17
$\begingroup$

Let's assume that an airliner crew has insider information about the imminent annihilation of the airport where they are currently going through boarding. They need to get away as quickly as possible. It is a regular Airbus or Boeing long-haul.

Assuming that regular airport procedures have come to a stop: At which point would they be able to leave without assistance, under their own power?

For example, normally a passenger jet is pushed back from the gate. Could it back itself out if damage to the terminal etc. didn't matter? The bridge itself is, I think, not really attached to the aircraft, so it shouldn't be a problem.

I think the ground crew usually blocks/wedges the front wheels in to ensure that the aircraft stay in its place. Could those wedges be manually removed by the crew?

Anything I miss that would require specialists or special gear on the ground before an airliner could pull away?

Improve this question
$\endgroup$
8
  • 3
    $\begingroup$ Could someone manually remove a chock? Yes, that's how the ground crew do it... $\endgroup$
    – Cloud
    Commented yesterday
  • 2
    $\begingroup$ there's an enjoyable S.King's Langoliers vibe in this one, and a (maybe less enjoyable) Beebo Russell too $\endgroup$
    – user721108
    Commented yesterday
  • $\begingroup$ @user721108 Re Beebo Russell: Well, the crew is on board, fully professional and capable. And smart. :-). $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 3
    $\begingroup$ @Peter-ReinstateMonica imo if one single dude is smart enough, one full crew can do whatever is needed by splitting tasks =) $\endgroup$
    – user721108
    Commented yesterday
  • 2
    $\begingroup$ You might be interested in Worldbuilding "Worldbuilding Stack Exchange is a question and answer site for writers, artists and others using science, geography and culture to construct imaginary worlds and settings." $\endgroup$
    – Jamiec ♦
    Commented 18 hours ago

4 Answers 4

Reset to default
22
$\begingroup$

Assuming that regular airport procedures have come to a stop: At which point would they be able to leave without assistance, under their own power?

Here are some ideas for a scenario where the ramp personnel is not helping for the departure.

Precompressed air and electric power

In most cases at large airports the aircraft doesn't use its internal APU (a small turbine supplying both compressed air and electric power) to save noise, pollutants and cost.

Instead there are connections to the bridge, to a truck or to the ground. For example the preconditioned air used for air-conditioning flows in these yellow flexible pipes (see @Ralph comment):

Aircraft preconditioned air connection

Source.

Other connections: Water, wasted water, fuel

There can also be other connections still in place (fuel, water, wasted water). The crew would need to disconnect corresponding pipes and cables; it's possible and that doesn't require any tool.

Here is a typical ramp scene for the A320; vehicles do not come or leave at the same time:

A320 ramp layout

Source: Airbus, Airport and Maintenance Planning.

Everything must and can be disconnected

Everything must be disconnected without damaging the sockets. It would be hazardous to just move the plane until the connections break, e.g. the refueling nozzle would likely stay connected to the wing tank, allowing fuel to leak (see mechanism here); with engines running a fire is almost certain.

The aircraft crew can still go down the ramp using the bridge stairs (below the bridge on the first photo) and disconnect everything.

Ramp obstacles

The crew may also have to move some cart, truck or generator that might be in the way, but that should be manageable.

Open doors, servicing panels, locking devices

There are other points to be considered, like open doors and panels (on engines, on cargo holds, etc), chocks in place, gears moored with mechanical anchors. All of them are manageable without ground support. You can read about these elements on the same linked Airbus document, e.g. the connection points are all described at page 204, and mooring anchors at page 190.

Risks associated with powerback

Using reverse thrust to taxi back is possible but not entirely safe. In normal conditions such operation would have to be validated by the operator and the airport using OpSpec C065.

Taxi and take-off roll times

It can take time to reach the runway, depending on the airport layout. Taxiing faster than the allowed speed is not an option.

It also takes some time to align and accelerate for take-off.

Such departure in a novel would be credible to a pilot, providing the crew takes the related actions.

Improve this answer
$\endgroup$
13
  • 1
    $\begingroup$ Great! Also a valuable document in the link. $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 1
    $\begingroup$ Detaching comm cords & towbar would be straightforward. Getting out of a towbarless tug would be more involved, if they'd already captured the nosewheel. For storytelling purposes, if the author doesn't want to explain towbarless pushbacks, I'd suggest going with "not hooked up yet" & leave it at that. $\endgroup$
    – Ralph J ♦
    Commented yesterday
  • 3
    $\begingroup$ One other thought: the air hoses are long & flexible & really, really must be secured, because an engine running at high power can absolutely generate enough suction (wind) to pull a hose right into the motor, and that is a certain way to destroy your engine. Pilots would probably be aware of this, but even in a hurry, that's not a step they can afford to omit. Maybe they could park a baggage cart where it immobilizes the hose... not normal ops, but if in 10 minutes everything is pulverized anyway... why not? $\endgroup$
    – Ralph J ♦
    Commented yesterday
  • 8
    $\begingroup$ If nuclear war is really on the horizon and the pilots can convince the ground crew of the imminent danger and say "if you get the hoses, etc. removed in the next 2 minutes and climb up the stairs we'll take you with us, if not we'll leave anyway and take our chances with stuff still being connected, I think you might just get the ground crew on board (literally and figuratively). $\endgroup$
    – manassehkatz-Moving 2 Codidact
    Commented yesterday
  • 3
    $\begingroup$ @manassehkatz-Moving2Codidact That's a great idea, actually! I'll credit you with it if the story ever gets written :-) $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
4
$\begingroup$

I simply cannot imagine a scenario in which the "crew has insider information about the imminent annihilation of the airport" and in which disconnecting the bridge, fuel, water, waste and other cables, shutting all the cargo and other doors, removing the chocks, starting the engines and then using reverse thrust to back up onto the taxiway, with a high probability of striking another aircraft, ground vehicle or building, and then presumably taxi to the runway and take off without clearance, or a radio service, or having properly prepared the aircraft would in ANY WAY ever be a better option that simply leaving the aircraft and getting out of there on foot or by other means.

Never say never, but I can't imagine this would ever need to happen in any context.

Improve this answer
$\endgroup$
3
  • 3
    $\begingroup$ Thanks for the frame challenge -- I'm trying to prepare a story where an insider has knowledge of an imminent nuclear attack on Germany, including the city they are in (probably Berlin or Frankfurt). Nothing matters except getting the airplane a few km away from ground zero, and then, preferably, on to some suddenly very attractive, poor African country that does not have any oil or other resources needed in a war. That is, damage to structures, violation of procedure, minor damage to the plane etc. are entirely secondary. Yeah, you should avoid hitting something though, true. $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 1
    $\begingroup$ Whether it's possible for the crew to essentially finish ground operation (closing the cargo door, disconnecting anything that absolutely needs to be properly disconnected etc.) are basically the details that I'd like to get some information about. Otherwise the moment of decision would have to be exactly the 5 minutes between pushback and start, which is more unlikely and more contrived. $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 7
    $\begingroup$ This does not answer the question and would be better suited as a comment. "That would never happen" isn't a suitable answer to a hypothetical question. $\endgroup$
    – A McKelvy
    Commented yesterday
2
$\begingroup$

The crew could simply ask the ground staff (who would be there anyway) to expedite the clearance, but without authorisation, it is very improbable, meaning "crew knowledge" would be insufficient for a fast getaway. A localised event in the terminal - fire, bomb, attack etc, - would be sufficient to encourage the ground crew to expedite departure, or at the very least, separation from the terminal, making a fast departure more possible.

Improve this answer
$\endgroup$
1
  • $\begingroup$ Yes, interaction with the ground staff is also a possible path. (There will likely be some interaction with the tower where the pilot has an acquaintance who ignores some shutdown orders by the military advance command, something along those lines.) $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
1
$\begingroup$

For example, normally a passenger jet is pushed back from the gate. Could it back itself out?

Not really, a jetliner doesn't have a reverse gear 😉

It must be pushed back by a pushback tug. In the recent past there was the idea of electrifying the nose landing gear to get rid of the pushback tugs and to move the airplane toward the runway without using the engines to save some fuel but I don't know what happened to this idea.

You might resort to use the thrust reversals to "powerback" from the gate: it was used in the past and it's something no more usually done as explained for example here but it can be for sure used in your story.

Improve this answer
$\endgroup$
6
  • 6
    $\begingroup$ "When reverse thrust is used to push an aircraft back from the gate, the maneuver is called a powerback"? The reason it's not done is possible damage to near-by structures, I thought. $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 1
    $\begingroup$ Actually, the first google hit using the specific keywords (that didn't occur to me before) is an aviation SE answer! ;-). $\endgroup$
    – Peter - Reinstate Monica
    Commented yesterday
  • 3
    $\begingroup$ Furthermore, not all thrust reversers are actually capable of producing reverse thrust at static conditions. Many would actually be better called 'drag generators' than 'thrust reversers'. Imagine the flow into the engine. Most 'reversers' turn the flow. If they turn the flow up to 90 degrees, the axial component of momentum is reduced (causing drag in forward flight), but not negative thrust at static conditions. For that, they must turn the flow more than 90 degrees. $\endgroup$
    – Rob McDonald
    Commented yesterday
  • 1
    $\begingroup$ Eastern used to power back in the 80's. No tug required. $\endgroup$
    – RetiredATC
    Commented yesterday
  • 3
    $\begingroup$ @RetiredATC AA powerbacked their MD-80s until the early 2000's. Definitely caught your attention in the terminal. $\endgroup$
    – user71659
    Commented yesterday

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .