When to unlock the feathers
@RetiredF4 Nice find
@ janrein
I tried to start a list of the pros & cons of the unlock timing in post #5. Perhaps we can start to expand on this.
Obviously it needs something like:
- After any potential sources of [high?] aerodynamic [upward?] tail forces:
--- shock waves?
--- clean engine burn?
--- uneven engine burn?
--- flight-path induced?
- Exactly where the point-of-no-return (without feathers) occurs in the flight.
BTW what is the likely split of responsibilities in a two-person rocket-powered test crew?
- PF/PM seems inconsistent with the PNF apparently making an unrequested & unannounced change (inconsistent with the flight plan as far as we know it).
- If the PNF was handling the engine (and perhaps stability) the unlock seems more within his remit.
The fact that the unlocking seems to have been very early in some other Virgin test flights suggests that the high & M1.4 'rule'
was not strictly adhered to. The apparent need to deploy the feathers early in some flights [in response to instability?] suggests
that might have been unrealistic (at least for test flights examining the planes stability).