AN-124 - why it has to stay on the runway so long before t/o?

[Stuck_in_an_ATR]

The AN-124 has recently became a frequent visitor at my home base - actually it comes there every day. What I have noticed is that every time after lining up the runway, the crew says they need about 3-5 minutes before they can commence the takeoff. It usually causes quite a lot of mess in the airspace of what is a relatively calm airport. I can't imagine what would happen in say LHR, or FRA :} So - why do they have to stay so long on the runway?

[Colonel Klink]

I think they have to do an engine run before releasing brakes.

[NutLoose]

Yes they have to spool up the engines slowly over a period of time to full power allowing them to stabilize at set rpm's, about 10 mins in total if i remember correctly.

[flyboyike]

I haven't noticed that at MSP. They taxi out and scoot.

[Wycombe]

Then I'd suggest you're not looking at a 124. They always do the power check from what I've seen (and I've worked at one airfield where the beast is very nearly a daily visitor).

The conspiracy theories have it that the Lotarev's on the 124 (and 225) were "heavily based" on the GE CF6, after some were acquired by the Soviets from a DC10 that was trapped on the ground in Kabul when they invaded Afghanistan!

[flyboyike]

Then I'd suggest you're not looking at a 124.



Did you just suggest that an airline pilot doesn't know what a Ruslan looks like?

[Rhino power]

An-124s are very frequent visitors at my local, EMA/EGNX, and without exception the crew always request 3-4 mins on the runway to run up the engines - my understanding is its to do with stabilizing the internal temperatures - never has one just 'taxied and scooted' so i can't see why this would be any different for any other airport they operate from.

-Regards, RP:)

[Wycombe]

Flyboyike, yes perhaps I did, but I've met plenty of other pilots who don't have the best of a/c recognition skills, so don't feel I further need to justify that statement.

As others have said, they always do the power check.

I was at the Farnborough Airshow the day one blew an engine at the start of the display take-off roll - it was a big bang :eek:

[flyboyike]

Flyboyike, yes perhaps I did, but I've met plenty of other pilots who don't have the best of a/c recognition skills, so don't feel I further need to justify that statement.


You're right, I could have easily confused it with any of the dozens of other extremely large, high-winged, four-engine, conventional tail, 84000-series-tail-numbered aircraft. Sorry.

[chevvron]

Wycombe: I was at that one too and didn't notice the bang, but I was a bit surprised when he abandoned takeoff as I was the Tower Controller at the time!

[Bearcat]

with respect how would you "notice" the bang if you were cocooned in the tower? also why is ATCO suprised to see an RTO?

not being smart.....just interested in your thoughts chevron and what angle you guys have.

rgds

b

[BigBoeing]

they have to in the uk and im sure they do it everywhere else as well. As far as I know the oil seals can be blown easily if they put to much power on to quickly.

[VillWill]

When i was working in Shannon(EINN) there was always one or two AN-124's based there (Volga-Dnepr) as i remember and we would frequently watch them come and go. They always requested a few minutes on the runway before takeoff. Also had the pleasure of seeing the 225 there one night, fantastic sight.

[Rhino power]

84000-series-tail-numbered aircraft

er, An-124/225 are in the 82000 range actually................

Regards, RP

[NutLoose]

Touche' ;)

[samusi01]

The few times I've seen 'em - at Boeing Field in Seattle - they do the same delay prior to departure.

[flyboyike]

er, An-124/225 are in the 82000 range actually................

Regards, RP


Close enough.

[411A]

Those with long memories will recall the early TriStars with -22B engines did the same...initially.
Rather long run-ups at partial power prior to brakes release.
Early problems (big time) with the -22B's.
I recall seeing seven of these RR engines on the ramp on engine stands at MIA in 1974.
All, and I mean all the turbine blades were...ah, gone.:uhoh:
Must have been expensive:sad:

[FougaMagister]

I would have thought that with a 5- or 6-strong crew, they need all that time to complete the before take-off checklist :E ;)

[Jet_A_Knight]

I would have thought that with a 5- or 6-strong crew, they need all that time to complete the before take-off checklist

You mean, as in rollcall:8

[Wycombe]

Fkyboyike, let's move on shall we :) I can accept what you say, it's just it's at variance with everyone else who has commented on this thread. What we need is a 124 driver, or VP8 (who I believe is very well-versed with 124/225 Ops) to settle the discussion once and for all.

Chevvron, IIRC the engine that went bang was on the port side (facing the crowdline) so wouldn't have been visible from the Tower.

Of course, that episode led to the visit of the AN-22 which pitched-up carrying the replacement donk (the following day I think). The crowds outside "The Swan" were even bigger for that one :ok:

[CRMCaptain]

The engines are not as reliable as on the western aircrafts. They need to spool them up slowly and let them stabilize!

[Feather #3]

I thought it may have been the two engineers fighting with each other??

411A; it did send RR broke!

G'day ;)

[Dutch74]

Has anyone considered the possibility of some AN124's being retrofitted with newer engines? Maybe thats why at some airports they "scoot" and some they don't?

[chevvron]

Yes that was my theory; the engine that went was sheilded from view and hearing in the tower.
And the AN22 when it arrived nearly didn't make it, apparently trying to land on the grass following the display line markers which, being dayglo, stood out rather well! Made the remaining spectators run for it though.

[BEagle]

Yes, he made a right Cock of the landing.....

[Shamrock 602]

It's not just the An-124 which does this: although it has a completely different engine, I've experienced something similar when travelling as a passenger in the An-74T. Lined up on the runway threshold, it went up to what seemed like 70% of full power, and sat there for nearly three minutes, before brake release and further throttle up.
What was unusual was that in two later flights on the same aircraft that day, the delay was shorter: 2:45 on the threshold for the first flight of the day, then 2:10 for the next flight, and finally "only" 45 seconds by mid afternoon (by which time ambient temparatures were in the low 30s). Waiting for core tempatures to increase was what occurred to me as the reason.
It's an usual aircraft: high wing, with a turbofan mounted over wing.
If had been able to speak Russian, I'd probably be able to tell you more...
Shamrock

[Ozgrade3]

One night i was working the ramp at Sydney and noticed an AN-124 lining up on 16R, applied what seems like TO power and sat there for 15 mins, as timed by my watch. initially i thoght it was sngineers doing a high power run, but after 15 mins, with no change in power setting it began its take-off roll.

[dv8]

Don't ask were I got this snipit from, and it might be total B.

During the high power on brakes phase the FE is manually adjusting the 'fuel management'
......and I do stand to be corrected

[mtoroshanga]

I was slightly involved with AN124s when in Somalia with the UN and was told by a Ukranian friend of mine that the crew calculate a power setting before take-off using normal parameters ( runway length, OAT, pressure alt. AUW etc.) then set up the engines to a calculated power setting and use the whole runway. This is to preserve the engines and avoid operating at max power.The FCUs fitted are primative by western standards hence time to achieve settings. I may be on the wrong track but it seems logical to me.

[John Farley]

Some engine types have a measurable increase in thrust after the rotating components expand as they get hotter and the tip clearances (and losses) are reduced. Whether you run at high power before takeoff and wait for this improvement will clearly be affected by how much performance you desire on a particular takeoff.

[dgordon42]

"The conspiracy theories have it that the Lotarev's on the 124 (and 225) were "heavily based" on the GE CF6, after some were acquired by the Soviets from a DC10 that was trapped on the ground in Kabul when they invaded Afghanistan!"

The Ivchenko D-18T Turbofans on the An-124 are a three shaft engine, and are more likely to resemble a RB-211 then a CF-6.

"Those with long memories will recall the early TriStars with -22B engines did the same...initially.
Rather long run-ups at partial power prior to brakes release.
Early problems (big time) with the -22B's.
I recall seeing seven of these RR engines on the ramp on engine stands at MIA in 1974.
All, and I mean all the turbine blades were...ah, gone."

[muduckace]

Yeah, power assurance or slow spool to allow the turbine case to heat up, reduce wear/max thrust. Saw them do this down in Managua once. The reason others may see them turn'n burn may be light aircraft/long runway/reduced thrust t/o. Who knows? There are a ton of answers.

Their start sequence seemed like it took forever as well, they blew over a guard shack on taxi out, it was quite a show.

[Boroda]

My name is Ruslan but I am not An124 driver.:)
There was one right answer above - to reduse blade tip clearence in order to reach required power. There was a catastrophe after take off in Irkutsk wnen OAT was too low and load too high (new fighters to deliver) - clearence was big.
Why it takes so long - warm up is made two engines at a time to stay unmovable, 124 has 4.
It is one of the reasons they are forbidden to visit intensive airports.

[AircraftOperations]

What do you mean by "intensive" airports?

If that means "busy", then I'm sure LHR would fall into that category and the AN-124s have certainly visited LHR over the years.

[SincoTC]

I was at Farnborough that year too; watching the seeminlg endless run-up from the comfort of the GE Chalet, the thing I remember most as it started to move off, was the flash of flame out of the front of the nacelle just before the "Pop" reached us, follewed by a round of applause and much barely-disguised amusement from all the GE folk around me!

The consensus seemed to be that although they had made a passable job of reverse engineering the mechanicals, the FADEC was not up to the task. Apparently all attempts to purchase up to date engine managment systems from western companies, was vetoed by the US Goverment on the grounds that the technology would find its way onto the Blackjack!

[Boroda]

Aircraftoperations

Yes, I mean BUSY. And my statement is not a rule, even for such airports there is paid-up exception, I think.

[Uncle_Jay]

Hello my name Jayat am Ukraine please excus Enklish not so good was raisd by gypsy

Am AN pilot reason long delay is translat gibberish QRH Russki into Ukraine whilst sit on apron thank yuo.

[rubik101]

Some years ago I followed one of these behemoths on the taxiway at CGN. We were about 200m behind all the way and just as well. As you who know Cologne airport there is a bit of an up-slope at the holding point for 24. The Antonov came to a stop, waiting for a landing aircraft then lined up. They used so much power to get moving up the slope that the RWY Marker board and the A and B marker boards got blown away to the boundary fence.
When we called the tower and told him to send the Patrol Car down to recover the debris, we were asked several times to repeat the instruction. They just couldn't understand how they would have blown away!
I wonder if they sent them the bill for the new lights and boards?