What happens at Tahoe doesn't stay at Tahoe; What would Gramps say?

[PhrogLoop]

Huh? That makes no sense. HOGE = Hover Out of Ground Effect. We calculate ours for no-wind out of ground effect hovering. Unless you're talking about how high a hover you're in. (i.e. a 100 foot hover vice a 50 foot hover)

You should be able to clear a 100ft obstacle with HOGE, so basically if you can get in with HOGE, you should be able to get out. If you have to stabilize in an OGE hover just to get in, you'll need more than that. In other words, an OGE hover requires more than HOGE power.

Not to speak for busdriver, but I always looked at HIGE/HOGE as the number related to power required if your helicopter magically appeared in said HIGE/HOGE, not the practical application of flying an approach to or climbing into said hover. Say, for instance, the HOGE on a given day was 100pct. You would need more power than that, say 110pct, to arrest your rate of descent to come to a hover. If your power available was 100pct exactly, you just exceeded power required.

Note that I didn't speculate that this is what happened at Tahoe...I have no idea what happened at Tahoe...What happened at Tahoe????

 

[Pags]

SIR is on the wire.

 

[insanebikerboy]

http://www.military.com/news/article/navy-facebook-stunt-almost-dooms-helos.html?ESRC=eb.nl


Looks like it was for the all power Facebook photo!

 

[busdriver]

Sorry phrog, I just saw this. But this is basically what I was trying to say.

If you have no excess power and a decent is started for any reason (terminate approach, slight down draft, crappy hands) you won't have the ability to stop it, and if you try you'll droop the rotor.

Likewise if you're taking off with HOGE power available, and you apply that power while still in ground effect, the momentum generated down low should carry you up high enough to clear a 100ft obstacle, assuming you're using minimal control inputs to be as efficient at possible and winds and drafts are favorable.

 

[phrogdriver]

http://www.military.com/news/article/navy-facebook-stunt-almost-dooms-helos.html?ESRC=eb.nl


Looks like it was for the all power Facebook photo!

The article was okay. Reading the comments actually cost me 10 IQ points, and I had very few to spare already.

 

[revan1013]

I'm seeing a trend though. If the CO does it/condones it, it's gonna happen. I hope they at least got a good shot before they took the dip.

 

[lowflier03]

Since when are FNAEB results released to the public? I didn't think that kind of info got sent out.

 

[phrogdriver]

Not as if they're privileged. If the CoC thinks it's appropriate, they can publicize them. In this case, they'd want the public to know they did something.

 

[Treetop Flyer]

I would imagine the problems weren't caused by getting them wet, but rather by impacting the water.

 

[insanebikerboy]

Something that has confused me in this article is the half million dollar damage figure.

As I recall our helo's where out on the flight deck and operated in inclement weather, I would think the rotor wash alone would force salt water into all sorts of nooks and cranny's, granted not at the same volume. So how does dipping a helo in a freshwater lake result in half a million dollars worth of damage? Would the additional weight of the water overstress the engine components or airframe and result in the damage?

Water spray is a lot different than water immersion.

 

[exhelodrvr]

They used to do water landings as part of the syllabus in the H-3 FRS, in the St John's River at NAS Jax, and in Otai Reservoir at NAS NI. They stopped doing them after there was an HS-10 mishap (I don't remember what class it was) where they landed in the water too hard; did pretty significant damage to the electronics compartment area of the fuselage. (H-3 had a big door, approx 3' x 4', underneath the cockpit, for access to where most of the avionics were kept.) And that was with two instructors at the controls, doing a planned landing. It wasn't built to withstand that kind of stress in those areas. I assume the same is true with the H-60.

 

[Gatordev]

DISCLAIMER: NOT ASSOCIATED WITH THE -41 MISHAP BOARD...

I'm guessing the issue had NOTHING to do with water immersion, especially w/ fresh water. As someone who has dealt, firsthand, with a Bravo (which has the same basic airframe issues as a Romeo) aircraft impacting hard surfaces (Haiti, for anyone interested and read in), the damage came from the radome and datalink antennas. I don't remember how much our radome was, but one datalink antenna alone brought the mishap level to a C instantaneously. Apparently composite/fiberglass is very expensive.

 

[BACONATOR]

That is going to be a VERY rough couple of FNAEBs....

 

[busdriver]

This is largely what I was trying to say. I haven't been able to post lately due to being a banned IP address or some such.