Wheel Well FIRE INDICATOR? It's still NOT required by Part 25. The Douglas Products still do NOT have Wheel Well FIRE Detection (even after NationAir DC8fatal Hull Loss.
After ValueJet, industry went back to the 1947 regulations (the narrow-body's Fwd Cargo and Aft Cargo Compartments must have Detection/Protection). But the ValueJet CHANGES never forced WHEEL WELL Detection for DPD's DC9's, MD8's and DC8s.
What would have been the result, if the following GRND mishap, had instead happened inflight:
NWA / 3Jan98 DC9-51 N-776NC, ground mishap at DTW. Wheel Well fire, electrical wire (three phase) powering Aux Hydraulic Pump overheated after one phase failed. See FAA Incident Rpt 980103002669C, FAA web page.
Here's that PropAir case:
PropAir / 18Jun98 Sweringin Metro II diverted to Mirabel YMX crashed landed approach to Rwy 06-24, left side on fire, incl the engine -- observed by firefighters. Left wing departed with the engine in flames; off the rwy, swampy ditch, overturned. 11 sob killed. CVR recovered; MP mentioned that a/c suffered inflt breakup (wing separation) prior to landing. CBC rpts of 26Sep stated TSB/c said pilot did not know the source of smoke was a fire in the Left MLG Wheel Well [retracted]; hot break, fire, NO INDICATION. Design-annunciation of a/c should show WARNING of fire in wheel well. CBC Rpt 26Oct, final AAR not expected until '99.
Here's that monster fire, pilots crash landed:
USAF / 27Sep74 Lockheed C-5A 68-0227 hull loss: Wheel Well fire, in-flight, uncontained, at night, crashed-landed at grass airport (rwy lights in sight) at Clinton OK. [ Later mod'd LG Wells for fire detection and suppression. Date & ship # from Bill Harms, details merely from memory.]
Here's a B737 case, not wheel/tire really:
Pan Am / 2Apr86 B737 N164AF taxi-out at London LHR, at #1 spot prior to takeoff, following aircraft spotted smoke coming from the B737's Wheel Well area. An electric Hydraulic Pump had shorted, burnt through casing, hydraulic fluid-spray ignited. [Flt Int'l, 24Jan87, pg 39.]
Here's an example a what could occur on any DPD product (eg, an MD8):
Nationair / 11Jul91 Canadian registered DC-8-61 C-GMXQ ... crashed after an inflight fire; impacted 1.75 miles short of runway 34C at Jeddah. Prior to flight, mechanic determined that an inboard tire on Left MLG had low-pressure. To avoid a delay aircraft dispatched without servicing tire. \\ F/O's takeoff, at 50 Kts (15 seconds and 500' of roll) noted sounds of flat tire, followed by sound of second “flat” 2 seconds later. Flames visible in the left main gear until gear was retracted after T/O. \\ Taxi on under-inflated tires caused over-deflection, overheating and structural weakening of the tire. Friction created enough heat to start a self-sustaining fire; two wheels severely damaged, and piece of broken wheel rim struck the airframe (embedded in left flap). When gear retracted after T/O, burning rubber brought near hydraulic and electrical system components. Wheel well fire involved tires, hydraulic fluid, magnesium alloy and jet fuel (fire burned through center fuel tank). Fire spread from Wheel Well to Cargo Compartment, cabin floor was breached, control systems disabled. Cabin pressurization lost, hydraulic pressure lost. \\ Five minutes after brake release for T/O, F/A entered cockpit and reported, "smoke in the back, real bad." While at 2000' on downwind leg, SSW of field, CVR recorded F/O's comment, "I've got no ailerons!" Crew told ATC there was fire onboard, declared an emergency, and said they were returning to base. On final 11 miles out (suspected point that LG was extended) numerous pax bodies fell from the aircraft. \\ Airframe structural integrity lost, control lost prior to impact. Impacted 1.75 miles short of Rwy 34C. \\ Lessons: dangerous under-inflation of tire not discernible visually. After T/O, gear should not have been retracted. Sob = 14 + 247; all killed. [Extract of Saudi report in AWST Oct25'93 pg 49; better rpt excerts from ICAO's AAD; and "NTSB Reporter" Nov'93. DG's"AD" pg 214+ has some errors.]