F-35B/C Lightning II (Joint Strike Fighter)

[HeyJoe]

Why still have a canopy bow? The only ones I have ever seen are where the canopy actually separates and the F-22 doesn't have one.

Can't answer that, but it's not a conventional bow that separates and serves as mount for pieces of plexiglas as in a conventional configuration; it's internal (vvvv) to single piece of plexiglas. I can get you an answer next week though.

HJ photo

 

[Recovering LSO]

It has an amzing clutch that connects the lift fan to the engine. The novel fan provides 18,000 pounds of lift alone with no combustion.

and that's all driven by one engine.......right......? When this system was being pitched and sold as the most fail safe engine ever fielded did they send cranials, wrenches, hail, fine granular sand or bald eagles down the intakes?

I know, I know. I'm ignorant and need to get onboard with technology but I've had enough engines quit on me that I'm skeptical.

 

[PhrogLoop]

Why still have a canopy bow?

That's where the pilot puts his hands so HAL9000 can take care of business.

 

[Beans]

It looks like the strip of det cord going around the edge of the rest of the aft section of the canopy follows the aft edge that faux canopy rail. My guess is it's to hold the forward section in place, and to hold the rear-view mirrors in place. I want to emphasize that it's a complete guess.

 

[Banjo33]

Harrier has a canopy bow...canopy doesn't separate from a/c during ejection, instead it shatters. Can't eject on the ground with canopy open...well you can, but you're going to leave your legs in the jet.

I imagine the bow is there to provide structural integrity. Looks like a bulbous canopy anyway, at high airspeeds (Mach 1+) there's probably a lot of pressure on the canopy right there at the bow. IIRC, the JSF canopy stays attached during ejection too...don't want it going down the lift fan in a hover/slow flight with the fan doors open.

I imagine a/c with canopies that separate completely rely on forward airspeeds to help separate the canopy so the pilot doesn't pull a Goose. In an a/c that may have very little or no forward speed, it would take too much propellant and/or time to generate that separation.

 

[Flash]

Can't answer that, but it's not a conventional bow that separates and serves as mount for pieces of plexiglas as in a conventional configuration; it's internal (vvvv) to single piece of plexiglas. I can get you an answer next week though.

That is exactly why I am curious it is there. Looking forward to the answer!

I imagine the bow is there to provide structural integrity. Looks like a bulbous canopy anyway, at high airspeeds (Mach 1+) there's probably a lot of pressure on the canopy right there at the bow.

That is what my History major trained mind thinks but the F-22 doesn't have one and the one on the F-16 has the box/rail all the way behind the pilot and largely out of FOV, hence the curiosity.

 

[Pags]

I know, I know. I'm ignorant and need to get onboard with technology but I've had enough engines quit on me that I'm skeptical.

It also has the benefit of not being originally designed as a one way cruise missile motor.

 

[mmx1]

It also has the benefit of not being originally designed as a one way cruise missile motor.

Which one is that, the motor in the A-6?

 

[SynixMan]

Which one is that, the motor in the A-6?

http://en.wikipedia.org/wiki/AGM-28_Hound_Dog

 

[vick]

It has an amzing clutch that connects the lift fan to the engine.

A group of Harrier guys were picking the brains of a group of JSF engineers are few years ago when they were socializing the lift fan design. What happens when the clutch fails, we asked? They assured us that it was designed to be fail-proof. Since complexity tends to be the natural enemy of reliability we again asked - so, really, what happens when it fails? They again insisted it couldn't fail. We just gave them the stink eye for a minute and then one of them piped up with - "Well there is an auto-eject mode on the seat that is only triggered in the event of lift fan or clutch failure". Seems that if the lift fan were to fail or the clutch were to give out, the subsequent pitch rate would be impossible to beat with a manual ejection. So in that scenario, HAL takes care of business for you. At least that was the selling point, no idea if that design feature is still incorporated.

 

[JustAGuy]

They assured us that it was designed to be fail-proof.

Just like when asked, "So what happens when your engine fails?"

They assured us that it was designed to be fail-proof.

So, every flight is a single engine emergency?

Ok, right, gotcha. And go ahead on not put an internal gun in the thing as well while you are at it. Oh wait, they didn't.

 

[HeyJoe]

...go ahead on not put an internal gun in the thing as well while you are at it. Oh wait, they didn't.

Yes and no. Depends on variant. And for the ones they didn't, the decision was made well before OEF* so notion that fast movers would be called upon to strafe was considered ludicrous and notion that external stores would be carried was also scoffed at, but..........I was walking into Pentagon recently and saw an old friend who works for LMCO heading in same direction with a large box. As we chatted, he opened the lid and said it was first F-35 model delivered to building that had the full monty of external stores mounted on it.

*Backdrop: I went to very first meetings associated with JAST while still in uniform as the Navy AAM rep. It was all about first survivability across the beach in a double digit SAM threat environment. After retiring, I worked in Weapons Integration systems engineering mainly in AIM-9X arena, but also played in JSF quite a bit in their CONOPS development and in the novel NGC developed Sensor integration scheme. it was hard to get their minds off gearing for the big one just like the F-22 crowd who I also worked with. It was like the Cold War legacy Fulda Gap was so pervasive that they wouldn't or couldn't consider anything else even after we continued to get involved in skirmishes or protracted campaigns like Bosnia/Kosovo. By the time of 9/11, they had put JSF on the path it's on today. Oh well, so it goes as Kurt Vonnegut was wont to say.

 

[Pags]

Yes and no. Depends on variant. And for the ones they didn't, the decision was made well before OEF* so notion that fast movers would be called upon to strafe was considered ludicrous and notion that external stores would be carried was also scoffed at, but..

I remember hearing that when Lockheed game and gave us a brief when I was in grad school. As a lowly Ensign I asked "haven't we learned this was a bad idea before with the F-4?" "Well, the missiles are so much better now and no one is going to dogfight ever again." "Wasn't that the same rationale they used for the F-4 that turned out to be pretty wrong?"

 

[Pags]

Which one is that, the motor in the A-6?

http://en.wikipedia.org/wiki/AGM-28_Hound_Dog

What synix said. The J52 was orginally designed for Hound Dog.

 

[HeyJoe]

I remember hearing that when Lockheed game and gave us a brief when I was in grad school. As a lowly Ensign I asked "haven't we learned this was a bad idea before with the F-4?" "Well, the missiles are so much better now and no one is going to dogfight ever again." "Wasn't that the same rationale they used for the F-4 that turned out to be pretty wrong?"

Precisely. The F-22 cadre were telling everyone the era of the dogfight was over and nobody would ever "go to the merge" again. However, it just hasn't worked out that way since beginning of aerial engagements. In fact, I was in a Flag/General Officer meeting in 1993 timeframe in which Program Manager (SPO Director in USAF-speak) boasted that F-22 was so effective in medium range environment that they were considering dropping AIM-9 capability altogether after already reducing internal loadout from 4 to 2. However, he was at a loss for words when a sharp O-5 asked why it needed to be so maneuverable then or need a...drum roll...a gun.

Note: The developers and specifically the engineers that delve into aircraft versus aircraft like to model engagements as if they were two knights jousting. Problem is there aren't always adversaries willing to joust using our ruleset.