Lets say for this subject, a large jet, (OK A320) lands at a very small airport. (don’t matter why, we are playing) Now it is time for take off, and the taxi way puts the Jet on the runway, but being a short runway, the jet wants to back up to get more space. Ok, even use the blast pad. Can the reverse thrusters actually be enabled, and have the jet back up?
For this subject, I am not asking about the rules, legalities etc, more for the possibility of the equipment to actually do this. Be nice, no arguments!!!
Pretty rare these days, depending on what country you are in. Just don’t touch the brakes when you want to stop! Here are a couple cool videos of it being done:
It can be done. It has been done. It’s bad practice however, since the exhaust can kick FOD up off the ground and cause the engine to ingest debris.
Plus, you can’t see behind you, and if you brake your tail is gonna hit the ground, etc.
But it’s physically possible for some aircraft!
In fact, there was a situation a few years ago where a C17 landed at the wrong airport with an extremely short runway, somewhere in Florida. To take off, they used their reverse thrusters to back up all the way to the end of the runway. There’s a video of the takeoff floating around somewhere on YouTube; it was a pretty major incident at the time.
I was on a Northwest DC9 flight to Minneapolis-St.Paul in 2001 I think when they just didn‘t get a push back tug for some reason. Being a NW delivery and people wanted to reach their intercontinental flights they became pretty demanding when after more than half an hour we still didn‘t move. Some passengers seriously suggested to get out and push the plane back themselves. So in the end they managed to get the rampies make sure they were clear behind and we used the reversers. For me as an aviation fan it was pretty cool. Unfortunately in 2001 there were no smartphones around yet
Don‘t think they would do it with wing-mounted engines though.
yeah i think these days powerbacks aren’t done as much. if they are, i’d suspect to see them in rare occurrences at major airports and more likely at smaller airports with less infrastructure in older aircraft
Yep. Remember back in the day sitting on a 727 at Raleigh/Durham … after closing up the pilot powered up and with a mighty roar, ‘reversed’ away from the gate. (should point out it was the airplane that roared, not - as far as I know - the pilot). Both myself and aviation buff colleague I was traveling with were pretty shocked - never having seen it done before.
Let’s see, you can use thrust reverse to push back the airplane, some pilots do that, if it is correct? Well, maybe isn’t the best thing to do, but I have seen one C17 globe master doing that to start taxiing. To be honest, is not a good practice but can be done and is also dangerous in my opinion
Old airliners with clamshell reversers that block the exhaust flow coming out of the tailpipe can be used to back the airplane. Examples are the 727, 737-200, DC-9 and MD-80.
Modern airliners with bypass reversers cannot. These are not actually “thrust” reversers at all. When the translating cowl slides back, blocker doors in the bypass duct close and direct all of the bypass air out of vents in the side of the cowl. Some of the redirected air does flow forward, but most goes sideways.
Some bypass reversers might produce enough forward airflow to move a very lightly loaded airplane backwards, but doing so would require almost maximum reverse power, and would never be an approved procedure.
Since the majority of the engine thrust in a modern jet engine comes from the bypass air, (not the jet exhaust), just setting a bypass reverser to the idle reverse setting will kill about 80 percent of the forward thrust of the engine. The braking action these reversers provide on landing comes from the tremendous increase in drag produced by the spinning fan blades when the bypass duct air is blocked and diverted. That drag is maximum at higher forward speeds of the airframe - which is why bypass reverse rapidly becomes ineffective below about 80 knots on landing.
Idle reverse can be used in taxi to slow an aircraft without using brakes excessively, but it is not due to any braking action provided by the bypass reversers, but due to the fact that the thrust of air flowing backward through the bypass duct is diverted.
Turboprops with fully reversible propellers can be used to back the airplane. When I was in the Air Force, going through tech school at Keesler AFB, I used to see C-130s of the the Hurricane Hunter squadron that was based there doing this all the time.
To be fair, this is what I was doing to reverse an aircraft from a gate when MSFS came out, just because I hate the default pushback and there weren’t any plugins out yet (We’re still missing something as good as XP11 BetterPushback though)
For us, it’s easy, just because we can go into an outside view and see what’s around us, but in real life, using reversers or just in overall reversing a plane by a pilot is not a great idea, just because you can’t really see the back of the plane.
That said, here’s a 757 reversing at Skiathos (0:55)
C-17s are somewhat unique in the the reversers are hybrid - they can do both bypass and exhaust reverse. The amount that the translating cowl slides is fixed on most aircraft engines. On the C-17 the degree of cowl movement is variable. When it slides fully back, it provides both bypass diversion and also exhaust blocking, which is why the C-17 can backup using reverse.
If the translating cowl is slid back only slightly it causes enough bypass air drag for aerodynamic braking in flight, without killing all forward thrust. This gives the C-17 a lot of versatility in its military role. Being able to back on the ground is very advantageous on the small unimproved fields they might have to use in action.
I’ve trained pilots to do it at FlightSafety in the Falcon 900. But as mentioned above, don’t use the brakes or you will unceremoniously tip the airplane onto it’s tail. That is usually a career ending event for both pilot and airplane
Theoretically possible although a very bad idea. You could get FOD in the engines, the engines will ingest their own exhaust gasses (depending on the reverser system) causing compressor stall / surge. Without a marshaller you don’t know what’s happening behind you so you are backing up blind (no mirrors installed ). Most jets are not certified for this, when they are it is only to powerback from a gate or stand under marshaller guidance. NEVER EVER use brakes while powerbacking or the aircraft will tip over on its tail. On the ATR we are powerbacking from the gate all the time.
