Category: Tips

Calculating cross wind and headwind

Posted on November 17, 2025 by Mike Naylor - IMC rating, Navigation - PPL, Tips

We need to calculate or estimate cross winds for several reasons

To check whether the cross wind is within limits for take-off and landing
To calculate wind drift (the difference between heading and track) on a cross-country flight
To estimate wind drift for an unplanned diversion
To calculate wind drift / heading correction on an instrument approach

There are several ways we can go about this this.

- For a cross country flight, calculate the required heading (and implicitly the drift) before flight using our trusty CRP-1 (Whizz wheel) or with a planning app like SkyDemon, or with a wind protractor.
- Use an app like Windstar to calculate headwind / tailwind, cross wind and cross wind drift, so we have the info ready to use when needed
- Use a graphical calculator, on the fly, like the one which I present on my VFR reference card
- Calculate the maximum cross wind drift using this formula: Drift = wind speed x 60 / TAS

TAS –>	60 kt	90 kt	100 kt	120 kt
Max drift	1x	2/3 x	3/5 x	1/2 x
	Wind speed in kt

And then estimate the actual drift, on the fly, using a simple rule of thumb

Roughly, ‘nothing, half, all’ rule

wind 30^o off, cross wind = ½ x wind speed and drift is ½ x max drift;

wind 60 ^o off, x-wind = full wind and drift = max drift

More precisely, ‘rule of sixths’

Take one sixth of the drift or wind

for every 10^o the wind is different to the runway or track direction.

And finally, how do we record the information we’ve derived? We could

mark the wind and max drift on the chart and do the rest in our heads
look at the app
put the info on a paper windstar and paper-clip it to the chart
write the info on the instrument approach plate (thanks to one of my students for inventing this!)

SkyDemon and IFR flight

Posted on October 6, 2025 by Mike Naylor - Advanced training, GPS, IMC rating, Planning tools, Tips

IRR students often ask “Can I use SkyDemon to navigate on an IMC training flight or test?”

The official and legally correct answer is “No”. SkyDemon is a VFR tool. Only certified,

installed GNSS navigators, such as an IFD550, GTN650 or GNS430 can be used to fly IFR and instrument approaches. Furthermore, the license conditions of SkyDemon expressly forbid its use as a primary means of IFR navigation.

In real-life flying, though, it is prudent to use anything which makes the task easier, provided it is not inherently unsafe or misleading. Many IFR pilots run SkyDemon in the cockpit as an adjunct to their formal navigation aids.

In what ways can you use SkyDemon to support your IFR planning and flying?

For route planning, use it to generate the data for an IFR PLOG (including VOR radials and DME distances from turning points)
For situational awareness, whilst navigating cross country
To display traffic detected from an external source such as SkyEcho
To store and call up instrument approach plates in flight
For situational awareness whilst flying an approach

There are a few set-up steps to be undertaken on your planning computer and in-flight device:

Mapping: in Airfield, enable show Radio Navaids and Airways Reporting Points (these are the 2-syllable, 5-letter names in the database of GNSS navigators)
Setup – Planning: enable ‘Show IFR features’ (otherwise Instrument plates will not appear when you look at aerodrome information)
Setup – Planning: set the MSA calculation to IFR (1000 feet above, 5nm either side of track)
Setup – Navigation – Moving Map – set the display to Heading up. In-flight, pressing on the Little North arrow (bottom right) allow you to Select Track up – which is the default SOP for GNSS navigators.

For route planning, we can do all the normal stuff to generate a PLOG, check NOTAMs etc. Flying IFR, we may route via Airways reporting points and the SkyDemon PLOG delivers everything you need to know. If we are using VOR radials and distances to achieve a desired route and avoid Controlled Airspace, we might construct these with SkyDemon to get really accurate Track, Heading and Distance. It’s a bit of a faff; I find it easier to draw the lines on a paper chart and measure the radials and DME distance. It’s your choice.

We can use Instrument Approach plates from SkyDemon in 2 ways:

Simply use your inflight device to display the plates – they should have downloaded automatically to your device before flight if you have selected the airfield as ‘Land here’.
As you get closer, the ‘Make Approach’ button will appear bottom left. you can select either Visual or Instrument approach for the desired runway. If you select Instrument approach, the relevant plate will be superimposed (georeferenced) onto your SkyDemon map. Unfortunately, the moving map goes back into North Up mode, as the georeferencing can’t cope with anything else.
You could also GeoReference the approach plate onto the SkyDemon display from the Airfields Tab, where the Instrument approach plates are listed, by using the ‘Pin’ button.

The georeferenced display are helpful for situational awareness, but not to fly the approach accurately – you need the radio navaids for that! not accurate enough to fly the approach– they are not a substitute for ILS receiver or certified GNSS navigator onboard!

Give it a try – ideally with a safety pilot onboard. In any event, don’t allow operating SkyDemon to distract you from the task of flying the aeroplane.

Navigating the PPL theory exams

Posted on February 27, 2025 by Mike Naylor - General, Regulation, Test, Tips

What are the theory exams, when do I need to pass them and how can I go about learning? These are questions that most aspiring student PPL’s ask, sometime even before setting foot in an aeroplane.

The basics

There are 9 theory subjects, each with between 12 and 20 multiple choice questions.
You must pass all the exams in 18 months. The 18 months begins from the end of the month in which you took your first exam (pass or fail!) – e.g. if you took the exam on the 10^th, you actually have 18 months + 20 days to pass the rest.
Your training organisation has to recommend you as ready for each exam.
You can take as many or as few exams in one go as you wish. You may have heard about the 6 sitting rule. Don’t worry – it has been abolished.
You can make 3 attempts per subject; a 4^th attempt requires CAA approval after mandatory re-training.
In the unlikely event that you don’t pass all the exams within 18 months, you have to start all over again. Don’t let that happen!
You must pass all the theory exams before taking the PPL skills test.
Once you have passed all the theory exams, you have 24 months (from the date of the last exam) to complete your training, pass the test and apply for your licence.

What are the subjects?

The 9 subjects are shown here, with the links and overlaps between them.

Do I have to start the exams immediately?

I’d always recommend having a few practical lessons, and make sure that PPL flying is something you want to do, before investing time and money in theory studies.

Is there a preferred order for the subjects?

To some extent this can be governed by your own interests.
Most theory subjects will help your practical flying in some way and to varying degrees. For example, you will find that meteorology helps in figuring out whether your lesson will go ahead, and if it is suitable for cross-country flying. Navigation theory will help you plan your cross-country flights, although some students find that the theory makes more sense after the first few cross country flights.

There are links and overlaps between the different subject, e.g. between Air Law and Operational procedures, between FPP (Flight Performance and Planning) and elements of Navigation and Principles of Flight.
If studying more than one subject at a time, it makes sense to pair one of the bigger, more challenging subjects with one of the easier or smaller ones.
Your training school will recommend what order to do things. Some require you to pass certain exams (for example Air Law, Human performance and Operational Procedures) before your first solo flight, and other exams before going solo cross-country (Navigation, Communication, Meteorology). The order shown below is a good approach.

How can I study for them?

The CAA don’t mind how you study, but bear in mind you will have to demonstrate readiness for test to your flying school – your school may set you a mini-quiz for example, or examine the scores you have been getting in an online question bank.
Choose a method that suits your personal learning style and your own self-discipline (or lack of it). Options include
1. Self study from books
2. Self study from e-learning materials, which usually have an integrated question bank with progress tests and mock exams.
3. Self study, topped up with some one-to-one tuition from your instructor – perhaps focussing on the bits you ‘don’t get’ or would like to know more about
4. Classroom ground school at your flying school, in a group or one to one. Traditionally these were face to face, but Zoom works just as well.
5. Intensive one-to-one or small group ground school over a week or so – there are a few schools and individuals who offer this.
Do you have specific recommendations? Of course, please get in touch.

It sounds expensive, how can I economise?

Exams fees are about £50 each, so don’t waste money by failing a test because you’re not ready!
A set of books will cost around £100 to £150 and a set of practice paper books (highly recommended) are about £40. You could buy books second hand, but check that they are up to date editions.
Online learning materials and question banks typically cost £5 to £15 per subject per month. They are cost effective if you focus, learn quickly and move on to the next subject.
All inclusive intensive ground school for 9 subjects is of the order of £1000 – £2500. This is an approach which people who are short of time (but not short of money!) use. Whilst they will get through the exams, you may find you don’t retain much of the knowledge afterwards.
Top-up instruction, from your own instructor, is about £30 per hour.
Clearly the most economical approach is self-study, perhaps augmented with selective top-up instruction.
With e-learning, you might avoid buying any books, but many materials lack the detailed, personal explanation you may need to understand a difficult subject.

Anything else?

An RT practical exam (the FRTOL exam) is also required. It is not one of the 9 subjects (though it does require a Pass in Communications theory). It does not have to be completed within the 18 months and can be done before or after the skills test (but you can’t apply for your licence until you have passed it).
We recommend that you pass the RT practical exam before your qualifying cross-country (QXC) flight.
I’ve heard that the exams are now Online? Yes, that’s correct. We’ll write more about that shortly.

And finally, remember – your aim should be to become a competent, safe and well informed pilot, it is not just about ticking the exam box.

Buying an aircraft share – eyes wide open

Posted on April 16, 2024 by Mike Naylor - Advanced, Aircraft, Tips

So you’ve got your PPL. Congratulations. Now you want to buy an aircraft share. What do you need to think about? I’ve tried to summarise key considerations in this blog but the most important advice is to avoid an impulse buy, and get advice – your instructor may be a good starting point n how groups work, and a licensed engineer may be able to help on the technical and mechanical aspects.

Firstly the aircraft – is it what you need?

What is your ‘mission’ and is the aircraft suitable for that. Local bimbling or hour-building on your own, VFR touring with family, IFR training and flights will each set different requirements. If it doesn’t meet your needs, you’ll get frustrated. If it exceeds your requirements by a long way, you are paying for capability you don’t use.

Is it a match for your abilities? A modest step-up is a reasonable ambition, but a big ‘step-up’ in performance or complexity may require a lot of additional training and mentored flights before you can head off on your own. The insurance company may also set a certain level of experience.

If you are considering something more exotic that a Cessna 172 or a PA 28, do your homework – find out about handling characteristics, known issues, maintenance costs etc. See and buy before you fly. If you’re starting a group, then follow all the advice about buying an aircraft outright – pre-purchase inspection, through review of maintenance records etc.

Secondly the budget – how much can you afford to spend?

Always buy comfortably within your means. With the best will in the world, there will be unforeseen costs, even in something as routine as a 50 hour check.

In most groups, you will pay a lump sum for your share, a fixed monthly charge to cover fixed costs like hangarage, insurance and annual maintenance, and an hourly rate which typically covers oil, fuel and the 50 hours maintenance checks. But some groups have different arrangements which may be more or less advantageous to a frequent or infrequent user.

Ask how the group funds upgrades and replacements. An inevitable big cost is the periodic engine replacement. Current regulations allow you to run an engine past TBO hours and calendar life, subject to annual checks, but the older an engine gets, the more likely that something can go wrong. A well-run group will put aside money from the hourly rate to contribute to an ‘engine fund’, and may have a fund to replace old tech with new. If that is not the case, I would shy away from an aircraft with a very high hours engine.

If you are the rookie pilot, the insurers may increase the premium and a group may expect you to cover the difference.

Thirdly the group – what is the group ethos? Sharing with like-minded people is important to avoid friction and disappointment later.

What is their attitude to upgrades and non-essential repairs? Are they a group who want to fly as cheaply as possible, and if that means a scruffy aeroplane, so be it. At the other extreme, are groups owning a cherished asset to be handled with kid gloves. A happy medium is a group which wants their investment to maintain value and are they willing to upgrade things periodically. If your ambitions and skills are different to the others, you may have different views on non-essential repairs, upgrades and investments.

Understand how much the other group members fly. For you, the ideal might be members who don’t fly much but always pay their bills. On the other hand, several frequent users might impact your plans, and a fair booking system will be essential.

Some groups are highly social, which means potentially you have a buddies with whom to share the cost and pleasure of flying. Does that matter to you? Do they have a preferred instructor for training and checkouts, or better still an instructor who is a group member?

Fourthly, where is it based?

An aircraft close to home will get flown more than one which is an hour’s drive away. Is the airfield suitable for your kind of flying – do you need access out of hours, the ability to land at night and in all weather? What landing fees are you going to be paying?

Fifthly, understand the group rules

There are many things to consider here…… the group’s currency rules? How are decisions made? Does the group hold regular meetings? What paperwork and log-book keeping do you need to do? How are bookings made? Is there a fair use policy to ensure 1 or 2 people don’t hog the aircraft? Can you sell your share to anyone you choose, or does the group set the sale price and vet potential new members? Who manages the money and maintenance?

Many groups use a first-come first served online booking system but have some proviso to ensure fair use and allow members to take the aircraft away for longer trips.

A VFR kneeboard reference card

Posted on February 9, 2024 by Mike Naylor - Flight Performance and Planning - PPL, Navigation - PPL, Planning tools, Tips

As part of my teaching toolkit, I offer PPL students a VFR reference card which fits on the kneeboard. A few people have expressed interest in it, so I am posting a copy here. Other handy planning aids can be found here and downloaded from here.

One side is for Planning with, for example, a checklist of items to be checked prior to a cross-country flight, the CAA take-off and landing performance factors, some Meteo rules of thumb and common conversion factors.

The other side is an In-flight aide memoire, with handy reminders of VOR intercept techniques, the standard closing angle for regaining track, checklist mnemonics, descent planner and a cross wind / drift estimator.

It’s written for a 90 kt training aeroplane, so will serve well for a Cessna 152 and PA28 Warrior. The original form is customisable for other aircraft speeds through an inbuilt spreadsheet.

Know your approach plates

Posted on September 30, 2022 by Mike Naylor - Advanced, Advanced training, IMC rating, Tips

When flying an instrument approach in a test, you’ll know ahead of time which approach is to be flown and can prepare on the ground. In real life, you may not be able to prepare in advance, so know your way around the plate so that you can extract essential information quickly.

Some pilots use unwieldy and generally unmemorable acronyms to brief the approach. I find that a flow, or visual scan, around the plate is a better way to self-brief. You can use a pen on the plate to highlight key information. The only elements requiring any maths are the approx. descent rate which varies with ground speed, and the all-important minima.

Presentations vary, but here is a ‘flow’ that works for the UK AIP plates.

Do I have to use the whizz wheel?

Posted on September 28, 2022 by Mike Naylor - Flight Performance and Planning - PPL, Navigation - PPL, Test, Tips

First a confession. I am a big fan of the flight navigation (dead reckoning) computer, a.k.a. the whizz wheel. Sure, it takes a little investment to learn how to use it, but once over that hurdle, it is fast and accurate.

A bit of history

The ‘flight computer’ was invented in the 1930’s by Lt. Philip Dalton, a US military scientist and US Naval Reserve Pilot. It was portable and intuitive. “Really?”, I hear you say! In those days. slide rules were how mathematical and engineering calculations were performed. They were adopted by the US and UK military and soon made their way into civilian aviation too.

And in the 21^st century?

In this digital age, virtually every PPL holder uses app’s on their smartphone for weather, navigation planning and maybe even for weight and balance. So is there an alternative to the whizz wheel in those pesky theory exams? Well yes there is.

An app (and there are many of them!) on a phone or tablet is not acceptable to the UK CAA– the concern here is that it is also a communication device and may hold other apps with which a candidate might cheat.

However, the UK CAA’s exam instructions state that a candidate may use: a “Scientific calculator, or a mechanical navigation slide rule (DR calculator), or an electronic flight computer”. Electronic flight computers were all the rage 20-30 years ago and Sporty’s E6B and ASA’s CX3 are still available, if you have £100 to £150 to spare.

Save your cash

Here’s the solution which several flying schools offer…. Buy Sportys E6B app for your phone and practice with that. It will cost under $10 on Android and a bit more if you insist on using an iPhone or iPad. For the real exam, borrow a Sporty’s E6B electronic computer from your friendly and helpful instructor. The user interface is well-nigh identical. Job done!

2025 edit – the CAA have now decided that electronic flight computers , in any form, may NOT be used for theory exams. You may still use them in the skills test, but expect to be tested on how they work and alternative manual calculations!

Geo-referenced instrument approach plates

Posted on September 5, 2022 by Mike Naylor - Advanced, Advanced training, IMC rating, Tips

Aircraft with sophisticated GNSS (aka GPS) navigators may have approach plates installed in the database. SkyDemon offers a simple way of accessing geo-referenced plates. It uses the AIP plates (whose format varies from one country to another). Geo-referenced? This means that they are displayed to scale, in the right location on the map display.

They are a great aid for situational awareness and for coarse positioning on an instrument approach. They should not be used as a substitute for receiving the relevant radio navigation aid (VOR, NDB, ILS, GNSS) using NAV equipment such as a CDI (Course Deviation Indicator).

Here’s how to go about it:

In Setup, Planning options, enable IFR features
Right click on Airfield, right click on Information
Click on Instrument Plates. Select the plate(s) you want. Green means they are available on your device. On some devices, you may have to click on individual plates to make them available offline
In flight, click on the Airfields tab. Click on the Pin symbol to display the plate you want. It appears to scale on the chart.

LSA’s in Europe (again)

Posted on July 31, 2022 by Mike Naylor - Advanced, Aircraft, Official documents, Tips

It’s the middle of summer, with travel plans made or indeed already flown. I’m returning to the question of permits for UK registered factory built LSA’s (i.e. UK Permit aircraft), which cannot be operated freely in EU members states without specific permissions. Below is a list of the permission requirements and processes for different countries:

SWEDEN – apply at https://www.transportstyrelsen.se/en/Forms/Aviation/Airworthiness/Application-for-permission-to-fly-within-Swedish-airspace-with-foreign-registered-aircraft-which-has-not-an-approved-ICAO-CoA-or-EASA-Permit-to-fly1/

IRELAND – fill out form 138C: https://www.iaa.ie/docs/default-source/publications/forms/airworthiness-application-forms/awsd-f-138c-rev-2.pdf?sfvrsn=c4ab0df3_20 with copies of Certificate of Registration, UK CAA flight permit, permit conditions (form 18B and the Datasheet). Send to arc@iaa.ie If o response, contact Ruth Bagnell, Aeronautical Inspector, Tel.: + 353 1 603 1463, Mob: + 353 87 279 8054, Ruth.BAGNELL@iaa.ie . There is no fee and the permit was for 12 months.

FRANCE – Step 1….. Go to https://redevances.dcs.aviation-civile.gouv.fr/index.php/laissez-passer-permit-to-fly.html/ and select “Validation d’un certificat étranger – MTOW < 5,7. create an account and reply to the confirmation email. Then pay 50 euros online. Take a screenshot of the payment page in case the pdf receipt by email gets lost (it takes several hours). Step 2….. Download, complete and save form LP6. Google “France form LP6” to find it. Step 3…. Send form by email to dsac-nav-bf@aviation-civile.gouv.fr , with relevant aircraft documentation – “Airworthiness document issued by the State of registry, along with the associated validity certificate and/or operating limitations = UK Permit, the EASA form 18B and the aircraft Datasheet). Include the receipt for payment. The permit arrives in a few working days. Mine was valid until 7 days before permit expiry, so it’s a once per year exercise.

BELGIUM – go to https://mobilit.belgium.be/en/Temporary_permission_to_fly and download the application form. Fee 108 euros.

NETHERLANDS – use form ILT.231 here . When I applied, permission was refused because my aircraft is not one of the categories covered by the tick boxes on the form. The Dutch allow microlights into their airspace and also amateur built aircraft – both on the basis of the ECAC agreement- but not factory built permit aircraft. We have taken this up with the NL branch of AOPA who are addressing it with the Dutch NAA but there has been no progress.

GERMANY – apply here https://www.lba.de/EN/Operations/EntryPermissions/Restricted_Authorisation.html?nn=2099536. No fee, max 180 days. Two working days notice are required.

UK LSA to France?

Posted on February 14, 2022 by Mike Naylor - Regulation, Tips

This is a bit of a niche topic of interest to owners of factory built (Part 21) LSA aircraft.

The problem

Thanks to a long-standing ECAC agreement, LAA permit aircraft (i.e. amateur built) can be flown in most EASA states – see this LAA document for details.

However, this does not apply to factory-built (Part 21) LSA’s, operated on a UK CAA permit , which pre-Brexit were EASA Permit aircraft.

To fly these outside the UK, you need specific permission from each State. This is one of those unintended consequences of Brexit. The rules and cost for a specific permission vary, but generally you can get a multi-entry permit for the duration of either the insurance or the current UK permit. Here’s how to get a French permit:

Three simple steps

Step 1. Pay the fee here . On the web page, select “Validation d’un certificat étranger – MTOW < 5,7″. You will need to create an account and reply to the confirmation email to activate the account. Pay 50 euros online. Take a screenshot of the payment page in case the pdf receipt by email gets lost (it takes several hours).

Step 2. Download, complete and save form LP6. Google “France form LP6” to find it.

Step 3. Send this form by email to dsac-nav-bf@aviation-civile.gouv.fr , with copies of relevant aircraft documentation. They ask for “Airworthiness document issued by the State of registry, along with the associated validity certificate and/or operating limitations”. I sent the UK Permit, the EASA form 18B and the aircraft Datasheet, which proved sufficient, plus the receipt for payment.

The permit arrives in a few working days. Mine was valid until 7 days before permit expiry, so it’s a once per year exercise.

Other countries?

I’ve not checked extensively but I hear that Germany ‘s LBA will also grant access. Reading their documentation, it appears that the Netherlands authorities will not (I haven’t tried). The Isle of Man has an exemption for UK CAA permits – so no paperwork or permission required. It is not entirely clear whether the exemption in the Republic of Ireland for LAA permit aircraft also applies to UK Part 21 permit aircraft – we have asked the question.