DH Aircraft

Why did I start with the Comet 4C rather than the Comet 1? There were several practical reasons:

Information
The Comet 1 was a revolutionary aircraft, but it was fatally flawed. After three major incidents and two appalling disasters, it was completely withdrawn, ending its service live after only 2 years. The Comet 4 was a thoroughly developed, successful aircraft and was in service for 22 years with 26 airlines. There is more information in circulation for the Comet 4, and more surviving aircraft in museums and collections.

As earlier airframes reached maximum flying hours, older aircraft were broken for spares. This was long before the invention of eBay, and an awful lot of stuff was simply thrown away. In 1979-1980, when the last Comets took their final flights, there was greater public awareness and more memorabilia was preserved for posterity. In short: it is easier to find out about the last Comets, and in particular the Comet 4C.

Performance
The Comet 4 was a more capable aircraft than the Comet 1. At maximum take-off-thrust (MTOW), the thrust/weight (T/W) ratio was 0.28 (similar to a Boeing 737-400), where the Comet 1 was only 0.17. The Comet 4's range was 3,225 nautical miles compared with 1,500 nm for the Comet 1. This made the Comet 4 an easier aircraft to fly.

Navigation
The Comet 4 was equipped with ADF, VOR and DME navigational aids. The automatic pilot was integrated with the radios, and was capable of performing coupled ILS approaches. By contrast, Comet 1 instrumentation was hardly any more advanced than a World War Two bomber; fixing position still relied on an optical sextant, and yet it flew twice as fast and twice as high, which made navigation a full time and stressful responsibility. The Comet 4 is an altogether more practical proposition for a flight simulator.