Modern Aviation Mythbusters

[vanir]

Follow on from FlyboyJ's WW2 Aviation Mythbusters Thread in the WW2 aviation forums. Seems to me there are a lot more lesser known myths about modern warbirds, considering Cold War propaganda continues to be published about technical specifications in all popular media.

So, all set to open a can of worms, here's a couple I brought up in a recent email to an aviation journalist, which where continuing to promote Cold War propaganda effectively act as arms dealers rather than reporters. I mean, have they never spoken to an Eagle or a Foxbat pilot, say for this case in point correcting several errors this journalist published. He lists upon a "specialist modern aviation database conceived in 2010 designed for professionals such as military personnel as a quick reference and guide, containing the latest information" and yet he provides within the ancient propaganda of Eagles fancifully exceeding Mach 2.5 all over America whilst Foxbat still in service apparently do 3.2 Mach.
Plus all the other popularisms of Cold War media and arms manufacturer sales brochures which essentially contain wall to wall misinformation, disinformation and exaggeration. Here are my corrections:

F-15C/D Eagle. The engine management system of all Eagles automatically imposes an airspeed limitation of 1.78 Mach (600-610KIAS), which is the aircraft's actual balls out top speed under any normal flying condition, at any altitude.

The 1974 F-15A/B version of the Eagle initially had a pilot override switch installed, for the purposes of sabre rattling with the Russians in performance record achievements with specially prepared versions of service aircraft. With risk to engines and flight safety, the Eagle's airframe can sometimes exceed 2.5 Mach using this feature. It was deleted in 1978.

The normal top speed of any Eagle in service conditions is a shade over 1000kt TAS although it'll take tremendous warloads, climb like a rocket to the edge of space and spike 11G manoeuvres without so much as a crack in the fins (demonstrated in service). The Eagle is no need of any exaggerated performance claims, it's probably the strongest fighter airframe ever built and the best dogfighter of its age. Its avionics are courtesy of the space program and extremely powerful even today. Its potency is unquestionable and its combat record unsurpassed.

All versions of the MiG-25 Foxbat are normally speed restricted to 2.5 Mach SOP on the Mach index and have an airframe design limitation of 1620km/h IAS (2.8 Mach). At supersonic speeds above 2.5 Mach extremely limited bypass ducting and inlet design cannot compensate inlet shock or airspeed through the compessors and the turbines produce a phenomenon known as "runaway rpm," whereby mechanical operation of the fuel system continues to supply full throttle to the engines irrespective of the management system or pilot input, including trying to shut them down. The aircraft continues to accelerate to a critical airspeed limit of around 2100mph IAS, until the engines destroy themselves or the airframe breaks up, whichever comes first. This is how isolated examples of Foxbats exceeding 3 Mach in service have been recorded. The pilots were lucky to survive, the engines in each account did not and one entire aircraft based in Egypt (Soviet operated) had to be scrapped, this was the one which infamously recorded 3.2 Mach between Israeli ground stations near Jordan in 1973. It is not the aircraft's top speed, but an air crash phenomenae. It happens in other types just not at such a speed.

(added here: Attaining the airframe design limitation of 2.8 Mach requires careful management of the throttles by the pilot. Exceeding 2.5 Mach requires authorisation from a ground controller according to Russian Foxbat pilots)

The RB series of 1970 introduced the bombing feature using more powerful engines with improved TBO life, a cruise capability of 2.35 Mach and demonstrated supersonic capability of 2.8 Mach carrying 2x 500kg bombs under the fuselage and 2x 500kg bombs under the wings, tested and recorded by Mikoyan OKB although I am unsure if this was a specially prepared test airframe or a service example.

Fittings and fire control for air-air missiles are not installed except for the outer wing hardpoints, which may carry R60 type defensive missiles without a fire control set. In the tactical bomber role the nominal armament/stores are 2x 500kg bombs and 2x R60 defensive missiles under the wings, plus 5,300-litre conformal fuel tank under the fuselage. In the reconnaissance role delete the bombs. In practise these aircraft rarely see more than 2.35 Mach and it is likely the external fuel tank imposes a further, heavy speed restriction when carried.

The commonly published, excessively high Mach ratings are in fact Cold War propaganda. Many of the airspeed benchmarks of 2nd and 3rd Gen fighters are. The Cold War is over. People have assumed the propaganda stopped and published figures are now accurate. They don't seem to have noticed that hasn't happened at all and in fact the same figures continue to be published. Now, I thought journalists weren't salesmen, death merchants or arms dealers.
All this information and quite a bit more detail wasn't that hard to discover.

I know how uncomfortable some people can get when things they took for granted are challenged, this isn't posted to have an argument over though as mentioned I know doing things like this opens a can of worms every time.

Still, the point of the thread would be that there are a very wide array of commonly held misconceptions about modern warbirds moreso than WW2 birds for which most myths have long since been dispelled and the remainder generally obscure.
From the comparative performance of modern Russian birds to points that might've been brought up in the Stealth Thread. Whether or not I just burned someone's worship of the mighty Eagle, or some Foxbat enthusiasts sentimentalities, I'm sure there are lots of modern aviation mythbusters which aren't in any way obscure, but actually against the grain of popularism.

 

[FLYBOYJ]

Good thread, but I'd like to know the background of this "aviation journalist" you mention with regards to his information. I have a few former Eagle drivers who work in the next building, I'll hit them up for some info regarding this. Some of these folks stopped flying the F-15 as little as 6 months ago.

This looks like a page from the book "MiG Pilot."

 

[tyrodtom]

This isn't about modern jets, but it is about jets.

Did the F-104 have to have pads put on front wing while on the ground, to protect the ground crew from the sharp leading edge?

I've seen a F-104 on display at a museum, it had a sharp leading edge, but not that sharp. I have a feeling if it did have pads installed when on the ground, I think it might have been to prevent dents on the perfect leading . F-104's were operational when I was in the USAF, I heard that rumour then, but I was never stationed anywhere that they were flying from.

What say the experts ??

 

[FLYBOYJ]

F-104 L/E covers? YES. Although later in its career it seems many operators stopped using them.

He's the XF-104 at Edwards, looks like the L/E covers are taped on

Here's F-104s deployed to Vietnam. You can see the L/E covers

NF-104s at Edwards

F-104 Production Flight Line, Plant 42, Palmdale, CA

 

[tyrodtom]

But were they installed to protect the ground crew from the sharp leading edge, or were they there to protect the leading edge ?

 

[pbfoot]

But were they installed to protect the ground crew from the sharp leading edge, or were they there to protect the leading edge ?

Both but later it would only be installed when the general public was around. The worst hazard while working on the 104 according to the guys I knew was when up on jacks the gear went up and gear doors closed incredibly fast.

 

[vikingBerserker]

I remember as a wee lad on the flight line my dad telling me about the wing protectors.

 

[tyrodtom]

When I was a kid I read every thing on aviation I could get my hands on.

This is a rumour i've heard several times, in different aviation books of the 50's.

A Navy jet , early Phantom, or Cougar, shot some 20mm in level flight, entered a dive, leveled out, then was hit by it's own fire.

Even IF it's possible, it seems very unlikely.

 

[Capt. Vick]

It has always been my understanding that a Grumman Tiger did just that...

 

[vikingBerserker]

I wonder if he got credit for it?

 

[tyrodtom]

If you check out the Grumman Tiger on wikipedia it mentions the incident, even names the pilot.

Thanks, I aways though that was just one of those wild "latrine rumours" that floats around in the military. But i'm still a little skeptical.

 

[Messy1]

There is also a story I read about in Flight Journal where a F-14 pilot was testing a new missile (sorry can recall the exact details at the time) and the missile ended up "shooting" down the F-14 it was fired from. I'll see if I can find the article.
ADDED
Ok, found the article. It was Pete Purvis and he was testing the Sparrow missile. Here's a link to the story.
http://www.ejectionsite.com/F-14 SHOOTDOWN.pdf

 

[FLYBOYJ]

When I was a kid I read every thing on aviation I could get my hands on.

This is a rumour i've heard several times, in different aviation books of the 50's.

A Navy jet , early Phantom, or Cougar, shot some 20mm in level flight, entered a dive, leveled out, then was hit by it's own fire.

Even IF it's possible, it seems very unlikely.

The F-104 might have done this. I do know it had a problem with spent cannon cases flying up and hitting the fuselage

 

[vanir]

I'd really like if you can confirm the deletion/when of the engine management override for high Mach operation FlyboyJ. I did speak to an Eagle pilot (sn "EagleDriver" and admin at a commercial aviation site you may know), but there is issue with what material is declassified and he could talk about that he mentioned. Same with an ex B-1B pilot I spoke to once about other stuff. He simply left it that the Eagle can do 1.8M, but it'll do it with a load and people who've actually been that fast would know how fast it is. It's a very fast fighter. By comparison most supersonics can barely make supersonic with anything but a pair of sidewinders.
The nature of the override and/or the 1.78M normal limitation was both mentioned by him and is published ("Fighter" by Jim Winchester), however similarly from various independent references it was deleted in the midlife update, which I'd like to confirm as the C/D introduction which was mostly an update of the management system anyway. That would then be 1978 onwards, although it would've been the mid-80s before all were updated, then they had another midlife update. So I'd like to confirm details about it. The override definitely was an initial feature of the type, but most people including some who claim to have served in the USAF don't know about that switch, which further reinforces the assertion that it was deleted quite some time ago, more likely in the C/D transition than the 80s update.

So any details or inferrences at all you can squeeze about it would be awesome mate. And of course as always with anything academic, I'm open to absolute correction and will turn about face on a dime in the face of qualified new information. Just operating on the best info I have at this time is all I can do, but I've never even been anywhere near an F-15 personally.

 

[vanir]

When I was a kid I read every thing on aviation I could get my hands on.

This is a rumour i've heard several times, in different aviation books of the 50's.

A Navy jet , early Phantom, or Cougar, shot some 20mm in level flight, entered a dive, leveled out, then was hit by it's own fire.

Even IF it's possible, it seems very unlikely.

This got discussed at CombatAce forums iirc (place where that B-1B pilot is), and a link to a fairly recent publication of the story was given. From what I remember, I can't remember the type involved either. But iirc the article mentioned details were inconclusive, pretty sure it wasn't confirmed he was hit by his own fire but it makes for a nice air safety advertisement for military cadets.
Two Phantoms I think, in a combat turn, one may have got hit by his own fire but I could be misremembering, it was a while ago I read it. Try scouring CombatAce forums, you might find it.

 

[vanir]

The F-104 might have done this. I do know it had a problem with spent cannon cases flying up and hitting the fuselage

Had a lot of trouble in that plane pioneering the Vulcan apparently. The spent cases weren't ejecting at all when first tried. Gun overheat too, electrical problems, all sorts of teething issues.
Took years to figure why the longitudinal instability out, she didn't like any alpha at all. Blocked all the air over the t-tail so you almost immediately lost elevators then rudder. Not a dogfighter but very fast, very popular with the talented pilots. Gigalos don't exactly go for fatties I suppose