Wow! Great work on that model. Very well done!Hey, Astro, I'm on a F4 fan page on Facebook and someone posted this photo of a model F4 the same day you posted this pic... The previous Victory 211!
How Fast Can The F-16 Fly?
- Thread starter BlueOvalFitter
- Start date
Somehow I came across this in a search and I remember seeing some video of pilots talking about the maneuverability of the F-14. It was kind of crude, but it was something in the line of "Dances pretty well for a fat girl."
Astro, I was on the GW for about 5 years, many many moons ago. Back when the Tomcat was still flying, I remember recognizing that was one special plane. Passageways on all decks suddenly became wide open when a Tomcat pilot was coming thru.
My favorite was watching night ops from the 04 level (think so? Itâs been 20+ years) on the catwalk on the side of the island when the F14s were doing touch & gos. My skin still tingles at those thoughts. Thanks for the memories!
Does aircraft operation work the same as automobiles that if the air is cooler that more power can be had? My stepdad has a grandson who flies at Whiteman AFB and we think but can't confirm he operates a fighter jet. I liked the episode of Captain Slo or James May in the U2 spy plane.
Yes, cooler air is more dense. So, more power.
Basically, if youâre moving the same volume, but the weight is higher, youâre getting more thrust.
Thrust in a jet (unlike a rocket) is a function of transferring momentum to the ingested air.
You could feel the difference between a winter day in Oceana (say, 30 degrees) and a summer day. The jet had a lot more thrust.
Astro,
When you go into full burner on a modern jet fighter engine, especially when the airplane is static, how can that not screw up the EPR? One would think the afterburner would totally unbalance the Engine Pressure Ratio, to the point it would blow out the front. Creating a gigantic compressor stall.
How is the engine able to keep all of that combustion pressure, and subsequent thrust generated by the burner, going out the back?
When you go into full burner on a modern jet fighter engine, especially when the airplane is static, how can that not screw up the EPR? One would think the afterburner would totally unbalance the Engine Pressure Ratio, to the point it would blow out the front. Creating a gigantic compressor stall.
How is the engine able to keep all of that combustion pressure, and subsequent thrust generated by the burner, going out the back?
Iâm not an engine builder, but here are a couple things to keep in mind.
Modern jet engines donât burn all the air. Not all the oxygen is used. Further, not all the air goes through the combustion section. the old turbojets routed some air around the combustion section, leaving a supply of cold air that was used for AB liner cooling, AB oxygen, and things like that.
Next, AB isnât an all or nothing proposition, at least since the 1960s. AB is variable, having a range of fuel flow and thrust increase. âMin burnerâ was just that - a bit of the flame lit, a bit of thrust augmentation. âMax ABâ is when all the flameholders are lit, fuel flow, and thrust increase, are at their max. Fuel flow in the GE F110, for example, is over 1,000#/minute when full AB is used. Yes, that number varies with speed and altitude (fuel mass and air mass are related, go higher and fuel flow goes down, go faster, and it goes up). Not a typo, thatâs 150+ gallons/minute for each engine. Just over 2 gallons a second.
Also, the AB wouldnât stage in older engines until they were at 100% RPM. So, the turbine output pressure was at the max. In modern engines, AB will begin to light at 80+% RPM, but they wonât be fully lit until the engine is at 100% RPM and the pressure ratio in the engine itself is maxed out.
This part is important - the engines with AB have a variable exhaust nozzle. It changes area as AB goes from min to max, partly to keep those pressure ratios in line. The GE F110, for example, would open the nozzle a bit with min burner and the engine at 80% RPM, to keep the pressure ratios in line and allow the engine itself to accelerate.
Watch the carrier launch sequence again in the opening of âTop Gunâ - youâll see the F-14 TF-30s stage through each of five distinct âzonesâ of AB, with the nozzle opening a bit each time. The variable nozzle allows the hydro mechanical fuel control to manage engine pressure ratios between inlet and AB for stable operation. And yes, that engine was still hydromechanical - like a complex carburetor- to manage engine fuel flow, AB fuel pump operation, and nozzle position to maintain stable operation in response to throttle input. Balancing pressure ratios the entire time.
Iâd have to dig out my tech school books for a more technical answer but I remember that afterburner operation did not / could not affect engine operation
This video kind of shows the convergent/divergent nozzle in operation as the AB lights and goes full. It is âclosedâ at full âmilitaryâ power then opens as more AB is added. This is the F110-100 for an F-16
This video kind of shows the convergent/divergent nozzle in operation as the AB lights and goes full. It is âclosedâ at full âmilitaryâ power then opens as more AB is added. This is the F110-100 for an F-16
Notice that the nozzle is partly open at engine idle. It closes as the RPM goes up.
Also, the nozzle isnât fully open in AB during this test.
The mass in the air flow is not near maximum. When the airplane is going fast, more air, hence more mass, is getting pushed into the engine, so, the AB is flowing more air at high speed, and the nozzle needs to be able to open more than it does at static thrust.
I talked about this in my F-14 thread. For the GE F-110-400 in the F-14, static (zero airspeed) thrust in full AB was 23,800#. The engine was sucking in all the air.
But at 450 KIAS, when the big, variable inlet on the F-14 was ramming, and compressing, the incoming air, the thrust in full AB was 32,000#. A big increase because the amount (in lbs per second) of air being run through the engine went way up as a result of aircraft speed and inlet efficiency.
The engine had to be built to balance that flight regime, to accommodate that increase in flow and thrust, so, the nozzle at full AB in a static test still had room to open.
I know the inlet airspeed has a LOT to do with AB output. I remember reading about the SR-71 engines. Kelly Johnson said that a very high percentage of the thrust at Mach 3 was created by just moving the "spike", (Inlet Ram), in or out.
I don't know if this was automatic, or something the pilots did. But it effectively made the engine into a ramjet at very high speeds.
I don't know if this was automatic, or something the pilots did. But it effectively made the engine into a ramjet at very high speeds.
Automatic. Analog controls, and I believe it was initially hydro pneumatic- later upgraded to electronic. Inlet positioning on the SR-71 had to be very precise, on the order of 0.1â to maintain the shock front in the inlet.
A slight mis position of the inlet spike would lead to a loss of the shock front - and what was known as an âunstartâ. The engine would lose all thrust, because the air would spill around the intake instead of being compressed and slowed inside the intake to be fed to the engine.
Hey, Astro, I'm on a F4 fan page on Facebook and someone posted this photo of a model F4 the same day you posted this pic... The previous Victory 211!
If you look up the word "confident" in the dictionary, there's a picture of a guy flying a $20K+ R/C jet.
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Flying very fast RC aircraft is not as much fun as medium or slow RC aircraft because with fast ones you are constantly having to turn or at least make a huge loop, because you can NEVER let it get out of range of direct sight.
"How fast can the F-16 fly"..... Apparently a lot faster than this SAAB Gripen. This is what happens when you spend more on your paint job, than glue. The fun begins at 1:30.
When I first started flying my COX .049 Stukas (in circles) I wasn't very good either. I think my mom bought me 5-6 before I really got the hang of it. That and I only filled the fuel tank to 1/2-1/4.
