Yellow crust/incubater chick struggling barred rock

[Bigviewminifarm]

Hey everyone! I have a dilemma..
I never help any of my incubator chicks hatch. I always let nature take its course. Having said that.... I am encountering the strangest hatch I've ever seen. She pipped well over 24 hours ago. 12 hours after pipping, she began to unzip but instead of going around the egg... she has hammered out a huge hole just around her beak/head (size of a qaurter). I can see inside very well and can see alot of the inner membrane is in tack but it does look like most of the blood vessels have faded. She has a dark yellow crust/ooze seeping out of the egg that I've never seen. She is very vocal and really fighting to get out. Do I assist? I've always been against it but I've never had one this close... then not be able to finish. What is the yellow crust? Did she bust her yolk sac? I've never had this type of hatch!

 

[BirdsBeesTrees]

Yes they make a huge hole instead of zipping if they are too large, or too small to zip properly. I'd start assisting now and stop if blood starts to flow , if it does give it a few more hours.

 

[FoodFreedomNow]

Do you have a pic? Sometimes that yellow gunk is excess moisture in the egg and it can dry like concrete on a hatchling. I'm with @BirdsBeesTrees on carefully exploring, incrementally, to ensure her beak area is clear and better understand what's going on. Are you referencing this helpful guide to assisted hatching?

Best of luck!

 

[Bigviewminifarm]

*Update*
With a very small amount of assistance she has hatched and as of now doing well. It was definitely a ruptured/unabsorbed yolk sack and she is covered in it. Her "belly button" is slightly open but nothing that belongs internal is external thankfully. I tried cleaning her off but didnt want to stress her anymore than she already was. She is very active and talkative.... still resting frequently. Keeping her in a brooder by herself until I figure out how to safely clean her off. Lots of good threads about it on here I'm sure!