F-14 Flap/Slat Info



Over at ARC someone asked the following question;



Quote: Am rebuilding a Monogram 1/48 F-14A and would like to display it with wings open.



But as you know the slats are an integral part of the wing in that kit, and come in the up position.



Was there a way to lock the slats in the up position? Want to know as I will not deploy the slats ( ) and I would like the kit to be as accurate as possible.



Many thanks in advance,



First of all, the Tomcat had Slats, they were not leading edge flaps or any of that stuff, they were slats. Three of the most hated words in the Tomcat community were Flap/Slat Lockout, to this day those three words will cause any Tomcat guy to break out in a cold sweat and if you were an Airframer, you would probably just pass out. More on Flap/Slat Lockout later.



The Tomcats flaps and slats were not tied to the wing position and worked independently of the wing sweep system. The flaps and slats were electrically linked together so if the flaps came down, so did the slats, you could not isolate the two by pulling circuit breakers either (at least we never did). The flaps were connected by what is called torque tubes, long tubes that connected each drive mechanisms together so that all the flaps (except the aux flap, it could be isolated) would deploy together, the slats were also connected together so that all sections of the slats deployed together, uniformly.



The most common configuration for the flaps and slats was the up position, and the wings folded back into oversweep. If the wings were left out, the flaps and slats were most likely in the up position. Usually the only time the flaps and slats where down with the plane parked was that it was set up for the wash job or for maintenance such as a phases inspection, special inspection or the dreaded flap/slat lockout.



For takeoff, especially carrier, the flaps and slats were always deployed; it was a requirement, no matter what the wind over the deck was. You will see pics of the Tomcats taxing up with the flaps and slats up, you will see pics of it in kneel, launch bar down and it looks like the plane is about to be launched with the flaps and slats up but look closely, you will see the launch bar is not in the shuttle but resting on top of it and heres why. The flap and slats were powered by the flap/slat drive hydraulic motor, which was not cooled while on deck. When the temperature was hot we would leave the flaps and slats up until the last minute to keep from burning the motor up. In colder weather it wasnt an issue but on hot days, you did not want to run that motor if you didnt have to, it was a REAL PITA to replace. So, that is why you will see photos of the Tomcat on the cat with the flaps and slats up, and even on land with the engines running.



On land they could take off with them up, depending on the aircraft load. In the two videos posted on ARC you will notice that both aircraft dont have tanks or weapons rails, they are lightly loaded so the aircraft can get off the ground without the use of the flaps/slats. A put tanks and weapons rail on it and its a different story. I rarely saw a Tomcat take off without flap/slats down, but then again, we just about always had at least two rails and both tanks installed.



So, it was very common that when the wings were out that the flaps and slats were in the up position. If you want to do a diorama with the bird going down the cat, the flaps and slats better be out, but if you are doing one where its taxing up to the cat, you can easily get away with leaving them up.



One more thing about flaps/slats, in flight, it was possible for the flaps and slats to be deployed with the wings swept to 50 degrees. This was called maneuver flaps or bomb mod. When the wings where swept back out of 22 degrees the aux flap (inner most flap) was locked in the retracted position but the other flaps (including the slats) could still deploy as long as the wings didnt go past 50 degrees, once past 50 degrees the flaps/slats were locked in the retracted position. When the wings were fully swept forward (22 degrees) and flaps/slats were deployed, the wings were locked forward and could not be swept in order to prevent the aux flap from striking the fuselage. Part of the pre-flights checks was to drop the maneuver flaps (basically the flaps and slats minus the aux flap) and sweep the wings until the stopped at 50 degrees. If the wings didnt stop the flaps would strike the fuselage so the PC, Pilot and troubleshooter had to watch closely when this was done or it would be hell of a time explaining it to the MMCPO why you just let one of his jets get crunched.



Now for that dreaded flap/slat lockout I talked about earlier. The flaps and slats were most of the time controlled by the aircraft computer during flight. During ACM the computer sometimes was playing catch up with the aircraft changing aerodynamics and thus would constantly retracting/deploying the flaps/slats. If the computer changed them too fast, it would cause the torque tubes in the system to break due to the forward/reverse driving of them. Basically, take a paper towel roll and twist one end one way and the other end the other way, thats what was happening to the torque tubes. When a tube failed the whole system would drive to the full deployed state and lock up.



Now everything in the system had to be timed together, so when one tube broke, it threw the whole timing off, basically FUBARing it. When a plane came back with a flap/slat lockout you could not retract them, which on the boat made parking it even challenging. In order to fix a flap/slat system, you had to replace the broken torque tubes, inspect everything and then rebuild the drive system which meant you had to re-time everything. After you had it all put back together you had to hook up a test set to the system and run it, it would give you a read out that looked like an EKG that would tell you if the system was timed correctly, if not, you broke everything loose again, re-timed it all over, and then run the test all over again.



Hopefully someone will find the above useful,

Gerry



BTW, here is the description of the flap/slat system from the NATOPS.



Quote: FLAPS AND SLATS

The flaps and slats form the high-lift system, which

provides the aircraft with augmented lift during the two

modes of operation: take off or landing and maneuvering

flight. The flaps are of the single-slotted type,

sectioned into three panels on each wing. The two

outboard sections are the main flaps utilized during both

modes of operation. The inboard section (auxiliary flap)

is commanded only during takeoff or landing. The slats

consist of two sections per wing mechanically linked to

the main flaps. Flaps down greater than 10° enables the

wheels warning light interlock, and greater than 25°

enables direct lift control.



Main Flaps.

The main flaps on each wing

consist of two sections, simultaneously driven by four

mechanical actuators geared to a common flap driveshaft.

Each wing incorporates a flap asymmetry sensor

and flap overtravel switches for both the extension and

retraction cycles. Cove doors, spoilers, eyebrow doors, and gusses

operate with the flaps to form a slot to optimize airflow

over the deflected flap. The cove doors are secondary

surfaces along the underside of the wing forward of the

flap. As the flaps pass 25° deflection, a

negative command received from the DFCS depresses

the spoilers to 4 1/2° to meet with the cove doors.

Because the spoilers do not span the entire wing as do

the flaps, gusses inboard and outboard of the spoilers

perform the flap-down function of the spoilers. With the

flaps retracted, the eyebrow doors, which are the

forward upper surface of the flaps, are spring loaded in

the up position to close the gap between the trailing edge

of the spoiler or guss and the leading edge of the flaps.

Mechanical linkage retracts the eyebrow door when the

flaps are lowered to provide a smooth contour over the

upper surface of the deflected flap.



Auxiliary Flaps.

The auxiliary flaps are

inboard of the main flaps and are powered by the

combined hydraulic system. The actuator is designed to

mechanically lock the auxiliary flaps when in the up

position. In the event of high dynamic-pressure conditions,

a bypass valve within each control valve opens

causing the auxiliary flap to be blown back, thus

avoiding possible structural damage. During loss of

electrical power, the control valve is spring loaded to

retract, retracting the auxiliary flaps within 1 minute.

The auxiliary flaps use cove doors, eyebrow doors, and

gusses identical in purpose and operation with those

associated with the main flaps.



Slats.

The slats on each wing are divided

into two sections, both of which are driven simultaneously

by a single-slat driveshaft. The slats are

supported and guided by seven curved tracks. Im sure some of you are probably going to be telling me that I shouldnt be doing this but I felt that the information would be useful to members here.Over at ARC someone asked the following question;The answers varied from it was uncommon to it was a standard take off configuration. I feel that the question hasnt been answered totally nor explained so here is some information on the F-14s Flap/Slat system from someone who has scrapped a knuckle or two working on them. The information below is from my experience and is not intended to be all encompassing, there were exceptions and Im sure if you looked you will find photos to contradict the information I am providing as far as the configuration information, so if you find a photo keep in mind you found an exception, not the norm. The configuration information is based on the general day to day operations in a Tomcat squadron and the happenings on the flight line at Oceana between 1987 and 2000.First of all, the Tomcat had Slats, they were not leading edge flaps or any of that stuff, they were slats. Three of the most hated words in the Tomcat community were Flap/Slat Lockout, to this day those three words will cause any Tomcat guy to break out in a cold sweat and if you were an Airframer, you would probably just pass out. More on Flap/Slat Lockout later.The Tomcats flaps and slats were not tied to the wing position and worked independently of the wing sweep system. The flaps and slats were electrically linked together so if the flaps came down, so did the slats, you could not isolate the two by pulling circuit breakers either (at least we never did). The flaps were connected by what is called torque tubes, long tubes that connected each drive mechanisms together so that all the flaps (except the aux flap, it could be isolated) would deploy together, the slats were also connected together so that all sections of the slats deployed together, uniformly.The most common configuration for the flaps and slats was the up position, and the wings folded back into oversweep. If the wings were left out, the flaps and slats were most likely in the up position. Usually the only time the flaps and slats where down with the plane parked was that it was set up for the wash job or for maintenance such as a phases inspection, special inspection or the dreaded flap/slat lockout.For takeoff, especially carrier, the flaps and slats were always deployed; it was a requirement, no matter what the wind over the deck was. You will see pics of the Tomcats taxing up with the flaps and slats up, you will see pics of it in kneel, launch bar down and it looks like the plane is about to be launched with the flaps and slats up but look closely, you will see the launch bar is not in the shuttle but resting on top of it and heres why. The flap and slats were powered by the flap/slat drive hydraulic motor, which was not cooled while on deck. When the temperature was hot we would leave the flaps and slats up until the last minute to keep from burning the motor up. In colder weather it wasnt an issue but on hot days, you did not want to run that motor if you didnt have to, it was a REAL PITA to replace. So, that is why you will see photos of the Tomcat on the cat with the flaps and slats up, and even on land with the engines running.On land they could take off with them up, depending on the aircraft load. In the two videos posted on ARC you will notice that both aircraft dont have tanks or weapons rails, they are lightly loaded so the aircraft can get off the ground without the use of the flaps/slats. A put tanks and weapons rail on it and its a different story. I rarely saw a Tomcat take off without flap/slats down, but then again, we just about always had at least two rails and both tanks installed.So, it was very common that when the wings were out that the flaps and slats were in the up position. If you want to do a diorama with the bird going down the cat, the flaps and slats better be out, but if you are doing one where its taxing up to the cat, you can easily get away with leaving them up.One more thing about flaps/slats, in flight, it was possible for the flaps and slats to be deployed with the wings swept to 50 degrees. This was called maneuver flaps or bomb mod. When the wings where swept back out of 22 degrees the aux flap (inner most flap) was locked in the retracted position but the other flaps (including the slats) could still deploy as long as the wings didnt go past 50 degrees, once past 50 degrees the flaps/slats were locked in the retracted position. When the wings were fully swept forward (22 degrees) and flaps/slats were deployed, the wings were locked forward and could not be swept in order to prevent the aux flap from striking the fuselage. Part of the pre-flights checks was to drop the maneuver flaps (basically the flaps and slats minus the aux flap) and sweep the wings until the stopped at 50 degrees. If the wings didnt stop the flaps would strike the fuselage so the PC, Pilot and troubleshooter had to watch closely when this was done or it would be hell of a time explaining it to the MMCPO why you just let one of his jets get crunched.Now for that dreaded flap/slat lockout I talked about earlier. The flaps and slats were most of the time controlled by the aircraft computer during flight. During ACM the computer sometimes was playing catch up with the aircraft changing aerodynamics and thus would constantly retracting/deploying the flaps/slats. If the computer changed them too fast, it would cause the torque tubes in the system to break due to the forward/reverse driving of them. Basically, take a paper towel roll and twist one end one way and the other end the other way, thats what was happening to the torque tubes. When a tube failed the whole system would drive to the full deployed state and lock up.Now everything in the system had to be timed together, so when one tube broke, it threw the whole timing off, basically FUBARing it. When a plane came back with a flap/slat lockout you could not retract them, which on the boat made parking it even challenging. In order to fix a flap/slat system, you had to replace the broken torque tubes, inspect everything and then rebuild the drive system which meant you had to re-time everything. After you had it all put back together you had to hook up a test set to the system and run it, it would give you a read out that looked like an EKG that would tell you if the system was timed correctly, if not, you broke everything loose again, re-timed it all over, and then run the test all over again.Hopefully someone will find the above useful,GerryBTW, here is the description of the flap/slat system from the NATOPS. __________________

Something to offend everyone.



People who disrespect the American flag never had to worry about coming home under one.