Tanker aircraft can use one or both of two refuelling systems:

  • Flying boom: A rigid boom is lowered from the tanker and inserted into a receptacle on the roof of the recipient aircraft.
  • Probe\drogue: A flexible hose with a (usually) canvas cone on the end is unreeled from the tanker, and the recipient aircraft flies a forward-pointing probe into the center of the cone.

Aircraft can have multiple drogue units...

A Handley Page Victor tanker trailing its three refuelling hoses

...but are limited to a single boom.

A Boeing KC-135 tanker showing off its single boom

What prevents a tanker aircraft from having two or more booms?

  • $\begingroup$ Which plane is it in the first image? $\endgroup$ Commented May 20, 2018 at 3:41
  • 1
    $\begingroup$ @HarshilSharma Victor tanker. $\endgroup$
    – Coxy
    Commented May 20, 2018 at 5:01

1 Answer 1


There are several reasons why it is hard to support multiple booms on a single tanker:

1) Booms need an operator who is located in the fuselage. Video systems provide for remote control on newer tankers, but older ones still use direct view or looking straight down the boom at the refueling point in the receiving aircraft.

2) The boom is physically large. Its weight, large diameter and telescoping tube length would be difficult to install on a wing.

3) A wing bounces around a lot more than the fuselage does. Since the boom is rigid, this complicates keeping a good connection.

4) The high flow rate of a boom is only useful for larger aircraft like bombers, which are too big for simultaneous refueling. This somewhat reduces the advantage of having multiple refueling points.

Probe and drogue has a lower flow rate through a lighter, narrower hose. It is passive from the tankers point of view, and it is flexible.

  • 2
    $\begingroup$ The Airbus A330 MRTT has had a remote control only boom in service for several years now, no need to wait for the KC-46. $\endgroup$
    – Moo
    Commented May 20, 2018 at 4:44
  • 1
    $\begingroup$ Good catch. It looks like Airbus has also had some success demonstrating automatic receiver contact with the boom. $\endgroup$
    – Pilothead
    Commented May 20, 2018 at 5:25
  • 1
    $\begingroup$ The KDC-10 and KC-767 also use remote controlled booms. $\endgroup$
    – fooot
    Commented May 28, 2018 at 17:41

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