This suprised me. I know there are 4 engines but I would have thought it prudent to declare an emergency in case of undiscovered issues associated with a failure.

 

 

Many cases of 747's on 3 engines and it not being an emergency.  The plane is more than capable on 3 engines and is in no danger to itself or others, not sure why it would be an emergency if they have followed proper procedures and aren't getting any immediate errors or warnings.  

BA actually departed with 3 engines on a LAX-LON flight, that's how capable the 747 is on 3 engines...

https://simpleflying.com/ba-la-uk-three-engines/

 

2 hours ago, psolk said:

The plane is more than capable on 3 engines

 

Oh yes, I'm aware a 747 can fly on three engines, in fact they can fly on two and its claimed one in level flight under the right conditions. I was just surprised that given how cautious, sometimes overcautious, the authorities are it was designated a non-emergency. 

It’s often initially declared as a mayday then downgraded to a pan.

I once had a flock of seagulls play chicken with me on a takeoff roll in the 747, it ruined my day but they came off worse.

That led to a precautionary shut down on number 3, it was still producing thrust but the vibrations and noise were like a chainsaw. 
 

on that occasion if I recall it was an initial pan call and then advising ATC of the shutdown ( as required) .

The aircraft handles fine on 3 engines once a bit of rudder trim is applied, and I’d go as far as to say it will still out perform the anemic 787 with all its engines running.

Upon landing we also found bird splat on the side of engine number 2 less than a meter from the intake. 
 

Now if that bird had  taken out a second engine it would have been a more dramatic story but still quite manageable . An immediate return to land rather than loitering to dump fuel.

The issue with the 747 was loosing 2 engines on the same wing, then you ran into VMCA issues.

The 2 Eng go around procedure calls for continuing to descend to accelerate and get some air over the rudder while SLOWLY bringing the power up, inboard slightly ahead of outboard.

And yes she will just about stay up on one engine.

I really miss that big old bird ( the 747, not the seagull )

21 minutes ago, jon b said:

I really miss that big old bird ( the 747, not the seagull )

Yep, definately the best commercial aircraft ever built.

9 hours ago, psolk said:

 

BA actually departed with 3 engines on a LAX-LON flight, that's how capable the 747 is on 3 engines...

https://simpleflying.com/ba-la-uk-three-engines/

 

And BA was admonished by the FAA never to do that again! 

The authority to continue flight on a four-engine aircraft following an engine failure is a historical left-over from the DC-7 and Connie days when it wasn't uncommon for an engine to fail in flight.  I seem to recall that with the L-1649 and DC-7C, one in four crossings had an engine shutdown.  The regulation allows the PIC to elect to continue the flight to the destination rather than diverting to an alternate, if in their opinion doing so was the safer course of action.  The BA crew lost the engine just takeoff from LAX and flew all the way to London with failed engine.  That was not the intent of the rule, although technically the crew was allowed to do it.  The FAA came to a gentlemen's agreement with BA and CAA  that this would not occur again in US airspace.

Rich Boll

From the US AIM on Emergency and Aircraft in Distress:

Emergency Condition- Request Assistance Immediately

1. An emergency can be either a distress or urgency condition as defined in the Pilot/Controller Glossary. Pilots do not hesitate to declare an emergency when they are faced with distress conditions such as fire, mechanical failure, or structural damage. However, some are reluctant to report an urgency condition when they encounter situations which may not be immediately perilous, but are potentially catastrophic. An aircraft is in at least an urgency condition the moment the pilot becomes doubtful about position, fuel endurance, weather, or any other condition that could adversely affect flight safety. This is the time to ask for help, not after the situation has developed into a distress condition.
2. Pilots who become apprehensive for their safety for any reason should request assistance immediately. Ready and willing help is available in the form of radio, radar, direction finding stations and other aircraft. Delay has caused accidents and cost lives. Safety is not a luxury! Take action!

 

If there is distress, deviation from a clearance, or priority assistance required, it may not be necessary to declare an emergency. 

Rich Boll

2 hours ago, jon b said:

it will still out perform the anemic 787 with all its engines running.

Could the 747 even do this?

 

2 hours ago, dmwalker said:

Could the 747 even do this?

Yes.

Anything the 787 can do the 747 will do better, except not as economically.

In an air display scenario like that the 747 has a simply massive envelope for the power to weight ratio to change in. The difference in an empty 747 with minimum fuel and it’s MTOW is well in excess of 200,000kg, it’s almost at the figure for  for the 787-9”s  MtOW of 252,650KG.

So because of this you can have an absolutely huge underload on the 747 whereby empty they have a similar power to weight ratio of a loaded previous generation fighter-bomber.

On normal line operations the initial target pitch for the 747 is 15 degrees, on the 787 it’s 12 for example.

I’ve taken off empty 747s with 25T of fuel and  full power and they pitch up to over 20 degrees ,initial  climb rates in excess of 10,000fpm, you’re passing the end of the runway at 3,000ft it’s literally breathtaking.

It’s a similar story with trucks that aren’t carrying trailers (I know they have limiters to stop stupidity) but a massive power to weight shift. The 787 in comparison would be more of a family car.

Having said that I have taken off 787s light at full power (due LLWS advisories) and they can shift when asked, but still they’re not in the same league as a jumbo in a similar scenario.

Edited July 27, 20223 yr by jon b

13 hours ago, richjb2 said:

And BA was admonished by the FAA never to do that again! 

The authority to continue flight on a four-engine aircraft following an engine failure is a historical left-over from the DC-7 and Connie days when it wasn't uncommon for an engine to fail in flight.  I seem to recall that with the L-1649 and DC-7C, one in four crossings had an engine shutdown.  The regulation allows the PIC to elect to continue the flight to the destination rather than diverting to an alternate, if in their opinion doing so was the safer course of action.  The BA crew lost the engine just takeoff from LAX and flew all the way to London with failed engine.  That was not the intent of the rule, although technically the crew was allowed to do it.  The FAA came to a gentlemen's agreement with BA and CAA  that this would not occur again in US airspace.

Rich Boll

Doesn't change the fact the plane was more than capable and they weren't really admonished...

Quote

Technically speaking, British Airways and its pilots fully complied with aviation regulations when choosing to keep the flight going. The 747 is certified to fly on just three engines, and there was no indication of any damage to the aircraft's other engines. Safety experts and aviation regulators still questioned the decision to operate such a long flight with one engine out.

The FAA was against the decision and wanted to impose a fine of $25,000 on British Airways for operating an unairworthy aircraft. However, British Airways countered by claiming they were following the UK's Civil Aviation Authority (CAA) regulations. The FAA eventually backed down but requested changes to British Airways' procedures in return.

The British Air Line Pilots' Association challenged the new European Union regulations, questioning whether they forced airlines and pilots into making risky decisions to avoid costly fines. In the aftermath, British Airways did not make any changes to its procedures, and the FAA retracted its claim that the aircraft was unairworthy.

So they weren't admonished, it was much ado about nothing in the end and the FAA retracted all their claims.  

Edited July 27, 20223 yr by psolk