Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Procedure; Environment - Non Weather Related
I've had four Flaps 1 departures in the last four days; which is cool; because I get why we are doing it. It provides less engine stress because if you have adequate runway; it reduces your takeoff power significantly; BUT it also causes a significantly longer takeoff run. So; every takeoff in the last three days we hit the proceeding aircraft wake turbulence around 400 feet; and continued to stay in that wake turbulence till one of us made a turn away. B737; Airbus...etc wake can be quite disturbing but manageable; but if that happened behind a heavy; that might be more than disturbing.So; in the past; where a normal flaps 5 departure; we were probably all rotating at similar points; and the 737 was climbing maybe even above someone's low level wake; now; at flaps one; we're rotating most likely PAST previous aircraft rotation point and hitting their departure wake; fairly consistently; when it is at its strongest; low level; low speed; and heavy.Without any condescension at all; I'm guessing nobody thought about how a longer takeoff roll might impact initial rotation and climb into wake turbulence at high volume departure airports. Since the new performance software seems to lean in the direction of Flaps 1; if there's an available runway; this might increase controllability issues or worse on a more frequent basis.Flight dynamics; TERPS criteria and engine performance are not my expertise. I don't have a solution. I really like the new software. Maybe suggest that in high traffic airports; when there are multiple close in departures in affect; where low level wake turbulence could be a concern; the crew use their judgment to possibly run Flaps 5 data; and if permissible; run change triangles prior to departure? Only thing I can think of.
B737 First Officer expressed concern about using Flap 1 takeoff procedures; because with the longer takeoff roll a wake turbulence encounter is more likely.