F-16 ceiling limit. Where it is?

Patriot · by **Patriot** » 15 Jan 2011, 22:01

Roaming around database I found kinda interesting photo:

The guy sitting in the preasure suit in the Viper! :crazypilot:

Never seen before. Could somebeody put a little feedback on that? I guess they wanted to figure out how high the Viper can go? Now, is that 50 000 feet the real upper edge of where it can fly?

http://www.f-16.net/gallery_item293953.html

jbgator · by **jbgator** » 16 Jan 2011, 01:03

Looks more like a test to see if you can fit in a Viper in a pressure suit...maybe for some potential future test. The airplane is an A-model, you can tell from the HUD and looks rather beat up. Also does not seem to be any hose connections to the pressure suit (unless modified the F-16 has no such capability). That being said I have been to 52,000 in a clean Blk 15 at Mil Power...took a while to get there and I didn't stay long as we are not supposed to be there w/o pressure suit and the ECS decided to quit right about then causing a slow decrease in cabin pressure. Got so quiet I thought the engine had quit...quick glance at RPM and I was breathing again and quickly got down lower to get ECS back. But it still had a little up VVI at that point so I think it could have gone higher. That was an F100-PW200, never tried with a PW220 and on my last flight in 2005 I was in a Blk 30D and tried to see how high it would go but again the ECS decided to quit around 50K so I gave up. Maybe a design conspiracy in the ECS to keep us from breaking the rules? A good thread for all the quacks on here!!! Evil brass designs in limit on ECS to keep wayward LTs from breaking altitude rule...

Zooming is a whole different story. Can-get-to altitude is different than service ceiling by the way....not a test pilot so I don't know the definition of service ceiling by heart but you can get a jet above its service ceiling...ask Chuck Yeager about the service ceiling of an F-105...

JB

jbgator · by **jbgator** » 16 Jan 2011, 01:06

PS, by the way it is not an ACES II seat either so may be a non-flyable mockup or MX trainer. There is no upper ejection handle on an ACES II.

vinnie · by **vinnie** » 16 Jan 2011, 01:36

Look at the AGE equipment, it's yellow, wasn't AGE yellow back around 1980

Patriot · by **Patriot** » 16 Jan 2011, 02:50

About the aircraft from the photo - it's 2nd prototype YF-16 #72-1568. See and compare yellow-black "WARNING" caption just under canopy http://www.f-16.net/aircraft-database/F ... profile/2/ See also photo description:

A pilot wears a pressure suit while sitting in the cockpit of a YF-16 aircraft at Edwards AFB on February 27, 1974

So the photo were taken just barely 2 weeks from Viper's first official flight..

jbgator, :thanks:

you share your experiences!
One thing come on my mind. What could happen in a theoretical scenario, if let's say you're supersonic with full afterburner around Mach 2 at 40 something kilo feet, then you pulling back into straight up climbing.. Is it possible to hit hmmm... 100k feet and survive?
ps. What ECS is?

jbgator · by **jbgator** » 16 Jan 2011, 03:05

That makes sense, the prototypes did not have ACES II, I think it was called a STAYPACK (SP?).

To your questions Patriot, the ECS is Environmental Control System (cooling air for pilot and avionics and...most importantly cockpit pressurization). You would have to consult an aero engineer and a physicists to know how high a Viper would go zooming from 40K at Mach 2 (assuming you could ever get one going that fast) and it would depend on how hard you pulled, what angle, etc (Mach goes away real fast when you pull hard on the pole up there). But I am fairly sure you would not have a pressurized cockpit too far into that zoom so I would not want to attempt w/o said pressure suit. My guess is it would go pretty high if you did Gum's zoom to a tail slide and then survived the departure to ride it home and probably need to do a restart of the engine. That Aero Engineer and physicist would probably tell me the proper profile to get the max altitude but I'm not that smart nor felt the need to know the answer.

JB

jbgator · by **jbgator** » 16 Jan 2011, 03:54

PS.....pretty high but not 100K.

And correction to my previous, it was an F-104 that Chuck Yeager took on a wild ride, I mistyped F-105. He did that zoom with rocket packs and he was wearing a pressure suit.

Usually when the ECS shuts down you get a slow decrease in cabin pressure but I did have an RD (rapid decompression) in a B-model on an FCF (Functional Check Flight) at about 40K and the cockpit went to 40K almost instantaneous. I would not want to go through that again much less at a higher altitude. Not interested in astronaut wings, give me breathable air outside if I need to punch out.

JB

exfltsafety · by **exfltsafety** » 16 Jan 2011, 04:33

The highest altitude I've seen recorded data for was around 86,000 feet. It was achieved using a zoom maneuver. As I recall, the only way we learned about it was that engine rpm rolled back and the EPU activated. During post flight inspection, maintenance found that the EPU had been activated and the pilot couldn't/wouldn't explain why. Maintenance sent in the data from the FLCS seat-mounted data recorder (didn't have CSFDR then) and we could tell what had occurred. Not sure if the Air National Guard pilot received any disciplinary action as a result - he probably did. I think this occurred not too long after The Right Stuff movie came out in the early 80's.

faust · by **faust** » 16 Jan 2011, 17:21

jbgator... that's exactly what's happens in this video:

http://www.youtube.com/watch?v=hm8piHiEmE4

a real intercept of a U-2 over Venezuela by FAV vipers back in 1992

the HUD shows an altitude of 54kft and the pilot said that the U-2 was at 55Kft

just before dissapearing the HUD symbology, the pilot said "i have the equipments hot" and after he said: "I lost the pressurisation"

jbgator · by **jbgator** » 16 Jan 2011, 17:52

Video is pretty grainy and cannot make out mach number but someone can get out their calculator and figure it out. He starts his pull up around 44K at ~320 KCAS (that is going real fast) and peaks at 56.5K at 130 KCAS. Not sure if they have PW200 or PW 220 motors. Because ECS provides both cockpit and avionics cooling as well as cockpit pressurization that is why the equipment hot light came on. ECS would have been low to no output well before that so I am sure he was losing pressure probably by the time he started his zoom. At 130 KCAS at 56.5K I don't think he had a whole lot more he could have gotten anyway. FltSafety not sure how you could get another 30K to 86K but again I'm not the aero engineer or physicist.

Clean Blk 30 or 50 could probably do a little better energy wise but I doubt ECS would be any different. Patriot I think you have your answer.

JB

LinkF16SimDude · by **LinkF16SimDude** » 16 Jan 2011, 22:51

**** entered in error. please delete - Link ****

exfltsafety · by **exfltsafety** » 16 Jan 2011, 23:51

FltSafety not sure how you could get another 30K to 86K but again I'm not the aero engineer or physicist.

JB, my recall is really sketchy on the details but I think he climbed to near 50K then did a slightly descending acceleration to at/near Mach 2, then zoomed and apexed in an arcing trajectory at/near 86K. The 320 KCAS at 44K is a little over Mach 1.1.

faust · by **faust** » 17 Jan 2011, 05:05

jbgator wrote:Not sure if they have PW200 or PW 220 motors.

-200... F-16A block15 "as it" from 1983-86

ECS would have been low to no output well before that so I am sure he was losing pressure probably by the time he started his zoom.

there's no warning light of losing cabin pressure?

That_Engine_Guy · by **That_Engine_Guy** » 17 Jan 2011, 06:50

faust wrote:
jbgator wrote:Not sure if they have PW200 or PW 220 motors.

-200... F-16A block15 "as it" from 1983-86

The Fuerza Aérea Venezolana (FAV) Viper engines were upgraded in the late 1990s (1997-?) from F100-PW-200 to the PW-220E
(Which through the use of an upgrade kit makes it a PW-220 Equivalent)

Juan wrote:the original F-100-PW-200 engines were upgraded by Samsung in Korea to the PW-220E model.

Ref: http://www.f-16.net/f-16_forum_viewtopic-t-70.html

F-16A Venezuelan Viper by Fabian Nevarez wrote:Another major program was the refurbishment of the F100-PW-200 engines to bring them up to PW-220E standard.

http://hyperscale.com/features/2002/f16afn_1.htm

Keep 'em flyin' :thumb:

TEG

jbgator · by **jbgator** » 17 Jan 2011, 15:06

Makes sense a 220 would do much better in that environment.

Yes there is a cabin pressure light but it doesn't come on till a pretty low pressure alt. I don't recall what it was. I am sure someone on here has access to a Dash-1 although I don't think it matters much. Looks like he was clearly interested in completing the intercept and probably would have continued regardless.

FltSafety I'm not trying to be argumentative but I still am skeptical of 86K. This guy went from 44K to 56.5 starting at ~1.1 mach or about 12.5K higher. I'm not sure .9 mach more is going to get you +36K (50K-86K) which is 3x the zoom in thinner air. But again, I am no physicist so I'll still concede it may be possible. I wonder how accurate the air data is at that altitude so the seat recorder might have recorded 86 when it really didn't get that high. Just a thought...not trying to start a back and forth.