CliveL
A warm welcome to the forum, please keep your most illuminating posts coming!
EXWOK
I'm trying to remember what drove the fixed nose-down elevon input at low EAS/high alpha which I alluded to earlier. Presumably it wasn't superstab but some other element of the autostab system
Digging out my old BAeAS notes, if you still have them, the reference is in the
Anti High Incidence section at 7.4.82. In addition to the following systems, already mentioned by
NW1:
- Incidence Trim
- Super Stab
- High Incidence Directional Stability
- Auto Trim Inhibit
- Stick Shaker
- A/P disconnect
- Stick Wobbler
there was a further protection called the
4° Nose Down Demand, although, like you, I seem to remember it was referred to on the course by other names. The requirements to trigger this were:
- IAS below 140 kts
- Incidence greater than 19°
It operated through the pitch auto-stabs, so at least one of them had to be engaged for the system to operate, as well as the associated anti-stall being on and the ADCs agreeing. There was a
high-rate-of-increase of incidence protection incorporated in this system, and it could be activated at an incidence as low as 13°.
Purely in the interests of historical accuracy, may I point out that I did once complete a load sheet on a charter flight, but this occasioned such ribald comments from the starboard side of the flight deck, accompanied by ill-suppressed mirth from the maroon Mafioso in the engine room, that I decided in future to delegate all further such calculations to the F/O.
Merry Christmas to all
Bellerophon