V Speeds Flashcards
Vs1
T/o config
Vs0
L/d config
Vs
Stall speed
94% of Vs1g
Stall warning - 5kts or 5% of vs, whatever’s the greater
Stick pusher - 2kts or 2% of Vs
Vs1g
Stall speed at 1g / straight + Level
VsR
Reference stall speed
Defined by the manufacturer, may not be less than the Vs1g stall speed
Min t/o speeds governed by EASA to provide a saftey margin
Small a/c - 30% faster than Vs0 and 20% faster than Vs1
FES
Flap extension speed
10% faster = 20% larger landing distance
Vx
Speed for best angle of climb
Vmd for a jet - movement of the drag curve could alter this
Vmp for a prop - 76% of Vmd
Power required in a climb
Drag x TAS
Power available in a climb
Thrust x TAS
Climb gradient %
T-D/W x 100
Rule of thumb for %gradient
5% = 3 degrees
Vmo
Speed for max operating
Max speed that must not be intentionally exceeded during any phase of flight
MMO
Max Mach operating
Vne
Never exceed speed, applicable to small a/c
Vno
Max structural cruise speed
VLE
Max l/d gear extended speed
Max speed that the a/c can go with the gear down and locked
VLO
Max speed with the l/d in motion speed
Slower than vle
VFE
Max flap extension speed
VFE for each stage of flap
Vb
Speed at which the a/c can handle a vertical gust
20,000 - a/c must be able to withstand 66ft/s of air movement
50,000 - 38 ft/s - linear decrease
Vra
Velocity for rough air (vturb)
Faster than vb and mor practical
Vc
Max speed without causing structural deformation
Vd
Design dive speed
Exceed this and you could brake the a/c
Must be able to withstand 25fps at 25,000 ft
Va
Max speed you can get to without over stressing the a/c - a/c will stall first
NLL
Normal load limit
ULL
Ultimate load limit
Pass this and you will cause structural failure
22% higher than va speed
Min control speeds
Min speed we can go to have the effect of the rudder at engine failure
They will be faster in low altitude, cold locations as they are all about thrust
VMCG and how it is determined
The fastest of VMC speeds The a/c is in ground effect or on the ground Determined for - max available thrust on operating engines - most unfavourable CG position, aft - a/c trimmed for t/o -MTOM - the most critical t/o config
VMCA and how it is determined
The a/c is airborne and out of ground effect
Only allowed max bank of 5*, roll reduces force on tail and makes this speed faster.
Determined for
- max available thrust on operating engines
- most unfavourable CG position, aft
- a/c trimmed for t/o
-MTOM
- the most critical t/o config (but without the gear)
- the prop is windmilling, if it has auto-feather then feathered
VMCL and how its determined
All about the landing Has a roll requirement which may cause it to be faster than the min speed for directional control Determined by - max available thrust/go around power on operating engines - most unfavourable CG position, aft - a/c trimmed for l/d -MTOM - the most critical aprch and L/D config
