The navy at least had the good sense to restrict it only to research.
The USAF, on the other hand, well we seemed to think it was the perfect EPU approach for line service Falcons. Single engine places a premium on backup power.
F-14 Questions Answered - Ask Away
- Thread starter Astro14
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The USAF, on the other hand, well we seemed to think it was the perfect EPU approach for line service Falcons. Single engine places a premium on backup power.
Hi @Astro14
I apologise if my questions have been covered previously.
That hot weather we have been getting here in England got me to thinking about Pilot and RIO comfort in the F14 cockpit.
You are both sat under a large area of glass, you are also surrounded by electrical equipment that i guess give off a lot of heat.
The F14 you are in is waiting in the queue for the catapult. You are in tropics or the seas of the middle east. Does the F14s climate control system keep you both at a level that is comfortable, or do you need to get airborne in order to get colder airflow over the Tomcat?
I apologise if my questions have been covered previously.
That hot weather we have been getting here in England got me to thinking about Pilot and RIO comfort in the F14 cockpit.
You are both sat under a large area of glass, you are also surrounded by electrical equipment that i guess give off a lot of heat.
The F14 you are in is waiting in the queue for the catapult. You are in tropics or the seas of the middle east. Does the F14s climate control system keep you both at a level that is comfortable, or do you need to get airborne in order to get colder airflow over the Tomcat?
Hi @Tikka - I may have covered it - I may not - can’t remember.
The short version - it had really, really effective cockpit cooling.
On a humid summer day in Virginia Beach, with temps nearing 100F (38C) on the ramp, it would be blowing air so cold that ice chunks would be flying out of the distribution tubes.
It would cool off the cockpit enough that you would be comfortable, even on those days.
Once you were in the air, with lower absolute humidity, the ice chunks would stop and you could set the temperature to anything you like.
It was often nearing 100F on the flight deck of a carrier in the Gulf, and the jet would cool off pretty quickly after engine start. It would take a while for everything in the cockpit to become cool to the touch, but even on that steel deck in 100F - it kept you at a reasonable temperature.
The short version - it had really, really effective cockpit cooling.
On a humid summer day in Virginia Beach, with temps nearing 100F (38C) on the ramp, it would be blowing air so cold that ice chunks would be flying out of the distribution tubes.
It would cool off the cockpit enough that you would be comfortable, even on those days.
Once you were in the air, with lower absolute humidity, the ice chunks would stop and you could set the temperature to anything you like.
It was often nearing 100F on the flight deck of a carrier in the Gulf, and the jet would cool off pretty quickly after engine start. It would take a while for everything in the cockpit to become cool to the touch, but even on that steel deck in 100F - it kept you at a reasonable temperature.
Let me add that the system for providing cool air to both the cockpit and the radar, was fairly standard, but it was also quite robust because of the power contained in that radar. The F-14 radar had nearly 10 times the power output of the F/A-18 (before AESA)
Big transmitter = big cooling requirements.
Hidden between the intakes and the fuselage were a couple of small ram doors. These doors provided airflow over the heat exchangers when the aircraft was in the air. When the aircraft was on the ground, two small turbine fans drew air from below and forced it over the heat exchangers.
Compressed (and therefore hot) bleed air was taken from the engines and fed through the first heat exchanger to cool it. It then went through a turbine, in which it was compressed again, which means it got hotter (PV=nRT still applies) and that hot, compressed air went through a second heat exchanger, where it was cooled.
That cooled, compressed air was then routed back through the other side of the same turbine where it was expanded, and therefore cooled even more. Now you had cold air available and you could mix it with the original hot bleed air to get any temperature you wanted.
The expansion turbine was under the RIO’s seat on the right side of the airplane. I said the system is robust, it is, it has high capacity, but a “BLEED DUCT” light was a serious emergency in the airplane. It meant that there was an overheat somewhere in the system, usually by the expansion turbine. We lost a couple of airplanes to that expansion turbine running when a bleed leak was present and causing a fire in the avionics below the RIO.
So, “BLEED DUCT” warning light procedure was to close the bleed valves (AIR SOURCE - OFF in the manual) so that all hot air was isolated out of the system. That works to prevent a fire, but also shuts down all of the cooling I described above. You could get some ram air cooling - outside air forced into the cockpit - but it didn’t work well.
Those landings, and I had to do one, were pretty sweaty.
Big transmitter = big cooling requirements.
Hidden between the intakes and the fuselage were a couple of small ram doors. These doors provided airflow over the heat exchangers when the aircraft was in the air. When the aircraft was on the ground, two small turbine fans drew air from below and forced it over the heat exchangers.
Compressed (and therefore hot) bleed air was taken from the engines and fed through the first heat exchanger to cool it. It then went through a turbine, in which it was compressed again, which means it got hotter (PV=nRT still applies) and that hot, compressed air went through a second heat exchanger, where it was cooled.
That cooled, compressed air was then routed back through the other side of the same turbine where it was expanded, and therefore cooled even more. Now you had cold air available and you could mix it with the original hot bleed air to get any temperature you wanted.
The expansion turbine was under the RIO’s seat on the right side of the airplane. I said the system is robust, it is, it has high capacity, but a “BLEED DUCT” light was a serious emergency in the airplane. It meant that there was an overheat somewhere in the system, usually by the expansion turbine. We lost a couple of airplanes to that expansion turbine running when a bleed leak was present and causing a fire in the avionics below the RIO.
So, “BLEED DUCT” warning light procedure was to close the bleed valves (AIR SOURCE - OFF in the manual) so that all hot air was isolated out of the system. That works to prevent a fire, but also shuts down all of the cooling I described above. You could get some ram air cooling - outside air forced into the cockpit - but it didn’t work well.
Those landings, and I had to do one, were pretty sweaty.
You had me at the ideal gas law!
I remember seeing a documentary on the making of Top Gun and how hot the actors got in their back seat rides were on a hot day in San Diego. Not sure why, because I would think the electronics were extremely sensitive to high ambient temperatures. I heard they had to be well cooled.
When I say reasonable - you could get it down to about 80F when it was 100F and sunny. The insolation under that big canopy was fierce. You’re also wearing full flight gear - flight suit, boots, gloves, helmet, G-suit, torso harness, survival vest.
Don’t forget, they’re actors. They’re not athletes. They’re not fighter pilots.
They’re going to whine and tell you how hard it was because they have no context and no experience. They live for drama.
They haven’t had to sit in the cockpit of an A-4 in the El Centro sun, where it’s 115F in the shade and at least 20 degrees hotter in the cockpit, which is why we taxied with the canopy open, and closed it only when we were cleared for takeoff.
The F-14 was a Cadillac by comparison. Nice and cool. Once in the air, with all that ram air moving over the big heat exchangers, you could freeze yourself, even in the Persian Gulf.
Surprisingly, the F/A-18 was significantly warmer inside than the F-14 when it was hot on the flight deck. I flew the airplane out of Cecil Field in the summer and was really disappointed at the performance of the cockpit cooling.
Does the Navy use a special product to clean the canopies inside and out? Those things are a lot bigger and longer than they look. And being parked on a carrier deck, I'm sure they get that white, salt film on them in no time. Or do they use a common spray on glass cleaner?
I honestly don’t remember, exactly. I know that our plane captains* cleaned them every launch. I just don’t remember exactly what they used. It was called “canopy polish” and my recollection is that it was like a fine white abrasive in a can. Wipe on, let dry, wipe off. Something like that. Like plastic polish you would find in a detailing catalog.
No idea if that’s still used, or if the coatings on something like the F-35 require special consideration.
*In the Navy, a Plane Captain was a junior sailor, usually E-3, sometimes E-4, assigned to take care of the airplane. They handled things like cleaning and servicing. In the USAF, it was a much more senior enlisted, but the Navy gave responsibility to young sailors. Plane Captains had to be trained, through an extensive process, each step signed off in their training book (PQuaker State for those who were in the Navy), and then interviewed by a board, consisting of maintenance personnel, and air crew. I’ve sat on a few Plane Captain Boards. Any fact on the airplane was fair game for the board, e.g. the oil specified for the engines was Milspec 23699. Plane Captain was a big deal - and in recognition of that - we painted their names and home towns on the nose gear doors of our F-14s. You would see something like this on the nose gear doors:
AN ROBERT SIROIS
LANSING, MICHIGAN
