Is a Nose Gear Lock Pin necessary on pushback?
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Not all aircraft are the same. However most modern RPT a/c that I have worked on such as B737, B747, B767, B777, A320, A330, A340 require considerable hydraulic pressure (approx 1650 PSI) to the "gear up" hydraulic circuit to unlock the individual gear lock actuator(s) to break the over centre lock.
The only way to achieve this is to have the applicable system pressurised and to move the gear lever to "UP". Again the above a/c all have interlock systems that require the a/c weight to be off one or more of the gears before the lever can be moved to "UP".
Any force in either direction on the nose gear, or in fact the main gears only forces the over centre lock towards the lock position.
The B707 was one a/c that did not have a very positive overcentre lock and most airlines required the fitting of a "bicycle handle" type nose pin for pushbacks on this a/c.
The only way to achieve this is to have the applicable system pressurised and to move the gear lever to "UP". Again the above a/c all have interlock systems that require the a/c weight to be off one or more of the gears before the lever can be moved to "UP".
Any force in either direction on the nose gear, or in fact the main gears only forces the over centre lock towards the lock position.
The B707 was one a/c that did not have a very positive overcentre lock and most airlines required the fitting of a "bicycle handle" type nose pin for pushbacks on this a/c.
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NLG
My apologies MATKAT I did misread your bits, blame it on the fumes!
As for NLG pins I have experience on a few occasions of NLG fitted to 747’s on pushback and they have forgotten to pull them and the aircraft have had to dump fuel before landing to have it removed. (Not me and Companies I have not worked for)
Reference: the fitting of NLG pins for push was that some aircraft depressurise their systems so the possibility of a pull forward etc could collapse the NLG. This possibly answers the question why not fit all?
So I think basically that it is some Companies requirements that they either do or don’t?
The normal requirement for towing is fit all and tech log it.
For push and towing most ground handling companies have their own pins so that is the ones that do not go in the tech log hence the incidents above.
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easy to clarify
The pin must be only be inserted in case of PULL the plane. In this case is mandatory to insert the pin.
In case of PUSH the plane it's not needed, it depends on the plane to need or not the nose wheel steering by-pass.
This is the way how spanish airlines work.
Best regards
In case of PUSH the plane it's not needed, it depends on the plane to need or not the nose wheel steering by-pass.
This is the way how spanish airlines work.
Best regards
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bypass
Originally Posted by Koan
Any current EMB-145 drivers care to comment on the Steering Disconnect PB?
Ground crews are supposed to check with the flt deck that this is pulled before tow bar connection.
It is then re-connected after push and after towbar has been disconnect and ground equipment clear.
Again I still would like to stress that different airlines have different procedures for pushing and towing.
The most common aircraft that company's like both NLG & Depressure pins fitted are the SAAB 340 & 2000.
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I fly the B737 and we don't use the nose wheel steering pin. We turn off the "A" pumps. Company started with the B737-200 which does not have the lockout. Now flying -300, -500, and -700. The -200's are gone and still turn off pumps for push back.
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Confused!
I must say one must stop reading and replying when I come home from the pub!!
Interesting that we all seem to get confused that the origional comment was on Nose Landing Gear Pins (NLG) and we all go straight on to Depressure Pins?
Most aircraft that I have pushed back always have the depressure pin / torque link disconnected or the CB pulled. This covers most types of aircraft.
As for NLG for push back only the SAAB's use both and are handed back to the flt deck via the hatch.
Towing, all pins are fitted from flt deck and TECH LOGGED.
Interesting that we all seem to get confused that the origional comment was on Nose Landing Gear Pins (NLG) and we all go straight on to Depressure Pins?
Most aircraft that I have pushed back always have the depressure pin / torque link disconnected or the CB pulled. This covers most types of aircraft.
As for NLG for push back only the SAAB's use both and are handed back to the flt deck via the hatch.
Towing, all pins are fitted from flt deck and TECH LOGGED.
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At BA mainline all pushbacks have the pin inserted as the tow crew will bring the required type. As part of the procedure the headset man will tell flight deck that he will clear to P 1 or P 2 side of the aircraft and hold up the pin and tape in his left hand to show it has been removed. Or to be more accurate this is what should happen? Watching pushbacks by various companies and at times including BA many of them are very slapdash and seem to have little or no procedures in place.
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HZ123 you are talking about the 'Steering depressurisation/bypass pin' the original question is about the Nose gear downlock pin...which prevents the gear from retracting.
Most airlines I have been involved with fit the downlock pin only for towing the aircraft, often they are towed without any hydraulic pwer on (towbarless tugs etc). For normal pushbacks then the downlock pin is not fitted. However it will depend on each companies own policy. I do know of one major airline at LHR that fits the downlock pins for push backs. just means that the ground crew will have to show 2 pins to the crew before they taxi off.
Most airlines I have been involved with fit the downlock pin only for towing the aircraft, often they are towed without any hydraulic pwer on (towbarless tugs etc). For normal pushbacks then the downlock pin is not fitted. However it will depend on each companies own policy. I do know of one major airline at LHR that fits the downlock pins for push backs. just means that the ground crew will have to show 2 pins to the crew before they taxi off.
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CR Thanks I realise they are intirely different but the thread has muddyed. Is the nose gear locking device the same then as that long bar that is placed upward on the 747 forward nosegear?
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NEVER
AFTER 42 YEARS AS A LAE I HAVE NEVER I REPEAT NEVER PUT IN A DOWNLOCK PIN FOR A PUSH BACK AND HAVE NEVER WORKED FOR A AIRLINE (6) THAT WANTED YOU DO. AS WAS STATED THE AIRCRAFT IS BUILD NOT TO NEED ONE AND ITS ANOTHER THING TO FORGET ON PUSHBACK ON A WINDY WET DAY OR NIGHT WHEN THINGS CAN GET A BIT BUSY. KEEP THEM OUT AND KEEP THEM FLYING. FROM PAPA PETE
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SLACK PRACTISE?
[QUOTE=Perrin]AFTER 42 YEARS AS A LAE I HAVE NEVER I REPEAT NEVER PUT IN A DOWNLOCK PIN FOR A PUSH BACK AND HAVE NEVER WORKED FOR A AIRLINE (6) THAT WANTED YOU DO.
Why do two airlines (that I know for a fact) fit them on push back this is referring back to the NLG & De-pressure pin on SAAB 340 / 2000?
The procedure is to hand pins back to the Captain through a hatch after completion of pushback. (TO ELIMINATE PROBLEM OF LEAVING EITHER PINS IN)
I do admit that this can not be done on large / wide body a/c.
If Company procedures are slack?
Should an ASR / EOR be filed?
Why do two airlines (that I know for a fact) fit them on push back this is referring back to the NLG & De-pressure pin on SAAB 340 / 2000?
The procedure is to hand pins back to the Captain through a hatch after completion of pushback. (TO ELIMINATE PROBLEM OF LEAVING EITHER PINS IN)
I do admit that this can not be done on large / wide body a/c.
If Company procedures are slack?
Should an ASR / EOR be filed?
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Used to handle Air Jamaica 340's and the pins they supplied joined with steel wire were a steering bypass disconnect pin and the nose leg downlock pin. We had to install both on arrival, and as they were joined with steel wire you had to remove both to show the crew you have removed them after pushback.
On our own a/c 747, 330, 340, 777 we only install the bypass pin.
p.s perrin stop shouting!
On our own a/c 747, 330, 340, 777 we only install the bypass pin.
p.s perrin stop shouting!
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Sorry from Perrin
Sorry to all, I found the caps lock key at last.
I see I have been proved wrong there are airlines that request downlock pins very surprised to hear it but will go with the flow.
I see I have been proved wrong there are airlines that request downlock pins very surprised to hear it but will go with the flow.
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Ground lock pins?? As a tug driver ( limited knowledge! ) I will only tow empty 777 / 747 ( my main a/c ) with them in.
Perhaps it's the fact that the nose overhangs my cab???
Different airlines display different rules, but I can insist on them being IN if I'm responsible for the tow!!
Never a puchback though..... Onlt STEERING bypass......
I had a ' thing ' with a pilot who refused to put his beacon on before pushback, I said to him, ' then why is ground lock pins part of your before starts then?? ' He replied by saying that they were before engine start, not pushback... So he'd be happy to find ground lock pins missing during the push.. I think not.. And the catering truck imbeded in his tail??? MAD boy he was!!!!
Perhaps it's the fact that the nose overhangs my cab???
Different airlines display different rules, but I can insist on them being IN if I'm responsible for the tow!!
Never a puchback though..... Onlt STEERING bypass......
I had a ' thing ' with a pilot who refused to put his beacon on before pushback, I said to him, ' then why is ground lock pins part of your before starts then?? ' He replied by saying that they were before engine start, not pushback... So he'd be happy to find ground lock pins missing during the push.. I think not.. And the catering truck imbeded in his tail??? MAD boy he was!!!!
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According to Airbus Maintenance Manual, it is NOT necessary to install Lock pin if the a/c is doing a pushback for flight. Is is only necessary to instal the pin of we are towing the a/c. Airbus say it is optional to instal the pin for a regular pushback.
Having said this, my company use the Downlock pin on pushback for the 330's, for the simply reason that its attached to the bypass pin by a connecting wire. there are Remove Before Flight streamers on both pins. Its just the belt and braces method. Whats the harm. Its little or no hassle removing the Lock pin from the 330. And as they are both attaced to each other, it is virtually impossible to forget to remove them both.
A few years back our companies Engineering Dept sent Query Notes to Airbus and Boeing asking them the question Are Downlock pins required for pushback in relation to positioning the a/c for flight. Both Replied with NO. only the steering bypass pin is required.
I heard lately that a certain airlines flight out of DXB, the captain refused to allow the a/c to be pushed back without the Nose downlock installed!! He delayed the a/c departure. Turned out he was in the wrong. company MOE stated only bypass needed and this was of course stated in the M.M. also. Suppose he was just used to seeing us display both pins on pushback as we use them both out of habit.
Having said this, my company use the Downlock pin on pushback for the 330's, for the simply reason that its attached to the bypass pin by a connecting wire. there are Remove Before Flight streamers on both pins. Its just the belt and braces method. Whats the harm. Its little or no hassle removing the Lock pin from the 330. And as they are both attaced to each other, it is virtually impossible to forget to remove them both.
A few years back our companies Engineering Dept sent Query Notes to Airbus and Boeing asking them the question Are Downlock pins required for pushback in relation to positioning the a/c for flight. Both Replied with NO. only the steering bypass pin is required.
I heard lately that a certain airlines flight out of DXB, the captain refused to allow the a/c to be pushed back without the Nose downlock installed!! He delayed the a/c departure. Turned out he was in the wrong. company MOE stated only bypass needed and this was of course stated in the M.M. also. Suppose he was just used to seeing us display both pins on pushback as we use them both out of habit.
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Out of interest.. Does anyone use a steering bypass pin during a startup only??? For their own safety??? Just to ensure the flight deck have something to look at to ensure ground crew are clear???? Do cockpits have an indication of this system being bypassed????
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On the airbus, you indeed get an ECAM message saying the steering is bypassed when the pin is installed. If you look at this, it is a green message without engines running. when engines are started, this then turns amber for the simple reason of alerting the crew so as not to depart with it installed.
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Pins
BCAL: DC10 had a hockey stick downlock pin with a steering bypass pin on a chain - both used for pushbacks and towing. On 747 and A310 A320, used only bypass pin for pushbacks, downlock pin inserted (with open log book entry) for tows. On 1-11 - no pins for pushbacks but sys 2(?) hyd pump off during eng start, downlock pin inserted (with open log book entry) for tows.
My current co (not hard to work out who that is then):
747 - only bypass pin for pushbacks, downlock pin inserted (with open log book entry) for tows (again - we have ground use only hocky stick types)
The aircraft carry thie own full compliment of gear pins.
A340 - only bypass pin for pushbacks, downlock pin inserted (with open log book entry) for tows.
The thinking behind any company that does not require downlock pins for push backs is - manufacturers advice! and that you are primarily driving the gear in the "extend" direction during the push (okay - not when the tug is slowing the aircraft, or when a slight "pull forward abeam XYZ" is required).
A tow is a prolonged force in the direction of gear downlock "breaking" and retraction.
Paul
My current co (not hard to work out who that is then):
747 - only bypass pin for pushbacks, downlock pin inserted (with open log book entry) for tows (again - we have ground use only hocky stick types)
The aircraft carry thie own full compliment of gear pins.
A340 - only bypass pin for pushbacks, downlock pin inserted (with open log book entry) for tows.
The thinking behind any company that does not require downlock pins for push backs is - manufacturers advice! and that you are primarily driving the gear in the "extend" direction during the push (okay - not when the tug is slowing the aircraft, or when a slight "pull forward abeam XYZ" is required).
A tow is a prolonged force in the direction of gear downlock "breaking" and retraction.
Paul