'push back approved'

[mmilano]

listening to ground on liveatc at a class C airport. does 'push back approved' refer to the ground crew pushing the airliners away from the terminals?

 

[Dave Krall CFII]

listening to ground on liveatc at a class C airport. does 'push back approved' refer to the ground crew pushing the airliners away from the terminals?

A-firm...

 

[Richard]

A-firm...

If the push back occurs in a non-movement area who is it who grants the request? Why them?

 

[HPNPilot1200]

If the push back occurs in a non-movement area who is it who grants the request? Why them?

Sequencing....in addition to spacing pushing aircraft with aircraft taxiing inbound to the gate/ramp.

You'll often hear "tail to the west" or "tail to the east on Taxiway Alpha" if a pushing aircraft would conflict with another taxiing aircraft. This allows ground to specify which direction the plane is heading as well as allowing a shorter taxi by instructing a push to put the tail pointing a certain direction so a large-radius turn doesn't have to be made.

Terminals also have ramp control at larger airports which coordinates with Ground, Aircraft, and APRON operations.

Jason

 

[Richard]

Sequencing....in addition to spacing pushing aircraft with aircraft taxiing inbound to the gate/ramp.

You'll often hear "tail to the west" or "tail to the east on Taxiway Alpha" if a pushing aircraft would conflict with another taxiing aircraft. This allows ground to specify which direction the plane is heading as well as allowing a shorter taxi by instructing a push to put the tail pointing a certain direction so a large-radius turn doesn't have to be made.

Terminals also have ramp control at larger airports which coordinates with Ground, Aircraft, and APRON operations.

Jason

If you knew you could have held off to give someone else a chance. I know I didn't make that clear.

Here's another: since GND needs to clear the movement areas in a timely and orderly fashion why couldn't a guy push back and hold short of entering the movement area without prior approaval and PIC assumes all responsibility of remaining clear of traffic clearing the movement areas?

 

[HPNPilot1200]

If you knew you could have held off to give someone else a chance.

Huh, Richard? I guess I shouldn't post in response to questions? I don't quite understand your sentence fragment there....

Jason

 

[mmilano]

lol yeah, it did look like a question and not a game.

 

[Bones]

Thank god for Ramp Control at airports like IAD, and IAH. If you didn't have Ramp Control timing, and orchastrating push-backs it would be a free for all! Airport Authorities and Airline's insurance wouldn't like it much either.

 

[Richard]

Huh, Richard? I guess I shouldn't post in response to questions? I don't quite understand your sentence fragment there....

Jason

No, answer away. But what I'm talking about is when a question is posted it begats a process. The question is there for all to read, ponder, and perhaps answer. That process is truncated when the correct answer is given in the very first response. I wasn't clear about that so don't worry about it.

 

[Steve]

I've observed AA MD-80 series aircraft "pushing back" without ground crew assistance at MSY. I'm sure it doesn't do much for engine life...

listening to ground on liveatc at a class C airport. does 'push back approved' refer to the ground crew pushing the airliners away from the terminals?

 

[Richard]

Thank god for Ramp Control at airports like IAD, and IAH. If you didn't have Ramp Control timing, and orchastrating push-backs it would be a free for all! Airport Authorities and Airline's insurance wouldn't like it much either.

It sure would be a free for all. But is it illegal for a guy to do as I had suggested? It may not be a good idea at some of the aprts listed in Appendix D to Part 91 or during certain hours but what, other than traffic flow, would prohibit it?

Or to put it another way: is a pilot legally bound to comply with ATC instructions (other than clearances) when in a non-movement area?

 

[NC Pilot]

I've observed AA MD-80 series aircraft "pushing back" without ground crew assistance at MSY. I'm sure it doesn't do much for engine life...

If you notice, when a plane pushes back by reversing it's own engines it first moves forward a little, then reverses it's engines. Why does it do that?

 

[Steve]

Don't recall noticing that, sorry. Maybe they're throttling up before the clamshells completely close, or the clamshells don't completely close and there is some initial reaction to the first impulse before the deflected flow is maximized.

Dunno.

If you notice, when a plane pushes back by reversing it's own engines it first moves forward a little, then reverses it's engines. Why does it do that?

 

[poadeleted20]

It sure would be a free for all. But is it illegal for a guy to do as I had suggested? It may not be a good idea at some of the aprts listed in Appendix D to Part 91 or during certain hours but what, other than traffic flow, would prohibit it?

Airport rules.

Or to put it another way: is a pilot legally bound to comply with ATC instructions (other than clearances) when in a non-movement area?

Yes. In fact, if you're taxiing for takeoff, you are supposed to call ground before moving, even from a non-movement area.

 

[Skip Miller]

If you notice, when a plane pushes back by reversing it's own engines it first moves forward a little, then reverses it's engines. Why does it do that?

This is nothing but an educated guess:

The engines generate forward thrust far more efficiency than reverse thrust.

When a jet is stationary, there is "stiction" - a force greater than that necessary to keep it moving - that must be overcome to get it moving. Notice that I put "stiction" in quotes. Stiction is a valid concept in physics but I am not sure that what we observe in a jetliner at the gate is stiction classicly defined. It probably has more to do with the tires taking a "set" while parked. But that is a guess too.

The jets go forward to break the "stiction" and then hit the reverse thrust to back up, without stopping for more than an instant. Breaking the "stiction" with reverse thrust alone would need a higher engine power setting, saturating the local area with jet blast - not desirable with all the equipment on the ramp.

-Skip

 

[Greg Bockelman]

This is nothing but an educated guess:

The engines generate forward thrust far more efficiency than reverse thrust.

When a jet is stationary, there is "stiction" - a force greater than that necessary to keep it moving - that must be overcome to get it moving. Notice that I put "stiction" in quotes. Stiction is a valid concept in physics but I am not sure that what we observe in a jetliner at the gate is stiction classicly defined. It probably has more to do with the tires taking a "set" while parked. But that is a guess too.

The jets go forward to break the "stiction" and then hit the reverse thrust to back up, without stopping for more than an instant. Breaking the "stiction" with reverse thrust alone would need a higher engine power setting, saturating the local area with jet blast - not desirable with all the equipment on the ramp.

-Skip

Pretty good guess, Skip. That is pretty much the reason they do it.

Having been a rider in a cockpit a couple of times during the proceedure, the crew does in fact add forward thrust before they engage the reversers. It is basically to overcome the flat spots on the tires because forward thrust is indeed more efficient than reverse.

 

[Richard]

Airport rules.

Yes. In fact, if you're taxiing for takeoff, you are supposed to call ground before moving, even from a non-movement area.

Authoritive references please.

 

[NC Pilot]

Pretty good guess, Skip. That is pretty much the reason they do it.

Having been a rider in a cockpit a couple of times during the proceedure, the crew does in fact add forward thrust before they engage the reversers. It is basically to overcome the flat spots on the tires because forward thrust is indeed more efficient than reverse.

Ding Ding Ding Dingggg.... You got it. I noticed this every time we would use the engines to back out of a gate and ended up asking the captain. He was impressed and said nobody had ever asked that question before, then told me the reason why, which is exactly what you said. The tires get flat spots and it is easier to move forward a little, then reverse to get things rolling. Kind of like rocking a car to get it rolling.

 

[poadeleted20]

Authoritive references please.

AIM 4-3-14a.

 

[mdreger]

Or to put it another way: is a pilot legally bound to comply with ATC instructions (other than clearances) when in a non-movement area?

I would say no. ATC does not have responsibility for non movement areas. If they had responsibility, those areas would become movement areas.

At MDW all aircraft call for push back. ATC will say something like "...push your discretion.", "...wait for two inbound aircraft then push your discretion..", or something else along those lines. The push back area is a non movement area. There are a multitude of people, vehicles and equipment wandering around that area, so it is not possible to give a "clearance" that will guarantee that the operation is safe and will not impact anything or any one else.

Nearly all aircraft call for push back. There may be airport rules that require the pilot to call ATC first, but as far as ATC is concerned, we only advise, not control.

Aircraft call for taxi while in a non movement area, because they need a clearance before entering a movement area. ATC will generally give advisory instructions, even for other non movement areas like FBO ramps if there may be a traffic conflict there. This doesn't stop people from cutting one another off, and I would imagine someone doing that habitually would be councelled one way or another in the pilot lounge by the pilot he cut off.

 

[Richard]

AIM 4-3-14a.

Pardon me, I wasn't clear. Yes, get on the freq but what I was questioning was when you said, "Airport rules".

Since 4-3-14 does not specifically mention non-movement areas I interpret the paragraph as a blanket statement to cover all aprt operating areas. But that couldn't be correct since non-movement areas are defined as not under air traffic control. Further along it says to remain on freq while taxiing.

I interpret that as: get on the freq to advise them of your intentions, monitor the freq (unless advised by twr), and taxi as you please as long as you remain in a non-movement area. That is, you don't need permission to push or taxi.

Even still, the AIM chapter does not specifically address n-m areas.

I'm not saying it's wise, I'm simply saying it is permissable and no enforcement action can be taken against the pilot who chooses to do it.

 

[poadeleted20]

Pardon me, I wasn't clear. Yes, get on the freq but what I was questioning was when you said, "Airport rules".

Airports like ATL, JFK, ORD, etc., have their own sets of rules for ramp operations. They are not published in the AIM or anywhere else easily accessible to those to whom they do not apply, but all air carrier pilots operating into those airports are required to know them (part of training and line qualification). While the FAA may not take action against a pilot who pushes back without clearance, his company will, because it's their ramp and their rules. Since we aren't even allowed in those air carrier areas, we never see those rules, although sometimes they are part of the ATIS. So next time you're in your 747 at JFK ready to push back, don't do it until you get push-back clearance from ramp control, but if you're in your C-172 at Moosebutt Municipal, you can forget about it.

 

[Everskyward]

Yes. In fact, if you're taxiing for takeoff, you are supposed to call ground before moving, even from a non-movement area.

Here's a different opinion from the AIM.

4-3-18. Taxiing​

a. General. Approval must be obtained prior to moving an aircraft or vehicle onto the movement area during the hours an Airport Traffic Control Tower is in operation.​

1. Always state your position on the airport when calling the tower for taxi instructions.​

2. The movement area is normally described in local bulletins issued by the airport manager or control tower. These bulletins may be found in FSSs, fixed base operators offices, air carrier offices, and operations offices.


​

The trick is to know where the non-movement area is located if you're at an unfamiliar airport. At the home airport I know where it is and it actually encompasses a pretty large area. If I'm repositioning a long distance in the non-movement area I'll let ground know as a courtesy, but I've also been told by them that it isn't necessary.

 

[Richard]

Airports like ATL, JFK, ORD, etc., have their own sets of rules for ramp operations. They are not published in the AIM or anywhere else easily accessible to those to whom they do not apply, but all air carrier pilots operating into those airports are required to know them (part of training and line qualification). While the FAA may not take action against a pilot who pushes back without clearance, his company will, because it's their ramp and their rules. Since we aren't even allowed in those air carrier areas, we never see those rules, although sometimes they are part of the ATIS. So next time you're in your 747 at JFK ready to push back, don't do it until you get push-back clearance from ramp control, but if you're in your C-172 at Moosebutt Municipal, you can forget about it.

Alrighty! I just learned something new. I didn't even think of Company policy. Thanks, Ron.

 

[Richard]

Here's a different opinion from the AIM.


4-3-18. Taxiing

a. General. Approval must be obtained prior to moving an aircraft or vehicle onto the movement area during the hours an Airport Traffic Control Tower is in operation.

​

1. Always state your position on the airport when calling the tower for taxi instructions.


2. The movement area is normally described in local bulletins issued by the airport manager or control tower. These bulletins may be found in FSSs, fixed base operators offices, air carrier offices, and operations offices.



​

The trick is to know where the non-movement area is located if you're at an unfamiliar airport. At the home airport I know where it is and it actually encompasses a pretty large area. If I'm repositioning a long distance in the non-movement area I'll let ground know as a courtesy, but I've also been told by them that it isn't necessary.

It becomes more than courtesy after the twr closes. Several times I resolved a traffic conflict before it came close to happening by announcing my intentions to taxi in a non movement area. Cheers.

 

[poadeleted20]

Here's a different opinion from the AIM.

4-3-18. Taxiing​

Perhaps I didn't highlight it, but I said "supposed to," not "must." 4-3-14a says "should" call before moving for departure. 4-3-18 says "must" call before crossing the yellow line. At many airports, you can ruin the taxi flow if you get up to the yellow line before calling ground. You may even find yourself beak-to-beak with traffic inbound to where you were and no place for either of you to turn around. Sure, there's no need to call Ground if you're not leaving the non-movement area, but if you're going to enter the movement area, do everyone a favor and call ground before moving.​

 

[Everskyward]

My bad for not knowing the difference between "supposed to" and "must".

 

[Richard]

My bad for not knowing the difference between "supposed to" and "must".

Thanks for the lead in. Dig this, always in the past it's been, even though the AIM is advisory only to not comply could be used to prove 91.13 violation. Always, always, always.

Now it's 'supposed to', as in it's only a suggestion???

 

[Everskyward]

Thanks for the lead in.

You're welcome!

But this is where I bow out. I'm not so much in touch with my "inner lawyer"... as I've been told before.

All I can say is be careful when taxiing and use some common sense.

 

[Greg Bockelman]

If in doubt, ASK!!!

 

[poadeleted20]

Thanks for the lead in. Dig this, always in the past it's been, even though the AIM is advisory only to not comply could be used to prove 91.13 violation. Always, always, always.

Now it's 'supposed to', as in it's only a suggestion???

For most of us, it's a suggestion. But when operating on an air carrier ramp where it's mandatory, it's mandatory. How do you know it's mandatory? You will be told as part of your training. And if you're not getting that training, you won't be allowed on an air carrier ramp (security zone).

 

[Richard]

If in doubt, ASK!!!

That is sound advice, but for the purpose of this thread it's unacceptable. This thread was to explore the hypothetical. How much can a pilot do. Asking ATC not required or even allowed in the hypothetical sense.

Ron finally explained it all quite well and for that I am grateful because I developed some insight into what governs who in non-movement areas, even though it took some digging.

While I've always had the idea I could move about freely in a non-movement area I felt there was more to it. Ron explained that.

 

[poadeleted20]

While I've always had the idea I could move about freely in a non-movement area I felt there was more to it. Ron explained that.

Just keep in mind that there's a big difference between the non-movement area on a public GA airport and the privately-leased ramp space on an air carrier airport.

 

[Richard]

Just keep in mind that there's a big difference between the non-movement area on a public GA airport and the privately-leased ramp space on an air carrier airport.

I think that is the most pertinent thing. I hadn't really thought of it, probably because I didn't know the ramp was leased.

 

[jdwatson]

Yes. In fact, if you're taxiing for takeoff, you are supposed to call ground before moving, even from a non-movement area.

The operative word here is from a non-movement area, yes ? It seems at most airports I've been at, Ground Control doesn't care about you in the non-movement areas like around hangars, FBOs and etc. I usually find an appropriate place to do my run-up, run my pre-taxi checklists and then call ground.

The times I've called Ground in non-movement areas, I was told call-back when you're at X-Y-Z or approaching taxi-way BlahBlah-3.

 

[poadeleted20]

The operative word here is from a non-movement area, yes ? It seems at most airports I've been at, Ground Control doesn't care about you in the non-movement areas like around hangars, FBOs and etc. I usually find an appropriate place to do my run-up, run my pre-taxi checklists and then call ground.

The times I've called Ground in non-movement areas, I was told call-back when you're at X-Y-Z or approaching taxi-way BlahBlah-3.

Some towers may not care, but the AIM calls for it, and at many airports, failure to call before starting to taxi when you're going into the movement area, even if you're starting from a non-movement area, can result in two airplanes beak to beak with no way to go around each other. Of course, if you're not going to enter the movement area, yes, there's no need or even real purpose to call Ground.