Tag Archives: ef2000

Typhoon Air Data System

Working through some older shots for another project, I ended up looking at some shots of an RAF Typhoon displaying.  As I was zoomed in on some of the shots, it was interesting to see the air data vanes on the underside of the front fuselage as the plane maneuvered.  There are several vanes around the underside of the front fuselage and the differences between them can tell yaw and pitch angles.  In one shot when the jet was climbing straight up, the vanes are all pointing in similar directions.  Shortly before this, as the jet was pulling hard, the angle of attack was higher and the flow up around the front fuselage results in some significant differences in vane angle.

This is the sort of thing that is very important when designing and clearing a flight control system.  We had a front fuselage wind tunnel model for the Typhoon during the development program.  This was used for intake design but also for air data system modeling.  The way in which the various vanes move is vital to understanding the control law requirements.  It is also important when considering failure modes.  If one vane should fail, how much it impacts the flight control behavior and how much the system detect the failure.  Will the aircraft be vulnerable to control loss in the interim?  The Tornado did not have as complex a flight control system, but it did have augmentation of the controls and, as it rolled, you would get quite different readings from the angle of attack probes on each side of the fuselage.  How much of a difference was normal versus what was a failure was an interesting analysis problem which I enjoyed working on.  My days on Typhoon were relatively limited and shortly before first flight so I never got involved with the results of the testing program, but I do enjoy looking at the resulting aircraft whenever I get the chance.

Back to My Roots with the Typhoons

C59F3875.jpgThe Brits were at Red Flag in numbers too for 16-1. An E-3D Sentry was part of the AWACS fleet while a C-130J Hercules launched each day I was there. Judging by the dust and dirt on the underside, they were landing on rough strips out on the ranges during their missions. However, the thing I was most looking forward to seeing was the Typhoon. The RAF brought eight jets from 3 and 11 Squadrons. Most days six of them launched.

C59F4789.jpgIn my youth, I worked on what was to become the Typhoon in my BAE days. I was an aerodynamicist looking at airframe loading and the possible flight envelope for the first flight. I was not looking forward to the job when I was given it but working on loads turned out to be a great task and taught me a lot about structural limits, flight controls and the process for expanding the flight envelope. A mentor of mine had told me it sounded dull but was very valuable and he was spot on. I guess he is a smart guy because he has gone on to be rather successful in the company!

AU0E8613.jpgBack on topic, the Typhoon is something I am very pleased to have worked on. Getting to see them in action is great. The launches when we were out by the runways were great. When we were by the EOR, we were directly across from the ramp that the Typhoons were using so I managed to see them crewing up for the launch. Then, of course, they had to come right by us as they taxied out. I know it was a long time ago but I can’t help but still have a soft spot for them when I see them in use.