Leading edge spoilers

[n6346m]

The wings on my L-2B did not have the leading edge spoilers on them as they were apparently left off at the last recover. According to the parts manual page 12 item #49 they are part no. D8046 and I have the drawing to make new ones. My question is exactly where are they placed on the wing leading edge? Also does the B series Taylorcrafts have similar spoilers since they are the same airfoil?

Bob Picard

[3Dreaming]

When you say spoilers on the leading edge I assume you mean a stall strip. If that is the case then the B model does not have them.

[Mark Bowden]

As Tom indicates in today's convention they are called stall strips but spoilers in the parts list. The attached drawing may help. I haven't found where on the airfoil contour they are located. The plan view drawing would imply 0% chord. Typically they are located more towards the root to get the stall started inboard first vs. the outboard wing. In this view the are just inboard of the aileron root rib. Wing wash out can create the same effect.

Mark

[sully]

I haven't found where on the airfoil contour they are located. The plan view drawing would imply 0% chord.

Mark

This drawing maybe

[Mark Bowden]

That would do it.
Notice it is slightly lower than than being exactly centered on the most forward part of the airfoil or 0% chord. The reason is the airflow stagnation point is on the lower side of the leading edge at higher angles of attack.

[n6346m]

When you say spoilers on the leading edge I assume you mean a stall strip. If that is the case then the B model does not have them.

According to the parts manual they are used on all the the L-2 models. Am I missing something or misreading the parts list?

[n6346m]

Thank you everyone for your help/input. As mentioned in one of your comments, it seems strange to have "stall strips" way out there.
Bob Picard

[Mark Bowden]

I would guess and it's only a guess, is that it is just inboard of the aileron to act like a stall fence to maintain aileron effectiveness as long as possible through out the stall as it moves from root to tip.

In this case of it being located more "outboard" it creates and behaves more like vortex generator and keeps flow energized and attached in the rib bay just inboard of the aileron.

Again, a guess at intent without flight test or wind tunnel data. Given it is not on the B-models, effectiveness was perhaps was not so good. However, with the intent of the L2 to be low and slow nearly all the time the little bit it did was valued. Where the B model typically was used in "high speed cruise at high altitude" it wasn't worth the expense and never used.

[n6346m]

Mark,
You and 3Dreaming both state that these are not used on the B model. Am I missing something because the parts list shows them to be on all models and both the metal and wood wing assembly drawings clearly show them as being installed.

Bob

[3Dreaming]

Mark,
You and 3Dreaming both state that these are not used on the B model. Am I missing something because the parts list shows them to be on all models and both the metal and wood wing assembly drawings clearly show them as being installed.

Bob

What parts list? I have never seen one installed on a B model. I have never seen a picture of one installed on a B model, and I have looked at a lot of old period photos. I have seen one installed on a clip wing Taylorcraft.

[n6346m]

3Dreaming,
My reference source is the US Army parts manual (Tech Order 01-135DA-4 dated May 1, 1944). The lack of a number and asterisk preceding the part number indicates that the part is used on all models and serial numbers of the US Army L-2, L-2A and L-2B, referred to by the FAA as the DC-65 and DCO-65.
Bob Picard

[n6346m]

3Dreaming and Mark.
My apologies for being confused about your responses. In my original post I asked if they were used on the B series aircraft meaning BC, Bl, and BF and you answered correctly. When you said they were not used on the B model I mistakenly thought you meant the B model L-2.

[Dick Smith]

Bob, I wonder if you called the Alaska Aviation Museum at Lake Hood...and asked if they had the strips attached to their Taylorcraft L-2 display.

[n6346m]

Dick,
Dick Benner sent me a picture of the museum's L-2 and the spoilers (stall strips) are on there. However, it's one of the other two L-2s that are in Alaska and they are both M models.

[Edwin Otha]

The stall strips will give you an indication in the stick for the impending stall. Without the strips, the plane will just mush without stalling unless you whip stall it. We had them on all of the L2 trainers.

EO