How Much Weight do Composites Really Save?

Outside of aeronautics, composite materials are very fashionable, they represent everything high-tech, cutting edge and well engineered. There are carbon fibre golf clubs, bath tubs and suitcases. Within the aeronautics industry composites are also held in high regard; the path to weight savings, complex geometries and fewer parts. Yet it is also very hard to quantify exactly how beneficial composites are. They are very different to aluminium, and challenges such as impact resistance, expensive manufacturing processes and repairability lead to different design philosophies, which in turn make it difficult to compare composite and metal designs directly. The Boeing 787-9 and Continue Reading

Who Wants a Nuclear Powered Cruise Missile?

Back in February 2019 when Russian news websites posted the first articles about the new Burevestnik “nuclear powered cruise missile”, I almost wrote about how ridiculous the idea was, since clearly nobody would be silly enough to build a nuclear powered cruise missile. The whole thing was surely just Russian propaganda exaggerating the abilities of a new project, like they had with the PAK-TA back in 2015. Fast forward to August 2019 and an apparent explosion during an engine test killed at least five people and spewed radiation into the atmosphere. I’m no longer so sure, maybe the Russians really Continue Reading

A Flying Rotor?

Helicopters are the ugly ducklings of the aerospace world. They are noisy, suffer from high vibrations and are much slower than fixed-wing aircraft. They have a shorter range and have higher maintenance costs. In short, people use helicopters when they have to, since they can land almost anywhere, but whenever there is is choice, fixed-wing aircraft are still the transport of choice. Is it Time for Something New? At the same unmanned rotorcraft have advanced greatly in recent years, such that consumer drones can now be purchased for the same price as a bicycle. Military drones such as the Northrop Grumman Continue Reading

What is a Payload-Range Diagram?

A typical payload-range diagram looks like this: There is aircraft range along the horizontal axis and payload carried along the vertical axis. What are they used for? As a Pilot First and foremost a pilot can look at an aircraft’s payload range diagram and confirm that an aircraft is able to achieve a given mission, i.e. can fly a give combination of payload and range. Everything within the three lines is an achievable payload-range mission combination for a particular aircraft and everything outside is not. When flying close to the boundary pilots may have to pay close attention to make sure Continue Reading

Why Aspect Ratio doesn’t Matter

In the ever-present drive to improve the efficiency of aircraft, “higher aspect ratio wings” are frequently named as one of the reasons that new aircraft are more efficient than previous generations. Here are a couple of examples: “… carbon fiber allowed designers to produce a higher-aspect-ratio wing for lower drag…” (Aviation Week, May 2015) “… wings with high aspect ratio generate the lowest lift-induced drag…” (Flight International, April 2006) “A higher aspect ratio wing has a lower drag…” (NASA, May 2015) Indeed there seems to be a general consensus that higher aspect ratio wings are more efficient. This is however misleading, since Continue Reading