Ask The Pilot

[Major]

So can the Caribou and C130

 

[jb747]

Well, as some have already answered, some aircraft, in particular turboprops, can. But, the current batch of mainstream airliners cannot. Even 60,000 lb thrust engines produce precious little actual reverse thrust (in the order of 5%).

 

[markis10]

Can a plane reverse under its own engine power?

Can a plane reverse under its own engine power over chocks?

Saw this in a movie once and wondered how much was real vs Hollywood?

The Q400s often push themselves off the bay in CNS under their own power, even jets at times, however its not common and banned by many airports and airlines, often the aircraft will move forward first to get off any possible flat spots:

AIRCRAFT POWER BACK - AERONAVE DANDO RÉ... - YouTube

 

[richie9x]

For anyone that is interested I found some videos on youtube of powerbacks by jetliners.

NorthWest DC-9 Powerback @KMSP - YouTube

Boeing 727 pushback with thrust reverser in LCG-LECO , A Coruña - YouTube

Airtran 717 Powerback out of TPA A17 - YouTube

 

[Flying Fox]

OK so follow-up question.

Why can a C17 reverse and commercial jets not do the same? Is it due to the original design & requirements of the aircraft in question?

So based on that, could a B747 or A380 be designed to reverse?

 

[tuppaware]

OK so follow-up question.

Why can a C17 reverse and commercial jets not do the same? Is it due to the original design & requirements of the aircraft in question?

So based on that, could a B747 or A380 be designed to reverse?

The C17 was designed as a STOL plane (Short take off and landing) - in particular the C17 I think it has dual thrust reversers or both bypass and exhaust where normal design is only bypass air to reverse. In that I thought the reverse on the normal jet was only to make the plane settle on the wheels and destroy lift.

 

[jb747]

OK so follow-up question.

Why can a C17 reverse and commercial jets not do the same? Is it due to the original design & requirements of the aircraft in question?

So based on that, could a B747 or A380 be designed to reverse?

I guess that if given the task, the engineers could come up with designs for anything.

In a turbofan engine, most of the thrust is produced by the fan. Most of the larger aircraft engine reversers simply block, and redirect, the fan air. They have no effect on the hot core flow. Because of the way the blocking is done, most of the flow is actually just blown sideways, with a fairly small vector in the forward direction. Normally you have to be out of high power reverse by 70-80 knots, and totally out of reverse by taxy speed (say about 30 knots).

Beyond that though, there is just no need. How could you safely reverse something like a 747 away from the terminal (when you are generally not allowed to have any engines running)? Touching the brakes might give an interesting effect too. Taxiing forwards has dangers enough..imagine being able to back into something.

 

[markis10]

To add to the replies above, the C17 is designed to operate into sub 1000m runways where there is no ground assistance, so it needs the ability to reverse, and actually directs it's reverse up and forward, allowing it to back up a 2% gradient.

 

[Mattg]

Hi jb747, just a couple of random questions...
1. Do the pilots get told if there's someone famous on the flight, or perhaps a national sporting team of some sort?
2. Is there any reason why the ferry flights of the 747s & a380s (ie. Positioning the aircraft MEL-SYD or SYD-BNE) aren't run as domestic passenger services, so that Qantas could make a bit of money out of them? Is it just me or does it seem pointless to fly them without pax when Qantas could be making money?

Thanks in advance

 

[jb747]

1. Do the pilots get told if there's someone famous on the flight, or perhaps a national sporting team of some sort?

Cabin crew might tell us, but no not officially. More than likely there's someone of some level of fame on every flight. Anyway, all passengers are important.

2. Is there any reason why the ferry flights of the 747s & a380s (ie. Positioning the aircraft MEL-SYD or SYD-BNE) aren't run as domestic passenger services, so that Qantas could make a bit of money out of them? Is it just me or does it seem pointless to fly them without pax when Qantas could be making money?

The effort would not be worth it. These flights often have quite loose timing, and as often as not are not cleaned or in any way catered. They never have cabin crew. You aren't going to have the 3-400 passengers that you'd need to make it viable, unless you cancelled a couple of the domestic flights. But those aircraft would be needed at the other end too, and so you'd just as likely need to ferry them... I'm sure they'd do it if it were viable, but the most cost effective way of handling ferries is to do as few as possible.

 

[harvyk]

The effort would not be worth it. These flights often have quite loose timing, and as often as not are not cleaned or in any way catered. They never have cabin crew. You aren't going to have the 3-400 passengers that you'd need to make it viable, unless you cancelled a couple of the domestic flights. But those aircraft would be needed at the other end too, and so you'd just as likely need to ferry them... I'm sure they'd do it if it were viable, but the most cost effective way of handling ferries is to do as few as possible.

If the ferry flight has no cabin crew, what about things such as arming and disarming doors and other things which cabin crew typically do to look after an airplanes non-flying systems? Is there typically a cabin crew member on board to look after such things, or are things like doors not armed, or does one of the pilots have a couple of extra duties before \ during \ after the flight itself?

 

[anat0l]

What are the safety instructions for the flight deck crew? That is, loss of oxygen procedures, escape evacuation and life jackets?

I'd imagine there is no brace position as such for pilot / co-pilot as the full body belts are meant to mitigate against this need. Could be very wrong here, though.

There must be special oxygen masks for the flight deck to both enable oxygen flow and to maintain comms, right?

When flight deck has to evacuate the aircraft, do they just open the flight deck door and proceed to the nearest aircraft exit, or is there another means of escape for the flight deck (for example, breaking and discarding the windshield glass)?

----------
This anat0l content, if it must be known,
Was sent via Aust Freq Fly app, but not from an iPhone.

 

[QF029]

Cabin crew might tell us, but no not officially. More than likely there's someone of some level of fame on every flight. Anyway, all passengers are important.

Hi JB. You've mentioned previously that you sometimes say hello to passengers. Do you have any favourites - either because you're a fan of theirs or they seemed particularly nice?

 

[markj23]

The effort would not be worth it. These flights often have quite loose timing, and as often as not are not cleaned or in any way catered. They never have cabin crew. You aren't going to have the 3-400 passengers that you'd need to make it viable, unless you cancelled a couple of the domestic flights. But those aircraft would be needed at the other end too, and so you'd just as likely need to ferry them... I'm sure they'd do it if it were viable, but the most cost effective way of handling ferries is to do as few as possible.

If they could firm up the timing a little more, they could do well out of it - if it was only held say 1-2 times a year and marketed appropriately. I know it would likely be my own chance of getting on another of that size, and i would probably fly myself down from CNS to either SYD/MEL/BNE to take the flight. I wouldn't bother much on the catering, just give everyone a bottle of water and some biscuits

Whilst i haven't posted a question, i have spent a fair bit of time reading the thread and check it often (maybe too often) so just wanted to say thanks for taking some time out of your day/night to answer the questions

 

[jb747]

If the ferry flight has no cabin crew, what about things such as arming and disarming doors and other things which cabin crew typically do to look after an airplanes non-flying systems? Is there typically a cabin crew member on board to look after such things, or are things like doors not armed, or does one of the pilots have a couple of extra duties before \ during \ after the flight itself?

On long ferries a cabin crew member will be carried, largely to keep an eye on the cabin. But on short flights, anything that needs to be done, will be done by the pilots. The ground crew have a 'ferry procedure' that they will carry out, and which will be entered into the aircraft's tech log. Basically though, that entails making sure things are secured, and that power is shut off to most of the systems (galleys, IFE, unnecessary lighting). As part of our preflight, we'll also do a check of the cabin. We don't arm all of the doors, just those near the coughpit.

 

[jb747]

What are the safety instructions for the flight deck crew? That is, loss of oxygen procedures, escape evacuation and life jackets?

There must be special oxygen masks for the flight deck to both enable oxygen flow and to maintain comms, right?

When flight deck has to evacuate the aircraft, do they just open the flight deck door and proceed to the nearest aircraft exit, or is there another means of escape for the flight deck (for example, breaking and discarding the windshield glass)?

Loss of oxygen..something dear to my heart. We have quick donning masks that are totally different to the system in the cabin (A320 aircraft pilots Oxygen Mask - YouTube). These seal tightly, and will provide oxygen under pressure if needed. The crew oxygen supply is also from a different system to the passengers. Pax systems vary amongst aircraft types. Some, like the 747 and 380, rely on a large number (10 plus) of bottles in which the oxygen is stored at around 1800 psi. This sort of system is always used for the crew, but from separate bottles (normally 2). Aircraft like the 767 use a chemical generator system, in which there is a generator mounted above each group of seats, which normally serves 3-4 people. Gaseous systems can provide enough oxygen for hours, whilst the chemical generators last from about 12 to 20 minutes.

Evacuation...we'd normally plan on coming back into the cabin, and making our way from there. In a ditching for instance, my assigned raft is actually at the other end of the aircraft. We can evacuate from the coughpit though. In aircraft in which the side windows can be opened, there will be an escape rope. On the 747, there was a hatch onto the roof, and an escape reel system.

I'd imagine there is no brace position as such for pilot / co-pilot as the full body belts are meant to mitigate against this need. Could be very wrong here, though.

No, no brace position, but a 5 point harness.

For what its worth, the coughpit glass is armoured. I doubt that you'd break it with a sledgehammer.

 

[jb747]

Hi JB. You've mentioned previously that you sometimes say hello to passengers. Do you have any favourites - either because you're a fan of theirs or they seemed particularly nice?

I try to do so on every daylight/early evening sector. I also visit the lounge on any departure that I do from Melbourne. Some people are just easy to chat to and there's no rhyme or reason to that. As I mentioned on another thread, I had a chat to Kylie on one occasion, but I had no idea who she was. Most interesting celebrity would easily be David Attenborough. Most interesting person...one from quite a while back now..he was a transplant surgeon from Adelaide. Nice bloke with an amazing skill.

 

[QF WP]

Most interesting person...one from quite a while back now..he was a transplant surgeon from Adelaide. Nice bloke with an amazing skill.

Sounds like Professor Russell Strong - there's a photo in the story...

 

[harvyk]

An Airbus question, can a pilot change which law the plane flys in manually? Or are all law changes done automatically?

If a pilot can change from normal law into alternate law for what ever reason can the pilot change back into normal law or will the rest of the flight be done in alternate law and the only way to get the plane back into normal law is by an engineer "flicking a switch" on the ground?

 

[jb747]

Sounds like Professor Russell Strong - there's a photo in the story...

Whilst the picture doesn't ring a bell, I do recall that he said he did livers, so I guess that's him.