Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Boeing First Quarter Results Update: China is 10% of the backlog, with 500 in “Unidentified” April 24, 2025
- Boeing First Quarter Results: Tariffs, Return flights, $10.55bn asset sale April 23, 2025
- RTX Q1 2025 Earnings: GTF Talk Takes A Back Seat To Tariffs April 22, 2025
- Tariffs Tumult Takes Over GE Aerospace Q1 2025 Earnings Call April 22, 2025
- Boeing reports mixed results of latest employee survey, but middle management and officers remain key obstacles April 22, 2025
Bjorn’s Corner: Supersonic transport revival, Part 4
By Bjorn Fehrm
August 31, 2018, ©. Leeham News: In the last Corner we discussed supersonic lift wave drag and how suddenly the length aspect ratio is more important than wingspan aspect ratio.
Now we talk about the problem of going from subsonic to supersonic flight.
Figure 1. The Supersonic drag hump. Source: Wikipedia.
Bjorn’s Corner: Supersonic transport revival, Part 3
By Bjorn Fehrm
August 24, 2018, ©. Leeham News: In the last Corner we discussed how supersonic wave drag can be higher than any other drag for a blunt fuselage trying to fly at supersonic speeds. If we try to fly supersonically with a Dreamliner fuselage, the volume wave drag is four times as large as the whole Dreamliner drag when flying at its normal cruise speed.
Besides wave drag based on bodies volumes we also have wave drag when we angle lift surfaces like wings against air to create lift.
Figure 1. The last Supersonic transport, the Concorde. Source: Wikipedia.
Bjorn’s Corner: Supersonic transport revival, Part 2
By Bjorn Fehrm
August 17, 2018, ©. Leeham News: In the last Corner we outlined several challenges facing a supersonic airliner or business jet.
We will now go through these challenges one by one. We start with the aerodynamic challenge.
Figure 1. The last Supersonic transport, the Concorde. Source: Wikipedia.
Bjorn’s Corner: Supersonic transport revival
By Bjorn Fehrm
August 10, 2018, ©. Leeham News: The interest in civil supersonic flight has been revived in the last years. Aerion Supersonic is well advanced with its AS2 supersonic business jet and there are several projects looking at restarting supersonic airliner service, 15 years after the Concorde stopped flying.
We will examine the unique challenges facing these projects in a series of Corners.
Figure 1. The latest rendering of the Aerion AS2 supersonic business jet. Source: Aerion Supersonic.
Bjorn’s Corner: Largest navigation change since radar, Part 8
August 03, 2018, ©. Leeham News: In seven articles we have discussed the largest change in how air navigation is done since the Second World War when Radar was invented.
It’s time to summarize the changes and what it will mean for how we fly in the future.
Figure 1. Airbus Vahana Air Taxi concept. Source: Airbus.
Bjorn’s Corner: Largest navigation change since radar, Part 7
By Bjorn Fehrm
July 27, 2018, ©. Leeham News: Last week we discussed new air navigation procedures which can benefit from the universal adoption of ADS-B.
Now we shall discuss some other needed developments for air navigation. The complement, and long-term replacement, of radio traffic with text messages.
Figure 1. CPDLC display in an Airbus A330. Source: Google images.
Bjorn’s Corner: Largest navigation change since radar, Part 6
July 20, 2018, ©. Leeham News: Last week we discussed how a TCAS (Traffic Collision Avoidance System) works and how ADS-B will improve the system.
Now we discuss other areas of aircraft navigation and separation which are enabled when all players have ADS-B and transmit their 3D position and where they are going.
Figure 1. Air traffic is getting denser and denser. Source: flightradar24.
Bjorn’s Corner: Largest navigation change since radar, Part 5
By Bjorn Fehrm
July 13, 2018, ©. Leeham News: Last week we discussed ADS-B in capabilities and how the US second channel at 978MHz brings the bandwidth for many useful services.
Before we discuss what improvements in navigation ADS-B will bring long-term, let’s sidetrack to describe the present Traffic Collision Avoidance System (TCAS) and why it’s eventual replacement with ADS-B will improve air safety further.
Figure 1. A TCAS II display with warnings and advisories. Source: AeroSavvy.com
Bjorn’s Corner: Largest navigation change since radar, Part 4
By Bjorn Fehrm
July 06, 2018, ©. Leeham News: Last week we discussed the different forms of ADS-B out and the reason FAA went for a second channel for the US ADS-B.
We also discussed the basic ADS-B in function, Traffic (TIS-B). Now we discuss the added functionality of the ADS-B in on 978MHz, the UAT link.
Figure 1. The functions of the US ADS-B ground stations. Source: FAA
Bjorn’s Corner: Largest navigation change since radar, Part 3
By Bjorn Fehrm
June 29, 2018, ©. Leeham News: Last week we explained ADS-B out, the mandatory equipment needed from 2020 for flying in the US Airspace where a C-type transponder is needed today.
Now we continue with describing the ADS-B in, the listening capability of the system, which is nonmandatory. It offers exciting possibilities, however.
Figure 1. The ADS-B is mandatory in most US airspace areas. Source: FAA