The Jaguar has a rather unusual feature in some of its variants, overwing pylons for missiles to free up points under the wings for heavier bomb or missile loads.
Although it looks extremely odd I was wondering why more manufacturers didn’t give the idea a try?
They’re mentioned in the wikipedia article but no further explanation is given
Thanks!
It would be harder to install the missiles on an overwing pylon than an underwing pylon for obvious reasons, and the pylons are less useful for the same amount of weight/drag since you can only mount certain types of weapons. It looks like it’s considered a choice of last resort - only used when you have a shortage of underwing space due to landing gear or tank arrangements.
I’d imagine Grumman got it in one - from a weapon loader’s point of view, overwing pylons must be a real pain. Another thing that comes to mind is that the stores on those hardpoints would be more difficult to jettison in an emergency.
Most missiles drop, then fire…as opposed to firing from the rail.
Bombs and wing tanks would be equally troublesome for the same reason. Gravity is not your friend when your wing is under whatever you’re trying to drop.
Let’s not forget we’re trying to maintain laminar airflow over the wing to get efficient lift. Pylons on top can only spoil that effort.
Interestingly, Honda is producing the HondaJet…a small, twin-engine jet that has its engine pods mounted on the tops of the wings. Putting engines up there makes at least a little sense; keeping the engines as far from the ground as possible reduces the chances of foreign object damage, and is also a bit safer for ground crews. However, it also makes maintenance that much harder (and risky). A dropped wrench while working on a Citation results in a loud clank as the wrench hits the floor. Do the same while working above the wing…sharp-bottomed dents are a no-no in aviation. It also makes it difficult for routine pre-flight checks.
Basically, there’s no good reason to put anything above the wing.
Plus, stuff on top of the wings may inhibit the pilot’s field of vision more than stuff underneath them. And his vision might get affected more by the firing of a missile.
The HondaJet’s engines are pretty much in the same place relative to the wing (and the fuselage) as in other small bizjets, really. The reason for having the pylons come down to the wing instead of over to the fuselage has to do with cabin size relative to fuselage size - you can put useful interior room in the space where there’d be a carry-through structure otherwise, while keeping weight down. The pylons come down from the sides of the engine, not the center, so they align with the landing gear mounts, limiting the amount of heavy structure required in the wing.
All of the pictures in the article show underwing missiles, tanks, etc., don’t they?
Here is what you’re looking for.
Nice pic, I always thought the Jaguar was a good-looking plane myself.
Thanks for the answers everyone!
Well, there was the YC-14, which mounted the engines above and ahead of the wing. The engine blast gave some airflow over the wing even standing still.
The YC-14 only got as far as two prototypes, but there was a similar Russian design that entered production.
I think the STOL Russian jet you’re talking about is the An-72. The unusual configuration allowed the jet exhaust to directly blow on the flaps. Coanda effect then helped direct some of that exhaust downwards. It resulted in an airplane with 5000 kg payload and 350-400 kt cruise to still be able to take off in 450m. Useful, when you think about the lack of infrastructure in Russia.
That’s the one. There was also a research program where NASA put new wings on a deHavilland Buffalo, that one with four engines.
The design is called Upper Surface Blowing (USB). It helps with short takeoff or landing performance. Not sure how much of the benefit is from the Coandă effect and how much is high-speed airflow over the wing.
