Engine Changes
 

As a rough guide, how long does it take to change an engine on a large wide bodied aircraft and how many people do you need?

Also, if an aircraft was undergoing something like a C8, a D check or a long modification. Are there any requirements (apart from possibly inhibiting) for the engines? ie do they need to be rotated periodically so that all the weigh is not on one part of the bearings etc.

Thanks,

Saintsman

Depends on a lot of things. Is the new engine complete. A lot of spare engines need fitting out with IDG, Hyd pumps etc.
But my record was in the Gulf Air hangar at BAH. I came into work at 1400 and everything was ready. The new RB211-524 was complete and in the hangar, The engine change team was waiting, and the TriStar was just being towed in. I had a good team of mechanics, all local Bahrainis, and they were experienced. They changed an engine every week. It was a wing engine and we used a bootstrap (we didn't have a 10 ton hangar crane). The aircraft was out on the run bay at 1830. We then had to do all the runs as the engine had not been test bed run. (In those days GF changed modules in BAH but had no test bed.) So it was tests 1-17 incl., and we had it up on the ramp at 2015 ready for a 2130 departure.
To change a RB211 you need about four technicians and a total of about 12 people. The other 8 assemble the bootstrap equipement, raise the stand, lower the engine, raise the new engine and then lower the stand and dismantle the bootstrap gear. A RB211 weighs about seven tons, and we pulled it up with chains, so a lot of energy is expended. A Centre engine took about 12 hours because everything had to be lifted up into posn.
Away from base it will take a lot longer.

5 blokes about 10 -12 hours without busting a gut - 4 good techs and 1 lae to oversee. Thats everything including swapping the nose cowl, IDG and hanging the bootstrap kit on. I would reckon about this time for RB211 (all types including trent) CF6 -80 and CFM56.

Now retired after 42 years in the game, changed lots of engines so I look forward to this topic going on and hope its gets like the
TV quiz I can name that song in two.
Keep them flying safely as we take lots of hols.

We would change a pw 2040 on the 757 including nose cowl and idg, using a bootstrap kit and have it ready to go outside for runs on a 10 hour nightshift.

It is about the same for a rb211 on the 757 however this can be reduced quite a bit by knowledgable mechanics and a tech that has a good eye for the hoists as this can be time consuming when it goes wrong.

B757 with RB211, 8 hours on the apron in Dalaman, Turkey, 3 mechs and 2 engineers (including little old me). CNA, IDG and some other good bits to swap. However we worked like mad men, damned near impossible to do that every shift.

For those that have changed a 535, you'll know just how easy the disconnects are:D


This is again As I See It

737NG, QEC kit in the hangar andready all around when it comes in 7hrs.

Forgot this one, was on OJT with SwissAir in Geneva in about 1984 with Saudia and Swissair guys brought a A310 in the hanger just before midnight used air driven hoist's etc and it was on the line ready for passenders at about 0800. We couldn't get over it but they said that's the time they always have taken.:ok:

I remember HKG chums telling me once that Haeco did an RB211-524D4 in something like 3 hours, possibly less.

747-200 RB211 took about 16 hrs including runs.

Best we could manage is 3hr 20 mins RB211 on a 744 including runs. . . . . not done it since though:uhoh:
Trent and GE90 thats another story, and if it's done down the line you have to double up as a scaffolder.:eek:

During my time on 21 shillings and 6 pence, ex members know what I mean, managed to string a Tristar wing engine change out to five days in Dubai. It was the middle of summer and the tempurature on the ramp was about 50`C. The whole episode cost a fortune. The only available means to get the engine and Bootstrap kit to Dubai was a Heavylift Belfast via Akrotiri, at 80K a day. Still had a good time and ended up in Cairns afterwards because it was cheaper to take us with them than send us home civvy club class. But the operating outbound crew went back to Akrotiri on the Belfast at short notice, no catering or drinks, just eight hours in a very hot, noisy, rattly Belfast.

Great fun.:ok:

Doesn't it depend on whether the engine WANTS to change? ;)

F27, probably dosen't fit into the big engine stuff.

4 and 1/2 hours, including ground runs. Good crew on duty and all meshed in on the day.

Best i know of.

And yes, jack W was on the crane......

That's true of many jobs. "You tell me what problems I'm going to find, then I'll tell you how long it will take!"

You hairdryer widebody boys have got it so, so easy ;) .

'Takes a team of about 6 people, split into two 12 hr shifts about 24 hours to change an engine on one of our Do328's. That is from towing the a/c off the line into the hangar ( & giving it a daily too) , to parking it back on its apron slot, ready to make money again. They are non stop, balls out shifts too !

Blow jobs are always less hassle than screws....

It's all very well doing the rapid change when all is going smoothly and no defects are found etc..
The management always use this as a benchmark though and want it every time afterwards.
I'd rather do a quality, safe job than try and get in the Guiness book of records (or Aviation Disaster Yearbook!).
BA apparently did a 74 RB211 in 4.5 hours recently, hope they're ready for the abuse when the next one takes double the time.

On the RB211 747-400 the thing that will slow you down is the H.P. air duct clamp. I have seen them go straight on and I have seen them take hours!!!
4.5 hrs for a RB change is good going though .But I bet it wasn't down the line using the "Bootstap kit"!!!!

Rgds Dr I.

Apparently some of you work for more well-heeled organisations than I do.

Send me dirty messages and tell me what it feels like.

QEC? What's a QEC? Is that some sort of code for, "take every damned thing off including wiring harness and quickly throw it on the other engine." ?

Throw in finding damaged generator drive shafts, tach-gens, etc. , no spares and then scheduling the whole thing during a summer long weekend with everyone away and you've a recipe for a six day change.

SeldomFixit is correct. HAECO did change a RB211-524C on a CX747-200 in just under 3 hours chock to chock. The aircraft was on a test flight and taxied to the hangar area and redeparted from the hangar. At least 2 engine change teams were used (guys crawling all over and under it) and the replacement engine only needed a quick leak check and Grd Idle/Flt Idle check engine run. It completed the CAA test flight in daylight after returning around 1400.
On the other side of the coin the first DC10 No. 2 engine change took 3 days. UTA ferried in from SIN with a failed #2 engine. Captain jokingly said "see you in 3 days". Everyone laughed but he was right. Main problems were all the engine change gear and engine were GE property and HAECO had not bothered to practice assemble it so numerous things did not fit properly and no-one in HKG had ever done it before. It was a purely manual bootstrap kit with ratchet chain hoists that left dozens of exhausted chinese mechanics laying on the hangar floor panting.