what’s the use of the cart that pushes back the airplane? Can planes not reverse without it?
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The wheels on planes aren’t motorized, the only propulsion the aircraft has are the engines.
Thrust reversers dont push air straight back, instead they push a lot of air out to the sides. Because engines are close to the ground, this can create a lot of noise, become hazardous to anyone standing somewhat close by, and can potentially knock up debris from the ground and potentially lead to that debris entering the engine
It also burns fuel, which airlines don’t like wasting unless it’s necessary.
Planes reverse by redirecting the air out of the back of the engine forwards — called a powerback. While most aircraft can do powerbacks, it is usually not allowed by company procedure since it blows debris on the ground up into the engines. Planes with tail mounted engines were more likely to powerback than planes with low wing mounted engines.
https://en.wikipedia.org/wiki/Powerback
Airplanes can reverse. Most terminals windows cannot handle the force from the jet blast, along with the bag carts and everything else on the ground that would have to be secured.
When planes land they use reverse thrust to slow down.
I asked this same question to a few pilots .
They technically could using reverse thrust but it uses a lot of fuel, can suck in debris, damage the gate, and hard due to the pilots not being able to see the rear of the aircraft. It just makes more sense to have the ground crew do it
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What everyone else posted…
Plus…
When pilots perform a powerback maneuver, they can’t see what is happening behind them. A tug operator **can** see behind and beside the plane in addition to the ground crew assist. They can steer and stop according to the needs and safety of the aircraft.
Major airline pilot here. We don’t have backup cameras or mirrors, which in a safety-minded industry introduces a lot of potential risks if we were asked to just backup on our own. We also can’t see much of the plane from the cockpit… All the pointy sticking-out bits are behind us. Plus, there’s a lot of coordination that goes into backing off the gate that’s best conducted with a team. Wing walkers are great for alerting other vehicles to our movement, helping to avoid hitting ground equipment or fixed obstructions, and directing us to our specific spots on the ramp before being released for movement under our own power. Even if I had motors in my wheels, I wouldn’t want to move a machine over 100ft long in every dimension without someone making sure I wasn’t going to break it.
Aeronautical engineer here:
The real reason why airplanes don’t go backwards using reverse thrust is not noise, it is the risk of an engine surge.
Reverse thrust is only used during landing while the airplane is still going forward at a certain speed (notice that the reverse thrust is shut way before the airplane is at rest, during landing). The risk is that the engine sucks back up its exhaust gases + the fact that reverse thrust increase considerably the air flow pressure in the rear side of the engine. At low speed, if this pressure gets too high, the air struggle to moves backwards in the engine and the air flow can stall in the compressor leading to a [compressor surge](https://en.m.wikipedia.org/wiki/Compressor_stall) which is very damaging.
Airplanes are not really designed to be on the ground…
So firstly they just don’t have any way of powering the wheels – to add in an engine and motor big enough to derive a plane about and reverse it would add notable weight and complexity to the plane – both of which are generally considered the enemy is efficient and reliable flight.
You then have to add to that a high cockpit position without a clear view of the ground, and zero view behind – okay for trundling along a clear taxiway, but dangerous in close quarters where the pilot would be maneuvering completely blind and trusting to an external watcher.
So what we end up with is the decision to use a tug while near the gate and needing to do fine maneuvering near people, structures and equipment – after all, a plane is already heavily reliant on ground based equipment anyway, so it isn’t a huge addition. And then when clear of buildings it can then use its engines to push itself along.
In theory, yes, most planes can use reverse thrust to reverse out on their own, however that also results in directing the power of that thrust at the departure gates and other structure, which is pretty far from ideal. Ground crew don’t really want to have to clear everything nearby and reinforce the windows just to move a plane.
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