F-14 Questions Answered - Ask Away

[Astro14]

Originally Posted by Fastzntn
Thank you for taking time out of your day to do some Q&A about such an iconic fighter! I'm just coming off of a trip to the National Museum of Naval Aviation- what a great place.

Two things I'm curious about-
1- are the cockpit controls configurable differently in any way for left handed pilots?

2- was there any specific watch or timepiece F-14 pilots were issued to wear when flying, and if so are you able to talk about it? I'm interested in watches, and seeing the last Omega "moon watch" worn on the moon at the museum was neat. Plus the Breitling Emergency line is an interesting concept, both the first gen in 121.5mhz and the newer gen with dual 121.5/406.040mhz.


1. Nope. You learn to fly the jet "as is". You needed both hands to operate the airplane anyway, and if you saw all the buttons on the throttle, you would know that both hands are quite busy when flying, so left hand or right hand isn't really an advantage...

2. Nope. Back in my time, few guys had the show piece watches. Rolex, Breitling, etc. were names that I'd never heard of until much later. A lot of us had the Casio G-Shock. It was tough, kept good time, and was easy to read. Anecdotally, we knew about an A-6 crash in West Virginia, at night, on a low level training route. The pilot's G-Shock was still intact though the rest of the airplane, and crew, was not.

I like watches, too. It was rumored that the 8-day clock, a mechanical timepiece with a stop watch function, in the airplane, just under 2" in diameter and above the pilot's right knee, was made by one of the Swiss makers.

But was never able to confirm that.

I used the clock all the time for timing instrument procedures and tactical execution... It was a good clock.

 

[Astro14]

Originally Posted by y_p_w
Originally Posted by Astro14
If you drove Formula 1, getting in a rental car doesn't pose a big challenge...

A lot of race car drivers have gotten speeding tickets. I heard of a NASCAR driver who had his driver license suspended for going 120 MPH in a school zone. So the challenge is driving like the rest of us. And a driver can't toss around a street car like an open wheel car. Strangely enough, Formula 1 requires that all drivers have a valid road license. Not sure how that might work if someone had a license suspended and tried to get a license in another jurisdiction.

Quote
https://www.formula1.com/en/champio...iver_changes_and_additional_drivers.html

As well as securing enough points, drivers will have also have to have spent at least two years in junior single-seater categories, hold a valid road driver's license and pass a test on the Formula 1 sporting regulations.


However, I remember playing some racing video game and then getting back in my own car. Felt kind of strange for a minute.


It was an analogy. Not meant to be accurate to a precise degree, but to convey a concept simply.

 

[y_p_w]

Originally Posted by Astro14
Originally Posted by y_p_w
Originally Posted by Astro14
If you drove Formula 1, getting in a rental car doesn't pose a big challenge...

A lot of race car drivers have gotten speeding tickets. I heard of a NASCAR driver who had his driver license suspended for going 120 MPH in a school zone. So the challenge is driving like the rest of us. And a driver can't toss around a street car like an open wheel car. Strangely enough, Formula 1 requires that all drivers have a valid road license. Not sure how that might work if someone had a license suspended and tried to get a license in another jurisdiction.

Quote
https://www.formula1.com/en/champio...iver_changes_and_additional_drivers.html

As well as securing enough points, drivers will have also have to have spent at least two years in junior single-seater categories, hold a valid road driver's licence and pass a test on the Formula 1 sporting regulations.


However, I remember playing some racing video game and then getting back in my own car. Felt kind of strange for a minute.


It was an analogy. Not meant to be accurate to a precise degree, but to convey a concept simply.

I understood. However, I've certainly heard of those used to high performance vehicles having a hard time adjusting to the real world.

 

[Garak]

Originally Posted by y_p_w
Strangely enough, Formula 1 requires that all drivers have a valid road license.

OT, but that specific aspect of the regulation is fairly new. Daniil Kvyat had his Super License before his road license. That was in 2015, and I believe he was the last one.

 

[The_Eric]

Here's another question for you Astro - I had watched a video of one of our fighters (I believe) setting various climb and/or altitude records. They said that to set one climb/altitude record, they would perform a specific maneuver - it had a name but I don't remember it, then do the climb. However to set the next higher, they used a different maneuver and so on as they set more. Why is that? Why the need to perform a specific maneuver prior to climbing and why vary them? What are the advantages over a straight climb?

 

[Astro14]

Well - I'm not certain what you mean by 'straight climb"... Constant path? Pitch? Airspeed? True Airspeed?

Basically, for a high performance airplane, you can plot, on a series of complex curves, the specific excess energy that exists at each altitude and airspeed.

When I say excess energy, that means the amount of energy added by thrust that exceeds the amount needed to maintain that altitude and airspeed. So, excess energy can be added to the airplane in the form of airspeed (kinetic energy in physics) or altitude (potential energy in physics).

Now, as an airplane changes airspeed, the drag changes. So, at very low airspeed, you have a tremendous amount of induced drag - that is, drag that is created by airflow over the wings as it generates lift. At high airspeed, you have much lower induced drag (which varies with angle of attack) but much higher parasitic drag - that is, drag created by the resistance of air moving over the airframe.

If you calculate both induced and parasite drag, and add them up, you end up with a drag curve. Very high at low speed, and very high at high speed, but there is a place in the drag curve where it is minimum, this spot is known as L/D max - where you get the greatest lift over drag ratio. An important spot. That's the speed at which you have the lowest drag and best L/D...so, that's the speed at which you have your best endurance (fuel used over time), your best glide range, and your best climb angle.

The drag curve takes into account wing characteristics and airframe characteristics and it's true for every airplane. In little airplanes, like a Cessna, it's simple and absolute.

But that curve has not taken into account the change in thrust with respect to airspeed. For high-performance airplanes, like an F-15, or F-14, there can be a big change in thrust with respect to airspeed. For example, and I think that I discussed this earlier in the thread, the F-14B, with the GE F110-400 engines, had 23,800# of thrust per engine under static (zero airspeed, sea level) conditions, but when the airplane was going 450 KIAS at sea level, that thrust increased to 32,000# per engine.

Big difference.

So, the derivation of specific excess energy (or power, or thrust, it's all the same) has to take into account the drag, both induced and parasite, and the changes in thrust. We're going to call it PS (it's actually P sub S but I can't type that on the forum).

When all that is done, you get a measurement of specific excess power. Again, for example, if you got super slow in an F-14, you could have so much induced drag that the excess energy was negative. I've flown the airplane there, and the only way out is to reduce the AOA so that the induced drag is reduced and the engine power can start adding airspeed. At a higher airspeed, drag is reduced and now the airplane will be at zero excess, or perhaps positive excess.

When you're trying to get to a new altitude, and you want to get there as quickly as possible, you want to climb at the airspeed that gives you the greatest PS. That speed changes as the variables change. An engineer named Rutowski figured this out in the 1950s and developed the climb profile that allowed the Navy's new airplane, the F-4, to set all kinds of time to climb records.

What he did was link the max PS points and climb the airplane at those points. So, for an F-14, you would climb at 0.9 IMN in full AB until you hit 35,000 feet, then you would unload (fly at zero G, which gets rid of induced drag), accelerate and descend, and resume climbing at 1.2 IMN. At 32,000 feet or so, the PS at 1.2 IMN was GREATER than the PS when subsonic, even though the drag was higher, the thrust was higher still. Drag on a supersonic airplane is a complex curve...

As you gained altitude, you would allow the speed to increase to 1.4 IMN, and continue climbing.

What you were doing was keeping the airplane at the precise speed (airspeed down low, mach up high) that would give you best PS....that speed changes, and you have to fly the airplane in a counter-intuitive way to keep it at best PS.

Now let's talk about setting records...

At some point in the climb, you're willing to trade airspeed (kinetic) for altitude (potential)...right? You're trying to get to that altitude as fast as possible. Doesn't matter if you get there with zero speed, you got there and at that instant, the clock stops. So, you climb on the Rutowski profile, and then at some point, you sell all your airspeed in a zoom to the target altitude. You exchange kinetic for potential. IF you had stayed on the Rutowski profile, you would get there, but it would take you longer, as you would still be going the best climb airspeed.

So, each target altitude in the time to climb effort required a different profile, a combination of Rutowski/best PS profile and a trade-off at the end.


By the way, we used to do a demo in the F-14B for those who hadn't seen the climb ability of the airplane. From 250 KIAS at sea level, start the clock, select full AB. At 450 KIAS pull up to a 70 degree pitch. At 200 KIAS, roll over to level flight. You would be at 40,000+ feet less than 60 seconds later. The airplane would stay pretty close to the Rutowski profile until 35,000 feet, when instead of descending and accelerating to 1.2 IMN, you were just zooming to get to 40,000 feet. It was an awesome ride up, by the way. Not a stunt plane, like the Streak Eagle, and not an extraordinary day, like the days on which records were set, just a demo of the airplane's performance...

A demo of its ability to generate truly awesome PS numbers..

 

[billt460]

Originally Posted by The_Eric
Here's another question for you Astro - I had watched a video of one of our fighters (I believe) setting various climb and/or altitude records. They said that to set one climb/altitude record, they would perform a specific maneuver - it had a name but I don't remember it, then do the climb. However to set the next higher, they used a different maneuver and so on as they set more. Why is that? Why the need to perform a specific maneuver prior to climbing and why vary them? What are the advantages over a straight climb?

Astro is the guy with the stick time here, so he can feel free to fine tune anything I'm writing. But when the F-15 set all the time to climb records back in the 70's, the method they used to set them was to have the aircraft tethered to the runway while the pilot ran the engines up to full power.

The aircraft was then released. The pilot lifted off very quickly, retracted the gear, and allowed the airspeed to build on the deck to a specific number, depending on which altitude record they were trying to break. When that airspeed was reached the pilot then pulled up into a, "giant Immelmann maneuver". Basically a big half loop, rolling out from inverted at the top going in the opposite direction. (For the lower altitude time to climb records, the pilot simply pulled up until the aircraft was vertical after achieving a specific airspeed).

He would then continue to allow the airspeed to build to a higher specific number. When that was reached the pilot then pulled up to achieve a specific climb angle, (again depending on the altitude record they were trying to break), and hold it until that height was reached.

I posted these before, but here are the 2 videos showing what I just described when the F-15 set all the time to climb records in North Dakota in the dead of Winter. When the air was the most dense:

 

[billt460]

Astro,

I know this would be a very rare occurrence, but I'm sure the Navy has a plan and a method for it. Let's say you had several aircraft low on fuel, waiting in the pattern for their turn to land on the ship. And one was involved in a catastrophic accident on landing that had parts, fire, and pieces of airplane all over the flight deck, completely blocking it. Did they have a team trained just for such a thing, that was capable of clearing everything quickly, before waiting aircraft started running out of fuel?

Or was there always an air tanker near by to allow them to get a drink while they waited? I remember you saying these aircraft can't land with a lot of fuel due to weight restrictions on the gear, airframe stress, etc. But they must allow some type of margin for what I just described. Is it a difficult balancing act, added fuel weight in exchange for added time aloft in an emergency?

 

[Berto]

To Astro14: Thank you very much for this awesome thread sir! Much appreciated! I came here for the oil stuff, then to my amazement discovered this hidden gem.

If I may ask, what was the purpose of this piece of string that can be seen in close up from ~1:10 onwards? (probably a silly question, but has puzzled me for decades)

 

[Astro14]

Berto - that's a yaw string.

Common in gliders, the yaw string allows the pilot to see yaw simply and quickly, because the string would remain aligned to the relative wind over the nose.

It allows you to trim the airplane to zero slide slip. You would think that a multimillion dollar fighter would have something more sophisticated, but the yaw string was cheap and effective.

There is a side slip indicator (ball) on the ACM panel, standard in jets and airliners, but they were difficult to keep in calibration. The yaw string required no calibration. No adjustment.

 

[Astro14]

Originally Posted by billt460
Astro,

I know this would be a very rare occurrence, but I'm sure the Navy has a plan and a method for it. Let's say you had several aircraft low on fuel, waiting in the pattern for their turn to land on the ship. And one was involved in a catastrophic accident on landing that had parts, fire, and pieces of airplane all over the flight deck, completely blocking it. Did they have a team trained just for such a thing, that was capable of clearing everything quickly, before waiting aircraft started running out of fuel?

Or was there always an air tanker near by to allow them to get a drink while they waited? I remember you saying these aircraft can't land with a lot of fuel due to weight restrictions on the gear, airframe stress, etc. But they must allow some type of margin for what I just described. Is it a difficult balancing act, added fuel weight in exchange for added time aloft in an emergency?


It's always a balancing act. Time, fuel, deck availability...

We kept a tanker airborne for each recovery. In difficult conditions, we would keep two airborne, and perhaps one on a 15 minute alert (able to be launched in 15 minutes).

In the old days, we used A-6 tankers. Then the S-3 took the mission (and did it very well, it burned very little fuel itself, carried a lot, and had lots of weight available to land with lots of fuel to avoid jettisoning if the fuel went unneeded).

These days, the F/A-18E can be configured with a buddy store thus making it a tanker. At least one airborne, and one on alert.

Every carrier has a crane (called "Tilley" though I don't know why) and the ability to remove a wrecked airplane in minutes. Practiced a lot. Rarely used. But even if the landing area is fouled with wreckage, the bow catapults are available. Tankers can be launched to get the airplanes overhead to a divert field, or to give them the fuel to remain overhead until the landing area is clear.

 

[Berto]

Originally Posted by Astro14
... that's a yaw string ...

^ Thanks for answering sir. I'd been suspecting that, but as you say the notion that such a simple device still had a place onboard the most sophisticated interceptor of its time was a bit perplexing. Guess every bit helps when you're trying to land such a beast on a carrier's deck.


Originally Posted by Astro14
... Every carrier has a crane (called "Tilley" though I don't know why) ...


This memorable scene from The Bridges at Toko-Ri shows a 1950s-vintage "Tilly" in action:



I know nothing but from what I've read elsewhere the name might have evolved from Utility Crane => Utility => Tilly in WW2 times.

 

[spasm3]

Astro, the legend of the Bones? Are the bones really of Jack Ernie or are they symbolic of his story?

 

[Astro14]

Originally Posted by spasm3
Astro, the legend of the Bones? Are the bones really of Jack Ernie or are they symbolic of his story?


The "Bones" are absolutely real human bones. Carefully guarded. Always treated with respect and reverence.

Ensign Jack Ernie's bones were with us wherever we went. In the ready room in Hangar 202 at Oceana. In Ready Room 8 on the ship. In Fallon.

Everywhere.

The legend is, well, a legend. I've never questioned it. Never researched it. I'm happy with the legend as told. As handed down from Jolly Roger to Jolly Roger.

 

[DoubleWasp]

I have a question. Not exactly F-14 specific, but how does the IFF system work in the F-14 and other planes?

My understanding is that this is a signal passed from friendly to friendly to let them know who is who? If my understanding is actually correct, how is this signal kept from detection by the enemy?

 

[Astro14]

IFF Mode 4 responds with an encryption that's changed daily. It has to be keyed before every flight. Just to query the encryption requires sophisticated radar/interrogation. The query is encrypted and therefore the whole system is very, very hard to decrypt, spoof, or hack.

We had to be keyed and checked on deck before every launch.

 

[DoubleWasp]

I assumed it had serious security, but didn't know how. Thanks.

 

[ArrestMeRedZ]

Wiki has a pretty good description of the IFF system in allied military aircraft. Suffice it to say, if your IFF is on, you can be detected by the enemy. Modes 4 and 5 are encrypted, which makes this more difficult, but not impossible.

If you are operating against a stone-age enemy, you would leave IFF on to reduce the risk of fratricide. Against an advanced enemy, it used to be common procedure to turn it off just before entering enemy territory, and turn it on again just before returning to friendly territory. The number of Patriot missile kills against friendly aircraft coming back from enemy territory into their missile envelope may have altered that strategy.

 

[Kamele0N]

Quote
Not all asymmetric wing conditions are accidental... During the development and testing of the F-14; The US Navy raised concerns regarding the dangers of asymmetrical wing sweep. A series of flight tests were conducted by Grumman's Chief Test Pilot, Chuck Sewell, who took F-14 #3 up for several trials with the right wing locked in the forward position of 20 degrees, and positioned the left wing at 35, 50, 60 and 68 degrees of sweep in flight.

It was determined that the mighty F-14 could maintain controlled flight, and even be acceptable for carrier landings in a configuration up to as much as 60 degrees.

That is one bad [censored] cat!

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[BMWTurboDzl]

Were some parts on the F-14 interchangeable with the F-111?