def get_accategories(soup):
    
    """
    Gets aircraft category labels from <strong> elements within <p> tags 
    
    Returns list of categories
    
    """
    # ptags are parent of <strong> labels and <ol> and <li> items
    p_tags = soup.find_all(name = 'p')

    # <strong> labels include aircraft category names
    strong_labels = [strong.find_all('strong') for strong in p_tags]

    # loop to grab and strip <strong> labels
    ac_labels = []
    for label in strong_labels:
        for l in label:
            ac_labels.append(l.text.strip())

    # labels are index [1:] -- see below

    # ['Welcome',
    #  'Vectored Thrust',
    #  'Hover Bikes/Personal Flying Devices',
    #  'Lift + Cruise',
    #  'Wingless (Multicopter)',
    #  'Electric Rotorcraft']

    return ac_labels[1:]