An original Douglas C-47, also known colloquially as "Rosinenbomber" (German for "raisin bomber") and used during the Berlin Airlift, stands on the tarmac during a celebration to mark the 70th anniversary of the Berlin Airlift at the U.S. Army's airfield in Wiesbaden, Germany, June 10, 2019. REUTERS/Ralph Orlowski

An original Douglas C-47, also known colloquially as "Rosinenbomber" (German for "raisin bomber") and used during the Berlin Airlift, stands on the tarmac during a celebration to mark the 70th anniversary of the Berlin Airlift at the U.S. Army's airfield in Wiesbaden, Germany, June 10, 2019. REUTERS/Ralph Orlowski

An original Douglas C-47, also known colloquially as "Rosinenbomber" (German for "raisin bomber") and used during the Berlin Airlift, stands on the tarmac during a celebration to mark the 70th anniversary of the Berlin Airlift at the U.S. Army's airfield in Wiesbaden, Germany, June 10, 2019. REUTERS/Ralph Orlowski

An original Douglas C-47, also known colloquially as "Rosinenbomber" (German for "raisin bomber") and used during the Berlin Airlift, stands on the tarmac during a celebration to mark the 70th anniversary of the Berlin Airlift at the U.S. Army's airfield in Wiesbaden, Germany, June 10, 2019. REUTERS/Ralph Orlowski

Original Douglas C-47, also known colloquially as "Rosinenbomber" (German for "raisin bomber") and used during the Berlin Airlift , stand on the tarmac during a celebration to mark the 70th anniversary of the Berlin Airlift at the U.S. Army's airfield in Wiesbaden, Germany, June 10, 2019. REUTERS/Ralph Orlowski

Visitors look at an original Douglas C-54, so called "Rosinenbomber" (German for "Raisin bomber"), used at the Berlin Airlift, during a celebration to mark the 70th anniversary of the airlift at former Tempelhof Airport in Berlin, Germany, May 12, 2019. REUTERS/Hannibal Hanschke

Visitors look at an original Douglas C-54, so called "Rosinenbomber" (German for "Raisin bomber"), used at the Berlin Airlift, during a celebration to mark the 70th anniversary of the airlift at former Tempelhof Airport in Berlin, Germany, May 12, 2019. REUTERS/Hannibal Hanschke

Visitors look at an original Douglas C-54, so called "Rosinenbomber" (German for "Raisin bomber"), used at the Berlin Airlift, during a celebration to mark the 70th anniversary of the airlift at former Tempelhof Airport in Berlin, Germany, May 12, 2019. REUTERS/Hannibal Hanschke

Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, arrives at a ceremony with Berlin's Major Michael Mueller (not pictured) for the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany, May 10, 2019. REUTERS/Annegret Hilse

Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, smiles during a ceremony with Berlin's Major Michael Mueller (not pictured) for the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany, May 10, 2019. REUTERS/Annegret Hilse

Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, smiles during a ceremony with Berlin's Major Michael Mueller (not pictured) for the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany, May 10, 2019. REUTERS/Annegret Hilse

Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, smiles during a ceremony with Berlin's Major Michael Mueller (not pictured) for the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany, May 10, 2019. REUTERS/Annegret Hilse

Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, smiles during a ceremony with Berlin's Major Michael Mueller for the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany, May 10, 2019. REUTERS/Annegret Hilse

Berlin's Major Michael Mueller welcomes Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, during the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany May 10, 2019. REUTERS/Annegret Hilse

Berlin's Major Michael Mueller welcomes Gail Halvorsen, Airlift veteran and Raisin Bomber pilot, during the 70th anniversary of the end of the Berlin Blockade, in Berlin, Germany May 10, 2019. REUTERS/Annegret Hilse

Raisins noisettes chocolates are displayed during the annual news conference of Swiss chocolatier Lindt & Spruengli in Kilchberg, Switzerland March 5, 2019. REUTERS/Arnd Wiegmann

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne TPX IMAGES OF THE DAY

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 22, 2018. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne TPX IMAGES OF THE DAY

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne

Students from St Andrews University are covered in foam as they take part in the traditional 'Raisin Weekend' in the Lower College Lawn, at St Andrews in Scotland, Britain October 23, 2017. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. REUTERS/Russell Cheyne