Originally Posted by
gipsymagpie
The weather at IAD on 25th was at some periods BKN010 it may just have been weather that prevented the climb. The controllers clearance was the major issue; not clear enough.
I wondered this - but the video gives the date as
22nd Apr, the cloud was above 5000ft all day/night.
Radgirl is correct.
I am both a clinician (anaesthetist) and aviator (CPL/FI).
Anecdotal evidence does not carry any scientific value.
In 12 years of HEMS the only event I recall where asked to fly as low as viably possibly was a patient who had decompression sickness and who needed to be relocated without delay to an appropriate hyperbaric chamber for treatment. I’m not sure how critical each 500ft would be in that instance, but there is
a published paper on it which states “
three patients with the DCI symptoms worsened when the helicopter altitude exceeded 213 m (700 feet)–304 m (1,000 feet) above the ground level.[5] In the remaining three patients, no changes in symptoms were observed when the helicopter remained below 152 m (500 feet) above the ground level.”
Seems odd they use the term altitude ‘above the ground level’, where ground level has nothing to do with it unless relative and flying over a totally flat surface. I interpret they mean altitude.