One of the easiest parts of the PPL is the cross country, after all you only have sit there, fat, dumb and happy and look out of the window! Strange then that students, and even instructors, tie themselves up in knots with this very simple exercise.
Lets start at the beginning.
Planning on the ground is everything with cross country flying – a cockpit in a light aircraft is not the best place to have to completely plan a new route or make a major adjustment to an existing one.
We need to consider some important planning aspects before flight, let’s start with 3 essential items:
Obtaining the latest aerodrome forecasts (TAF) and actual reports (METAR), together with en-route weather information are essential for any cross country flight. Always ensure the information you obtain is current. On one particular internet site the TAF and METAR for Birmingham was for a long time 9 months out of date! I have also seen people mistakenly plan cross countries with yesterdays weather!
I always work on the premise that forecast Wx is valid for 3 hours only.
I sacked an instructor once for trying to send a student on a qualifying cross country with just a Metar for the two destinations, no forecast at all, ( the forecast in fact was out of limits) incredulous! A year later an instructor on the same airfield sent a student on a QXC and he spun in on the approach in an 8/8th cloud base at 200 feet and was killed.
For student solo cross country our minima is virtually CAVOK – max wind speed 15kts, max crosswind 10 kts and no cloud below enroute safety altitude. All flights must be planned to land 1 hour 30 minutes before sunset.
Make sure you take enroute weather into consideration too.
It’s embarrassing on a student cross country to find out that your destination airfield has an air display with you arriving centre stage! And oh yes, it has been done, several times! I can also remember a student flying to an airfield where it had closed for the day for motorcycle racing! You must check the notams before flight, not only the destination but your alternates too and enroute – flying through the national gliding championships can really spoil you day!
Get away from this ‘half tanks’, ‘full tanks’ and ‘Christ the fuel is the low’ type of fuel planning, be professional. Making off the cuff statements like, “well you only need xyz amount of fuel to go to Clipton Shagsbury and back” isn’t professional planning, it’s sloppy planning. By all means load full tanks (if it doesn’t have a weight penalty) but don’t just plan a flight on full tanks its a very bad habit to get into!
Work backwards! Consider this, you’ve just had the worst cross country experience of your life and you are sitting at the diversion airfield with 30 minutes fuel left in the tanks, having a coffee in the airfield cafe complimenting yourself on your PRE FLIGHT PLANNING.
Now isn’t that a lot better than being in a farmer’s field up the road with the local fire brigade trying to cut you out of the wreckage! Always think about how much absolute minimum fuel you would really like to end up with in the tanks, on the ground after an emergency diversion and then work backwards to get to that point and that’s how much fuel you need!
Running out of fuel, you think I am making it up? I can remember one very experienced PPL taking a Cessna 150 aircraft with long range tanks from Coventry to Liverpool and back. Except he never made in back, he ran out of fuel and landed on the roof of a factory at night on the approach to runway 15 at Birmingham. Great picture of the fire brigade trying to get him down on the front page of the local paper!
Even airliners run out fuel, in 1953 an Aer Lingus DC3 from Dublin to Birmingham landed in a farmers field near Alcester after it ran out of fuel in the descent for Birmingham.
An Alidair Vickers Viscount ran out of fuel on the approach to Exeter and again landed in a field.
A BMI Argonaut on the approach to Manchester crashed short of the runway in Stockport after running out of fuel.
The moral of all these stories is very simple: You need to load enough fuel for the flight and diversion and manage that fuel.
So again going back to sitting in that cafe, how much fuel would you like to know are in your tanks now as an absolute minimum to land. My choice is 30 minutes – I never ever want to be in the air with 25 minutes fuel left in a light aircraft. I want to be landing with a GUARANTEED 30 minutes fuel left as an absolute minimum and that is AFTER an emergency diversion. For a normal flight I would always expect to land with at least 45 minutes fuel minimum ( we say 1 hour for students)
So we now need to consider this for an aircraft that burns five gallons per hour at normal cruise power setting, mixture full rich, at a speed of IAS 90 kts (still air)
Taxy fuel 1 gall
Flight fuel Sleap- Halfpenny Green – 20 minutes = 2 galls
10 % contingency = 1 gallon
Circuit & land = 1 gallon
Diversion fuel, either back to Sleap or Wellesbourne = 2 gallons
Circuit & land = 1 gallon
Plus min 30 mins fuel left or 1 hour for students 3 galls or 5 gallon.
Total minimum fuel on board for engine start = 13 gallons
Also consider that you need the same amount of fuel to go back from Halfpenny Green. So working backwards if you do not refuel at HG you need to add the total forecast fuel burn to your 13 gallons making 18 galls(inc cont). So if we set off with 18 galls from Sleap all should be well! Unless of course you get lost enroute, yes trust me to spoil it for you but you know some people do get lost and that’s why I always add an extra 30 minutes fuel to a student cross country!
OK you have got the fuel, really? How do you know how much fuel is in those tanks. Remember my adage, never trust one man, one instrument, one gauge or one engine. In the technical log there should be a fuel log which is crossed checked against aircraft time in the air and fuel loaded. For instance if you have a 20 gallon tank(useable) and an aircraft that burns on average 5 gph after 3 hours flying you expect to load 15 gallons back into that tank to bring it to full tanks (if you started with full tanks). If you load say, 19 gallons into it-you have an error or a problem! Without some form of reconciliation like this you cannot cross check fuel contents-so you are back to ‘one gauge’ territory and I don’t like it! Every aircraft should have a properly calibrated dip stick as this is the most reliable way of checking fuel contents. Do not fly aircraft with faulty fuel gauges, your life could literally depend on those gauges. Landing on a factory roof at night is definitely not the way to end a flight although it makes for a very interesting log book entry!
Route & airfields next