Hand Signals
 

Does anyone know the hand signals that are used between the flight deck and ground for clearance to pressurise hydraulics?
I have looked in the ICAO Annex 2 and there appears to be none.

It's been quite a while but I seem to recall the signal was somewhat like this:

While making the 'OK' sign with your left hand (but only done in countries that find that gesture unoffensive) firmly press your right index finger to your pursed lips. Upon making visual connection with said ground staffer, puff one's cheeks (ala Dizzy Gillespie)....

Or at least, that's what i recall... :D

Air-Geko

(behaving as if this is Jet Blast)...

Hand signal for pressurising hydraulics: lay the hands out flat, with the palms facing up, and raise both hands upwards.

two fingers pressing both eyes: "pressyoureyes"

Could be wrong (probably am), I agree with previous statement. I have always put fingers towards eyes. Press your eyes for pressurise. Whenever I have done this the person I was signalling to seemed to know what I was referring to.

Temps the Technician (not allowed to call myself an Engineer)

While were on about strange hand signals
What this one for?
Drawing a figure of eight with a pointed finger

Thought it was from groundcrew to pilot to say "you're on fire!"

Figure of eight horizontally.

Figure 8 is the old hand signal for fire. Problem is that some marshallers couldn't count that high and made confusing motions that a pilot might mistake for a movement signal.

Now it's a sweeping motion with one hand below the waist.
There isn't any specific universal signal for pressurization or depressurization of hydraulics any more because nobody at the ATA conferences can agree on anything.

General rule is that if the sign is being made below the belt level it's an abnormal, non-movement, or emergency sign and signs above the waist are normal movement signals.

My personal opinion - it's long past time to get one set of standarized signs like we had pre-1985. The current "system" of whatever the marshaller feels appropriate is woefully inadequate and often borders on dangerous.:(