FoxHunter From United States of America, joined Dec 2001, 59 posts, RR: 0 Reply 1, posted (9 years 4 months 3 weeks 1 day 21 hours ago) and read 4714 times:
Most airlines had the Flap 40 position blocked off so it could not be used. Using it burns too much fuel, plus you make a lot more noise. I did fly 72s that did no block it off and when 40 was selected it felt like you deployed a drag chute.
Vref for any 727 is 1/2 the gross weight over 100,000 lbs +7kts flaps 30. Example 130,000 lbs ldg wt= 1/2 X 30=15+7=22, so Vref is 122 kts.
Normal landing flaps for the DC8 was Flaps 50. I do believe that may have changed with some of the Hush Kits but the normal landing flap was always 50.