Purpleheepster From United Kingdom (Scotland), joined Jan 2005, 62 posts, RR: 0 Posted (3 years 4 months 3 weeks 5 days 12 hours ago) and read 1668 times:
I recently uploaded a picture of a Cargolux 747F and commented that it took off with only three engines operational. I mentioned that it had some kind of "locking device" had been fitted and lots of you opened the large picture to see it.
Thanks for that!
Here's a link to a picture that gives a better view of the device. I'd be interested to know what it actually is and what it's function is. Anyone got any ideas?
Norfolkjohn From United Kingdom, joined Jan 2005, 251 posts, RR: 5 Reply 1, posted (3 years 4 months 3 weeks 5 days 11 hours ago) and read 1641 times:
Tony,
In your picture you can see that the fan blades have been removed and this will obviously prevent the fan (LP Spool) from windmilling. This will reduce drag as the fan blades act a bit like a windmilling propeller which has not been feathered. A blank has been fitted over the inlet to the core of the engine in front of the IP (intermediate pressure) compressor. The lack of airflow through the core will prevent both the IP and HP (High Pressure) spools from rotating. Note that I believe this is an RB211 engine hence the three spools rather than just the two of GE and PW engines. I'm not sure about the 211 but on some engine types it is also possible to lock the core / HP spool by fitting a locking device to the gearbox which is driven off the core / HP shaft but obviously you can't see this as it would be under the cowls.
Apart from the drag issue from the fan mentioned above it is necessary to lock the engine rotors / spools to prevent bearing damage. When an engine is windmilling there is no (or minimal) pressure oil feed to the bearings as the oil pump is not being driven at high speed. Over a period of time - generally a few hours - but sometimes less than an hour damage can be caused to the bearings due to lack of lubrication. The risk of this happening depends on the internal design of the engine.
Hope this makes some sense to you.
All the best.
John
One thorn of experience is worth a whole wilderness of warning.
Purpleheepster From United Kingdom (Scotland), joined Jan 2005, 62 posts, RR: 0 Reply 2, posted (3 years 4 months 3 weeks 5 days 7 hours ago) and read 1573 times:
John,
Many thanks for your detailed reply. It is much appreciated.
Kaddyuk From Wallis And Futuna Islands, joined Nov 2001, 4124 posts, RR: 27 Reply 4, posted (3 years 4 months 3 weeks 4 days 8 hours ago) and read 1504 times:
I've spoken to a number of people involved in three engined ferrys and it can be quite a scary occourance. I had a friend involved in an A340-300 3 engined ferry, they took a rolling start, used max thrust on a 12000ft runway and STILL went all the way to the end before reaching V1.
Whoever said "laughter is the best medicine" never had Gonorrhea
Newark777 From United States, joined Dec 2004, 8796 posts, RR: 39 Reply 5, posted (3 years 4 months 3 weeks 4 days 8 hours ago) and read 1500 times:
I had a friend involved in an A340-300 3 engined ferry, they took a rolling start, used max thrust on a 12000ft runway and STILL went all the way to the end before reaching V1.
Doesn't that happen even with all 4 engines working.
ChrisM001 From United Kingdom, joined Jan 2005, 65 posts, RR: 4 Reply 7, posted (3 years 4 months 3 weeks 4 days 6 hours ago) and read 1467 times:
Quoting Kaddyuk (Reply 4): I had a friend involved in an A340-300 3 engined ferry, they took a rolling start, used max thrust on a 12000ft runway and STILL went all the way to the end before reaching V1.
I thought A340's only got airborne due to the curvature of the earth.....!! Sorry, couldn't resist that one as I often watch the A340-300's of AC, VS et al lumber down the runways at LHR and lurch into the air, give me an A340-600 any day!
Only a small number of crews are generally cleared for three engine ferries, but fortunately they don't happen to often. Have been involved in them with a/c varying from RJ100 to 747-400.
PhilSquares From Ireland, joined Mar 2004, 3827 posts, RR: 53 Reply 9, posted (3 years 4 months 3 weeks 3 days 5 hours ago) and read 1338 times:
The above photo link is somewhat misleading.
There is a MX procedure that allows for cargo straps to be used to secure the N1 fan section. Although, not desirable, it is done. IIRC there are some limitations associated with it, such as duration of flight and some other issues.
As far as being a "scary occurrence". I have done numerous 3 engine ferries on the 744 and 747 and they're not. Your takeoff performance is based on losing another engine. If you look at it realistically, at the gross weights for the ferry flights, you have more thrust available then than you would at a MTOW with 4 engines!
The most eye opening flights were on the 727 stretch with the -7 engines. Those were certainly an interesting experience!
Mr Spaceman From Canada, joined Mar 2001, 2765 posts, RR: 14 Reply 10, posted (3 years 4 months 3 weeks 3 days 3 hours ago) and read 1297 times:
Hi guys.
Although these are photos of airliners with an "extra" engine that's being ferried for maintenance reasons, they show some other methods of flying with an engine that's not running.
I think the dome covering this engine's intake reduces drag as well as allowing the engine to be ferried without removing the Fan. That's just a guess
Here's a few more shots of engines being ferried, and the equipment that's used to protect them & reduce drag.
DH106 From United Kingdom, joined Jun 2005, 491 posts, RR: 0 Reply 12, posted (3 years 4 months 3 weeks 2 days 17 hours ago) and read 1202 times:
You can actually see in the two 747 shots above, the aircraft leaning slightly on it's undercarriage with the weight of the 5th engine on the left side.
Does carrying that 5th engine on a 747 interfere with the operation of the Kruger flaps inboard of #2 engine ? Wonder if one or two of them need to be isolated.
Cancidas From Poland, joined Jul 2003, 4112 posts, RR: 15 Reply 14, posted (3 years 4 months 3 weeks 2 days ago) and read 1018 times:
DALMD88, that's not scary at all. with the proper precautions being taken anything (within reason) can be done to bring whatever equipment you need anywhere in the world. in this case, it is definately cheaper to bring a fifth engine along for the ride than hire a cargo carrier to carry the thing for you.
"...cannot the kingdom of salvation take me home."
HAWK21M From India, joined Jan 2001, 26086 posts, RR: 51 Reply 15, posted (3 years 4 months 3 weeks 1 day 19 hours ago) and read 989 times:
Quoting DALMD88 (Reply 13): The scary part of the Chinese 747 is that it wasn't a ferry flight. It was a revenue flight from Asia to Europe with the intention of a return flight
Any Link.The Article that reflected it could not prove it was of a chinese Airline & had flown commercial.
Very Unlikely that an Airline would do that.Its quite noticeable.
regds
MEL
DALMD88 From United States, joined Jul 2000, 1766 posts, RR: 7 Reply 16, posted (3 years 4 months 3 weeks 1 day 8 hours ago) and read 933 times:
I think you guys are missing something here. The Chinese 747 was dispatched on a revenue flight with a shelled out engine from it's home base to Europe. It wasn't in a pod it was in the number three slot. On further inspection two more engines had similar damage and had to be replaced before the Germans would allow it to leave FRA. If that isn't scary to you you shouldn't be a mechanic.
Any Link to that Article.Cant find it.About a strapped Engine fan blades.
Its difficult to believe that it was a commercial Flight.And if as you say Three Engines had damage & one was Blanked out & it flew Commercial.
regds
MEL
PhilSquares From Ireland, joined Mar 2004, 3827 posts, RR: 53 Reply 18, posted (3 years 4 months 3 weeks 19 hours ago) and read 836 times:
DALMD88
As I previously stated, that picture and the associated urban legend about that being off a revenue flight is completely wrong.
The alleged aircraft was never released for a revenue flight with 3 engines. That picture has been going around the internet for years. No proof at all.
Sponsor Message: 
.gif){kind=small}
From United Kingdom (Scotland), joined Jan 2005, 62 posts, 
From United Kingdom, joined Jan 2005, 251 posts, 
From Luxembourg, joined Aug 1999, 1403 posts, 
From Wallis And Futuna Islands, joined Nov 2001, 4124 posts, 
From United States, joined Dec 2004, 8796 posts, 
From Spain, joined Oct 2004, 1222 posts, 
Never done it myself, except at the simulator, it is certainly tricky, not anything you'd do without having practiced it before.
From Belgium, joined Dec 2001, 344 posts, 
From Ireland, joined Mar 2004, 3827 posts, 
From Canada, joined Mar 2001, 2765 posts, 
From Poland, joined Jul 2003, 4112 posts, 
From India, joined Jan 2001, 26086 posts, 
