptable 05 grass landing out of the way and with great support from a friendly Air Traffic controller, we repositioned to fly the 28 Grass circuit.

 In the 2.5 years it took to get my licence, I’ve landed on 28 Grass :  Once!

I’ve landed on shorter grass runways, to date the shortest grass runway I’ve landed on is Northampton Sywell 05 Grass (602m / 1,975ft) with passengers.   But all the same, without a crisis forcing the situation, I wouldn’t have dreamed of electing to ask for 28 grass on my own.   It comes with many headaches:

  • It’s a very under-used runway, ATC need to be in a good mood as you’ll be getting in the way of everyone to fly its circuit.
  • The climb out is straight out over central Cambridge – engine failure?   The options would be ‘interesting’ and limited (a football pitch or broke basically).
  • It’s 700ft shorter than 05 grass – as illustrated above, touch down early or the book says you might well find yourself running off the far end.
  • Where is the circuit for this runway again?

With an instructor though, it was making my day to have a go at landing on 28 Grass, it’s been ages!!

A jet at Cambridge meant ATC had to ask us to not turn base leg until we were 2.5 miles away.  This would mean flying in over Fulbourn, not sure they’d be thrilled.

Much more emphasis on the Point & Power technique, final approach felt like flying right on the edge of the stall.  Indicated Airspeed was 49-50knots, as we broke 100ft height the stall warner was intermittently bleeping away, my immediate reaction was to go for the throttle – the instructor assured me it was ok as long as it wasn’t constant.  In every way imaginable, this approach felt like a more advanced landing then I’d ever tried to do before, I can only imagine the heart attacks I’d have given other instructors if I’d tried flying approach with the stall warner going off/on/off while not even over the runway!  Of course I’m a little more experienced then a student having their first go and learning how to get it down and stopped on the limits, is the point of the training.

With the wind, we must have had a ground speed of 35-40 knots and touched down just a tiny bit past the numbers.   The plane would have stopped in a heart beat, we’d used maybe 1/4 of the runway and were back on with the power.

I’ve never took off from 28 grass, the climb out feels insane, you’re climbing up over the outskirts of the city essentially and you’d never normally be allowed to be at 1,000ft over the houses.

I was hoping second time round on 28 Grass would be a charm, but if anything it was a touch worse.  I felt a bit more comfortable now withe the airspeed sitting at 50 knots and with the line of trees that await you on the approach, all be them 700ft from the 28 numbers (~10 seconds of flight time from crossing the trees touch down).

What I couldn’t quite perfect was that at these slower speeds, the controls were less responsive then I was used to and so need more input, more immediately…… not a million miles from what goes wrong when you first try to master landing.

Back on to 05 Grass

Another touch and go on the grass, but this time I tried too hard to bring it down on the numbers and we bounced.

Demonstrate you’re a safe pilot first and foremost:  So I just pushed the throttle right in, got the airspeed back and declared “Golf Romeo Charlie Going Around”

It could have been landed, the instructor was quite clear that he didn’t think it had been a huge bounce and far from the ballooning they drill you to not hesitate on going around for.    On my own I think I might have gone to land it, but with an instructor it felt too hard and with so little touch down speed, I wanted to take no chances…….Subconsciously perhaps my biggest fear was reaching the end of this hour and being told I wasn’t good enough and the lesson needed to be repeated before continuing.

One final go, this time to land.   I’m so used to having some degree of float, that this time I was simply aiming to far before the runway.   The result was I had to add power just to reach the numbers, not ideal either, but it highlights the difference 15 knots of approach speed has on your ability to float down the runway……approach at 50 knots, forget floating.

All in all….

Considering that on face value, this was “just” circuits at my home airfield.   I enjoyed myself immensely!   I felt I learnt a lot from only 50 minutes in the air and that the theory explained in the briefing, I could now fully appreciate from practical experience.

A few more grass strips and I might actually be able to do it properly and be confident to do it on my own without vast experience and wisdom in the right hand seat talking me through my mistakes 🙂