24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force 24th anniversary of the 60th helicopter airbase of the Bulgarian Air Force