#envoyair

N255NN, one of Envoy’s E175s flying as American Eagle, heads out for departure at DFW. ⁣ ⁣ As Embraer was finalizing the details on the E2 family of E-Jets in 2013, they also realized the existing E-Jet family was still very popular and would benefit from modest upgrades aimed an increasing fuel efficiency. ⁣ ⁣ Part of that upgrade involved two sets of fuel-burn improvement packages. The first one (called Package 1) was set of aerodynamic clean up features to reduce drag across the airframe- gap filling seals to close up spots on the tail, revising the rain deflectors above the passenger doors, lower drag wheel fairings, and revised environmental control system inlets, were based on work done for the E190/195 family and retroactively applied to the E175s. ⁣ ⁣ In addition, changes in the operation of the environmental control system and the anti-ice systems reduced engine bleed air demands which in turn improved engine efficiency. ⁣ ⁣ Package 2 also did an aerodynamic clean up around the APU and introduced new lower drag anti-collision beacons, but the most distinctive change were new bigger winglets that were canted out 45 degrees and adds nine feet to the wingspan. The new winglets do increase aerodynamic bending loads on the wing, so localized strengthening of the wing box and skin skins adjacent to the new bigger winglet are necessary. ⁣ ⁣ The biggest benefactor of the new winglets are the E175s which get a 5.5% reduction in fuel burn. The E190 gets a 3.5% improvement in fuel burn and the E195 gets a 4% improvement in fuel burn with the new winglets. ⁣ ⁣ The winglets aren’t retrofitted but are on new build E175s. The new winglets debuted in March 2014, first installed on a United Express E175. I have heard the called “shruglets” and “pterodactyls” but Embraer calls them EWTs- Enhanced Wing Tips”.⁣ ⁣ #Avgeek #aviation #aircraft #planeporn #KDFW #DFW #airport #igTexas #planespotting #airlines #Embraer #E175 #N255NN #AmericanAirlines #AmericanEagle #EnvoyAir #DFWavgeek #instagramaviation #splendid_transport #instaaviation #aviationlovers #aviationphotography #flight #AvGeeksAero #AvgeekSchoolofKnowledge #AvGeekNation (at DFW Airport) https://www.instagram.com/p/B3BWXwRBYcw/?igshid=lmx8et35digd

An Embraer E175 of Envoy/American Eagle, N225NN, heads out for departure at DFW. ⠀ ⠀ Note the engine nozzle chevrons on the GE CF43-8E5 engines. Unlike the 737MAX and 787 that have the engine noise reducing chevrons on the fan cowling, the E175 has them on the hot section nozzle as does the CRJ900 (the 747-8 has them on both the hot section and fan cowling). ⠀ ⠀ Now we’re going to get into a little aeroacoustics here, so take notes. ⠀ ⠀ Jet exhaust noise comes in two forms- turbulent mixing noise and shock noise. Turbulent mixing noise comes from the high speed jet exhaust’s boundary with slower surrounding air creating turbulence and turbulence creates noise. Chevrons on the fan cowling as well as the hot section nozzle speed the mixing of the air which dampens turbulence and lessens noise. ⠀ ⠀ Shock noise, however, comes from the speed of the jet exhaust moving near the speed of sound and it creates shockwaves in the exhaust (the afterburner shock diamonds from high performance jets is a perfect visualization of those shockwaves). Sometimes those shockwaves interact with the turbulent flow and this creates a self-propagating acoustic wave. ⠀ ⠀ This wave we perceive as a high pitched whine and it’s called jet screech. Hot section chevrons like on the CF34 engine here also break the self propagation of the jet screech acoustic wave, dampening high pitched sounds from the jet exhaust. ⠀ ⠀ Got it? There’s gonna be a test next week on this.⠀ ⠀ #Avgeek #aviation #aircraft #planeporn #KDFW #DFW #airport #igTexas #planespotting #airlines #Embraer #E170 #American #AmericanAirlines #AmericanEagle #EnvoyAir #DFWavgeek #instagramaviation #N225NN #splendid_transport #instaaviation #aviationlovers #aviationphotography #flight #aviationphotography #AvgeekSchoolofKnowledge #AvGeeksAero #AvGeekNation (at DFW Airport) https://www.instagram.com/p/B5HId6-BJGa/?igshid=6676jfg1uigf

N851AE, one of Envoy’s ERJ-140s, turns into the ramp at International Terminal D at DFW. ⁣ ⁣ Hot on the heels of the launch of the Bombardier CRJ, Embraer launched its own regional jet in 1989 as well as the EMB-145 which started out as an evolution of the EMB-120 Brasilia turboprop. In fact, the original design of the EMB-145 would have had 75% parts commonality with the EMB-120. The Brasilia’s fuselage was stretched 18 feet and 6500-7000 lb thrust class turbofan engines were installed in overwing nacelles so the new regional jet could still use the Brasilia’s main landing gear. The wing was slightly swept and had winglets. It was thought that an evolution of the Brasilia would speed development and make it attractive to existing EMB-120 operators. ⁣ ⁣ By 1990, wind tunnel tests showed that a new swept wing was needed, but the engines remained in overawing nacelles. Further testing in 1991 refined the wings further but now the engines were moved to conventional underwing nacelles to improve drag. Another design change came in 1992 that moved the engines to the aft fuselage with the EMB-145 acquiring its final design layout. ⁣ ⁣ Further design refinements from 1992 resulted in the redesigned ERJ-145 (though the type certificate says EMB-145) diverging further from the EMB-120 Brasilia design to the point that only the structure of the nose section and cockpit are similar with some parts in the nose section having the same part numbers. ⁣ ⁣ #Avgeek #aviation #aircraft #planeporn #KDFW #DFW #airport #igTexas #planespotting #airlines #Embraer #ERJ140 #N851AE #AmericanAirlines #AmericanEagle #EnvoyAir #DFWavgeek #instagramaviation #splendid_transport #instaaviation #aviationlovers #aviationphotography #flight #AvGeeksAero #AvgeekSchoolofKnowledge #AvGeekNation (at DFW Airport) https://www.instagram.com/p/B2dKOwNBRUh/?igshid=h368o3bx9fcc

Sunsets & Airplanes. Two of my favorite things. #avgeek #envoyair #embraer145 #sunset #ramplife #sunuptosundowner #instagramaviation (at Springfield-Branson National Airport)

Fractals. #embraer145 #envoyair #avgeek #aviationlover #ramplife #prisma (at Springfield-Branson National Airport)

Messing around with Prisma. Thanks @angelrosegoes for showing me this app! #embraer145 #oncomingstorm #prisma #avgeek #envoyair #instagramaviation (at Springfield-Branson National Airport)

Sunset on the flight line. Photo courtesy of @captinlex #americanairlines #envoyair #embraer145 #sunset #ramplife #avgeek (at Springfield-Branson National Airport)

Due to the light holiday schedule, our gates were full this afternoon. A rare site during the day. #embraer145 #americanairlines #envoyair #ramplife #avgeek (at Springfield-Branson National Airport)