I heard some ATCos requesting pilots to report, on holding point, and also hold short. Is there any difference on them?
The U.S. and holding point
It depends on the locale and context. For taxiing in the US holding point is not used as the FAA ATC manual refers to it as an ICAO term for a visual (or otherwise) holding point in the sky.
HOLDING POINT [ICAO]− A specified location, identified by visual or other means, in the vicinity of which the position of an aircraft in flight is maintained in accordance with air traffic control clearances.
Elsewhere and hold short
Elsewhere for taxiing, holding point is where the intended departure will take place from a runway. Check eurocontrol.int for examples (direct linking not available), but here's an example they give:
TAXI TO HOLDING POINT [number] [RUNWAY (number)] VIA (specific route to be followed), [HOLD SHORT OF RUNWAY (number)] or [CROSS RUNWAY (number)]. [REPORT VACATED]
- Taxi to holding point A, runway 36, via A.
That means take A all the way to the end where it meets runway 36 and stop at the hold short line or behind whoever is ahead.
- Taxi to holding point C, runway 36, via A and C.
Here the runway was shortened (an intersection departure) and the pilot will hold at C and then line up from C when cleared.
Report holding point means report when you get there.
- Tower, Stack 1 is at holding point A, fully ready.
Hold short is the same everywhere and applies to any intersection or runway on the way to the runway/gate.
- Taxi to holding point A, runway 36, via A, hold short C.
Here the pilot will hold where C meets A and awaits clearance to continue.
Hold your position is an instruction to stop right now.
Some airports employ LAHSO (Land and Hold Short Operations), where a hold short line exists on the runway you are landing on.
- Example: Cleared to land runway 27, hold short runway 22L.
Example in Boston Logan (blue circle):
The holding point is usually a fix in the STAR where aircraft are "held" flying a pre-defined radial for traffic congestion purposes; and I have only heard it in context of ATC referring to aircraft flying.
Holding short is very important. It means stopping before entering a runway area and is marked by two solid lines. You should hold short (ie, before) the solid lines.
Here is a picture of an aircraft that is stopped short (source: google maps of OMDB):
The lines are marked as two solid lines, followed by dashed lines; the holding side is on the solid lines:
The holding position however, is a place on the ground where aircraft are to report once they taxi to it.
From the OMDB AIP:
Red inset lights supplemented with elevated lights on either side of the holding position. Runway holding positions (CAT I and CAT II / III) and intermediate holding positions for general service road crossings are provided with Stop Bar Lighting.
RWY Guard Lights: RWY holding positions are provided with a pair of yellow flashing lights on either side of the Stop bar
Intermediate Holding Position Lights: A set of three amber lights or full red stop bar are provided at intermediate TWY holding positions.
Source : DCGA Website
Further on the same page:
18.104.22.168.2 Pilots in receipt of a conditional line-up clearance on a preceding departing aircraft shall remain behind the subject aircraft but may cross the runway holding point, subject to no illuminated red stop bar and then enter the runway upon receipt of the clearance. There is no requirement for the subject aircraft to have commenced take-off roll before entering the runway. Pilots must be aware that there may be a blast hazard as the aircraft on the runway applies power.
However, ATC may give an instruction on the ground such as:
November 5 Bravo, taxi to holding point Charlie Runway 30R
This usually refers to a physical holding position.