C130 Windmill Starting

[splitbrain]

During my time at Lyneham I recall that the C130 K crews had a method of starting the Allison T56 engine when the starter was U/S by either thrapping down the runway or sitting in the propwash of another Albert. This action windmilled the prop (and hence the core engine) allowing the engine to be started. I understand that this was possible largely due to the direct coupled arrangement of the core engine.
So, with its free power turbine arrangement is it possible to windmill start a J in the manner described?

[Solid Rust Twotter]

Not unless you could blow a truckload of air into the intake to spin up the compressor, one should think.

Recall listening to one of our crews helping a RAF C130 start a donk at Bunia in this manner as we were inbound.

[juliet]

J Free Turbine

The J has a buddy-buddy system whereby two aircraft, each with their own section of hose, join together. Bleed air is transferred from one to another. Because the J has a free turbine, like many modern turbo props, spinning the prop wont spin the engine. In fact if you are brave enough you could hang on to the prop during start and stop it from spinning, even though the engine is running!

[r supwoods]

"In fact if you are brave enough you could hang on to the prop during start and stop it from spinning, even though the engine is running!"

Done that with a Turbine Islander

[ShyTorque]

In the early 1980s we watched a C130 make a number of fast runs down the Belize Airport Camp runway, three engines running, one not - while they tried to do a windmill start.

It didn't work. Strange thing was, the crew didn't notice it was U/S with prop feathered when they finally took off on three engines - until they had got almost all the way to Nassau, a far nicer place to wait for a new engine.

It's only rumour, of course. Especially as the AOC was on board.

[Aaaaaaaaaaaaaaaargh!]

In fact if you are brave enough you could hang on to the prop during start and stop it from spinning, even though the engine is running!

I must give that a try, though the only aircraft i have available is a 182.

Still how much difference could there be?

[Ken Scott]

The windmill start on the K allowed you to start an engine after a starter motor failure, the 'buddy-buddy' start described by Juliet will only work if the starter motor's still functional. If you HAD to get airborne in a J the only option would be a 3 engine take-off then an airborne unassisted relight (go fast enough to get the NG high enough).

[Wiley]

I've done one 'in anger' windmill start successfully, and if memory serves me right, the manual said you had to give it away with 5000' of runway remaining, (which was very conservative). I know a bloke who managed to get the last engine of an 'E' model up and running after a starter failure at Nui Dat, in South Vietnam - which was only 5,000' long. I suspect the latter stages of that windmill start that would have been a tad exciting, if not for the crew, then certainly for the grunts at the end of the field.

He got a king size kick in the arse on getting home, but the chances of the Herc ending up as a smoking pile of burnt aluminium had he stayed at Nui Dat overnight were pretty high. (They didn't call the silvers Hercs 'mortar magnets' without good reason.) And he got the load of very badly wounded medevac cases out to Butterworth that day.

The buddy start, where the aircraft with the dead starter lined up behind another Herc who then ran his engines at takeoff power was in the manual, but highly discouraged because of damage the aircraft at the rear would almost certainly suffer from stones and all manner of other junk kicked up by the propwash of the aircraft in front.

[splitbrain]

OK thanks for the replies.
It seems then that a windmill start a-la 'K' isn't possible in a J for the reasons I suspected.
And thanks Juliet, I was aware that the 'buddy' start you described could be done on a Merlin, but not a Herc J. Every day is a school day

[Phil_R]

Can you start one engine up off another, or does it have to be a separate aircraft?

Apropos of nothing.

Phil

[splitbrain]

Conventionally yes you can start one engine using the bleed air supplied by another.
This is normal modus operandi.

[herkman]

In the RAAF, with their A,E and H models, prior to being qualified as a Captain, you had to show that you could do a windmill start.

Regards

Col Tigwell

[mr ripley]

Video of Buddy Buddy

Happened to have found a couple of vids of a buddy buddy start.

Recall listening to one of our crews helping a RAF C130 start a donk at Bunia in this manner as we were inbound.

This was the one at Bunia in 2003.
Worked second time after donor raised flaps and recipient moved a little closer.
Seehttp://www.youtube.com/watch?v=bXj0sQzljUw
and http://www.youtube.com/watch?v=RXU4fRNFS1U

[Solid Rust Twotter]

Dat am de one...

[country calls]

Buddy starts would be used if there were no air supply available (GTC or Palouste), to start any engine. It is standard practice to 'cuff' a prop, before shutting the electrics off with no GPU available for just such an eventuality. No electrics would mean you would be unable to motor the blades to the air start position in the worst case scenario.

I can see no reason why a buddy start could not be used on an engine with a broken starter motor, but am willing to be corrected. It would not be a reason to use a buddy start where the ability to windmill start the engine is available. As previously mentioned there are major issues with the amount of crud thrown up and if you watch the videos the tail of the donor aircraft takes a right pasting!

I have heard that the intake guide vanes being effectively 'closed' would further complicate a J windmill start, anyone care to elaborate?

[nigegilb]

Tried to do a windmill start at a military airfield in NZ once. It was quite sporty, tried it on NVGs and the strip was a bit short.....Err, didn't work very well if my memory serves me correct.

[mr ripley]

I also managed a buddy and a windmill, both with sheared starter motors.

When the video was taken the temp was apparantly over 30 degrees and this combined with an elevation of over 4000ft would make for interesting conditions.

[US Herk]

Originally Posted by mr ripley

When the video was taken the temp was apparantly over 30 degrees and this combined with an elevation of over 4000ft would make for interesting conditions

Do them here at the Talon OCU - regularly 30C & PA 5300 at KIKR. You do use every bit of the recommended 7000' of runway to do it.

Interestinly, USAF now say buddy start preferred over windmill taxi. Methinks it has more to do with temptation of getting airborne should something go pear shaped - a la crash at Lajes many years ago, loss of Lockheed HTTB in '93/95??, & others...

Originally Posted by wiley

and if memory serves me right, the manual said you had to give it away wth 5000' of runway remaining

Currently, at 4000 remaining, you begin braking action.

Originally Posted by wiley

I know a bloke who managed to get the last engine of an 'E' model up and running after a starter failure at Nui Dat, in South Vietnam - which was only 5,000' long. I suspect the latter stages of that windmill start that would have been a tad exciting, if not for the crew, then certainly for the grunts at the end of the field.

Have heard this story. Way I heard it was run down RWY, quick 180, run back down other way, quick 180, run back down rwy & finally lit! Three trips down to get it spinning at sufficient speed...

Originally Posted by country calls

I can see no reason why a buddy start could not be used on an engine with a broken starter motor, but am willing to be corrected.

You're correct - it can be done with a duff starter. The buddy start was typically used after no electrics & prop cuffed though - otherwise, windmill is more efficient.

I do them regularly in our training syllabus. We can very easily get them going w/o the operating asymmetric engine at all & in less than 5000' even at 4200' (where we do most of our trng) at 25-30C. Another technique is leave it feathered, accelerate to about 40KIAS, then push/hold condition lever to airstart - works a treat.

[Wiley]

herkman, you're almost correct when you say:

In the RAAF, with their A, E and H models, prior to being qualified as a Captain, you had to show that you could do a windmill start.

In my case, I was cleared to the line as a captain without having done my 'windmill start' ride with the resident QFI and suffered the dead starter at Amberley within the first week or two of being let loose on my own. It took three runs up and down the Amberley runway before the engine finally cranked up successfully.

A week later, I was scheduled for my windmill start checkout, which I did. The QFI congratulated me on how well I handled it and was a little upset when I told him I probably should be able to as it was my fourth windmill start run in a week.

And US Herc, the story you heard is pretty accurate. A clear case of "needs must", where the rules are for the guidance of wise men. At that stage of the war, 'Charles' was still very much in evidence in the province and would almost certainly have had a go at such a high value target had the Herc stayed at Luscombe overnight - and the medevac patients he was to carry out that day were all very serious cases, too badly injured to be taken down to Vung Tau, so I think he won a lot of brownie points with the grunts. Still, on a (very narrow) 5000' strip, I shudder to think how much runway he'd have had remaining when he reached 100k, which from memory, was the min. speed to attempt a windmill start.

If memory serves me correctly, (no guarantee of that after all this time!), JL, the captain involved, who was very highly regarded on the squadron, went on to a long career with Cathay Pacific.

[billynospares]

Buddy start

A buddy buddy start using the hose cannot be carried out on a J model with a duff starter as there is no way to spin the core engine as it is a free turbine powered prop. That is as far as i understand it anyway