Block 42 re-engine program -220 to -229

[F-16ADF]

Article is a little old, but focuses on ANG Block 42 Vipers upgrading to the more powerful F100-PW-229 motor as opposed to the older -220.

[h-bomb]

Did any of the 42/52s come with the big mouth? I remember TEG claiming the 229 could benefit from the bigger inlet.

[Ender_Wiggin]

Did any of the 42/52s come with the big mouth? I remember TEG claiming the 229 could benefit from the bigger inlet.

No, only GE's had the big mouth inlet.

[f119doctor]

The -229 fan was sized to match the 250 pps flow capacity of the original small mouth F-16 inlet. The F100-232, which was never fully developed or produced, had a higher airflow fan that was sized for the large mouth inlet at 275 pps.

[F-16ADF]

The -229 fan was sized to match the 250 pps flow capacity of the original small mouth F-16 inlet. The F100-232, which was never fully developed or produced, had a higher airflow fan that was sized for the large mouth inlet at 275 pps.

F119doctor, didn't P&W have a potential upgrade (thrust) for the -220 back in the late 80's/early90's? I believe it was the referred to as the -220P. About how much of a thrust increase was it as opposed to the standard -220?



The OHIOANG Block 42 birds that I see on occasion, with the -229 make a 'chirp, squeak, whine' I really don't know what to call it; I am guessing it is the actuator, as when the pilot moves the throttle. You near always hear the sound when the jet is on final in the traffic pattern. The -220 powered jets also make the same sound, as we had some foreign A models here last year for about a week. Also, I was looking as some old tapes of Block 10/15 jets from 90-94, and I do not seem to hear that sound. Is that because of different actuator in the -200 motor as opposed to the newer -220 and -229?

[f119doctor]

F119doctor, didn't P&W have a potential upgrade (thrust) for the -220 back in the late 80's/early90's? I believe it was the referred to as the -220P. About how much of a thrust increase was it as opposed to the standard -220?

The -220P was flow down plan from the F100-232 proposal. In addition to new production of the -232, it was proposed to retrofit the existing -229 engines with the bigger 275 pps fan and low turbine to turn them into -232s. The -229 fans and LPTs removed from the retrofitted -229 engines would then be installed on existing -220 engines with a new intermediate case to match up with the -220 core module. This engine would have been rated at 26-27K lbs thrust at Max AB. General Electric was proposing a similar retrofit of the F110-132 fans onto the -129 engine, and flowing the removed -129 fans on the earlier -100 engines. The USAF declined to fund either proposal.

The OHIOANG Block 42 birds that I see on occasion, with the -229 make a 'chirp, squeak, whine' I really don't know what to call it; I am guessing it is the actuator, as when the pilot moves the throttle. You near always hear the sound when the jet is on final in the traffic pattern. The -220 powered jets also make the same sound, as we had some foreign A models here last year for about a week. Also, I was looking as some old tapes of Block 10/15 jets from 90-94, and I do not seem to hear that sound. Is that because of different actuator in the -200 motor as opposed to the newer -220 and -229?

The F100 nozzle is actuated by 5 ball-screw actuators, driven through spinning cables (like an old speedmeter cable) from the Convergent Engine Nozzle Control (CENC), which is a Roots style air motor powered by engine bleed air. The F100 nozzle has a balance beam construction with internal nozzle flaps forward of the pivot point, with internal air loads balancing the loads in the visible portion of the convergent and divergent sections. This greatly reduced the nozzle actuation loads, and the nozzle will actually blow shut if the bleed air is shut off. Closing the nozzle in this manner is how the F100-200 Backup Control (BUC) operated.

The CENC rotors turn approximately 290 revolutions (292?) from full open to full closed nozzle, creating a loud zipping noise as the air motor interlocking rotors passed air out of the CENC exhaust and overboard. The original -100 / -200 CENC responded to a push / pull cable connected to the Unified Fuel Control and had a flow restrictor on the outlet exhaust which limited the speed of the motor. The -220 / -229 CENC was electrically commanded from the DEEC, and the exhaust outlet was a wide open pipe to overboard. It was capable of going from full open to full closed in approximately 1 second, and was louder than the original CENC design.

When the aircraft is overhead in the pattern with the throttle at Idle, the nozzle is approximately 10% open. When the landing gear handle is lowered, the nozzle opens rapidly to about 90% open, with a very distinct Ziiiip sound. Then, as the pilot plays with the throttle to control descent, the nozzle tracks the throttle from Idle (90% open) to 50 degrees throttle angle (10% open), with little Zips each time the throttle moves.

[disconnectedradical]

IIRC, the F-16C after Block 25 all came with the “Big Mouth” intake? Or did the Block 32/42/52 have the small mouth intake because the F100-220 and F100-229 didn’t need it?

This may be question for f119doctor, but did the F100-232 have a Vmax mode? It’s normally rated for 32,500lbf thrust, but this table has a Vmax mode that gives 34,000lbf thrust.



Also, this according to Flight International.
https://www.flightglobal.com/fighter-en ... 52.article

The F100-PW-232 offers several thrust level options: a 29,000lb (131kN) thrust rating for 6,000 total accumulated cycles (TACs) inspection intervals, an increase of 40% over current increased performance engines; a thrust growth rating of 32,500lb for an inspection interval of 4,300 TACs or the equivalent of a 12% thrust enhancement relative to the current engines; and a time-limited V-max thrust rating of 34,000lb.

[f119doctor]

Block 32 / 42 / 52 / 72 all have small mouth inlets, along with early Block 30 (which did restrict the thrust of the F110-100 engines). Later Block 30, 40, 50, 60, and 70 have the large mouth inlet.

I know the -220 had Vmax scheduling in the DEEC. I don't think the -229 does, but I could be wrong.

The -232 initial development engines did demonstrate 36K thrust on a ground test cell. This was probably on a cold January day in Florida where rotor speeds and turbine temperatures are down from their limits, but it does demonstrate the aerodynamic capability of the engine. The graphic you show looks like a P&W marketing presentation, so I would say Vmax was a possibility. They are showing DEEC settings that could be accessed to limit thrust to 29K for increased peacetime durability, 32.5 for wartime capability while trading off some durability, and the Vmax mode. The 29K and 32.5K options should be selected using ground support equipment, and would not be selectable by the pilot, as opposed to the cockpit Vmax switch. As implemented in the -100, -200, -220, Vmax cockpit switch activation had no effect until you exceeded M1.2, so it was a high altitude, high Mn feature only. Which is why the 34K Vmax rating has the "sea level equivalent" proviso.

I don't know if there would have been a separate 29K Vmax and 32K Vmax rating, or if you could get the 34K Vmax straight from the 29K setting. Of course, the Vmax switch is guarded with the guard held closed with 0.020 safety wire. if the safety wire was found broken during post flight inspection after a peacetime training sortie, it was a immediate pilot visit to the commander to explain their actions.

FYI - the latest -229EEP production engines with the 97 enhancement package is rated for 6000 TCY cycles between depot inspections, even without the more efficient -232 fan to lower turbine temperatures for the 29K rating.

[disconnectedradical]

The Flight International article also says the F100-232 fan is bigger than F100-229 fan, but it would need to fit into the case interface as previous F100 variants?

Did F100-232 use the bulged fan case trick like F110?

Back on topic of F100-229 re-engine, part of me imagine what a lighter Block 20 Viper would be if it had that engine. Would be the ultimate hotrod.

[f119doctor]

The inlet interface was the same for all variants of the F-16. It was the inlet throat area that was different between the standard and big mouth inlets.

[f119doctor]

The -229 flight test was in a Block 10 B model. I’ve told this story before, but the test aircraft didn’t have the forward motor mount doubler needed for 9G capability, limited to 7G. During low level performance testing at 500 ft in the test range off shore from Ventura CA, they could not keep the aircraft from accelerating past 800 KIAS at the 7G limit