In the question What makes 21st century fairings so valuable that they'd potentially be recovered and re-used? I said:
21st century fairings are much more than passive rooftop boxes to "keep the wind off of the customer's stuff."
In the discussion in comments below this answer, the criteria for a safe altitude for fairing ejection was discussed. I did a quick check of five SpaceX webcast videos and their corresponding press kits, and found that the five fairing deployments were tightly clustered around an altitude of about 110 km, independent of (ground) speed or time after secondary engine start.
I've included an estimate of the target inclination. With that and the latitude at deployment, the actual air speed could be estimated, but I'm really looking only for rough ballpark numbers.
**** SpaceX - data estimated from telemetry in webcasts and press kits **** MISSION ground speed altitude post 2nd stage inclination m/s km/hr km ignition (sec) deg (estim.) ------- ------------ ---- -------------- ------------ ORBCOMM-2 1571 5657 111 13 45 THAICOM-8 2536 9131 111 51 ~0 Eutelsat/ABS 2517 9061 111 47 ~0 JCSAT-16 2459 8852 110 48 ~0 Iridium-1 2034 7322 107 40 86 Echostar XXIII 2847 10248 114 38 ~0
The atmosphere is quite rarified at 110 km, I estimate about 2E-06 of sea level using exp(-110 km/H) with a scale height $H$ of 8.4 km.
Satellites are built to endure huge g-forces during launch, but those forces on each component are proportional to the mass of the component. So any given section of all that light weight (kapton or mylar?) film wrapping the satellite may not experience a very large g-force in terms of Newtons, but once the fairing deploys, some surfaces will be exposed to very low pressure but very high velocity winds.
In addition to the force of the wind (momentum transfer) there is also energy transfer, and that will scale faster with velocity than the momentum transfer. So even if the bulk mechanical forces turn out to be low, there can be local drag-induced heating, and things that conduct heat poorly (like thin polymer films for example) could develop hot spots.
Further, considering that 110 km is between the E and F layers of the ionosphere, there will be a substantial electron and ion wind, which might also cause trouble.
Question: How strong and "hot" is the wind on the payload after the fairing is deployed at ~110km?
above: Photo from Spaceflight Insider's Sierra Nevada delivers final 11 ORMCOMM OG2 satellites for launch.