FOOKE enables efficient and sustainable aviation

Replace chemical milling on parts machined to residual wall thickness with new turnkey solution from FOOKE.

Outer skin processing in aviation

In aerospace 

weight is crucial 

Every gram saved helps to reduce fuel consumption, improve aircraft efficiency and ultimately reduce CO2 emissions. That's why fuselage segments for aircraft and missiles, outer shells of turbines and other aluminum sheets are designed in a specific thickness profile according to their structural load. In stressed areas, higher plate thicknesses are used. In areas not subject to high stress, the sheets are reduced to lower residual thicknesses to save weight.
Within a stretch forming process, flat-rolled raw sheets are shaped into spherically curved plates. The subsequent manufacturing of the pockets and thus achievement of the defined residual wall thickness can be realized by various removal technologies.

Typical components machined to residual wall thickness:

  •     Fuselage part segments of airplanes and rockets
  •     Lipskins of turbines
  •     other aluminum sheet parts in aerospace quality

Conventional chemical milling

The previous procedure

A complex but still widely used process, for example, is chemical milling, in which sheets are immersed in chemical baths to obtain the desired thicknesses. While this technology is well controlled and established, it has enormous drawbacks due to the high use of chemicals and the relatively long process time.


  •     Long cycle times
  •     High use of chemicals
  •     Very high environmental impact

FOOKE offers an alternative to reduce environmental impact and shorten cycle times


in milling residual wall thickness

Although many companies aim to reduce environmental impact and shorten cycle times, the mechanical processing of the sheets is highly complex, due to a variety of influencing factors. Since the thickness tolerance and also the specified geometry are decisive for the final result, special attention is already paid during the inspection and processing of the input dimension of the pre-formed sheet. Deviations caused by handling or forming processes, must be reliably detected. Further, a correct clamping technique, the insertion of the sheets into a fixture and the quality of the clamping must be ensured, at all times. With focus on these challenges, FOOKE specially developed a milling method for this application, that does not require the use of massive amounts of chemicals and reduces the processing time to a fraction

Pros and cons


+ Short cycle times                                                                        - Long cycle times

+ State-of-the-art machine technology                                        - High use of chemicals
   reduces energy consumption        

+ Green Technology - Low                                                            - Very high environmental impact
   environmental impact

- Complex in terms of precision                                                      + Well controllable accuracy


compared to reference processes, through highly dynamic linear drive technology, optimum component clamping and intelligent quality control.



Specially designed for mechanical thickness reduction of aircraft skins:

  •     5-axis gantry milling machine
  •     Hardtooling
  •     Component measurement
  •     Compensation calculation
  •     Creation of serial milling process

The pre-shaped sheets are vacuum-fixed in negative contour - so-called hard tooling - and the pockets are machined by a high-speed machine. Not the depth of the pocket is critical here, but the particularly tight tolerance of the residual wall thickness.

The manufacture of large, precise and highly dynamic milling machines has been part of FOOKE's success story for decades. But it is the process of component measurement and compensation, based on various measuring methods, with the associated data processing and visualization, that can be highlighted as FOOKE's decisive core competence.

Ultrasonic probe and FOOKE data processing algorithm for


Various measuring routines and complex data processing algorithms for component correction ensure maximum accuracy. Deviations and e.g. deformations of the clamping device can be reliably detected and compensated. The application includes fully automatic integration of ultrasonic component measurement into the machine control. Temperature influences are also detected and taken into account accordingly in the machining process. Time-consuming adjustments to CNC programs are simply eliminated.

Strict and continuous quality control and documentation meet the extremely high requirements of the aerospace industry.

50% WEIGHT REDUCTION of a 10 x 2 m fuselage by pocket milling with a FOOKE turnkey solution.

This turnkey solution was developed, validated and has been in production at a large, well-known aircraft manufacturer in northern Germany since 2020.


Vacuum clamping system with different clamping zones

  • Increase productivity through optimum component clamping.
  • Reduce set-up times through vacuum clamping system with different clamping zones.
  • Very high accuracies on the component due to clamping device with intelligent quality control.


Component measurement and compensation

by means of ultrasonic probe and FOOKE data processing algorithm

  • Continuous intelligent quality control during measuring and compensating.
  • Sheet thickness measurement by means of ultrasonic probe for high-precision milling.
  • No manipulation of the NC programs.

Mechanical removal - fuselage

Mechanical removal - milling to residual wall thickness

  • Reduce setup times.
  • Very high accuracies and surface quality.
  • Weight optimization through closely toleranced residual wall thicknesses.
  • Energy and resource efficiency through minimum throughput times.


Use our know-how for your process.



Make an appointment for a consultation!

FOOKE has been supporting OEMs and suppliers from the aerospace industry with productive manufacturing processes for over 20 years. Would you like to learn how FOOKE can support your company in the production of fuselage or lipskin components?

Then call us at +49 2861 8009 - 222 or contact us by e-mail

Zwei männliche Kollegen stehen zusammen und schauen sich was auf dem Tablet an.