Fighter training, the F16, and a math/physics question

Rastoff said:
Except that an F-16 wing provides very little lift.
......
The F-16 has almost no glide ability. If the engine dies and cannot be restarted, the pilot must eject. The plane cannot be glided to the ground; it just falls.

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Sorry, that is simply incorrect.

Here is a fairly famous video from 1996:

Air National Guard Capt. Chris Rose making a deadstick landing (no engine) at Elizabeth City Coast Guard Station in an F-16.

[ame]https://m.youtube.com/watch?v=Puia_yQxir8[/ame]
 
The reason that such a high percentage of fighter jet engine failures result in the pilots ejecting has nothing to with the planes not being able to glide. They glide just as they fly under power (assuming functioning control surfaces).

But their glide speed and necessary landing speed is so high that a survivable off-runway touchdown is pretty much impossible. So to glide to a landing, you have to have a long-enough runway within a reachable gliding distance, as in the video above.
 
DWalt said:
If a F-16 transitions from high-speed horizontal flight to an upward trajectory, there is considerable inertia assisting it to climb. Also, using the afterburner would add additional thrust.

I once saw an F-15 do exactly that. It went into a vertical climb with afterburners lit up and it went nearly out of sight.
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I live only about 50 miles from Andrews Air Force Base, outside of Washington, and used to take my sons almost every year to the annual air show there on Armed Forces Day. Every service branch was represented, and we got to see Harriers take off and land vertically...A-10s turn and bank and execute tight maneuvers...Tomcats come roaring over the field at low altitude...(and I do mean "roaring"...the ground shook!)...and F-15s, F-16s, and F-18s do that vertical climb...most impressive!

The photos below are from the 2006 show...and yes, that's an F-86 in the last photo... :)
 

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Rastoff said:
Except that an F-16 wing provides very little lift.

The OP's info on weight and thrust is wrong. The F-16 definitely produces more thrust than it has in weight. If it didn't it wouldn't fly at all.

The F-16 has almost no glide ability. If the engine dies and cannot be restarted, the pilot must eject. The plane cannot be glided to the ground; it just falls.
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Huh? Thrust opposes drag and lift opposes gravity. Thrust to weight matters when thrust counters gravity (weight) as in a climb. Greater than 1:1 thrust to weight just means it can accelerate in a vertical climb. Suck that puppy back to idle in a practice precautionary approach and it’ll fly just fine down to landing.

Lack of glide has more to do with operable flight controls. If it’s fully fly by wire, engine failure leads to loss of electrical and hyds which leads to lawndart. It can’t glide as far as a Cessna 172 but if it has emergency hyds with a wind turbine and doesn’t require trons (think T-45 Goshawk) you can deadstick that in. Hornets and Warthogs have a mech backup while the Superhornet doesn’t.
 
Thanksl,

It was advertised as have a greater than 1:1 thrust/weight ratio but I just took their word for it.;)

SOME planes may have a better than 1:1 ratio after they have burned of some fuel.

The Phantom was advertised as a Mach 2 plane but I don't think it ever got that if it was configured at all for fighting.
 
Fighter jets have large envelopes due to the various widgets that “normal” aircraft don’t have. So what a modern fighter can or can’t do depends a lot on the configuration and the actual weight. Just try to find something for an F-16 that’s relatively easy to determine for a C-172, like a clean stall speed and best glide speeds. The people who know what they are talking about will all tell you “it depends”.

But the video gives you an indication of the glide capability. If you listen to the radio comms, at the beginning he was at only 9000 ft and 7 miles from the airport. And he not only made it, but was able to maneuver for a proper centered approach.

I doubt you’d be able to do anything like that with a falling rock ;)
 
Absalom said:
Sorry, that is simply incorrect.

Here is a fairly famous video from 1996:

Air National Guard Capt. Chris Rose making a deadstick landing (no engine) at Elizabeth City Coast Guard Station in an F-16.
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I sit corrected. Never heard of that before and all the pilots I've talked to say it's virtually impossible. But hey, seeing is believing.

I wonder how he kept the hydraulics going? I was always under the impression they required external power or running engines to make it work. Without hydraulics, how did he get the gear down? It looks like a gear down landing.


Yes, I got my ratios backward, but the point is more power than weight. Some planes take off with a reduced fuel load and then refuel once airborne so they can carry more cargo/munitions.
 
Rastoff said:
I wonder how he kept the hydraulics going? I was always under the impression they required external power or running engines to make it work. Without hydraulics, how did he get the gear down?
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If you listen to the radio, after the F-16 is on the ground the other pilots are talking about alerting the tower to the still-running EPU (Emergency Power Unit).

On an aviation forum I found this info, which I’m just pasting here:

“The F-16 does have backup systems. The aircraft battery will supply power for a couple minutes, depending on what all you're using. The hydraulic accumulators will provide hydraulic power for a minute or two, assuming you don't get too crazy. And the Emergency Power Unit (a small, monopropellant turbine in the right strake of the aircraft) will start promptly after losing the engine, providing electricity and hydraulic power for several minutes as necessary (the battery and accumulators keep you under control while it spins up). Ergo, if you lose the engine, you lose propulsion but you still have electricity and hydraulic power. So you can still maintain control of the airplane.“
 
Ah yes, that makes sense. I forgot about the EPU. Different from an APU on larger aircraft. That would provide power to the hydraulics.
 
Drag, lift, down force, weight, momentum, aerodynamics and thrust, all combine to determine an aircraft's parameters.

All aircraft designs combine to find what they are. Development, research and human input and realization combine to find the "happy spot".
 
Rastoff said:
I wonder how he kept the hydraulics going? I was always under the impression they required external power or running engines to make it work. Without hydraulics, how did he get the gear down? It looks like a gear down landing.
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Do fighters have RAT's any more? (Ram Air Turbine)
 
Jeff423 said:
Do fighters have RAT's any more? (Ram Air Turbine)
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The F-14 didn't have a RAT. You could cross-bleed and turn an engine if needed. Worst case, you windmilled assuming things were not seized.

No RAT for any series of the FA-18/EA-18 either. You have the previous mentioned options, plus the addition of an Auxiliary Power Unit (APU). Of course the nicest thing about the APU is taking the jet on the road and not being restricted to bases with a huffer (start cart).

I'm ignorant of most things Air Force.
 
Yeah, hydrazine is no joke. When I worked at a calibration lab for the USAF we had to calibrate a hydrazine test set. It was always a big deal when it came in because it had to be purged a special way.

When that test set came in, if we smelled anything, seriously, anything, we all had to go to the flight surgeon. Fortunately, we never smelled anything when I worked there.
 
Chubbs103 said:
The F-14 didn't have a RAT. You could cross-bleed and turn an engine if needed. Worst case, you windmilled assuming things were not seized.

No RAT for any series of the FA-18/EA-18 either. You have the previous mentioned options, plus the addition of an Auxiliary Power Unit (APU). Of course the nicest thing about the APU is taking the jet on the road and not being restricted to bases with a huffer (start cart).

I'm ignorant of most things Air Force.
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Thanks, my experience with military aircraft ended in 1973.
 
I do like the 51:1 Glide Ratio of my ASK-21 though. It has Zero power to weight ratio, but I still have had it up for over 30 hours once.

Bob
 
CH4 said:
Who was at the controls while you were in the little boys room? :D
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gatorade-old.jpeg


:D
 
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