Forward speed in free fall

[tiger93rsl 5]

Yesterday I retook my AFF 2 for the third time and finally passed perfectly.  After the jump my instructor told my my legs were extended too far during the whole jump even though both instructors gave me a thumps up.  I guess they wanted me to fly forward, I don't know their reasoning but I maintained that body postilion.  After opening I noticed I was over the high school a mile south of the DZ and when I spotted I was directly over the DZ.  

I got on Google maps and calculated the distance and time traveled and calculated my forward speed during the jump at 50 MPH.  Is it possible to achieve this much forward speed during free fall? 

[dudeman17 269]

Another factor not yet mentioned is climbout time. Early level AFF's often take a bit of time to get set up in the door, do the hotel checks, and exit. Early AFF's aren't usually spotting yet, but if you're taking a look, that's ok. But if you're taking your look as you get to the door, then get set up, do your hotel check, count, and exit, you likely covered a bit of ground since your 'spot'.

Sounds like you're at Elsinore?

[skybytch 259]

2 hours ago, tiger93rsl said:

After the jump my instructor told my my legs were extended too far during the whole jump even though both instructors gave me a thumps up.  I guess they wanted me to fly forward, I don't know their reasoning but I maintained that body postilion

If you were stable in freefall, they didn't give you a legs in signal because you were stable. You will get additional training on body position before your next skydive - legs position that does not affect stability is not a priority on a level 2 (Cat B) skydive  Maintaining that body position was the right decision.  

2 hours ago, tiger93rsl said:

I got on Google maps and calculated the distance and time traveled and calculated my forward speed during the jump at 50 MPH.  Is it possible to achieve this much forward speed during free fall? 

Forward speed in freefall is not just a function of body position.  You can leave the plane at the perfect spot, in a perfect body position, hold it for the entire skydive and still find yourself a mile or more away from the dropzone when you open.  Why?  The higher the winds are at various altitudes, the more drift you will have in freefall. |
Think about being under canopy.  Once you turn final, is your forward speed in no wind the same as it is when the winds are at 10? How about downwind instead of into the wind?  The same applies to freefall.

[tiger93rsl 5]

2 hours ago, skybytch said:

If you were stable in freefall, they didn't give you a legs in signal because you were stable. You will get additional training on body position before your next skydive - legs position that does not affect stability is not a priority on a level 2 (Cat B) skydive  Maintaining that body position was the right decision.  

Forward speed in freefall is not just a function of body position.  You can leave the plane at the perfect spot, in a perfect body position, hold it for the entire skydive and still find yourself a mile or more away from the dropzone when you open.  Why?  The higher the winds are at various altitudes, the more drift you will have in freefall. |
Think about being under canopy.  Once you turn final, is your forward speed in no wind the same as it is when the winds are at 10? How about downwind instead of into the wind?  The same applies to freefall.

Thanks for the reply,  that's interesting I did not know when I was getting leg signals it was to help with my stability.  I got in 10 minutes of tunnel time before this jump.  As a result this was my first jump where I felt comfortable and got nothing but thumbs up signals from my instructors.  I forgot to mention the winds aloft were a steady 3 knots all the way up to altitude. 

[tiger93rsl 5]

Now that makes perfect sense I remember we were south bound on exit and I did seem too drift a little longer than I have on my past exits. 

[teri drao 2]

On October 5, 2012, the Swiss Marc Hauser set a first world record in speed tracking, a discipline he founded.^[2] The measured ground speed was 188.9 mph (304 km/h) over the dropzone of Skydive Empuriabrava, Spain.^[3] Only a specially adapted skydiving suit was used (no wingsuit, tracking suit, nor additional weights were used).^[4]

Safety[edit]

Even though inexperienced jumpers often take part on tracking dives, the risks of such dives should not be underestimated. An efficient track can reach horizontal speeds of nearly 100 mph (one experienced diver was witnessed to keep pace with a twin-engine plane as it took off from DeLand Municipal Airport in 1995 thus registering his speed in excess of 115mph). Collisions with other groups or with members of one's own group would result in serious injury or death. For this reason the number of inexperienced jumpers on a tracking dive should be limited by the organizer.

[20kN 93]

No, you're not going to achieve 50 MPH horizontal speed. The only way you can get that in freefall is with a wingsuit. Know that when you exit the plane, you're still moving in the direction of the plane horizontally for some time. It's not like you get out and you're immediately going straight down. You continue to fly in the direction the plane was traveling until that horizontal speed energy dissipates. In addition, the wind will move you horizontally while in freefall. This is called drift and it's the primary reason why exit order and exit separation exist. The wind will carry you in a certain direction for your entire time in freefall, so you're never moving truly straight down unless there is no wind. Between all these factors, it is completely reasonable that by the time you are under canopy, you're not over the same spot over the ground than when you were when you spotted.

Edited August 5, 2019 by 20kN

[gowlerk 1,904]

A 60 second freefall on a day when the upper winds are strong can easily move you that far. It's called freefall drift. Your instructors should be teaching you spotting skills, but they are often neglected at larger turbine DZs where the pilot basically does all the spotting using GPS.