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Optimal Glide Speed?


colyoap

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How can I figure out the optimal glide speed and ratio for a clean bug with 50%fuel? I couldn't find any diagrams in the NATOPS..?

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Thanks! Ive been scouring through the publication and found no such chart.. could you share the page?

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It's a pdf isn't it ? Just use the search function .

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Thanks! Ive been scouring through the publication and found no such chart.. could you share the page?

 

fwiw it will change with weight and config, but 250 is a fine approximation. Frankly, it is completely irrelevant outside very limited circumstances.

 

It isn't a Cessna with a 20:1 or whatever insane number it is glide ratio. The hornet has, if I had to guess, probably close to ten times the wing loading of a 172 (~120 lb/ft2 vs. maybe 15 or 20?). For a fighter that's not that high really, viper is higher for example, as are many larger aircraft like a B-1 or 747/A380. That’s not the whole story though. Trapezoidal wings favored by US have excellent flight performance at super/trans sonic speeds, but require aeros like leading edge flaps or strakes (f-16 uses strakes but they typically don’t play well with twin tails) to prevent poor high AoA performance. Actually, complex topic that you didn't ask about... so before this becomes a wall of text just take my word on it – hornet is a terrible glider. Ratio is around 1:1, similar to a brick.

 

More importantly, no where in the emergency procedures is there anything resembling “trim for best glide and scan for suitable emergency landing location.” The actual number is in the 200-300 knot range, but almost never does that factor in to desired airspeed. In a single engine failure she can get home. If both engines are lost priority is restart. By the way you also lost both generators, so MFDs and HUD are gone, and FCS likely MECH ON. Some can be brought back on by cycling batteries after minimizing electrical load. Again, regardless of bests glide, procedure is nose down until airspeed is ~400 knots and check RPM (easy does it if MECH ON). If RPM under 12%, increase airspeed until 12% (450-500) and attempt windmill restart. If stuck at 0% its seized frp, thermal expansion of rapid cooling. Level off to 200-300kts, again, easy does it when pulling, keep wings level, avoid slip, etc. If time attend to other troubleshooting (hydraulics, electrical, etc.) while descending to APU restart max alt (10k). APU accumulator can be charged via HYD ISO switch to ORIDE if you have hydraulic pressure. Good time to get pointed away from population or bad guys, radio (if powered, else survival radio). At 10k can attempt APU restart - should be wings level and 200kts or so at this point, into wind if possible, straps/helmet tight and gear checked as won’t have much time before ditch.

 

Tl;dr its 200-300 kts, but not many Qs its the rigth answer for


Edited by sk000tch
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just a dude who probably doesn't know what he's talking about

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Interesting sk000tch.

 

I suppose it is possible to dead stick almost anything, but I’m not disagreeing with you. Maybe someone will be lucky and have their failure over the salt flats.

 

I have a friend who flew fighters for many years starting on the Korean era. One of his very first flights in a single engine jet the instructor shut the engine down and told him to land it. Engine failures were quite common back then. Some time after the century series he shifted over to Boeing’s. He had a couple dozen dead stick landings in jet fighters and over 100 engine failures in his career.

 

Luckily we have better reliability now.

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Interesting sk000tch.

 

I suppose it is possible to dead stick almost anything, but I’m not disagreeing with you. Maybe someone will be lucky and have their failure over the salt flats.

 

I have a friend who flew fighters for many years starting on the Korean era. One of his very first flights in a single engine jet the instructor shut the engine down and told him to land it. Engine failures were quite common back then. Some time after the century series he shifted over to Boeing’s. He had a couple dozen dead stick landings in jet fighters and over 100 engine failures in his career.

 

Luckily we have better reliability now.

 

The hornet ingame lands off runway quite well, you can definitely dead stick it. Usually not much advantage to doing so, though it can be fun just to see if you can do it.

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What does the Hornet have for backup in case you run out of fuel? The Viper has an EPU that will run for 10-15 minutes to provide power to the FLCS and hydraulics. I've seen nothing in the DCS Hornet manual in regards to this.

 

The few times I've ran out of gas was circling the boat working on my Case I landings. Very little time to do anything when your below 1,000 feet and the engines flame out.

 

Though not a bad idea to practice this by starting at a high altitude and either run out of fuel or just shut down the engines. Doing this over Groom Lake with the nice salt flat would give plenty of room to dead stick it in. Mozdok on the Caucasus map has a good amount of flat land surrounding it too.


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The Vipers EPU isn't for when you run out of fuel, its for when you have an engine flameout.

 

The general idea is that you know how to plan and wont be running out of fuel, issues with the engine however are unexpected and therefore cannot be avoided.

 

Because viper only has one engine the risk of total loss of power is greater than in hornet, meaning it needs a backup.

 

AFAIK the logic behind hornet having a battery operated DEL or MECH control mode is that it will allow you enough limited control to make a 'safe' ejection.

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What does the Hornet have for backup in case you run out of fuel? The Viper has an EPU that will run for 10-15 minutes to provide power to the FLCS and hydraulics. I've seen nothing in the DCS Hornet manual in regards to this.

 

The few times I've ran out of gas was circling the boat working on my Case I landings. Very little time to do anything when your below 1,000 feet and the engines flame out.

 

Though not a bad idea to practice this by starting at a high altitude and either run out of fuel or just shut down the engines. Doing this over Groom Lake with the nice slat flat would give plenty of room to dead stick it in. Mozdok on the Caucasus map has a good amount of flat land surrounding it too.

 

It has an ejection seat lol. Not much else you can do out at sea, just try to get out of the carriers way.

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It has an ejection seat lol. Not much else you can do out at sea, just try to get out of the carriers way.

 

I thought the Hornet had an APU.

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Once, when I lived in Chicago, I remember an F-16 pilot with a flame out made a successful approach to a general aviation field near Ohare in real instrument conditions. I’m sure he was thankful for that EPU. Some great piloting, too.

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Since we're on the subject of emergency landings/traps...

 

Here's a clip posted today (from '99) Vid quality sucks but the audio is clear. Shows the same sequence from 3 different cams. Just watching the first will do...

LSO and the pilot got Air Medals for this one:

 

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