Huey max altitude

[Sheriff BurneR]

This is what i discover last night... 27800ft in Huey really? :megalol: Its not Airwolf :D

 

 

 

Edited January 9, 2020 by Sheriff BurneR

[BIGNEWY]

Maximum spawn height in the editor is 16404, did you use a script to spawn at that height?

 

Do you have a track replay?

 

thanks

[Sheriff BurneR]

Maximum spawn height in the editor is 16404, did you use a script to spawn at that height?

 

Do you have a track replay?

 

thanks

 

 

TacView? Yea i have it ... no scripts. I take off from the ground to this altitude on the online server.

Edited January 9, 2020 by Sheriff BurneR

[Ramsay]

This is what i discover last night... 27800ft in Huey really? :megalol: Its not Airwolf :D

 

Higher altitudes (thinner air) require increased collective but the increased blade pitch doesn't have the increased drag it should in DCS, so the main rotor has more lift/power available than IRL i.e. at SL - exceeding max GTW will stall the rotor; while at 6,000 ft the helicopter can lift off provided it doesn't exceed max EGT.

 

AFAIK BST/ED are reworking the engine model and rotor dynamics ATM, but it's taking longer than was initially planned due to issues such as you've discovered and the need to rebuild certain aspects of the flight model.

 

https://forums.eagle.ru/showthread.php?t=205247

 

We'll have to wait until the rework is complete, to see how it compares to the real UH-1H's tables.

Edited January 10, 2020 by Ramsay

[S. Low]

Since the last official word on the huey rework was so long ago, perhaps bignewy could do us a solid and provide an update :D

[Jester986]

"The highest altitude reached was 35,150 feet, without a payload."-New York time Dec 27, 1964 in a UH-1D which has the -11 engine in it that is weaker than our -13

 

https://www.nytimes.com/1964/12/27/archives/army-claims-11-speed-and-altitude-records-for-uh1d-helicopter.html

[Ramsay]

"The highest altitude reached was 35,150 feet, without a payload."-New York time Dec 27, 1964 in a UH-1D which has the -11 engine in it that is weaker than our -13

 

It's not possible to get into the specifics without details of GTW, Temps, Pressures, etc. but for example the base weight of the D/H as documented in 1964 was 5,144 lbs.

 

The DCS UH-1H is 6,047 lbs (likely due to different equipment specs., etc.)

 

The UH-1H SAC in FM 101-20 from 1981 gives a Service ceiling (100 ft/min) at Normal Power i.e. max EGT 615°C, of 24,210 ft for a combat weight of 6,164 lbs i.e. equivalent to a slick DCS Huey with 100lbs of fuel remaining.

 

While DCS's Huey can increase it's power i.e. use Mil Power (EGT 625°C max 30 min), expecting a 35,000 ft ceiling would IMHO seem unrealistic.

 

For info. Lycoming T53-L-13 at 30,000 ft (Standard Day)

• Mil Power = 600 HP / 27 PSI TQ

• Normal Power = 525 HP / 25 PSI TQ

 

1964 Normal Power Climb Chart for Clean Config = 5000 lbs

• approx. 952 ft/min @ 28,000 ft

 

So it looks like the record breaking 1964 High Altitude flight was taken using a very light airframe

Edited January 16, 2020 by Ramsay
Add detail on Engine Power and TQ available

[Jester986]

My point wasn't to say that our Huey should go up to 35k but show that the altitude reached by the OP wasn't completely absurd. Helicopters will frequently out fly their performance charts. Should you? No, but helicopter aerodynamics are so complex I think its unreasonable how people take DCS helicopters to the edge and past the envelope and complain about flight models. If it behaves right when you fly it within limitations I'd say were doing pretty good. In this case though its possible that the real aircraft could actually do what the complaint is about.

[Gunnars Driver]

It should not be very difficult to make a helo fly according to the charts in DCS. But it is time consuming to test and alter all parameters to make it fit the performance data. You also need a deeper understanding about helicopter aerodynamics and how Density Altitude affects the rotor system( lift drag etc) an how it affects a turbine engine. In most cases the limiting factor is not the same in different altitudes and temperatures.

 

Havent really flown the Huey that much lately, but earlier the EGT was limiting at low altitude and cold weather. That isnt the real behaviour.

Also, the NF/NR drooped way to early, not possible to reach the normal torque on the torquemeter.

 

Still, the performance was not that bad despite the engine performing very poor on the instruments.

 

There was another thead about the Huey not flying straight. After a test I found it to fly properly but there is something wrong with the ball, it does not center when flying straight and level, it also behaves strange during banking. I think the coding parameters do not take the right data into count.

[DeTesla]

Yesterday i reached an altitude of 26,000 feet.

Calm weather, calm wind, temp above 10k was -10C and dropping.

According to the official Flight Characteristic charts, a huey utility helicopter have a max altitude of 14k feet, 10k without oxygen masks.

*Shrug*

 

Video of the accurance

Edited January 9, 2021 by DeTesla