Saturday, October 20, 2007

Aerobatics - Spinning

Well the weather was perfect for aerobatics today. High pressure (1034 mb!) and clear(ish) skies, bit hazy but probably fine above the inversion.

I rocked up at the airport to find a TV camera and loads of police wandering around. At first I thought it might be some sort of minor VIP arriving, but as I was checking the plane out, three police wandered past airside, so I asked them what was going on – ‘There’s a protest at the proposed runway extension and we think they might try a runway incursion’. What? All because Gloucester are extending the runway by some 20 metres and bulldozing the house at one end of the runway so they can get back some of the displaced threshold? Just how wrong can local NIMBY’s and so-called environmentalist’s get their facts? The will never be any 737’s in garish orange livery at Gloucester – chill! The runway is simply and never will be long enough!

Anyway, I check the plane and despite a clear note in the booking folder to leave it half-full maximum, some ‘helpful’ joker had filled it to the brim, thus making it too heavy for controlled aerobatics. I met Max and gave him the bad news, but he took it well – and in his finest Gloucestershire burr said ‘I knew that would happen sooner or later – but that’s OK, we can do spinning instead’. Apparently, the Robin won’t spin with less that ¾ of a tank.

So I had a good briefing from Max. The Robin is apparently very marginal and very hard to spin properly, so far so good I guess? Then he goes on to explain ‘…..and if you DO get it into a spin and hold it in for more than three rotations, the engine cuts out, so you have to exit the spin and restart the engine’!!!! Uhhhh – is it just me or doesn’t that sound too good? ‘Oh, it’s no problem, just press the restart button and it gets going again fine’. Yeah right!

So it also spins better to the right than to the left and if you don’t get it right, it will go into a spiral dive – c’mon Max, you’re just trying to cheer me up now!

So we go through the spin entry, which is power to 1800 and pull back in classic ‘slow flight’ manner until the stall warner, then progressive right rudder and pull fully back and away she goes. Hold it in the spin with rudder and back pressure, then recover on his command, probably after two rotations so the engine doesn’t cut by power off, then full (or near full) opposite rudder and unload the back pressure on the stick to neutral – wait for the spin to stop then pull to level - don’t push forward or you will push it past the vertical. Oh, and look up to the horizon to establish the spin direction, NOT along the line of the nose or you will get a ‘plug-hole’ effect and get mesmerised by the spin. Oh yes, and things will happen pretty quickly.

OK - so it's and Extra 300 - but you get the idea!

OK, got all that as I mount up. We trudge out the long march to runway in use 09 and take-off. She flies herself off as I set course to the north east for our favourite stomping ground around Evesham. Climb past the inversion layer at 3500’ to 5000’. A few puffy cumulus along the inversion layer, but some big clearings so no worries.

Usual HASELL checks and Max demonstrates the first one and talks it calmly through. All I can say is ‘Holy cr*p Batman’ as the world rotates rapidly around me with us in a steeply nose down position as I watch the ‘plug-hole effect exactly like he told me not to do – DOH!

‘OK – did you follow all that’ he asks as he climbs back up to height and explains what he did, when and why as I try desperately to clear my head and figure out what the hell happened – my first spin – WOW! ‘OK – do you fancy a go’ he asks about as casually as you would if you had just shown someone something on a spreadsheet! Someone else in the cockpit with a voice very similar to mine answered with a confident sounding ‘Yep – let’s give it a crack eh?’ – can’t have been me, I was still trying to figure out what the hell happened!

So I give it a go. A bit slower and more considered on the controls with a more sluggish entry and exit and some intervention from Max as a result. But I did the right things in the right sequence and even managed to look in the right direction this time, so I get the idea.

Anyway, we do a total of three (or maybe four) to the right then three to the left. I have to say, I really think I got it in the end there and began to lose my fear (but not my respect) for the spin and the recovery.

The cloud is starting to box us in and we are still with ¾ fuel – so no quick aeros, instead a steady crawl back to Gloucester for a standard overhead join for 09. Landed long on the runway (as is normal for 09 – or you have a long taxi to the exit and make the guy behind you go-around).

On taxi past the western apron, I noticed four Cabair DA40’s parked in formation. Max explained that on a day like this, the often sent studes out for their QXC one behind the other, so they could ‘follow’ each other on the radio.

Taxi in and shut down. Debrief was good. I really think I got it then and look forward to getting back to ‘normal’ aerobatics next time. But I have to say, I managed to get a nice headache and was wired on adrenaline for the next three hours. Spinning is pretty terrifying at first, but once you have got the hang of it, it’s just another aerobatic manoeuvre, albeit one that chews through the altitude.

Wow – really enjoying this stuff!!!

Monday, October 08, 2007

Aerobatics - Lesson 4.5

Fourth full lesson on aerobatics. The weather didn’t look too clever. Fully overcast, but not too low. Before setting out, I estimated cloudbase at anywhere between 3000’ and 3500’, so could be marginal whether I fly aerobatics or not.

Turned up and saw Max. He said the cloudbase was 3400’ and probably rising as the day wears on, so we should be OK – so out to check out the plane. Filled to just over ‘one tick’ on the gauge (four ticks is full). I checked with Max and he confirmed that with us two larger guys, that would be ideal. Usual start-up, taxy and take-off. Again headed to the ‘aerobatics playground’ to the north-easy, not far from Evesham. Base is at 3600’ but opoor horizon as it is fairly ‘high pressure murky’. Usual HASELL check and off we go.

Rolls
First one not so good, but I think due to a mis-understanding. He had told me earlier to pull up to 45 degrees and that is what I was doing checking the wing angle against the horizon. In fact it should be 30 degrees. Tried again with much better results. Now flying alternate left and right rolls so I don’t become ‘handed’ and always favour one side. I am feeling pretty comfortable with simple ballistic rolls now.

Loops
I am now flying all aspect of the loop, including judging when to pull the power. First loop was not great – I saw a clear roll angle relative to the horizon in the inverted. Max thought I had not pulled straight, apparently a common fault. Next loop was better, but we only just ‘got around’ as I didn’t pull hard enough at the start. It was also interesting as at the top of the loop we entered some cloud! The rest of the loops seemed OK. I think I am starting to get there slowly on these.

Stall Turns
First couple were Max doing the throttle and aileron and telling me when to hit the rudders. They went fine. Then as I hoped for, my turn to do the lot, including deciding when to reverse the rudder.

Off we went. Hard pull up to the vertical, full power then centralise pitch. Check vertical by reference to the angle of the horizon (such as it is) against the wing. Feed in more right rudder as the slipstream coils tighter around the fuselage with reduced airspeed. Am I out of right rudder? What’s next? Oh yes, hard reverse rudder to full left and simultaneous right aileron. Looking for the point at which the aircraft is horizontal (called ‘knife’), before pulling off the power and centralising controls for the vertical dive back down, then…...

……..WHAP!

I think the aircraft was coming around to ‘knife’ when very suddenly the ground and horizon did something very peculiar as it took a second or so to register with me – all I could think is a rather feeble ‘this isn’t normal!’. The aircraft had stalled part-way through and flicked onto it’s back and in a heartbeat we were nose straight down picking up speed. Before I could figure out what was happening and manfully chicken-out with a ‘you have control’, Max stepped in with an ‘I’ll take it’ and recovered.

OK – interesting that one!

Max explained that he had done so many stall turns that he found it fairly hard to deliberately cock them up to show students what to do when it goes ‘pear-shaped’, so he thought the best way was to give me a go! Well any time you want help screwing something up Max, just let me know – I’m your man!

Max explained that what had happened is that I was late in reversing the rudder and not quick enough in the reversal. As a result the aircraft had become too slow and had stalled part way around, flopped over on its back and headed vertically down. Max simply closed the throttle and carried out a standard pull to horizontal. I would probably have got there, but not before the aircraft ‘red-lined’!

OK, learned a lot there! I was thinking too hard and running what I was about to do through in my mind first causing me to be too leisurely about the whole thing. I am somewhat comforted by the AOPA book saying that the stall turn was probably the toughest of the basic moves. Well, I have a lot to learn yet, but got some valuable experience from that one.

On the 15 miles back to the airfield, the fuel light started to blink menacingly. Max was fine with it but did say when it went solid red, get a straight in approach and land immediately. As it happened, we were given a standard overhead join as the scheduled flight to the Isle of Man was landing. Max had me carry out a flapless landing what went pretty well, except that the Robin really does not have much room between the relatively slight nose-up flare required and scraping the tail protector, I can tell you!

Again, another good lesson from my point of view, not my performance you understand, but what I have learned.

Monday, October 01, 2007

Aerobatics - Lesson 3.5

The forecast didn’t look at all promising, but as ever in the UK, you really don’t know until the day itself. Looked out on Sunday morning and saw what looked like alto-stratus, fairly thin and I estimated at least 4000’ – so looks like I am on for aerobatics!

Rolled up for a 10:00 session and Max was on time as usual. Got another brief on – you guessed it, rolls, loops and stall turns!

Checked the aircraft out and cleared out all loose fittings – it wouldn’t do to have a fuel tester loose in the cockpit!

Started up and cleared to taxy. Minimal wind but runway 09 in use. Unusually, it was so quiet at Gloucester (despite the METAR giving CAVOK), that I was given a full backtrack on 09, with approval for power checks on the active runway itself – why so quiet?

Off we went and the Robin quite happily flew itself off as usual. Climbing at 75kts initially and set course for the north east and the lower land between the triangle formed by Bredon Hill, Evesham and Broadway – using the Toddington railway line as a linear feature to line up for the aerobatics.

We made 4000’ easily and I would guess there was another 1500’ before the thin cloudbase.

Rolls
First one not good. I didn’t pull up far enough and was a bit leisurely with full aileron input, so as a result, I was ‘punished’ with a significant nose down exit. On the up side, I knew what I had done wrong before I was half way around. Next roll of course I pulled too much, bled off too much airspeed and yes, nose down exit. But again, I knew what I had done. The next couple were good. Oh well! You learn more from your mistakes etc….

Loops
The first two were with me doing most of it, but with Max pulling the power off as we started to loop back down. Then the third loop, I got to do the whole thing myself – which I thought went well – certainly, I rolled out on the direction of the railway line I started on. I was warned to pay more attention to starting with wings level and pay more attention to keeping it that way.

Stall Turns
He is nursing me into this, and I can certainly see and understand what he is doing. But of course, there are quite a few things to do at the top of the climb in fairly rapid succession. I was doing the pull-ups and the vertical climb. On the last of them, I was whacking in full opposite left rudder when he told me to, to get used to the speed at which you have to do it. I fancy next time I’ll be doing most of it.

All too soon, back to the airfield, calms down a bit and get the ATIS. Given left base approach for 09 not below 1500, and slot in behind the PA28. I saw the PA28, (500’ below) which was a bit too close to slot in behind, so started an orbit. About half way around, there was a flexwing microlight, happy as larry, bimbling along the Severn at 1700’ (yes, inside the ATZ). So keeping a close eye on him, we orbited underneath. Hopefully he realised that bumbling around inside at ATZ of a busy airfield is not such a hot idea.

Back to the circuit and a nice floaty and slow landing, long on 09 to save the long taxy to the end.

Well, probably one step back then two forward this lesson. Rolls were not as good as last lesson until the last two, but then that is the nature of learning – certainly, I can now see what I am doing wrong and correct. I guess I would hate to ‘accidentally’ get it right every time, then when I solo, have it all go pear-shaped.

I will internalise all that I learned during the coming week by ‘flying at the coffee table’ – yep, with my eyes shut, hands on imaginary stick and throttle and feet pressing imaginary rudder bars and mouth mumbling through what I am doing. Give it a try – it really works.