November 20, 2019

No-go, again

Unfortunately, but this time for a very good reason. But first I’ll take you through last night’s time-line. Readers have probably realised by now that over the past many weeks I’ve become something of an expert on southern UK and French weather. Or if not an expert, an obsessive at least.

As usual when I’ve been waiting and watching for a suitable weather window for my flight to France in 24ZN, the last thing I did before going to bed last night was… check the following day’s weather. And this was especially important after circumstances forced me to miss yesterday’s super flying conditions (closure of Headcorn due to air ambulance being on the ground there attending a serious road traffic accident) and with having moved the aircraft there in anticipation of an early morning departure today.

I should make it clear that ordinarily today would not have been my first choice as it has been evident for some time that the window it presents would be a fleeting one with high winds moving in in the next day or so throughout the length of France, in the south of England and, of especial importance, in the English Channel. However, by moving 24ZN to Headcorn I was more or less forcing myself to go for the crossing today.

But last night’s weather check revealed that whereas if I’d managed to get away yesterday I’d have faced fairly benign winds in France, that would probably not be the case today. Not so bad as to preclude the flight but with a headwind the whole way that would have made the flight hard work at the very least.

But that wasn’t my only consideration. The short hop from the private field where 24ZN had been parked to Headcorn had not been sufficient to give me much information on its flight characteristics. Sure, it had flown as well as I’d remembered it did when I first flew it several years ago but when planning a long flight the likes of the one I’m intending to do, you need to know pretty much exactly what its cruising speed will be and how much fuel it consumes.

And I really didn’t have a handle on either of those two things. This may not be too critical if you’re going to fly for the most part with a good tailwind but the reverse is true if you’re anticipating a headwind, especially if it will be strong and variable. And that was the picture that was being presented to me last night.

Being an ex-corporate planner, it’s pretty much natural for me to investigate how numbers react to changes in inputs and when I plugged in alternative assumptions for airspeed and fuel consumption, it became very clear that I could well find myself running dangerously low on fuel in more than one sector of my planned flight.

I went to bed early but awoke after a few hours with such thoughts still in my mind. On re-checking the weather data, things had in fact got worse in the few hours since I’d last used them in my flight planning spreadsheet and to cut a long story short, I found myself at 5.00 am this morning completely re-working my route to take the more negative wind assumptions into account.

The fact is that at any moment in time, nobody knows how ‘right’ any forecast will be. Sure, we know what the final outcome will be within certain reasonable limits but even analysis of historical data, a lot of which I’ve been doing just lately, cannot tell us precisely what those limits are. So in a case like mine where ‘failure’ might mean running out of fuel with possibly disastrous consequences, it makes sense to identify the downside and plan accordingly.

I’d covered my refuelling needs by leaving the UK with full, or almost full tanks and carrying two full 20 litre jerricans with me. My idea was to land at Abbeville where I can easily buy fuel and refill my tanks again there, conserving the fuel in my jerricans ahead of an extended leg to my next fuel stop just north of Chateaudun where I would then add the fuel from my jerricans.

But now the revised stronger headwind forecasts plus my ‘flexings’ of cruise speed and fuel consumption showed that if I made the second fuel stop at all, it could be with just a few litres left in my tanks, much less than I’m prepared to tolerate.

And the same thing would be repeated with my next planned refuelling and overnight stop at Le Blanc south-west of Chateauroux – that’s if I could actually make Le Blanc in a day given 24N’s likely cruising speed and the expected headwinds.

So it was clear that I needed to add in some extra intermediate refuelling stops together with alternative overnight possibilities and that I did by factoring in stops at Blois, where I know I can easily buy fuel, and Chartres where I could top up using fuel previously added to my jerries. And both locations could also offer overnight possibilities depending on the distance managed during the day.

There was also another wild card. I’d previously been advised by ATC ‘management’ at Le Touquet that so long as I didn’t intend coming in on a week-end and called before departing Headcorn to provide an ETA, the officer on duty would allow me to enter the zone and land there without the usually mandatory transponder.

This would be useful under current circumstances because it would preclude my having to head north to a first landing in Calais before continuing my flight south against the headwind. Luckily I took the precaution of phoning ahead this morning before leaving home and was told that landing at Le Touquet was ‘impossible’ without a transponder. This was inconvenient, of course, but at least I knew armed with my recent route revisions that I could still manage either Blois or Chartres today and was able to ditch all of my planning papers and charts that included a stop at Le Touquet.

And so I eventually turned up at Headcorn this morning slightly later than I’d intended but with the necessary French and UK paperwork and my flight-plan filed. I’d packed the aircraft the night before and only had to install myself, my small overnight bag and the equipment I needed for the flight before starting the engine, taxying and taking off.

The aircraft had been left out uncovered overnight and it was still only around 2-3 degrees Celsius but when I pressed the starter the engine cranked somewhat languorously but didn’t start. I repeated this a few times with similar lack of success and after less than a minute the cranking reduced to a slow turning of the prop.

For me this meant the end of my plans to depart today. At the very least the battery would need recharging but I already knew that it was a several years old Varley Red Top which I’d previously considered replacing as a precaution. How right my instincts had turned out to be, because there was no way that I could take the risk of finding myself in France with a dead battery and the aircraft parked outside in high winds with no tie-downs. I had to order a replacement battery to avoid such an eventuality.

I therefore had to return home to fetch my small tool kit to remove the battery and after having done so, on returning I tried the engine again after the temperature had risen a few degrees and naturally it started. The ATC man at Headcorn asked if I’d now be leaving for France but I’d made my decision, mainly because of the expected deterioration in the wind conditions. I’d already made arrangements to ferry 4ZN from Headcorn to Clipgate Farm where I’d done my microlight training and without removing the battery, that’s what I did this afternoon.

The flight over took twice as long as I’d expected due to the increasing wind strength and I succeeded in pulling off probably the best and most challenging cross wind landing that I’ve ever done in order to get in there. So 24ZN is now parked there outside but sealed under covers and securely tied-down and that’s where it’ll be staying for, I estimate, at least a week in order to ride-out the incoming bad weather and until I get hold of a new battery. I also noticed today that its fuel pressure at 0.2 bars at normal cruising rpm is at the minimum acceptable level so I think I’ll also order a refurbishment kit for its Mikuni fuel pump. I’m fairly certain that I’ll have sufficient time to fit it.