MIL 5606 Hydraulic Fluid Shortage

[RickH]

Just found out today that the major supplier to aviation wholesalers had over 10,000 gallons of 5606 rejected by the lab. There's a nationwide shortage while they try to catch back up. I bought the last 2 quart cans at Falconcrest in Houston and I understand most everyone else is out. Aircraft Spruce is back ordering to their customers.

[Cvairwerks]

Rick: I think that MIL-PRF-83282 is a direct replacement for 5606. I'd have to look at our specs at work. Unfortunately, I just got out of the hospital tonight, so it will be next week before I am back and can look.

[m50a1ontos]

83282 is synthetic, 5606 is still petroleum based IIRC. Mixing or converting may not play well with seals, o-rings etc? Been a while since I swam in that stuff

[CoastieJohn]

Wow...flashbacks!

Can't speak for all applications but in our helos we started out with 5606 and switched to 83282. This was back in the 1980's but I seem to recall 5606 is a temp alternative for 83282 for the H-65's. The H-52's was straight 5606. I'm vaguely recalling the switch in the H-65's was made because 83282 holds up to heat better than 5606 in our application. Again....this was a few years ago. I'd have to look in the maint manual to be sure.

Edit added: EBay has both for sale there.

[Cvairwerks]

From what I remember, the 83282 is 100% backwards compatable with 5606. The reason for developement of the 83282 was to provide a similar and compatable fluid to 5606 but with a high flashpoint and a raised operating temp capability. It is also a self extinguishing fluid, so that the instant you take the flame away, it quits burning. Flashpoint is above 205 deg C and autoignition is over 345 deg C., both higher than 5606. From a little reading, 83232 is also 100% compatable with MIL-H-87257.

[Scott 'Gunny' Perdue]

Mil-83282 is miscible with 5606.... it other words completely compatible. You do not have to flush the system or replace o-rings. It is synthetic and relatively non-flamabile (nothing is completely nonflammable). 87257 actually replaced it... as I remember because of the temp extremes.... but if you don't fly into the 40's you'd probably be alright.

I am switching everything to 83282... one brand is sold as Royco 782. I've got two gallons of 5606 I'd be happy to sell.... takers?

gunny

[CoastieJohn]

Surprised no one mentioned MIL-H-6083.

[brucev]

If anyone is having trouble finding 5606 locally, this morning Aviall is showing about 600 5 gallon cans and about 500 1 gallon cans in stock.

[Tinker51]

Mil-83282 is miscible with 5606.... it other words completely compatible. You do not have to flush the system or replace o-rings. It is synthetic and relatively non-flamabile (nothing is completely nonflammable). 87257 actually replaced it... as I remember because of the temp extremes.... but if you don't fly into the 40's you'd probably be alright.

Same thing the folks in our Maint Dept told me when I asked. We only have one aircraft that uses 5606 but lots of the guys have their own aircraft and have switched to 83282.

[RickH]

I knew 83282 was compatible with 5606 but most of the civilian guys wouldn't know that. We get both at times.