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-   -   B-727 Tailplane Icing (https://www.pprune.org/tech-log/128968-b-727-tailplane-icing.html)

Mach trim 4th May 2004 10:53

B-727 Tailplane Icing
 
Why does the Boeing 727's tailplane not pick up ice ? As it doesn't have or need anti-ice.

Thanks in advance for the input

mainwheel 4th May 2004 13:24

Interesting question.

What jet does have anti ice on the tailplane.

Only a guess, maybe that there are no significant pressure changes.

Sqwak7700 4th May 2004 13:33

Really?
 
I know of at least one plane that has tailplane ice protection. The EMB-145 I fly is protected by a hot bleed-air routed to the stabilizer leading edge, just like the wing. It is automatically activated by the Ice Detectors and comes on whenever the wing and engines come on.

I always thought that the smaller a surface, the better ice collector it becomes. I believe a good example is the C-5 Galaxy; someone told me it does not have wing ice protection. I walked up to the wing at an airshow, and I saw how big it is, which made sense. By looking at the stab on a 727, it looks pretty small. I know most vertical tails aren't ice protected, but I didn't know that about the 727

threestable 4th May 2004 13:35

The tailplane leading edge is designed to inhibit ice build up. The key is in the radius of the leading edge.It has to be large.
Similar to inboard wing sections on many medium and large transport aircraft.
Cheers...Ts.:ok:

oldebloke 5th May 2004 00:03

The DC8/9 family had tail deicing for the removal of ice at low speeds in the terminal area.The DC8 stipulated that if icing was suspected ,on the tail, then the tail deicing button(when pressed )dedicated all the heat to said surfaces for 3 mins.To be off by the outer markers to avoid run back icing on the grouns(unheated areas).The Douglas products,as opposed to Boeing had smaller size tail(stab) areas-hence the heating req'Boeing had no deicing heat on the tail surfaces (B727/747)as they had suficient area to support the weight.This question was raised ,with the developement of the MD11,and MD elected to stay with the smaller tail surface for lower drag/higher speed..:O

galaxy flyer 5th May 2004 01:23

I can confirm the C-5 doesn't have tailplane anti-ice, or wing anti-ice for that matter. Just the engines and inlet are anti-iced. I've 4-four transition flights in winter New England in ice and not gotten enough ice to chill a bottle of beer. It's hard to get the TAT below 0 degrees and have sufficient moisture to make significant ice.

GF

PW2040 3rd Aug 2004 10:38

Hi guys.

I do not know if it is a joke or not , but we where told in class for the B727 that the tailplane did not need anti-icing feature, because there is so many vibrations in the tailplane that ice will never stick.

See you out there;)

Mach trim 20th Oct 2004 20:17

Aerodynamics ? RJ ?
 
I am looking for a deeper aerodynamical answer, why some airplanes do and others donīt such as the 727 ? It came up again with the RJ since the RJ also doesnīt have Ice Protection on the Horizontal Stabilizer

What about the sweepback on the wings ?

In flight testing they obviously found that they did not pick ice. It is interesting to note that some other jets do have Ice Protection on the horizontal stabilizer.

Thanks for the input as I had an answer but I was not happy with it.

oldebloke 20th Oct 2004 23:40

I quoted this tailplane?stabiler size to carry the ice load as stipulated in articles as written of Boeing versus Douglas.
Boeing did 'sweep' the Wings ,more so than Douglas,to get the faster cruise,but aerofoil icing developes in the Terminal areas and speeds(-250knts)..Above this speed there is quite a ram rise on the leading edges to reduce the threat of heavy ice accretion.
Cheers
:ok:


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