737 Classic Maneouvre speeds after RSEP mods installed.

[Centaurus]

Regarding block speeds in 737 Classics. Is it correct to say that once all required rudder system modifications (RSEPand RPR) are completed the manoeuvre speeds (below 53 tonnes) go back to the old numbers of 170 knots for flap 5 and 160 knots for flap 10?

It is such a long time ago since the two fatal accidents attributed to uncommanded rudder movement took place and I was wondering if the flap 5 and 170 knots and flap 10 with 160 knots were the original numbers used before the accidents? I understand some operators have decided to stay with the revised speeds (Flap 5 and 180 knots and Flap 10 with 170 knots) even after all mods installed. Any idea why?

[alexban]

The system is redesigned now with the introduction of the RSEP modification.
Indeed, as specified in the FCTM the speeds after RSEP modification are F5-170, F10-160 , as were before deciding to increase them as a result of uncommanded rudder case analisys.
We tend to use F5-180 and F10-160 ,due to ATC requirement to keep 160 kt to 4 NM.

[BOAC]

I think those companies are looking at 'KISS', and while we are in the middle of mod incorporation across fleets it is obviously safer to stick with one set. I have not, however, seen anything from Boeing about reverting to 'old' speeds. Maybe CaptainSandL knows?

[CaptainSandL]

Hi Centaurus,

It is correct to say that on the 737-3/4/500 after all rudder mods, ie RSEP installed, you go back to Flap 5 – 170kts, Flap 10 – 160kts (Weights below 53,070kg). Ref FCTM Chapter 1, General Information - Flap Manoeuvring Speeds, Oct 31 2007.

What may be misleading is the current* FCOM Bulletin TBCN-11 (This is the generic Boeing number, it may be different in your airlines FCOM). Subject “Manoeuvring Speeds for 737-100/200/300/400/500 Dated Dec 3 1999. This shows two tables for the 737-3/4/500. The first, with RPR installed, is Flap 5 – 180, Flap 10 – 170. The second, with RR deactivated or not installed, is Flap 5 – 190, Flap 10 – 170.
*This bulletin should be removed from your FCOM when your fleet has completed the RSEP program and you can then go back to the speeds quoted in the FCOM above.

As BOAC says, if you still have a fleet with a mixed RSEP status, it is only sensible to remain with the old speeds until the mods are complete.

Regards

S&L

[Centaurus]

CaptainSandl. Thanks.