What is the correct procedure when pushing back from the gate?

 

I recall when I flew the 767 you could start number 2 engine during the push, but you had to wait until the push was finished and the brake re-applied before starting number 1, due to the amount of thrust developed by the engines I believe..

 

Is this procedure the same for the 737 or are we able to proceed with the number 1 engine start sequence whilst still being pushed by the tug??

 

Cheers

 

Steve

Generally, you can start both engines while on tug. The crew would notify you if they needed you to do something differently for one reason or another.

To be honest, it depends on the type of tug, the airline SOP and the Ground Ops Manual. Most airlines teach their rampies (or tell their contractor to teach their rampies) to do it a certain way, and the crews know this.

Another pushback question -

 

In the normal (PMDG version) 737NGX under normal circumstances (FSX settings) can someone explain the pushback procedure as it relates to the Normal Procedures... and the conversations the pilot has with the ground in the pushback in the sim-

 

page NP.21.30 talks about steering lockout pins and hydraulic pump switches, and what to do with one or the other. What exactly is going on during FXS pushback, and what hydraulic switches should be on/off at which times? Is there a nose gear steering lockout pin installed?

 

a side note- I always visualize the pilot doing the pushback commands to the ground is that pilot who landed the plane in the Hudson.

System A hyd pumps should be off until ground confirms pushback complete and the pin. I also take my feet off the pedals completely during pushback. This in the sim but I believe in line with the SOP.

So during pushback, System A hydraulic (both engine and electric) are off. System B (both engine and electric) are on. Turn on System A (both engine and electric) after pushback.

 

This must mean the PMDG NGX steering lockout pin is not installed?

 

What is the captain talking about in the pushback dialogue when he references the pin? I guess I can't recall exactly what he is saying, but I seem to recall talking about looking for a pin or something... this would make me think there is a lockout pin installed... and after pushback he is waiting for visual confirmation that the lockout pin is removed... if this is the case all hydraulic systems would be ON prior to pushback, no?

The RW SOPs that i have want you to switch OFF SYS A HYD pumps, with the pin installed or not installed. Its a safety precaution!

Different companies, different procedures. We turn on both electric hydraulic pumps prior to push back. The ground crew installs a steering lockout pin in the nose gear prior to push back.

Fair enough.

 

Why is this a safety precaution though? Physically & mechanically what does shutting down System A prevent? Why does having a lockout pin in make it possible to have System A on?

 

NP.21.31

 

If pushback is needed and the nose gear steering lockout pin is installed

      ELECTRIC HYDRAULIC PUMP switches - ON

 

(engine systems were turned on earlier, so all hydraulic is on both A & B)

 

I know this is sim world, but hey I'm still curious

I think that all NGs have pins. Boeing made that change after a series of real accidents took place in the -200 classics. Back then you would also leave the engine generators off as well as the hyd pumps in system A to prevent a shift in power source from causing a nosewheel movement. As some companies operate a mixed fleet (I think), or a an added safety feature, they leave the A pumps off. Some like the ground crew to physicaly show the pin and have a visual of it before turning generators and hydraulics on.

Because if by accident the ground crew forget to install the pin and you move the tiller there is a hell of alot of mechanical pressure thats going to swing that tow truck that could lead to serious injury or death.

Interesting. I would think that something mechanically in the gear would bust before the tug went swinging. I'll have to google to find a real-world incident and read about it.

 

 

and the conversations the pilot has with the ground in the pushback in the sim

 

[Prior to any of these calls, all ramp actions should have been completed. Ground power and air have likely been removed by hand signal requests, or by headset comms, and the steering bypass pin was likely inserted as soon as the aircraft was parked and chocked on the inbound flight.]

 

"Ground. Cockpit" - Flight deck to ground call to see if they're paying attention (the rampies have several jobs, so they're not always on the tug and ready)

"Go ahead Captain." - I'm here. What's up?

"We're all set to go up here. We've been cleared to push and start at your discretion." -  When you're ready to go, push the plane back and let us know when the engines are clear (from ingestion, or blast hazards).

"Roger that - ready for push. Power and air are clear. Doors closed. We are ready for pushback. Release parking brake please." - This is a verbal confirmation that the rampie sees that all ground power cables and air hoses (low or high pressure) are disconnected, and the doors are all closed. It finishes with a request to release the parking brake so that the tug can move the plane.

"Okay. Parking brake is off. Cleared to push." - Notification that the brakes are off and the plane can be moved.

"Brakes off. Here we go." - Confirmation that the last message was received and that push is beginning.

 

[As the plane is moving, ramp notifies crew that the engines are clear, and communicates any stops/breaks in the push due to obstacles, other aircraft, people, etc.]

 

"Push is complete. Set parking brake please." - Request for aircraft brakes to be set to ensure it doesn't move upon release.

"Brakes are set and pressure is normal." - Response that brakes are set and the instruments show that it can hold its position.

<Side comment: you wouldn't believe how many people have YouTube videos specifically referencing the pushback and cut the last part of this out, so this last part is off of memory...>

"Okay bar is off, pin is out - you're ready to go." - Towbar is disconnected, steering bypass pin is out and they're ready to go.

"You're cleared to disconnect. We'll be watching for the pin and release from guidance on the [left/right] side of the airplane and we'll see you guys next time through." - Message to note the rampie can pull the headset out, and that the crew will be looking for the bypass pin clearly shown and the release from guidance (usually a salute), to signify that the pilot is now in control of its own guidance/movement.

 

System A hyd pumps should be off until ground confirms pushback complete and the pin. I also take my feet off the pedals completely during pushback. This in the sim but I believe in line with the SOP.

 

This is a modification of the Boeing standard checklist that's a carryover from the older generation of 737s. Only certain operators use this, mostly because they operated the older versions, and continue to do it as they needed to for commonality when operating both types.

 

 

 

What is the captain talking about in the pushback dialogue when he references the pin? I guess I can't recall exactly what he is saying, but I seem to recall talking about looking for a pin or something... this would make me think there is a lockout pin installed... and after pushback he is waiting for visual confirmation that the lockout pin is removed... if this is the case all hydraulic systems would be ON prior to pushback, no?

 

The referenced pin is there to avoid having to monkey with the hydraulics, they can all be on prior to push if you so desire.

 

 

Because if by accident the ground crew forget to install the pin and you move the tiller there is a hell of alot of mechanical pressure thats going to swing that tow truck that could lead to serious injury or death.

 

Not really true. It'll swing the bar, and that'll probably bang up or break a leg if you're near it, but we were taught to always treat the bar as potentially active until it's connected to the tug (where the tug mass is high enough that it's not going to move). Unless you're especially skilled, it would be very difficult to get killed by a towbar. It's not going to move especially fast, though it will move fast enough that it's going to catch you and hurt you mostly because you're not expecting it.

 

For what it's worth, that pin should've been installed on arrival, so if it's "forgotten" you have other issues on the ramp...

 

Interesting. I would think that something mechanically in the gear would bust before the tug went swinging. I'll have to google to find a real-world incident and read about it.

 

Correct, but still highly unlikely. This is more an issue of assumptions without experience making their way into aviation forums (sorry, but it's true, and you all know how much I beat that drum   ).

 

For what it's worth, there's a lot of "ramp fiction" out on the ramp, too. I was told by a rampie that landing lights sent out harmful X-Ray (no joke) radiation that can damage your eyes, so he refused to marshal planes in if they left their lights on. If it was dark enough, I just threw my sunglasses on and the pilots usually got the point.

Incredible explanation, thanks!

 

I was looking for incidents, and found that the injuries were caused by the towbar swinging, not the tug.

 

I read one incident where they had System A off, and due to a series of events, the system pressurized and caused an incident. Incredible the chain of events (the cap accidentally turned on the nose wheel light... went to turn it back off and instead accidentally clicked off the APU.... which pressurized system A because [so they say]  System A was powered to close, and when power was cut  Sys A came alive.

No assumptions here kyle! Thats what the pilot said to me. Just for precaution.