How common are conformal fuel tanks?

geoffc
  • How common are conformal fuel tanks? geoffc

    I know that the F-16 (F-16I and Block 50/52/60 models) have conformal fuel tanks standard now on top of the wing/fuselage area. The Silent Eagle model of the F-15E proposed by Boeing for South Korea, and other F-15E customers had them added. The F-18E (Superhornet) has demoed a set recently.

    But on older aircraft, how common were conformal fuel tanks? Or have they always been drop tanks before?

  • Technically speaking, CFTs don't take up hardpoints, so I'm not sure what we have today has an equivalent in older designs.

    Otherwise, I'd say somewhat common; streamlined fuel tanks and other conformal packages have been used for quite a while in several different designs.

    The F-15E Strike Eagle you mention actually has a set permanently attached to the outer surface of the engine nacelles, which might fall under the 'older aircraft' category at this point.

    Some World War II Supermarine Spitfires used what was called a "slipper tank" - a streamlined package of up to 90 gallons (additional source).

    The early 1960s-era English Electric Lightning used a 'conformal ventral store' that could hold either a fuel tank or rocket engine (?!). The Gloster Javelin used a similar set of "bosom tanks".

Related questions and answers
  • I know that the F-16 (F-16I and Block 50/52/60 models) have conformal fuel tanks standard now on top of the wing/fuselage area. The Silent Eagle model of the F-15E proposed by Boeing for South Korea, and other F-15E customers had them added. The F-18E (Superhornet) has demoed a set recently. But on older aircraft, how common were conformal fuel tanks? Or have they always been drop tanks before?

  • Common solutions for aerobatic piston singles is to have either header tanks (for wing tanks, as I understand it) or flop tubes (for fuselage tanks). Do fuel systems in a fighter jet work on the same principles? Or are they somehow smarter to allow more erratic maneuvers?

  • Watching the first episode of Dangerous Flights, a ferry pilot has aftermarket fuel tanks fitted inside the cabin of an old Merlin IIB: What are the regulatory requirements to be able to do this? / How can you get permission to fit extra tanks inside a plane? Is there anything that needs to be specially considered when designing the tanks and valves etc? Is this commonplace when ferry flying long-haul?

  • I've been taught to always sump the plane's fuel system before going flying to check for water / contamination / proper fuel grade. However, I've yet to go flying in rain. What's the proper procedure to drain fuel during rain? If I took the fuel cap off to dump the fuel back into the plane, I'd be worried about rainwater getting in the tanks.

  • anymore. There was a passenger in the back seat, fuel tanks only half full so the CG was more aft than usual, but well within limits Ever since that flight I've wondered: What could cause this to happen? (My guess is it is CG related) And most importantly: If I would have continued this "mushing" flight, would it be possible to have entered a flat spin or a simple "drop out of the sky

  • We know that most of the plane accidents and deaths result from the explosion of fuel tanks in the planes, like when two planes collide, or when the plane falls on the ground. With the advent of technology, i wonder whether it is possible to prevent the fuel explosion. Can this be done by evaporating the fuel in the planes just before the collision? Or use a solid architecture encapsulating the fuel tanks in the planes, such that the fuel is not set to fire? What research has been done in this field and if so what were the findings?

  • It seems to me that takeoff weight is an important piece of data, and if one had weighing scales between the wheels and the aircraft body, one could precisely determine it. However, searching the internet, there seem to be no scales and cargo/fuel/passenger weight is estimated by adding up what is brought on board. Why aren't scales common? And are there any commercial airplanes that have them?

  • I mean, on the one hand it seems kind of obvious, if you had a fuel tank that was mostly water then you would lack combustible materials for the engine, but I get the impression that having any water in the fuel tank at all is considered a really bad idea. Why is that? Is it all right to have a very small amount of water in the fuel tanks? Is there a defined percentage of liquid in the fuel tank that must be fuel in order to operate safely? (say 99.87% or something?) And does this differ from prop to turboprop to turbofan to jet?

  • To most non-U.S. pilots who have little or no experience flying in the U.S., the concept of a FBO is not very well understood. What exactly is a FBO and what are the services that it can provide...? I've also seen many airports with multiple FBOs. How does that work? All I know is that FBO stands for "Fixed Base Operator". This may seem like a very stupid question but in Europe there's no such thing. If you need fuel you either taxi to the pump and fill up or call up the fuel provider (if you're lucky because they usually only serve private jets).

  • Inspired by a discussion in chat. Most GA piston singles are powered by either Lycoming or Continental engines. The engine designs used by both manufacturers are broadly similar (4-cycle, horizontally-opposed, gasoline-powered, air-cooled), and they're both generally available with either carburetors or fuel injection, but I know they're not "identical products". What are some of the differences between the designs used by the two manufacturers, and what practical implications do those choices have for pilots?

Data information