iPad Navigation in Microlights - is this a contentious development?
To obtain a cross country rating, trike (microlight) pilots are taught the usual simple Dead
Reckoning (DR) techniques and map reading skills. On trips, we have a WAC map and flight
plan in a clear-plastic map folder Velcro-ed to a thigh for easy access and it’s a system that
works well. Speaking for myself, given that I only occasionally do longer trips (which is typical
of most trike pilots), each time I have to re-teach myself how to use the flight computer slide
rule - mistakes are inevitably made and it’s slow. However, it’s a worthwhile process to go
through as it reinforces basic concepts that could otherwise be forgotten. Navigating using DR
in a trike is often difficult – my compass is often inaccurate, and in anything but still air, my
trike certainly does not fly a smooth trajectory, resulting in a swinging compass and me
having to constantly re-align the trike to my aiming point.
Most trike flying is done from sunrise to late morning, when there is often little or no wind.
However DR calculations are based on the winds given in the area forecast. On our most
recent flyaway a 20kt headwind was forecast for the leg from Swan Hill to Lameroo, but was
actually a pleasant 7kt tailwind at 500-1000’. Thus local wind variations, an early morning
start and the ability to fly low often render the area wind forecast and our consequent preflight DR calculations irrelevant and in fact, misleading.
Trike pilots have for years, additionally been using GPS for navigation and it is regarded as an
essential tool by removing most of the uncertainty. But as I can testify, manually entering
waypoint lat./long. coordinates is error prone. On a leg from Truro to Balaklava, it was not
until I was in the air that I noticed the GPS arrow pointing in the wrong direction (Balaklava’s
entry turned out to be 1° out!), by which time it was impossible to rectify, causing me to fall
back on DR. Nothing wrong with that I hear you say and you are right, but across a relatively
featureless landscape, in hazy conditions with a strong cross wind, I definitely did not arrive
at my destination by flying the straight line on my map!
On our club flyaway this year, 6 of the 12 pilots used OzRunways on iPads in addition to
carrying paper maps and I would have to say it was a liberating experience. We all had
different ways of mounting our navigation aids. In my case, I had the iPad in a dock strapped
to my left thigh and the map folder strapped to my right thigh. Setting up each day’s route in
OzRunways was easy, quick, accurate and reliable. The ability to graphically define a leg by
adding waypoints from OzRunways’ airfield database, including custom waypoints, directly
onto a map is just wondrous and hugely reduces the potential for error.
OzRunways contains the ERSA and it’s also possible to store the Country Airstrips Guides in
the separate iBooks app, along with PDFs of your aircraft manuals etc. Thus while I could
solely rely on the iPad for airfield information, I think it safer and more efficient to have
destination airfield details pencilled onto my flight plan sheet, where they are instantly
available rather than forcing my attention back into a computer.
Using 3G to obtain real-time weather made ETA calculation trivial. In the recent Sport Pilot
article “Let’s Get Real” an argument for DR being fuel management, was discussed. In trikes
this is not really such an issue because we generally only fly 1-2 hour legs. My 2-stroke trike’s
tank holds enough for a good two hours plus reserve and if I ever hit the limit without there
being an airfield in sight, I’ll find a paddock in which to land, preferably near a farm house
offering a cup of coffee! Though 4-stroke trikes have a much longer range, not being restricted
to airfields is a game changer.
There are negatives. OzRunways did crash once in flight but while disconcerting, it was easy
to restart it and reselect the stored route. An American pilot recently wrote that while flying
on a really hot day, his iPad automatically shut down after displaying and over-heating
message. The iPad3, in particular, can get quite hot and therefore should be carried or
mounted in such a way to allow heat to dissipate. Concern about iPads running out of power
in-flight is not really warranted, given that trike pilots already successfully use battery
powered GPS.
As using the iPad made navigation just so easy, to conserve its battery and because I enjoy
using my map reading skills, I would often switch the iPad off, just occasionally using it for
checking. It’s a challenge to correlate the WAC’s sparse information with what’s actually
visible on the ground and for me, being observant is part of the fun of flying. However, when
flying conditions are difficult or it’s important to know one’s exact location, I am far more
confident with it on. One of the nice features in OzRunways is the 10-mile circle displayed on
the screen around the aircraft icon, making it easy to decide when to give an inbound call.
Common sense tells me that it’s unwise to rely totally on any electronic device and that an inflight backup is wise. It can be argued that a second GPS could be the backup, as the chances of
both failing are tiny. However, given that trikes don’t have cockpits, mounting or accessing a
second GPS requires extra effort and care. In my opinion, the map folder is the ideal backup.
Replacing a conventional GPS with an iPad is a natural progression that is to be welcomed as
it will make cross country triking safer and more achievable.