Planes on carrier in rough weather

While working at Grumman, I saw a brand new F-14 Tomcat that was just out of the paint shop, and I was shocked at how glossy it was. Once on the ship, that gloss disappears in a hurry.

I own a 1/18 model of a Tomcat with what looks like speckled camouflage; it was just a ham-fisted attempt by the vendor to simulate carrier-based weathering.

 

I'll never forget this video of an S-2 Tracker (or perhaps a C-1 Trader) launching from USS Ticonderoga just as a huge wave crashes over the bow. You'd think the aircraft would be lost, but if you keep watching, you'll see it flying onwards.

[ame]http://www.youtube.com/watch?v=L4D6GxkPMgs[/ame]

 

They are washed frequently. Engines too, every time we start or shutdown.

 

Amazing.
A jet or turboprop would have flamed out.

Radials are tough.

 

Normally they try and time cat launches so that the bow is at its highest point right when the plane leaves the deck. In this case they obviously got it 100% wrong.

Of course, this was on an Essex-class carrier. I figure that on a supercarrier the rise and fall of the ship in similar seas would be rather less.

 

Not tough enough to survive a big gulp of water. Boat motors will occasionally push a connecting rod right through the top of a piston. No reason a round motor wouldn't do the same except their rods are nowhere near as strong. The only thing saved it was the prop turned the water to a spray.

 

I thought water-injection increased thrust.

 

Now you know why carrier versions of aircraft are more expensive. The beefed up landing gear and hook supports, plus folding wings, have to take 25 fps descent rate landings, being strapped to a catapult, and bad weather and spray over aircraft strapped to the deck. Next large buy of the F-35A will likely be around $85M per aircraft, but the F-35C will still be well above $100M a copy.

 

I would think they take off with the ignition on! At least, I would. Heck, I take off and land with ignition on all the time, after a friend of mine had a dual flameout.

 

F14 Tomcats are one of the greatest fighters,,i just [3-4 years ago] got to go to Calverton [to look at/pick up wreck/flood cars from hurricane sandy] just walking around was a trip,that place was huge,
thanks for working on my favorite planes
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It can, and up to 4 or 5% of inlet flow being water is a good thing. It tends to clean the compressor and as the water turns to steam in the compressor it reduces the temperature of the air leaving the compressor, increases the mass flow of air and you add the mass flow of water, and it also increases the pressure of the exit air. The increase in pressure and higher mass flow produce more power or thrust. The effect on the compressor is much the same as if it increased the speed of the engine, but at the same time compressor discharge temps actually decrease. We've run high rates of water injection on some small engines and the results were pretty amazing.

Since gas turbines have excess air in the process, so long as you have enough air to burn the fuel you are injecting, there isn't any power loss, all goodness..

Too much water can obviously drown a turbine, but that is pretty hard to do... With fan engines much of the water will get centrifuged out the fan duct and for those engines it's almost impossible to drown them out.

For turboprops you'd likely damage the prop blades before you ever got enough water into the inlet to damage them. Some smaller turboprops have inlets that separate water and other things (like ice) from entering the engine, so those would be even harder to choke out with water.

 

Thanks tons, great info.

 

Dude...I thought I survived 32 years in the AF without PTSD. Now I'm having disconcerting flashbacks to my Air Force Academy aero classes!

Seriously. Thanks for a great rundown. Interesting that for air it's a compressor but for water it's a decompressor! Key point...it's all about mass flow through a lit chamber!

 

Some of the guys I fly with report having engines (Rolls Royce AE2100 turboprop) "bog down" during periods of extreme precipitation. I'm pretty certain one guy has even had a engine flame out entirely after hitting some variety of mesocyclone / waterspout which is obviously an extreme example.

Here is a radar shot of some heavier stuff, the real Nasty stuff flashes in white on the radar.
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I remember that the KC-135 keel beam between the wheel wells held something like 450 gallons of distilled water that was totally expended on take off to prevent pre-ignition and reverse flame creep in the burners. It also gave the effect of decreasing the clearance between the compressor blades and the case thus increasing the compression ratio. ADI= Anti Detonation Injection

 

Pratt and Whitney tended to like water injection and there were provisions for both the J57 and J75, although the J75 was just afterburner injection to increase mass. The F-105 had a 38 gallon tank above the afterburner. I have already told the story of the F-105 at Holloman that had its water tank filled with JP4.

 

Whoa! Link, please...I gotta read that!

 

Will- Long time ago. Will do a short version tomorrow.

 

Taz...looking forward to it!

 

Will- Short version is the wing commander at Holloman got fired for two Class A accidents on the same transient F-105D. First major was caused by TA filling the 38 gallon water injection tank with JP4 (old, gasoline based jet fuel before kerosene based JP-8). Pilot had no clue, but when he lit the burners for take-off and dumped all that gasoline based fuel into a lit afterburner, it blew the rear off the aircraft. Pilot expeditiously exited the aircraft and was last seen still running towards Carswell AFB in Ft Worth. Big Bertha was sent to lift the remains off the runway, got her up to a pretty substantial height, and then dropped her. This generated another Class A. Not a good deal for what was then a peacetime wing commander (mid-70s).

 

Wow...wondered about what had happened with the supplemental JP-4 injected AB. Thanks for the story, Taz!

My Pops used to tell me about watching for the needle-width "blip" on the water pressure gauge that would happen after selecting AB for takeoff, knowing that if there was no "blip" and therefore no water injection, he'd end up in the dirt at the end of the runway at Korat.

(I started at the end of the JP-4 Age)

 

Aviation Fuel - Jet Fuel Information

http://www.cpchem.com/msds/100000014035_SDS_US_EN.PDF
According to this JP-4 is 70-90% kerosene by wt. Other references state 50-50 or 30-70 kerosene-gasoline. Obviously the 'gasoline' component gave JP-4 its high volatility, which was not a good thing at times.

 

Jim- There was a huge difference in volatility from JP4 to JP8. We had an F-111D lose a fan blade that went through the saddle tank in the fuselage (~9500 lbs of fuel). She instantly went up in flames. Firetrucks pored tons of foam on it, but it burned until that saddle tank was empty. Would not have happened with JP8. Some other benefits, too. Full internal fuel with JP4 was around 32,500 lbs, with JP8 it was 34,200 lbs. Only disadvantage was it made air starts a little more difficult.

JP4 is what is known as a wide cut fuel, mixed from a wide variety of distillation temperatures and products, so composition could vary depending on oil source, etc. We actually could run the TF-30s on pure gasoline for one time use. Would have had to be pretty desperate to do that.