This flight is far more than your typical bush trip. It recreates the first London to Australia flight made in 1919--a distance of more than 14,000 miles. It is considered one of the greatest achievements in aviation history.
The team flew a Vickers Vimy, piloted by Ross Smith, with his brother Keith Smith as co-pilot and navigator, and Jim Bennett and Wally Shiers as mechanics. That original flight took nearly a month.
As you fly, be sure to read the companion PDF document with more details of their trip, including historical photos and links to historical documents.
 
Some notes on this bush trip:

• The trip is long.  14,000 miles long.  It will take many days to complete.
• The adventure is split into four different bush trips: (1) London to Cairo, (2) Cairo to Calcutta, (3) Calcutta to Singapore, and (4) Singapore to Adelaide. They will show up under Activities/Custom Content. Note that FS2020 doesn't always put them in numerical order.
• The main download file contains the four bushtrips, plus a folder of PDFs with historic photos and a more detailed description of the historical flight. I strongly encourage you to read the PDF as you fly along.
• There is a secondary, optional download file containing a Flightbook, automatically created by BushTripInjector. It describes the specific waypoints used during the flight.
• For the most part, the descriptions of each leg should be clear enough for you to find the next waypoint. There are a few legs that are intentionally difficult to navigate, such as a 260 mile leg over much of France, where the Vimy was flying in between cloud layers and could only navigate with dead reckoning for several hours. With clear skies, you will have a much easier time.
• The default aircraft for the trip is a Savage Cub, so it has similar navigation abilities to the Vimy: a compass, an air speed indicator, an inclinometer, and a clock.  The Cub has a slightly higher cruising speed, a higher operational ceiling, but a shorter range. Unlike the Vimy, the Cub has the luxury of an enclosed cockpit. See below for details about how to change the default aircraft.
• Because of the shorter range, you will need to stop and refuel on some of the longer legs of the bush trip. If you land at an airfield where fuel is available, the "fuel" toolbar icon will appear for you to add fuel. Alternatively, you can assign a button or keystroke to the "Repair and Refuel" action which you can use at any time.
• A few airstrips were created specifically for this bush trip, including the starting location at Brooklands near London (where the Vimy was outfitted for the trip), and the first destination at Hounslow Heath (the official start of the race). All of the custom airstrips made for this bush trip have runway lights, to try to make them easier to locate. The navigation log also offers guidance for how to find them.
• The bush trip and accompanying documents are machine translated into several languages.
• Weather defaults to clear skies, but can be changed for a more challenging adventure.

Hints:

• Use maps to give yourself a sense of where you are going and what you are looking for. The navigation log has screenshots at most waypoints to help you find your way.
• Think like a 1919 pilot with limited navigation aids. Plan to follow rivers, roads, and railroads--but make sure you are following the correct one. Fly up valleys and over mountain passes, rather than take direct routes.
• If you get lost, there are plenty of opportunities to find your way again. If you are trying to find a city on a coastline, turn and find the coast first, and then look for the city.
• Sometimes, the simulator doesn't reset the time of day when you begin a new leg. This will cause you to run out of daylight on some legs. After you complete a leg, if you "Return to Main Menu" (instead of "Continue"), the next leg will start in the morning.

If you would like to change the aircraft for the bush trip (because you want something faster or with autopilot), you can use the MissionChanger program from BuffyGC.

Created with BushTripInjector by BuffyGC.
Special thanks to BuffyGC and the BushTripInjector community for answering questions and offering guidance.

Suggestions for improvement to these bush trips are welcome.

 
There are several add-on sceneries to consider, but none are required:

London to Cairo:
Brooklands Museum, UK  ( including airfield ) by mgh65
Viaduc de Ventabren by jeremy160189
Vesuvio by longastrino
Port of Naples cranes fix by Nimic
Aix TGV - L'arbois by jeremy160189
Cannes: Hôtels de la Croisette and Château de la Napoule by mv46
Château de Châteauneuf-du-Pape by mv46
Ibn Tulun Mosque, Cairo, Egypt by SUdashSMD
Marina Baie des Anges by eriktu
Muhammed Ali Mosque, Cairo, EGY by SUdashSMD
Papal Basilica of Saint Peter in the Vatican by sebick
Pisa Piazza dei Miracoli by WonderOfficial
Rome - Ansa del Tevere - Parco de' Medici by AntoRm
Monaco high detail new version by marktaylor
Avignon city center by wtacod30650
Avignon city, France by Comolas
Cagnes-sur-Mer city, France by Comolas
Cannes city, France by Comolas
Italy - Lerici & San Terenzo by IlParaCapo
Italy - Pisa + aeroporto by IlParaCapo
Lyon by Thalixte
Lyon city by AdrianL
Monaco by marktaylor
Monte Carlo (French Riviera) by Olmecslayer
Napoli - Da Mergellina a Villa Volpicelli by Lucio Sergio Barelli
Napoli - Da Santa Lucia a Mergellina by Lucio Sergio Barelli
Napoli - Naples, the harbour by Lucio Sergio Barelli
Napoli - Naples; Secondigliano, Casavatore e Scampia by Lucio Sergio Barelli
Napoli - Posillipo e Nisida by Lucio Sergio Barelli
Napoli: Zona ospedaliera by Angelokade
Nice, France by Thalixte
Pisa by RazorRay
pisa by slasko79
Porto Venere by IlParaCapo & Mauro Melone
Saint Jean Cap Ferrat, Alpes Maritimes, France by comolas
Saint-Jean-Cap-Ferrat city, France by Comolas

Cairo to Calcutta
India Gate by Viks
Mazar-E-Quaid Add-On Karachi by Syed Arbaz Rasheed
Bodhgaya by san

Calcutta to Singapore
Shwe Dagon Pagoda by ClemensFellner
Wat Arun by san
Bangkok Scenery by zinorules
Ipoh by Brandon
Singapore Downtown by EnjoyItFly
Singapore Changi Airport (WSSS) (Accurate Taxiways and Gates) by exocet_falling
Singapore Changi International Airport [WSSS] by ams7880

Singapore to Adelaide
ANZAC Bridge Sydney
Sydney Harbour Bridge (3) by
Three Sisters by c64orinoco
Aeronoms - Semarang Landmark for MSFS2020 by Aeronoms
Google Map -Supertree Grove Singapore by demotyken
IKEA Tempe/Sydney Airport by jarvoss
istiqlal mosque - jakarta by zibedvai
Parkes observatory by droide
Sydney Tower Eye (2) by
The National Monument - Monas by zibedvai
Adelaide CBD - Low Poly by High_Frame_Rates
Singapore Downtown by EnjoyItFly
Surabaya Overhaul by Haykl17
Sydney by JacobTang
Barcaldine, YBAR by Shanman
Charleville, YBCV by Shanman
Cloncurry -YCCY by Shanman
RAAF Darwin Airbase - YPDN - Northern Territory - Australia by Tag21
YBCK - Blackall Airport by kliff0rd
YWTN - Winton Airport by kliff0rd
Adelaide International Airport (YPAD) by Impulse Simulations
YCMW - Camooweal Airport by kliff0rd
RAAF Air Base Point Cook - YMPC - Australia - Tag21