PART III - HANDLING
Page 72(g) Outboard stores seriously affect the stall characteristics, particularly
the time taken for recovery after initiating recovery action. This
feature is aggravated if inboard stores are also carried.
73. High speed stalling
(a) (i) High speed stalling is subject to the overriding restriction of
para. 56 whereby pilots must not exceed +7G.
(ii) At airspeeds above 0.9M between 10,000 and 30,000 feet, unless
Mod. 533 is fitted, an accelerometer reading +4G must not be
exceeded. At airspeeds below 0.9M in that height band, G must
not be applied beyond the buffet stage.
(b) Pitch-up (Pre-extended wing leading edges)
(i) During turns and pull-outs adequate stall warning is given by
buffeting at all heights. If the backward pressure is continued
inadvertently after the stall warning, wing drop or a momentary
pitch-up and sudden increase in G may occur.
(ii) Below 10,000 ft. the maximum acceleration of +7G may be
applied at the higher mach numbers without stalling the air-
craft; no pitch-up is therefore experienced.
(iii) Between 10,000 ft. and 30,000 ft. at speeds above 0.9M the
pitch-up, if experienced, may be coincidental with the buffeting
and may be severe enough to exceed +7G. It is for this reason
that the restriction of +4G accelerometer reading is imposed.
(iv) Above 30,000 ft. it is not possible to achieve high accelerometer
readings, although pitch-up is still experienced.
(c) Pitch-up (Extended wing leading edges fitted)
When Mod. 533 is embodied the tendency to pitch-up is reduced and
the G limitations(accelerometer readings) are +7G and -3¾G at
all heights and speeds. Pitch-up may still occur to a reduced degree
when G is applied, at speeds above 0.9M in the height band 25,000
ft. to 30,000 ft. If pitch-up occurs it is still possible to maintain some
degree of longitudinal control. Buffeting is considerable and wing
dropping may occur.
(d) Jack stalling
Buffeting and/or limiting G can be obtained with little effort, par-
ticularly when ammunition is not carried, but if jack stalling occurs
it reduces the amount of G it is possible to obtain. If the stick is held
hard on the restriction stop an increase in G must be anticipated if
speed is decreased, because the jack unstalls and further stick move-
ment becomes possible as airspeed decreases. The increase in G will
be sudden if the jack unstalling is coincidental with the nose-up
change of trim as speed falls through 0.95M. When manoeuvring at
high I.A.S. near the ground, sufficient height must be allowed for a
recovery to be effected in the jack stalled condition using the V.I.
tailplane. Care should be taken when manoeuvring at high mach
numbers as it is easy to pull into the pitch-up inadvertently due to
the light stick force.